Glossary extracted starting with manual seeds, with BOW for the domain phy and language EN

troposphere	Lowest level of Earth's atmosphere, from zero altitude to about 15 km above the surface
superconductor	A piece of superconducting metal below the transition temperature at which superconductivity sets in
stagnation episodes	See stagnation periods.
collarbone	Clavicle: the bone linking the scapula and sternum.
schwarzschild filling factor	Ratio of the actual density to the limiting value for a system
light energy	electromagnetic energy in the visibility spectrum, i.e
inertia	Property of a moving body to continue moving at the same speed in the same direction - or of a static body to remain static - unless and until acted upon by some force for change
serrated	Containing sharply pointed teeth.
distribution function	A function that gives the relative frequency with which the value of a statistical variable may be expected to lie within any specified interval (cf
concretion	Knobby or rounded mineral concentrations in sedimentary rocks that are completely surrounded by rock.
larynx	An irregularly shaped, musculocartilaginous tubular structure lined with mucous membrane, located at the top of the trachea and below the root of the tongue and the hyoid bone
planck's radiation law	The energy radiated per unit area per unit time per unit wavelength range at wavelength from a black body at kelvin temperature T is given by
integrating detector	Any imaging device, like a photographic emulsion or CCD, which can build up more signal and contrast by a longer exposure to light or other electromagnetic energy.
khz	kilohertz (see Hertz)
lyman series	(a) A series of lines in the ultraviolet spectrum emitted by excited hydrogen atoms
magnitude	An astronomical measurement of an object's brightness; larger magnitudes represent fainter objects.
cp violation	A reaction between subatomic particles is said to be a "CP violating" reaction if the reaction produces a different result when the electrical charges of the particles are changed to their opposites and the mirror image of the particle trajectories is used.
root mean square	1
scales	Celsius
lighthouse theory	A theory that a neutron star produces pulses of radiation by sweeping radio beams around the sky as it rotates.
object luminance	a measure of light power reflected or emitted from an object itself within a solid angle of one steradian per unit area projected in a given direction.
inversion	The term used with CCDs to indicate that the applied voltage has not only driven away the majority carriers but has actually attracted the minority carriers of the opposite sign.
tomography	The technique of obtaining an X-ray picture of a selected layer in an object.
energy	(1) The capacity to do work
inversion	The term used with CCDs to indicate that the applied voltage has not only driven away the majority carriers but has actually attracted the minority carriers of the opposite sign
potassium	A soft reactive metal
thought experiment	An experiment that cannot be or is not carried out in practice, but can, given sufficient imagination and rigor, be reasoned through by thought and intuition alone.
transparency	The degree to which light passes through a substance.
paleontology	a division of geology that concerns itself with prehistoric life.
nasa	National Aeronautics and Space Administration, headquartered in Washington, DC with field centers across the country.
orogenesis	A complex phenomena that leads to the formation of mountain ranges.
bicarbonate	A salt containing a cation (any positively-charged ion) and the radical HCO3, e.g., NaHCO3.
oxygen burning	The stage when a star fuses Oxygen into Silicon and Sulfur
overstability	A form of instability which, when it sets in, sets in as oscillations of increasing amplitude.
nickel	A transition metal that occurs naturally as the sulfide and silicate
light extinction	A measure of how much light is absorbed or scattered as it passes through a medium, such as the atmosphere
q-switching	By changing the Q of the Fabry-Perot resonator from a very low to a very high value by either mechanical (active) or electro-optical (passive) methods the emission from a laser is released in a giant pulse rather than a series of oscillations
degree	(a) A measure of temperature (To convert to Celsius, subtract 273.) (b) An angle subtended in the sky: From the zenith to the horizon is 90 degrees; the distance between the pointer stars of the Big Dipper is 5 degrees.
2 test	A least-squares statistical test that measures the probability of randomness in a distribution
light	Radiant energy which gives the sensation of sight
parametric representation	An indirect means of expressing the solution to a differential equation in terms of an arbitrary parameter
cleavage	The tendency of stones to split along one or more definite directions, always parallel to a possible crystal face.
boltzmann factor	The factor e-E / kT involved in the probability for atoms having an excitation energy E at temperature F
climate	Average weather conditions of a region, including temperature, precipitation, and winds.
gangue	Minerals of no value associated in veins with ore minerals.
amplitude modulation	(AM) A type of modulation in which the amplitude of a carrier wave is modulated by an imposed signal, usually at audio frequency
aids	Asian Elephant
trace	Transition Region and Coronal ExplorerA NASA satellite launched in 1998
terminal velocity	The steady final velocity reached by a body in a fluid when the resultant force on it is zero.
induction	System of reasoning in which the conclusion, though implied by the premises and consistent with them, does not necessarily follow from them.
x process	The unknown nucleosynthetic process that Burbidge, Burbidge, Fowler and Hoyle said had formed the light nuclei Deuterium, Lithium, Beryllium, and Boron.
quantum genesis	(a) Hypothesis that the origin of the Universe may be understood in terms of a quantum chance
real image	A type of image created by converging
bridge	A denture anchored to teeth on either side of missing teeth.
uv	Ultraviolet: wavelengths shorter than about 350 nm
rods	The more sensitive cells of the retina of the eye
specific gravity	Ratio of the mass of a given volume of a substance to that of an equal volume of water.
microprocessor	A very large silicon integrated circuit with essentially all the functions of a computer on a single chip
gravity wave	In fluid mechanics (and thus helioseismology) this refers to a wave for which buoyancy is the restoring force.
diverging lens	A lens that can refract a parallel beam into a divergent beam
shimming	The process of improving field homogeniety by compensating for imbalances in the main magnetic field of an MRI system
open system	a system communicating with the environment by the exchange of energy and matter.
pacific rim	The countries and landmasses surrounding the Pacific Ocean.
optic axis	The direction of single refraction in a double refractive mineral.
escape velocity	The velocity needed to escape from the surface of a body
density	The amount per unit volume
echo train	a series of 180° RF rephasing pulses and their corresponding echoes for a Fast Spin Echo (FSE) pulse sequence.
umbra	The portion of a shadow cone in which none of the light from an extended light source (ignoring refraction) can be observed
proteinoid coagulations	proteinlike linkages of amino acids produced under laboratory conditions from repeated heating and cooling of simple organic molecules
bean iron ore	Globular aggregates of limonite that occur in karst cavities as weathering formations.
flash gate	An ultra-thin transparent electrode across the entire back surface of certain CCDs used to control the charge on the back surface and hence the QE for blue and UV light
natural motion	Objects move toward their proper place
pi	Pulse Invariant (also Principal Investigator).
susceptibility	Symbol: X The ratio, for a given substance, of the magnetization of a sample to the magnetic field strength applied
entropy	tendency of systems to become more disordered (and thus more uniform) over time; also a measure of disorder
haemorrhage	To bleed severely.
tsunami	A very large ocean wave that can be produced by an underwater earthquake, landslide, volcanic eruption, or the rare impact of a comet or asteroid in the ocean.
r galaxy	In the Yerkes9 1974 system, a system showing rotational symmetry, without clearly marked spiral or elliptical structure (formerly called D galaxy).
composite	An image of a face made up from separate facial parts.
viscosity	The property of a substance which determines the amount of its internal resistance to flow
gaussian noise	Random fluctuations in an otherwise smooth distribution of something
biological effects	Ecological studies to determine the nature or extent of air pollution injury to biological systems.
brightness distribution	A statistical distribution based on brightness, or the distribution of brightness over the surface of an object
plume	An upwelling of matter moving away from a source of heat.
objective	(a) The lens or combination of lenses nearest the object in an optical instrument
isopleth	a line drawn on a map through all points having the same numerical value.
centrifugal force	The apparent force that seems to push an object moving in a curved path away from the axis of rotation or center of orbital motion.
nano-	A prefix meaning 10-9.
element	A substance that is made of atoms with the same chemical properties, and which cannot be decomposed chemically into simpler substances.
neural networks	Pattern-recognition processes that iteratively search for the best solution using a network construction that is similar to neurones in the brain.
arc degree	A unit of angular measure in which there are 360 arc degrees in a full circle.
markovian process	a random process in which the probability of performing a transition to a certain state at a given time depends solely on the state in which the system is found at this time
solar constant	rate at which radiant solar energy is received normally per unit area at the outer layer of Earth's atmosphere; its value is about 1.94 gram calories/cm
volumetric imaging	a specialized technique where all the MR signals are collected from the entire tissue sample and imaged as a whole entity
light	radiant energy that is capable of exciting the retina and producing a visual sensation
law of gravitation	The law stating that any two bodies attract each other with a force that increases in proportion to their masses and decreases in proportion to the square of the distance between them (discovered by Isaac Newton).
genus	taxonomic category ranking below a family and above a species
diffraction pattern	A series of concentric rings produced by interference.
julian day	The Julian Day is the number of days since the year -4712
epicycle	(a) Circular orbit of a body round a point that is itself in a circular orbit round a parent body
ion pump	A small vacuum pump that works by ionizing air molecules.
optical fibres	Glass and transparent plastics can be made into very thin wires or fibers
spinor	A mathematical object that reverses sign after a rotation by 360 degrees and returns to itself only after a rotation by 720 degrees
plastics	Synthetic resin, hard, usually molded.
scattering	The process whereby light is absorbed and reemitted in all directions, with essentially no change in frequency
orientation	Applied to crystals, this means visualizing the disposition of the principal directions within the crystal.
rift zone	elongated valley formed by the depression of a block of Earth's crust between two faults or groups of faults of approximately parallel strike
alpha decay	The disintegration of an atomic nucleus, in which the final products are an alpha particle and a nucleus with two fewer protons and two fewer neutrons than the original.
compound lens	Two or more lenses used together as a unit
bus	The general term for hardware for dealing with the input-output pathway and backplane of a computer
nasa	the National Aeronautics and Space Administration
black smoker	A chimney-like structure made primarily of sulfide minerals that forms around hydrothermal vents on the ocean floor.
folding	The bending of layers of rock, usually due to compression.
metal	To an astronomer, a metal is any element heavier than hydrogen and helium; thus, not only are iron and copper metals, but so are elements like oxygen and neon.
reciprocal	The inverse of a number; for example, the reciprocal of 3 is 1/3, the reciprocal of 1/2 is 2.
biodegradable	Such materials are any organic substances that can be broken down by microorganisms into simpler, more stable compounds
watermark	A translucent name or design molded into the paper during the manufacturing process, usually in the border area; more visible when held up to a light.
torus	The two-dimensional surface of a doughnut.
bandwidth	(a) The width of the portion of the electromagnetic spectrum (the range of frequencies) that is permitted to pass through an electronic device (measured in cycles per second)
photocathode	A thin metallic plate housed inside an evacuated tube capable of releasing electrons through the "photoelectric effect" when illuminated by light
x process	The unknown nucleosynthetic process that Burbidge, Burbidge, Fowler and Hoyle said had formed the light nuclei Deuterium, Lithium, Beryllium, and Boron
hysteresis	(a) The ability to follow two different branches of states, as a parameter built in the system varies first in a monotonic fashion and subsequently comes back to its initial value by varying in the opposite direction
dissipation	When a galaxy forms and gas clouds start crashing into and impeding one another
detached binaries	Binaries which are not in contact and in which no significant mass exchange is occurring.
thermodynamics	(a) The study of the behavior of heat (and, by implication, other forms of energy) in changing systems
jpl	NASA's Jet Propulsion Laboratory in Pasadena.
cassini's division	A gap about 1800 km wide between the outermost rings of Saturn
asymmetry	A violation of symmetry.
metamorphism	(geological)..Changes in rocks brought about by heat and pressure acting in the rocks just below the surface.
population inversion	A condition that exists when there are more molecules in an excited state than an equilibrium distribution would allow
thermalization	An atomic or molecular transition is thermalized when the Boltzmann factor for the two levels of the transition takes on the value it would have in thermodynamic equilibrium
hydrothermal fluids	Hot brines either given off by cooling magmas, or produced by reactions between hot rock and circulating water, that concentrate minerals in solutions
30 doradus	A giant HII region, at least 300 pc across - one of the largest known - in the Large Magellanic Cloud
nodule	A lump or node.
paschen series	(a) A series of lines in the infrared spectrum emitted by excited hydrogen atoms
radius vector	In astronomy, an imaginary line connecting the center of an orbiting body with the centre of the body (or point) that it is orbiting.
refraction	the change of direction of a ray of light in passing obliquely from one medium into another in which the speed of propagation differs.
transition	The movement of an electron from one atomic orbit to another.
root mean square	The square root of the mean square value of a set of numbers.
supercooling	(a) The process by which a substance is cooled below the temperature at which a phase transition should occur, such as water that has been cooled to below zero degrees Centigrade but that has not yet formed ice
nicmos	Near Infrared Camera for Multi-Object Spectrography.
back focal length	The distance between the last surface of a compound optical system and the focal plane of the system
poisson distribution	An approximation to the binomial distribution used when the probability of success in a single trial is very small and the number of trials is very large.
root mean square	The square root of the mean square value of a set of numbers
microbe	(also microorganism) A microscopic single-celled living organism.
epitaxial	growing on a crystalline substrate in such a way as to mimic the orientation of the substrate
anthropologist	A social scientist who specializes in anthropology - the study of bones.
diameter distance	Any distance to a celestial object which is based upon the use of a standard ruler.
slice encoding	relates to the addition of phase encoding steps for 3D volumetric imaging.
franck-condon principle	A theoretical interpretation of the relative intensity of vibrational transitions in an electronic band on the assumption that the intense transitions correspond to situations where an endpoint in the lower vibrational level is vertically below the corresponding endpoint in the upper vibrational level
mascons	Abbreviated form of mass concentrations: apparent regions on the lunar surface where gravity is somehow stronger
transverse waves	Waves vibrating at right angles to the direction of propagation - e.g., electromagnetic waves
semi-convection	The partial convective mixing that takes place in a convectively unstable region where stability can be attained by the results of the mixing before the region is completely mixed.
clay	earthy material, composed mainly of hydrous aluminum silicates and other minerals, which is plastic when moist but hard when fired
micron	Unit to measure length
closed system	A set of one or more objects that may interact with each other, but do not interact with the world outside the system
inertial frame of reference	Any "standard of rest" or coordinate frame for which Newton's first law is valid
commander	often the pilot
keplerian rotation curve	A rotation curve is a plot of speed versus distance from the center of an astronomical system
hydrostatic equilibrium	The balance between weight of the material pressing downward on a layer in a star and the pressure in that layer.
quantum determinism	Property of quantum mechanics that knowledge of the quantum state of a system at one moment completely determines its quantum state at future and past moments
flux density	Flux of radiation through a unit surface; the strength of an electromagnetic wave, defined as the amount of power incident per unit area
inversion layer	a very thin layer of electrons trapped on an interface between a semiconductor and an insulator, or between two different semiconductors.
free parameter	A number which is needed to define a theory well enough so that predictions can be made, but which must be determined by experiment or observation
coal	Discrete dipole approximation (DDA)
dynamo	An electric generator that employs a spinning magnetic field to produce electricity.
free parameter	A number which is needed to define a theory well enough so that predictions can be made, but which must be determined by experiment or observation.
action-at-a-distance	A description of a force, such as Newton's law of gravity, in which two separated bodies are said to directly exert forces on each other
velocity encoding	a specialized technique used fro encoding flow velocities.
ethernet	A system for linking computers with a single serial cable
mean solar day	The mean length of time (24h00m00s) between two successive culminations of the Sun (i.e., the mean period from apparent noon to apparent noon)
achromatic objective	A lens of two or more components with different refraction indices (e.g., crown glass and flint glass), used to correct for chromatic aberration.
html	Hyper-Text Mark-up language.
schottky barrier	A metal to semiconductor interface without any insulation layer produces an energy barrier in the semiconductor which can be used like a diode
wave noise	Noise in the current of a detector, caused by fluctuations in the electromagnetic radiation falling on the detector (cf
dissipation	The removal of energy from a system to overcome some form of resistive force (mechanical or electrical)
taxon	group of organisms constituting one of the formal units in taxonomic classification (phylum, order, etc.) and characterized by common characteristics in varying degrees of distinction
radar	Radio Detection and Ranging.
fringing	The appearance of complex light and dark contours in a CCD image due to constructive and destructive interference effects of light reflected inside the detector
dna	deoxyribonucleic acid; the molecule that is the basis of heredity in many organisms
orient	Characteristic sheen and iridescence, as displayed in a good pearl.
epicycle	Circular orbit of a body round a point that is itself in a circular orbit round a parent body
collagen	insoluble fibrous protein used by vertebrates to hold themselves together (i.e., it is a chief constituent of connective tissue fibrils and occurs in bones)
metric tensor	the mathematical object that describes the deviation of Pythagoras's theorem in a curved space
epithermal vein	Formed at shallow depths from ascending hot solutions.
condensation nuclei	the small nuclei or particles with which gaseous constituents in the atmosphere (e.g., water vapor) collide and adhere.
stagnation periods	lengths of time during which little atmospheric mixing occurs over a geographical area, making the presence of layered hazes more likely
plume blight	visual impairment of air quality that manifests itself as a coherent plume. See an example of plume bight.
landslide	Any perceptible downslope movement of a mass of bedrock or unconsolidated rock, sand and dirt, or a mixture between the two.
minute of arc	A unit of angle equal to 1/60 of a degree.
ray	Ejecta from meteorite impacts forming white streamers radiating from some lunar craters.
chapman's equation	An equation expressing the velocity of a gas in terms of certain molecular constants
phase coherence	a term describing the degree to which precessing nuclear spins are synchronous.
ice core samples	Samples of layered ice from glaciers which may contain dust, chemicals, and gases that have been deposited with snow over hundreds of thousands of years
photoelectric emulsions	Materials in which the absorption of light leads to a chemical reaction.
aberration	(a) Defect in the image formed by a lens, mirror or optical system
oceanic basalts	rocks of the oceanic island volcanoes
inertial frame of reference	Any "standard of rest" or coordinate frame for which Newton's first law is valid.
tunel staining	(Terminal deoxynucleotidyl transferase-mediated dUTP nick and labelling)
open string	A type of string with two free ends
deep sea vent	Seafloor vent that releases hot, mineral-rich water from fissures at a mid-ocean ridge
grain	(Troy system)..480 grains to the oz.
optical depth	A measure of the integrated opacity along a path through a layer of material, measured by the amount of absorption of a beam of incident light
improve	Interagency Monitoring of PROtected Visual Environments; a collaborative monitoring program established in the mid-1980s as past of the Federal Implementation Plans
saros cycle	After 18 years and 11 1/3 days the eclipse pattern repeats The saros cycle does not mean the eclipse will occur in the same place
sidereal day	The length of time (23h56m4s.091) between two successive meridian transits of the vernal equinox (cf
reciprocal	The inverse of a number; for example, the reciprocal of 3 is 1/3, the reciprocal of 1/2 is 2
seismograph	An instrument that records seismic waves.
abstraction	a general concept formed by extracting common features from specific examples
genetic drift	random fluctuations (or "walk") of gene frequencies from generation to generation that occur in small populations
thermodynamic potential	a function of the state of a system which takes its extreme value on the asymptotically stable state reached by the system in the course of time.
mitochondrial	Of or relating to mitochondrions, one of the tiny granules (grains; particles), present in living cells, regarded as responsible for respiration and energy production.
crystal systems	The six main groups into which crystals can be classified: triclinic, monoclinic, orthorhombic, cubic, tetragonal and hexagonal.
nucleotide	compound composed of a nucleoside combined with phosphoric acid
graben rille	A linear feature on a planetary surface caused by the faulting and sinking of portions of the crust.
botanist	One who studies the science of plants.
sandstone	A clastic, sedimentary rock formed by the consolidation and compaction of sand (primarily quartz) in a matrix of silt or clay and held together by a natural cementing material, such as silica, iron oxide, or calcium carbonate.
ruthenium	A transition metal that occurs naturally with platinum
oblateness	Ratio of the difference between the equatorial and polar radii to the equatorial radius
equation of state	(a) A relation between the pressure, temperature, and density of a fluid
knudsen number	The ratio of the mean free path length of the molecules in a fluid to a characteristic length of the structure in the fluid stream
abscissa	In mathematics, abscissa refers to that element of an ordered pair which is plotted on the horizontal axis of a two-dimensional Cartesian coordinate system, as opposed to the ordinate...
electromagnetic spectrum	The electromagnetic spectrum is the complete range of wavelengths of the electromagnetic radiation.
lava	Molten rock that erupts onto the Earth's surface through a volcanic vent or fissure.
gas chromatographs	Diagrams representing the different speeds of various constituents in a substance, as they travel through a non-reactive gas.
midocean rift	Chasms that split the midocean rises where the crustal plates move apart.
signal averaging	a signal-to-noise improvement method that is accomplished by taking the average of several FIDs made under similar conditions
luster	A reflective property of mineral surfaces.
angular acceleration	Symbol: The rotational acceleration of an object about an axis:
relativistic	Approaching the velocity of light
achromatic lens	(a) Lens (or combination of lenses) that brings different wavelenghts within a ray of light to a single focus, thus overcoming chromatic aberration
geniculated	Knee like intergrowths of crystals.
gauss	A unit used to measure the strength of a magnetic field.
structure	Objects have structure if they have parts - that is, if they are made of other things
depth of field	The object distance range of an optical system (e.g
bound-bound transition	Transition between energy levels of an electron bound to a nucleus (the electron is bound both before and after the transition).
super-high frequency	SFH A radio frequency in the range between 30 GHz and 3 GHz (wavelength 1-10 cm)
metazoan	an animal whose body is composed of cells differentiated into tissues and organs and (usually) a digestive cavity
mitochondrion	cytoplasmic organelle serving as a site of respiration
2mass	Two-Micron All-Sky Survey.
wheatstone bridge	A device that measures the resistance of an electrical circuit to the flow of electricity
protist	any of a kingdom of living organisms (Protista) that includes algae slime molds, protozoa, and fungi, usually characterized by unicellular reproductive structures, true nuclei, and chromosomes
stratification	Deposition of sediment in layers or strata.
forward scattering	The optical property of finely divided particles to preferentially direct light in the original direction of the light's travel
chromatography	Chromatography is a method for separating mixtures based on differences in the speed at which they migrate over or through a stationary phase.
sulfate	Solid or liquid particulate matter composed of sulfuric acid [H2SO4], ammonium bisulfate [NH4HSO4], or ammonium sulfate [(NH4)2SO4]
2 test	A least-squares statistical test that measures the probability of randomness in a distribution.
dma	Direct Memory Access An efficient electronic method of transferring digital (numerical) information or data to a computer.
monodromy	The property that all paths of points of a body simply rotating about an axis shall return into themselves.
pascal	The derived SI unit of pressure
photomultiplier tube	A vacuum encapsulated photocathode from which electrons are ejected by the photoelectric effect followed by multiple cathodes from which many additional electrons are emitted in a cascade
helioseismology	The study of the Sun's interior by measuring oscillations (ripples) as they appear at the surface
phase	an angular relationship describing the degree of synchronism between two sinusoidal waveforms of the same frequency.
prosthetic group	nonprotein group of a conjugated protein (i.e., a compound of a protein with a nonprotein)
qeh	Quantum Efficiency Hysteresis An increase in QE after exposure to light
nec	Noise Equivalent Charge
radian	(a) A measure of angular distance; 2 radians equals 360 degrees
stable air mass	an air mass which has little vertical mixing
beta-particle	Particles first discovered in radioactive β decay - later identified as electrons.
latitude	A north-south coordinate measured on the surface of a sphere
decibel	Symbol: dB A unit of power level, usually of a sound wave or electrical signal, measured on a logarithmic scale
coronae	On Venus, circular features, not caused by impacts, they are domed plains caused by the rising plumes of molten rock from below.
midocean rise	One of the undersea mountain ranges that push up from the seafloor in the center of the oceans.
photometry	instrumental methods, including analytical methods, employing measurement of light intensity
wave	A propagating pattern of disturbance.
minute of arc	A measurement of the sky which includes degrees, minutes and seconds.
neutrino bremsstrahlung	The reaction in which an electron scatters from a nucleus, emitting a neutrino-antineutrino pair.
gene pool	total amount of information in all the genes of all the reproductive members of a biological population at any given time
polysilicon	A non-crystalline form of silicon with a high conductivity like a metal; preferred in CCD manufacture to the use of metals because it keeps the entire process in silicon and is more transparent to visible light.
pyroclast	A molten fragment of pumice and ash ejected during a volcanic eruption.
standard ruler	Any extended celestial object which is more or less constant diameter
hafnium	A transition metal found in zirconium ores
carbonate	Any mineral compound that contains the anion (negatively charged molecule) CO3-2.
cosmology	The study of the nature and evolution of the physical universe.
fractal	(a) A geometric figure in which a pattern is repeated ad infinitum on smaller and smaller scales
ram	Random access memory
density wave theory	(a) One possible explanation for spiral arms
intrinsic luminosity	The amount of light an object actually emits, as opposed to how bright the object looks from Earth
insolation	Amount of radiation received from the Sun per unit area on the Earth's surface per unit time
resolution	The ability of an optical system, including detector, to separate two adjacent objects - this is called "spatial resolution" - or two adjacent wavelengths in a spectrometer - this is called "spectral resolution"
pc	Photoconductor
newton	The SI derived unit of force, equal to the force necessary to give an acceleration of 1 meter per second2 to a mass of 1 kg
protein	complex polymer built of amino acids that contains the elements carbon, hydrogen, nitrogen, oxygen, sometimes sulfur, and occasionally others such as phosphorus and iron
adiabatic change	A change taking place in a system that has perfect thermal insulation, so that heat cannot enter or leave the system and energy can only be transferred by work
faculae	Bright areas on the face of the Sun, commonly in the vicinity of sunspots
polychromator	A polychromator is an optical device that is used to disperse light into different directions to isolate parts of the spectrum of the light
p-wave	Primary Wave: A longitudinal seismic acoustic wave that moves by compression
piezoelectric	A substance that becomes electrically charged by pressure.
ablation	Erosion of an object (generally a meteorite) by the friction generated when it passes through the Earth's atmosphere
symmetry	(a) A property of a physical system that does not change when the system is transformed in some manner
dendrite	A branching crystal with a tree-like structure.
ionosphere	(a) The region of Earth's atmosphere (80-500 km), immediately above the stratosphere
pulse position modulation	In pulse-rate modulation the rate at which pulses of equal amplitude are generated varies with the changes in the modulating signal
synthetic	Man-made, rather than occurring naturally.
bacterium	any of an extremely flexible class of microscopic plants whose members have a variety of structures, come singly or in colonies, live just about anywhere, and derive energy from whatever source is available
master equation	an equation describing the evolution of the probability of a state at a given time as the balance between transitions leading to this state, and transitions removing the system from this state
temperature inversion	in meteorology, a departure from the normal decrease of temperature with increasing altitude such that the temperature is higher at a given height in the inversion layer than would be expected from the temperature below the layer
massive	Minerals not bounded by crystal faces.
chance	Characteristic of a regime in which predictions cannot be made exactly, but only in terms of probabilities
twilight	The interval of time preceding sunrise and following sunset (see Sunrise; unset) during which the sky is partially illuminated
zetta-	Symbol: Z A prefix denoting 1021
deep water	The layer of the ocean between the intermediate water and the bottom water.
fission	Interaction in which nucleons previously united in an atomic nuclei are disjoined, releasing energy
pollux	A K0 III star 11 pc distant.
second of arc	1/3600 of a degree, or 1/60 of a minute of arc.
wheatstone bridge	A device that measures the resistance of an electrical circuit to the flow of electricity.
qeh	Quantum Efficiency Hysteresis -- An increase in QE after exposure to light.
manganese star	Star with an anomalously high Mn-Fe ratio, which show deviations from the odd-even effect for phosphorus, gallium, and yttrium.
macroscopic	Refers to scales typically encountered in the everyday world and larger; roughly the opposite of microscopic.
degassing	process whereby the atmosphere and ocean water have slowly accumulated through geologic time by emanating from Earth's interior in the form of volcanic gases
abyssal ocean	The deep ocean that lies in water depths of 4,000 meters or deeper.
semimajor axis	Half the long diameter of an ellipse
irradiance	Symbol: E The rate of energy reaching unit area of a surface; i.e
thermal convection	The energy transfer in a fluid by a mechanism of bulk hydrodynamic movement.
isotope	An atomic nucleus having the same number of protons as a more commonly found atomic nucleus but a different number of neutrons
equatorial mount	The classic type of telescope mount with one axis parallel to the Earth's polar axis (i.e
haemoglobin	A haem protein responsible the red colouring of blood and for the transport of oxygen to the tissues.
internet	A global spider-web-like network of computers and computer systems with no central hub or single point of control
quantum electronics	this is the name used for those parts of quantum optics which have practical device applications.
anisotropy	(a) A medium is anisotropic if a certain physical quantity differs in value in
chemosynthesis	synthesis of organic compounds using energy derived from chemical reactions
spring constant	proportionality between applied force and resulting change in length of a given spring
endothermic process	An adjective applied to a reaction in which a net input of energy is required for the reaction to occur
polytropic index	The polytropic index may have any value from zero (uniform density throughout) to 5 (entire mass concentrated at the center)
double cluster in perseus	see h and Persei.
crystal axes	"Lines" passing through a crystal in important symmetric directions, intersecting at the center of the crystal.
meter	The principal unit of length in the metric system, equal to 3.28 feet.
paste	Lead glass imitation stone.
bolometer	(a) An instrument for measuring small amounts of radiant heat or microwaves
dust grains	Elephas Maximus
atom	Smallest particle of a chemical element that retains the properties of that element
flip angle	the angle to which the net magnetization is rotated or tipped relative to the main magnetic field direction via the application of an RF excitation pulse at the Larmor frequency
iris	An arrangement able to vary the amount of light that enters an optical instrument
precursor pulse	A component of a Pulsar pulse which occurs slightly before the main pulse
adsorption	A process in which a layer of atoms or molecules of one substance forms on the surface of a solid or liquid
creationism	Belief that the universe was created by God in the relatively recent past, as implied by literal interpretations of biblical chronology, and that the species of terrestrial life did not arise through Darwinian evolution but, rather, all came into existence at once.
montmorillonite	soft claylike mineral composed of hydrous aluminum silicate
helioseismology	The study of the interior of the sun by the analysis of its modes of vibration.
endothermic	Referring to a process that absorbs energy.
moment of inertia	The product of the mass of a body and the square of its radius of gyration.
oersted	Unit of magnetic field strength
critical equatorial velocity	In rotating early-type stars, that velocity at which the ratio of centrifugal force to gravity at the equator is unity.
faculae	(a) Bright areas on the face of the Sun, commonly in the vicinity of sunspots
algae	Simple rootless plants that grow in sunlit waters in relative proportion to the amounts of nutrients available
technology	Two zone furnace, physical vapor deposition, calibration, temperature profile
promethium	Pm: An unstable rare earth
phase delay	signal travel time between two points in any signal path or circuit (measured in seconds or in degrees or radians of the signal frequency); to be distinguished from simultaneous phase difference between two points
principia mathematica	Short form of the title of Isaac Newton's great work, published in 1687; title also of the mathematically philosophical work of Bertrand Russell and Alfred North Whitehead, published in 1910-13
stromatolite	A widely distributed sedimentary structure consisting of laminated carbonate or silicate rocks
thymine	A white crystalline pyrimidine base, C5H6N2O2 which occurs in DNA and is one of the four main units upon which the genetic code is based.
specific absorption rate	an RF exposure concern that describes the potential for heating of the patient's tissue due to the application of the RF energy necessary to produce the NMR signal
transverse waves	Waves vibrating at right angles to the direction of propagation - e.g., electromagnetic waves.
ace	Advanced Composition Explorer
logic	Computer circuitry
ft-values	t = half-life of the -unstable nucleus, and f stands for an integral which depends on the -decay energy and the type of transition.
adenine	A purine base, C5H5N5, present in all living cells, mainly as a subunit of nucleic acids.
inversion time	the time period between the 180° inversion pulse and the 90° excitation pulse in an Inversion Recovery pulse sequence
alfvén speed	The speed at which hydromagnetic waves are propagated along a magnetic field: (VA) = B / (4 )1/2
circular velocity	The lateral velocity an object must have to remain in orbit
absorption	a class of processes by which one material is taken up by another.
brillouin scattering	Slight changes in the frequency of radiation, caused by reflection or scattering from the high-frequency sound waves that arise from thermal vibrations of atoms in the medium
ice sheet	A large mass of ice thick enough to cover the topography under it
intaglio	Incised carving; a sunken design, ie: cameo
generalisation	The process of making statements about the general population on the basis of relevant research.
bowen fluorescence mechanism	A mechanism first discovered by Bowen which explains the anomalously strong lines of O III in the spectra of some planetary nebulae as fluorescence involving the radiative excitation of the 2p3d 3Po2 level of O2+ (54.71 eV) from the 2p2 3P2 state in the ground term by He II Lyman-α photons (54.17 eV).
thermocline	A thin region of rapid temperature change separating the warm waters of the upper ocean from the cold waters of the abyssal ocean.
obliquity	In general the angle between the equatorial and orbital planes of a body or, equivalently, between the rotational and orbital poles
second of arc	See Minute of Arc
neutral region	A region where the magnetic field strength approaches zero
domain	a ferromagnetic material is composed of domains, in each of which there is magnetisation in a definite direction
coded mask	Mask made for example of lead, tungsten, aluminium, etc
quantum electronics	this is the name used for those parts of quantum optics which have practical device applications.[D89]
shock wave	A sharp change in the pressure, temperature, and density of a fluid which develops when the velocity of the fluid begins to exceed the velocity of sound
pair annihilation	Mutual destruction (annihilation) of an electron-positron pair with the formation of gamma rays, or of a proton-antiproton pair with the formation of pions
angular size	The angle subtended by an object on the sky
stray light	Stray light is light in an optical system, which was not intended in the design
vector space	A set of elements (called Vectors) for which a binary operation of vector addition is defined, such that u1 + u2 is a vector if u1 and u2 are vectors: and a binary operation scalar multiplication is defined, such that cu is a vector if u is a vector and c is a scalar (a real number or a complex number, according to specification of the kind of vector space); and a standard collection of conditions governing these two operations is satisfied
glacial period	See ice age.
rayleigh number	(a) A non-dimensional parameter involving the coefficients of thermal conductivity and kinematic viscosity which determines when a fluid, under specified geometrical conditions, will become convectively unstable
thermodynamic equilibrium	(a) The state reached ultimately by an isolated system.[D89]
chromatic aberration	(a) Introduction of spurious colors by a lens
specific heat	Ratio of the quantity of heat required to raise the temperature of a unit mass of a substance by a unit amount to that required to raise the temperature of an equal mass of water by the same amount.
covariant	An adjective applied to a set of relationships between mathematical or physical quantities if they remain unchanged after transformation to a different coordinate system.
aspect ratio	Ratio of the major axis (e.g., of a rocket) to the minor axis
pyrimidine	nitrogen base such as cytosine, thymine, or uracil that is a constituent of nucleotides and nucleic acids
carbohydrate	organic compound consisting of a chain of carbon atoms to which hydrogen and oxygen, present in a 2:1 ratio, are attached
apparent depth	Because radiation travels at different speeds in different media, the apparent depth or thickness of a transparent sample is not the same as its real depth or thickness
channel stops	Narrow, heavily doped strips in a silicon CCD which act like walls to prevent sideways movement of charge in a pixel.
flattening	A parameter that specifies the degree by which a planet's figure differs from that of a sphere; the ratio f = (a - b) / a, where a is the equatorial radius and b is the polar radius
metamorphic rocks	rocks formed by the action of great heat and/or pressure
oxidation	The process of oxidizing; the addition of oxygen to a compound with a loss of electrons; always occurs accompanied by reduction.
energy band	a continuous range of energies in a solid in which there are possible states for the electrons
differential equation	An equation that describes the evolution of a system over time, given boundary conditions for the system
bowen fluorescence mechanism	A mechanism first discovered by Bowen which explains the anomalously strong lines of O III in the spectra of some planetary nebulae as fluorescence involving the radiative excitation of the 2p3d 3Po2 level of O2+ (54.71 eV) from the 2p2 3P2 state in the ground term by He II Lyman- photons (54.17 eV)
voigt profile	Profile of a spectral line allowing for the effects of Doppler broadening combined with a Lorentz (damping) profile
critical path	A term used in project planning to indicated a segment of the proposed work which if not completed on time will result in one or more other segments being delayed with serious "knock-on" effects for the project
gluon	(a) Carrier of interquark force
moment of inertia	The product of the mass of a body and the square of its radius of gyration
bound-bound transitions	Transitions between energy levels of an electron bound to a nucleus (the electron is bound both before and after the transition)
fda	the United States Food and Drug Administration FID - see Free Induction Decay
cartesian	One who follows the philosophy of René Descartes regarding his logical analysis or interpretation of nature.
albedo	fraction of incident electromagnetic radiation reflected by a body such as a planet, star, or cloud
convection cells	The currents that are set up by convection.
pm	Post Meridiem
fundamental stars	Stars for which coordinates have been determined to a very high degree of accuracy
dsp	Digital Signal Processor A special kind of computer chip.
refraction	The bending of light passing through one medium to another
fluvial	Deposits from rivers.
headward erosion	The process by which the higher, originating end of a river wears away the rock around it, thereby lengthening tributary streams.
vug	An open cavity in rocks, often lined with crystals.
radiometric dating	Determination of the age of objects - e.g., earth and moon rocks - by means of the half-life of the unstable elements they contain
chemical equilibrium	The state in which forward and reverse chemical reactions occur at equal rates so that the concentration of the reactants and products does not change with time.
boundary layer	A thin layer of fluid, such as the one next to a solid surface past which the fluid is moving
bipyramid	Crystals that form symmetrically about a plane dividing it into two pyramids.
tesla	The derived SI unit of magnetic flux density
perturbation	(a) A small disturbance which makes the system deviate from its equilibrium state
midas	Munich Image Data Analysis System -- A suite of programs and a software environment developed at the European Southern Observatory for astronomy applications
dfe	Dark Frame Error
statistical model	A model or simulation based on a sequence of past observations.
x-rays	(a) Photons of wavelengths between about 0.1 Å and 100 Å - more energetic than ultraviolet, but less energetic than -rays
chondrules	Small spherical grains varying from microscopic size to the size of a pea, usually composed of iron, aluminum, or magnesium silicates
sphere	The outer surface of a ball
atmospheric window	Wavelength regions in which our atmosphere is transparent - at visual wavelengths, infrared and radio.
immunoassay	A test using antibodies to identify and quantify substances
diffraction	The spreading out of light in passing the edge of an opaque body.
guanine	A purine base, C5H5N5O, present in all living cells, mainly in combined form, as in nucleic acids.
greenhouse effect	The process by which a carbon dioxide atmosphere traps heat and raises the temperature of a planetary surface.
photosynthesis	a biochemical process operating in green plants in which carbohydrates are formed under the influence of light with chlorophyl serving as a catalyst
ataxite	Rare variety of iron meteorite (designated type D) made almost entirely of taenite, a solid solution of Fe and 27 to 65% Ni
ultraviolet	Of or relating to the range of invisible radiation wavelengths from about 4 nanometers, on the border of the x-ray region, to about 380 nanometers, just beyond the violet in the visible spectrum.
mohs scale	The relative scale of the hardness of minerals, from 1 to 10, the order of hardness with no significance to quantitative relationship.
horizontal parallax	The difference between the topocentric and geocentric positions of an object, when the object is on the astronomical horizon
kaolinite	mineral (a hydrous silicate of aluminum) that constitutes a principal part of the fine clay, kaolin
era	A system of chronological notation reckoned from a given date
flickering	Aperiodic behavior in an oscillating system; rapid, large-amplitude variations in light
refractometer	Instrument used to determine the refractive index of various substances.
rh factor	Any of one or more genetically determined antigens usu
newton's constant g	Newton's law of gravitation says that the gravitational for ce between any two bodies is proportional to the product of their masses and decreases as the square of the distance between them
rare earth elements	series of elements usually taken to include elements with atomic numbers 58 to 71, lanthanum, and sometimes yttrium and scandium
wave	A propagating pattern of disturbance
normal	The perpendicular to a reflecting or refracting surface at the point of incidence of the ray concerned
scientific model	A mental image ofhow the natural world works, based on physical, mathematical, and aestheticideas.
neoteny	attainment of sexual maturity during the larval stage
meteorite	(a) Object that enters the Earth's atmosphere and is too large to be totally destroyed by friction before it hits the surface
dynamical friction	(a) The process by which a large mass gets slowed down as it moves through a sea of smaller objects and feels their gravitational pull
disk	The plate-shaped component of a spiral galaxy, in which the spiral arms are found.
stability	A measure of how hard it is to displace an object or system from equilibrium
basalt	Dark, igneous rock characteristic of solidified lava.
acquisition	the process of measuring and storing image data.
profile	See line profile.
demeter	Unofficial name for Jupiter X
seismogram	The record of seismic waves on a seismograph after they have traveled through the Earth and arrived at a given seismic station
fringes	(a) The light and dark bands obtained by interference or diffraction of light. (b) Successive dark and light lines, caused by light beams that are out of phase alternating with those that are in phase
predictability	the ability to predict the future behavior of a dynamical system on the basis of the present knowledge available on this system.
clapeyron's equation	A fundamental relation between the temperature at which an inter-phase transition occurs, the change in heat content, and the change in volume.
denis	DEep Near Infrared Survey
eikonal approximation	An approximation in which the oscillation of a wave front is replaced by the direction of the ray which is normal to the oscillation
photomultiplier	A photoelectric cell in which the electric current generate is amplified at several stages within the tube.
ftp	File Transfer Protocol
thermal convection	The energy transfer in a fluid by a mechanism of bulk hydrodynamic movement
vapor pressure	The pressure exerted at a particular temperature by a vapor
chlorofluorocarbon	Synthetic chemical compounds used in refrigeration, solvents, and styrofoam manufacture
tellurium	A brittle silvery metalloid element belonging to group 16 of the periodic table
hardness	The resistance by a substance to actions which tend to modify its surface by scratching, abrasion, penetration.
unitarity	The principle of conservation of probability
absorption	Decrease in intensity of radiation, when it crosses a material medium, as a consequence of an interaction between the radiation and the material medium.
order	An integer (m) associated with a given interference fringe or diffraction pattern
anharmonic oscillator	A system whose vibration, while still periodic, cannot be described in terms of simple harmonic motions (i.e
inclusions	Substances within a mineral, example, other minerals, gas bubbles, liquids, or other foreign objects.
sampling	the conversion of analog signals to discreet digital values through a preselected measurement process
orbit	the path followed by an object in space as it moves moves around another object
chemical clock	an asymptotically stable regime of a chemical system in which the concentrations of the reagents are periodic functions of time
neumann lines	In iron meteorites, groups of very fine parallel lines that cross each other at various angles
equilibrium position	The position of an oscillating body at which no net force acts on it
joule	unit for work in the mks system of units: 1 J = 10
sulfide chimneys	A tower or chimney composed primarily of sulfide minerals and built up on the deep seafloor by mineral deposits precipitated from hydrothermal fluid ejected from a hydrothermal vent
autotroph	organism whose metabolism requires only external sources of carbon dioxide and nitrogen
flare	A violent eruption on the sun's surface.
pulse width	The interval of time between two successive pulses.
photomultiplier tube detector	A vacuum tube that amplifies and detects weak light signals.
fokker-planck equation	A modified form of the Boltzmann equation allowing for collision terms in an approximate way
dat	Digital Audio Tape
diffusion	a process by which substances, heat, or other properties of a medium are transferred from regions of higher concentration to regions of lower concentration.
maunder butterfly diagram	A graph showing the latitude of sunspots versus time, first plotted by W.W
surface channel	A semiconductor device construction in which the electron charges are held or moved near the surface of the silicon crystal
complexity	in information sciences, complexity measures the length of the shortest description of a given (finite) sequence of symbols
laminar flow	Steady flow in which the fluid moves past a surface in parallel layers of different velocities
arrow of time	The direction, apparently inviolable, of the "flow" of time that distinguishes the past from the future.The direction, apparently inviolable, of the "flow" of time that distinguishes the past from the future.
interline transfer	A CCD construction consisting of vertical strips which are alternately opaque and light sensitive
organic carbon	Aerosols composed of organic compounds, which may result from emissions from incomplete combustion processes, solvent evaporation followed by atmospheric condensation, or the oxidation of some vegetative emissions.
whistler	electromagnetic ultralow frequency radiation observed in planetary magnetospheres; energized by lightning and other discharges
azeotropic mixture	Aseotrope: A mixture of two liquids that boils without any change in composition
arrow of time	The direction, apparently inviolable, of the "flow" of time that distinguishes the past from the future.The direction, apparently inviolable, of the "flow" of time that distinguishes the past from the future
eikonal approximation	An approximation in which the oscillation of a wave front is replaced by the direction of the ray which is normal to the oscillation.
polymer	A natural or synthetic compound of high molecular weight composed of long chains of repeating units, each relatively light and simple.
gravity	The mutual attraction between any two masses, as was first described accurately by Newton
planck's constant	The number that relates the energy and frequency of light; it has a value of 6.63 x 10-34 joule seconds.
vagus nerve	Either of two cranial nerves extending through neck into thorax and the upper part of the abdomen - a pneumogastric nerve.
heisenberg uncertainty principle	(a) States that the position and momentum of a particle can only be known to a certain level of precision
krypton	A colorless odorless monatomic element of the rare-gas group, known to form unstable compounds with fluorine
soliton	A finite-amplitude hydrodynamic disturbance which is propagated through a fluid without any change of shape
absorption cell	A cell that is filled with a particular gas that absorbs light of particular wavelengths.
elastic collision	Particle reactions in which the same particles emerge from the reaction as entered it (e.g
proton density	the concentration of mobile Hydrogen atoms within a sample of tissue
blue-yellow light	The most intense, dominant light from the solar spectrum, it is absorbed by plants' chlorophyll to make carbohydrates.
virtual image	A type of image created by diverging
differential geometry	the mathematical discipline that studies curved spaces.
back trajectory	a trace backwards in time showing where an air mass has been.
darwinism	Theory that species arise through the natural selection of random mutations that better fit changing conditions in a generally uniformitarian Earth.
geode	A stone having a cavity lined with crystals; the cavity in such a stone.
super-high frequency	SFH A radio frequency in the range between 30 GHz and 3 GHz (wavelength 1-10 cm).
density	The mean density of a celestial body is generally reckoned as its mass divided by its volume, expressed either in comparison with the density of water, in kilograms per cubic meter, or in relation to some other known density
solar cycle	The 11-year period between maxima (or minima) of solar activity
gauge group	the mathematical group associated with a particular set of gauge transformations
precipitation	The transfer of moisture from the atmosphere to the surface of Earth, usually as rain, snow, and ice.
absorption edges	Sudden rises superposed on the smooth decrease of the curve of the attenuation coefficient, which cause the curve to have a typical sawtooth aspect
phase transition	An abrupt change in the equilibrium state of a system
viscosity	The internal friction of a fluid or liquid that tends to resist and dissipate its flow.
perseus ob1	See h and Persei.
fast scanning	a specialized technique usually associated with short TR, reduced flip angle and repeated 180° rephasing pulses.
fet	Field Effect Transistor A tiny transistor amplifier in which the current flow between two terminals, called the source and the drain, is controlled by the electric field generated inside the silicon by an external voltage on a surface called the gate electrode.
anorthite	A calcium-oxide-rich plagioclase feldspar mineral, typically white, that occurs in igneous rocks.
electromagnet	a type of magnet that utilizes coils of wire, typically wound on an iron core, so that as current flows through the coil it becomes magnetized
nonluminous	(not emitting light or visible) material that cannot be seen in the sky
asphyxiation	A medical term for suffocation, which leads to lack of oxygen in the blood.
refraction	A change in direction or the bending of light rays as they pass at an angle through different transparent substances, such as glass, water, or air.
surface channel	A semiconductor device construction in which the electron charges are held or moved near the surface of the silicon crystal.
pegmatites	..A very coarse platonic rock, generally granitic in composition
plate tectonics	model of the structure of Earth in which the surface consists of a small number of semirigid plates floating on a viscous underlayer [
receiver	the portion of the MRI equipment that detects and amplifies the RF signals picked up by the receiver coil
microwave	(a) An electromagnetic wave (in the radio region just beyond the infrared) with a wavelength of from about 1 mm to 30 cm (about 109-1011 Hz)
ghgs	See greenhouse gases
silica	The compound silicon dioxide (SiO2)
native oxide	The silicon dioxide layer which grows in air on the exposed backside surface of a thinned CCD.
molybdenite	A metallic, lead-gray, hexagonal mineral made of molybdenum and sulfur (MoS2.
lunar mare	Dark-colored, low-lying regions of the Moon comprised mostly of basalt.
bifurcation	a phenomenon whereby the number of solutions of certain type presented by a dynamical system changes abruptly, as one of the parameters defining the dynamics crosses a critical value
energy	capacity to do work
nbs	National Bureau of Standards (USA).
second law of thermodynamics	(a) A physical law formulated in the nineteenth century and stating that any isolated system becomes more disordered in time
rotate	to turn around a center point, or axis, like a wheel turns on a bicycle
oscillation	rhythmic periodic motion.
magnitude scale	Method developed by Hipparchus who divided the stars into 6 classes
deception	The act of deceiving.
equatorial velocity	The velocity at the surface of a rotating body, on its equator
mach number	(a) The ratio of the speed of a moving object (e.g
gradient magnetic field	A small linear magnetic field applied in addition to (superimposed on) the large static magnetic field in an MRI scanner
perovskite	The mineral CaTiO3. At high pressure the mineral pyroxene (MgSiO3) transforms to a form having the same structure, or arrangement of atoms, as perovskite
celsius	Scale of temperature for which water freezes at 0 degrees and boils at 100 degrees (under standard conditions).
island arc	A curving group of volcanic islands parallel to a deep-sea trench
manganese stars	Stars with an anomalously high mn-fe ratio, which show deviations from the odd-even effect for phosphorus, gallium, and yttrium.
imitation stones	Substances used to look like a genuine
primordial background radiation	Radiation from the hot clouds of the big-bang explosion
new inflationary universe	a revised form of the Inflationary Universe model that provides a mechanism to avoid the gross inhomogeneities which result from the theory as originally proposed.
choline	A B-fatty acid involved in the production of neurotransmitters in the brain that regulates mood, appetite, behavior, memory, etc
covariance	According to the general theory of relativity, theories of nature must have the same mathematical form in all coordinate systems
messier object	an object assigned a number by Charles Messier
imaging spectroscopy	Imaging spectroscopy is what UVIS does--it takes spectrographic measurements and turns them into a graph, but it can also turn the points on the graph into digital data that can then be made into pictures (images)
resolution	The degree to which fine details in an image are separated or resolved.
hygroscopic	readily absorbing moisture, as from the atmosphere.
zinc	A bluish-white transition metal, applied as a coating (galvanizing) to protect steel from corrosion
scattering	an interaction of a light wave with an object that causes the light to be redirected in its path
poseidon	Unofficial name for J VIII, the next outermost satellite of Jupiter
chromosphere	The part of the Sun's atmosphere immediately above the surface (the photosphere) and beneath the corona.
opaque	Not transparent or translucent
fossil strömgren sphere	A relict HII region which remains after the evolution of its exciting star
forward bias	A term applied to an electronic device known as a diode - usually formed by a junction of p-type and n-type semiconductor material - in which current flows easily if the externally applied voltage has the correct polarity or direction
meteor	Brief streak of light seen in the night sky when a speck of dust burns up as it enters the upper atmosphere
colloid	A substance containing very small particles (sizes in the range 10-9-10-5 m)
radius vector	In astronomy, an imaginary line connecting the center of an orbiting body with the centre of the body (or point) that it is orbiting
laplacian determinism	Clockwork conception of the Universe in which complete knowledge of the state of the Universe at one moment completely determines its state at all future and past moments
dna	DeoxyriboNucleic Acid, the macromolecule that carries the genetic information requisite to life on Earth.
getter	A chemical absorption method of removing (pumping) gas from a chamber by tying up molecules on a surface
doppler shift	Change in the apparent wavelength of radiation (e.g., light or sound) emitted by a moving body
monsoon	A wind system that influences climatic regions and reverses direction seasonally
era	A system of chronological notation reckoned from a given date.
concavo-convex	Describes a lens with one concave surface and one convex surface
data model	A description of the structure and organization of the data in a database
carboxyl group	Also called the COOH group; functional group consisting of a carbon atom double bonded to an oxygen atom and single bonded to another oxygen with a hydrogen on the other side
patina	The colored film or thin layer on the surface of a rock produced by chemical weathering.
wavelength	The distance between successive peaks or troughs of a wave
down-loading	The process of passing data or a program from one computer to another, often in a hierarchical structure where the source computer is the more powerful one.
primaeval soup	Mixture of water and chemical ingredients that constituted the oceans on Earth about three or four billion years ago
minimal surface	A mathematical term referring to surfaces that satisfy a minimization procedure
lagrangian	(a) A mathematical expression summarizing the properties and interactions of a physical system
multiplex	Combining many signals into one or a small number of signals
electromagnetic radiation	(a) "Waves" of electrical and magnetic "disturbance", radiated as visible light, radio waves, or any other manifestation of the electromagnetic spectrum
radial velocity	(a) Velocity along the line of sight toward (-) or away from (+) the observer
calcium	A moderately soft, low-melting reactive metal
integrated circuit	A small electronic component made of semiconductor silicon on which an entire electronic circuit of numerous microscopic transistor amplifiers, diodes and resistors has been constructed.
bit	(a) In computer terminology, a shortened form for binary digit (0 or 1)
geology	Scientific study of the dynamics and history of the earth, as evidenced in its rocks, chemicals, and fossils.
eutectic	form of a compound that has the lowest possible melting point
hydrothermal	Hot water or solution sometimes superheated
illuminated	Describes a type of electromagnetic wave detector
biochemistry	The chemical processes of living organisms; the scientific study of those processes.
titanium	A silvery transition metal
hazardous air pollutants	Airborne chemicals that cause serious health and environmental effects.
open universe	Any model of the Universe which does not contain enough matter to halt its expansion.
db	decibel; a unit of power ratio equal to 10 times the common logarithm of the ratio
chemistry	The scientific study of chemicals and chemical reactions.
cine	a series of rapidly recorded multiple images taken at sequential cycles of time and displayed on a monitor in a dynamic movie display format
intarsia	Mosaic inlay work using colored stones
scattering coefficient	a measure of the ability of particles or gases to scatter photons out of a beam of light; a number that is proportional to the amount of photons scattered per unit length.
dissipative system	a system satisfying the second law of thermodynamics
phosphatase	Any of numerous enzymes that catalyse the hydrolysis of esters of phosphoric acid and are important in the absorption and metabolism of carbohydrates, nucleotides, and phospholipids and in the calcification of bone.
firing pin	A plunger in the firing mechanism of a gun that strikes the primer and thus ignites the propelling charge of a projectile.
darwin ellipsoids	Ellipsoidal figures of equilibrium of homogeneous massive bodies describing circular orbits with a uniform angular velocity about each other on certain approximations relative to their mutual tidal influences.
pioneer spaceprobes	Series of US spaceprobes the first 9 of which concentrated predominantly on Solar exploration and research
bar	A unit of pressure equal to the weight of the atmosphere at one hundred meters above mean sea level.
lignification	deposition of lignin, the chief noncarbobydrate constituent of wood, in cell walls
chert	hard, flinty, siliceous rock, often arising through precipitation
stp	Standard Temperature and Pressure [LLM96]
ammonia	A molecule composed of one nitrogen atom and three hydrogen atoms (NH3).
accretion	(astronomy) the formation of a celestial object by the effect of gravity pulling together surrounding objects and gases.
aerosols	Fine particles or liquid droplets suspended in the atmosphere, some of which are byproducts of industrial pollution.
law	A theory of such wide and invariable application that its violation is thought to be impossible
occultation	The passage of a larger body in front of a smaller body.
rolling plains	The most common type of terrain on Venus.
span	Space Physics Analysis Network
great circle	A circle on the surface sphere whose diameter equal to the diameter of the sphere.
g-mode	A wave mode generated by a gravity wave.
density wave theory	Spiral structure is modelled as a small-amplitude wave propagating with fixed angular velocity, as the compression wave goes through, it triggers star formation on the leading edge of the spiral arms.
magnification	The effect of an optical system on the apparent angular size of an object
complex analytic	A particular property of mathematical representations of physical or mathematical systems
descending node	The point in the orbit of a solar-system body where the body crosses the ecliptic from north to south.
retrograde loop	The planets sometimes speed up in their movements, slow down, stop and even reverse direction
nmr signal	the electromagnetic signal in the radio-frequency range produced by the precession of the transverse magnetization of the spins
iron	(a) Element with atomic number 26, created mostly by type Ia supernovae, with an additional contribution from type Ib, Ic, and II supernovae
amphoterite	Obsolete name for LL (low-low Fe content) chondrites.
azimuth	(a) Directional bearing around the horizon, measured in degrees from north (0°)
timing waveform	A diagram showing the time sequence and voltage levels of a stream of pulses required, for instance, to perform charge-coupling in a CCD.
metal	(a) To an astronomer, a metal is any element heavier than hydrogen and helium; thus, not only are iron and copper metals, but so are elements like oxygen and neon
thallium	A soft malleable grayish metallic element belonging to group 13 of the periodic table
vertebrae	One or twenty-four moveable segments of the human spinal column
system noise	The noise in a radio telescope; composed of the receiver noise and the sky noise
kilometer	Abbreviated km
proper mass	Rest mass.
magnetic field lines	Imaginary lines that indicate the strength and direction of a magnetic field
set	disappear beyond the horizon.; "the sun sets early these days"
monodromy	The property that all paths of points of a body simply rotating about an axis shall return into themselves
calendar	A system of reckoning time in which days are enumerated according to their position in cyclic patterns.
thermodynamic equilibrium	(a) The state reached ultimately by an isolated system
forensic medicine	A branch of medical science that uses medical knowledge for legal purposes.
umbra	The portion of a shadow cone in which none of the light from an extended light source (ignoring refraction) can be observed.
mode	the maximum point in a plot of the frequency of occurrence of a variable versus the variable.
stalactites	dripstone, stalagmite..the formation of a conelike structure that grows from the deposits of carbonate of lime build up.
dichroism	Possessing the property of showing two different colors when viewed from different angles.
printed circuit	A compact double-sided circuit board with no wires but instead fine tracks, etched on a copped-clad board, perform the same function.
tropopause	Upper boundary of the troposphere, where the temperature gradient goes to zero.
kinematics	The branch of mechanics that studies bodies undergoing continuous change of position
standing wave	A pattern of oscillations in space in which the regions of maximum displacement and of zero displacement (the nodes) remain fixed in position.
sedimentation	The process of sediment accumulation.
doctile	Able to be drawn into a wire.
photopic	Vision or wavelength response of the cones of a normal eye when exposed to a luminance of at least 3.4 candelas per square meter.
daughter nuclide	A given nuclide produced by radioactive decay from another nuclide (the parent).
spina bifida	A condition in which the spinal cord does not close over the nerve column during the prenatal period
viscosity	a property of a fluid or semi-fluid that affects its mobility, and therefore its intensity in an image.
entrance pupil	The real object or image which defines the limit of valid light paths through an optical system
computer	A computer is a programmable machine designed to sequentially and automatically carry out a sequence of arithmetic or logical operations
domain theory	a theory of magnetism which assumes that groups of atoms produced by movement of electrons align themselves in groups called"domains" in magnetic materials.
pitch angle	Angle specifying the direction of electron velocity; or the angle between a tangent to a spiral arm and the perpendicular to the direction of the galactic center.
mira variables	Cyclic variables with cycles 100-500 days, and of spectral types K, M, S and C
sedimentary rocks	formed originally of sediment, including shale and sandstone, composed of fragments of other rocks deposited after transportation from their sources, and including those formed by precipitation, as gypsum, or by calcareous secretions of animals as in certain limestones.
prolate spheroid	A sphere stretched along its polar axis so its polar diameter is greater than its equatorial diameter.
polygraph	A medical instrument that records several physiological processes simultaneously (e.g
signal-to-noise ratio	The ratio of the amount of intelligible meaning in a signal to the amount of background noise
catalyst	A substance that increases the rate of a chemical reaction, without being consumed or produced by the reaction
standing wave	A pattern of oscillations in space in which the regions of maximum displacement and of zero displacement (the nodes) remain fixed in position
joseph von fraunhofer	Joseph von Fraunhofer was a German optician
enhydro	A chalcedony or carnelian geode having the center cavity filled with water.
cap	Crownwork: dental appliance consisting of an artificial crown for a tooth.
steady-state free precession	the name for any field echo or gradient echo sequence in which a non-zero steady state develops for both transverse and longitudinal components of magnetization
virtual particle	A particle that exists for an extremely short time in an intermediate stage of a reaction or transition.
deflection of light	(a) Gravitational effect that bends a ray of light
t2 weighted	an image created typically by using longer TE and TR times whose contrast and brightness are predominately determined by T2 signals
radiative zone	Region in a stellar interior where conduction and radiation dominates the heat flow
metastable	A state which is not stable, but which lives long enough to have significance, is called metastable
granulation	The fine structure visible on the solar surface caused by rising currents of hot gas and sinking currents of cool gas below the surface.
hemimorphic	Half formed crystals in which the faces that grow on one end are different in angle and position from the faces to be found on the other end.
tungsten	A transition metal, formerly called wolfram
haze index	A measure of visibility derived from calculated light extinction measurements that is designed so that uniform changes in the haze index correspond to uniform incremental changes in visual perception, across the entire range of conditions from pristine to highly impaired
iris	The contractile circular diaphragm forming the coloured portion of the eye and containing a circular opening (the pupil) in its centre.
breccia	An aggregate of angular fragments of stone or mineral cemented together as in calcite and chalcedony.
grazing incidence	Describes the low angle of incidence of incoming electromagnetic waves on a reflecting surface
placer	Concentrations of heavy or resistant minerals that have been transported to rivers or other water areas.
plano-concave lens	A diverging lens with one plane face and once concave face.
dark current	(a) The current that flows in a photoelectric cell when not illuminated
vector space	A set of elements (called Vectors) for which a binary operation of vector addition is defined, such that u1 + u2 is a vector if u1 and u2 are vectors: and a binary operation scalar multiplication is defined, such that cu is a vector if u is a vector and c is a scalar (a real number or a complex number, according to specification of the kind of vector space); and a standard collection of conditions governing these two operations is satisfied.
taylor column	A column that occurs over a fixed region in a rotating fluid because of the two-dimensional character of the motion in the absence of viscosity
dispersion relations	Formal relationships between the real and the imaginary parts of a complex mathematical function
ngc object	an object assigned a number in the New General Catalog of non-stellar objects
multi-dimensional hole	A generalization of the hole found in a doughnut to higher-dimensional versions.
polymerization	process of forming long molecules (polymers) out of small units (monomers)
vacuum expectation value	The value of the Higgs field (a constant value different from zero) is called a system's Vacuum Expectation Value
pipe	In geology, the tubular ascending structures in volcanic rock.
specific gravity	The weight of a substance compared to the weight of an equal volume of pure water at 4 degrees C.
carbonate sedimentation	A process by which carbonate sediment is deposited.
cds	Correlated Double Sampling A technique used with CCDs to remove an unwanted electrical signal, associated with resetting of the tiny "on-chip" CCD output amplifier, which would otherwise compromise the performance of the detector
plano-convex lens	A converging lens with one plane face and one convex face.
phase shift	a change in the periodicity of a wave-form such as light.
isomorphous	Minerals in which two or more elements can replace each other to any extent without notably changing the appearance of the crystal.
h and k lines	The two closely spaced lines of singly ionized calcium at 3968 and 3934 Å, respectively
traps	Irregularities in the silicon crystal lattice which can absorb free charges created in the semiconductor by, for instance, the absorption of light
p-wave	Primary or compressional seismic wave
sagittarius a	A radio source (the galactic center) about 12 pc in diameter
widmanstätten pattern	A geometric pattern found in some iron meteorites, consisting of groups of parallel lamellae crossing each other at various angles
coupling	An interaction between the components of a system
symmetry	A property of a physical system that does not change when the system is transformed in some manner
rockfall	The free falling of detached bodies of bedrock from a cliff or steep slope
reconstructed stones	Old method of fusing Stones made from chips
thermal	Relating to heat or heat transfer.
photoelectric effect	(a) Phenomenon in which electrons are ejected from a metallic surface when light is shone upon it
boyle's law	(a) At a constant temperature, the pressure of a fixed mass of a gas is inversely proportional to its volume: i.e
thin-layer chromatography	A chromatographic procedure used to identify drugs of abuse in urine using a thin layer of material such as silicon as a carrier
minute of arc	A unit of angle equal to 1/60 of a degree
carbon burning	The stage when a star fuses carbon into heavier elements, making neon and magnesium
oceanic trench	A narrow, steep-sided, elongated depression of the deep-sea floor.
infrared	A region of the electromagnetic spectrum
velocity	The speed and the direction of an object's motion.
span	Space Physics Analysis Network [LLM96]
fluorescein	An orange-red water-soluble compound, C20H12O5 whose solutions in alkalis produce an orange colour and a green fluorescence
microwave	Radiation in the electromagnetic spectrum between infrared and radio waves
analog-to-digital converter	a system that receives analog input data and produces digital values at its output
signal-to-noise ratio	The ratio of the amount of intelligible meaning in a signal to the amount of background noise.
kinetic energy	The energy associated with motion; the work that must be done to change a body from a state of rest to a state of motion, equal to 1/2 mv2 for a body of mass m moving at velocity v
crust	outer part of Earth, composed essentially of crystalline rocks
ccd	Charge-Coupled Device (a) A small photoelectronic imaging device (typically 1.5 cm square) made from a crystal of semiconductor silicon in which numerous (at least 250,000) individual light-sensitive picture elements (pixels) have been constructed
optical chaos	in many nonlinear optical systems the output response varies in an unpredictable and uncontrollable fashion despite being governed by deterministic laws
marching subpulse	The weaker component of a pulsar pulse when its period is more than half that of the main pulse, so that the subpulse occurs at progressively later intervals between successive main pulses.
bernoulli's theorem	Along a streamline the total energy per unit mass (including the internal energy and the pressure head p/) of an element of fluid remains constant as it moves
iridium	A white transition metal that is highly resistant to corrosion
thermal equilibrium	(a) A state in which there is no net flow of heat
stagnant	referring to meteorological conditions that are not conducive to atmospheric mixing.
bond albedo	Fraction of the total incident light reflected by a spherical body
secondary aerosols	aerosol formed by the interaction of two or more gas molecules and/or primary aerosols.
secular acceleration	Apparent acceleration of the Moon and Sun across the sky, caused by extremely gradual reduction in speed of the Earth's rotation (one 50-millionth of a second per day)
amino acid	acid containing the amino (NH
contact metamorphism	The change of rock due to the effect of high temperatures during contact with a lava flow, magma sloping, or igneous intrusion.
cytosine	A pyrimidine base, C4H5N3O, present in living cells, mainly in combined form, as in nucleic acids.
paramagnetic substance	a substance with weak magnetic properties due to its unpaired electrons
pulse- amplifier-discriminator	The part of UVIS that counts responses (pulses) to light falling on the detector
satellite	a small object revolving around a larger object
proton	Positively charged constituent of all atomic nuclei
nsf	National Science Foundation (USA).
organic	compounds of carbon, ie: coal, jet
bin	output signal channel in a multichannel spectrum analyzer or MCSA (q.v.)
rainbow	A rainbow is an optical and meteorological phenomenon that causes a spectrum of light to appear in the sky when the Sun shines on to droplets of moisture in the Earth's atmosphere
strontium	A soft low-melting reactive metal
phytochrome	Phytochrome is a photoreceptor, a pigment that plants use to detect light
silk	Fine rod like crystals embedded in a crystal
sunspot radiation	Intense, variable, circularly polarized radio waves in a noise storm.
coriolis effect	The acceleration which a body in motion experiences when observed in a rotating frame
convection model	A heat transport model based on convection, in which the energy is transported by means of motion.
network	See Chromospheric Network.
contrast	the relative difference of signal intensities in two adjacent regions of an image
resonance	One of the natural states of oscillation in a physical system, such as the periodic swing of a pendulum or vibration of a spring.
lacerations	Anything that has been torn roughly for example - a rough cut.
localisation	the wave-function of an electron is said to be localized if it is confined to a small region of a large system rather than being extended through the system.
encode	To convert plain text into a different form by means of a code.
mineralogy	The study of minerals, including their formation, occurrence, properties, composition, and classification.
acceleration	A change in velocity
transputer	A compact computer chip with a special design for linking to other transputers to make the program run faster
adiabatic index	The ratio of the fractional change in pressure to the fractional change in density as an element of fluid expands (or contracts) without exchange of heat with its surroundings.
minerals	Population
wkb method	(Wentzel-Kramers-Brillouin) A method for obtaining an approximate solution to Schrödinger's equation.
amino acid	An organic compound containing an amino (-NH2) and a carboxyl (-COOH) that link together to form proteins.
big-bang nucleosynthesis	The process, which took place between one second and 3-4 minutes after the beginning, in which the protons and neutrons of the primordial soup condensed to form the lightest atomic nuclei: Deuterium, Helium-3, Helium-4, and Lithium-7
lyot division	A gap between the B ring and the C ring.
streamline	(a) A line following the direction of the fluid in laminar or streamline flow
basalt	A dark-colored, fine-grained volcanic rock that contains more iron and magnesium and less silica than andesite (rhyolite, andesite and basalt span the compositional spectrum of common volcanic rocks).
passband	The frequency band that is transmitted with maximum efficiency and without intentional loss.
transputer	A compact computer chip with a special design for linking to other transputers to make the program run faster.
sheen	The iridescence of light reflected from the surface of a stone
aberration	Any effect in a lens or optical system which prevents a perfectly sharp image being formed
gray body	A body whose emissivity is constant and less than unity
depletion	The region of a semiconductor in which an electric field has swept out any free charge carriers such as electrons
isotropic	Materials in which the optical character is the same in all directions.
microwave	An electromagnetic wave (in the radio region just beyond the infrared) with a wavelength of from about 1 mm to 30 cm (about 109-1011 Hz).
integrating detector	Any imaging device, like a photographic emulsion or CCD, which can build up more signal and contrast by a longer exposure to light or other electromagnetic energy
pan	Unofficial name for Jupiter XI
hyoid	A U-shaped bone at the base of the tongue that supports the tongue muscles.
critical angle	The angle at which a ray of light passes from one medium to another, as a gemstone and air.
transition metal	One of the metals such as iron, manganese or platinum in the centre of the periodic table
power series	A series of the form a0 + a1v + a2v2 +
timing waveform	A diagram showing the time sequence and voltage levels of a stream of pulses required, for instance, to perform charge-coupling in a CCD
plumb bob	A pointed, tapering weight attached to a plumb line, used to measure the verticality of objects.
draco	1
ac	Alternating Current is a continuously changing flow of electrons that alternates its polarity at a periodic rate.
ionosphere	The region of Earth's atmosphere (80-500 km), immediately above the stratosphere
gamma	Unit of magnetic field intensity equal to 10-5 gauss
transition metal	One of the metals such as iron, manganese or platinum in the centre of the periodic table.
kilogram	The SI basic unit of mass (not of weight or of force)
grating	Material onto which microscopic parallel lines are inscribed
integrating nephelometer	an instrument that measures the amount of light scattered (scattering coefficient).
logistic equation	models the growth of a population as a competition between self-reproduction on the one side and inhibition arising from density-dependent effects on the other side
most impaired days	Data representing a subset of the annual measurements that correspond to the dirtiest, or haziest, days of the year.
coroner	A public official who investigates by inquest any death not due to natural causes.
post hoc fallacy	The erroneous assumption that, because B follows A, B therefore was caused by A
shock wave	A sharp change in the pressure, temperature, and density of a fluid which develops when the velocity of the fluid begins to exceed the velocity of sound.
am star	A-type or F-type object to which no unique spectral type can be assigned
transition zone	A region within the mantle that separates the upper and the lower mantle that is characterized by a rapid increase in seismic wave velocities
cnr	contrast-to-noise ratio.
luminal spray	A substance used to enhance fingerprints.
asic	Application Specific Integrated Circuit
twin crystals	Two or more crystals which have grown together in a symmetrical fashion.
sr ratio	strontium isotope ratio is used as a corrective factor in rubidium-strontium dating for studying the ultimate age of origin of igneous rock
refracting telescope	A telescope in which the principal optical component (objective) is a lens or system of lenses.
work-energy theorem	formula showing work done on rigid body by net force changes energy of the body
visibility impairment	Any humanly perceptible change in visibility (light extinction, visual range, contrast, coloration) from that which would have existed under natural conditions
astronomical twilight	The period from sunset to the time that the Sun is 18° below the horizon; or the corresponding period before sunrise.
euler number	A number used in fluid dynamics defined by p / v2, where p is pressure, density and v velocity
induction	System of reasoning in which the conclusion, though implied by the premises and consistent with them, does not necessarily follow from them
bile	A digestive fluid made by the liver and stored in the gallbladder that helps digest fats.
avogadro's number	(6.02 × 1023): The number of atoms in 12 grams of 12C; by extension, the number of atoms in a gram-atom (or the number of molecules in a mole) of any substance
cornerstone	Category name given to the European Space Agency's key missions in its long-term space science programmes Horizon 2000 and Horizon 2000+.
cosmology	The study of the origin, structure, and evolution of the Universe on the largest possible scale
digitized	Converting a signal value such as a charge or voltage into a numerical value within a given range
force	(a) Agency responsible for a change in a system
yttrium	A silvery metallic element
barred spiral galaxy	(in Hubble's classification, SB: in Morgan's classification, B) A spiral galaxy whose nucleus is in the shape of a bar, at the ends of which the spiral arms start
volcanology	The study of the causes and phenomena associated with volcanoes and volcanism.
navigation	directing the course of a ship or other craft
friable	Easily crumbled or pulverized.
igneous rock	Rock that has crystallised from a molten state (magma).
upper mantle	The part of the mantle which lies above the transition zone
fossil	Any remnant or trace of an organism of a past geologic or prehistoric age, such as a skeleton or the imprint of a leaf, embedded and preserved in the Earth's crust.
copenhagen interpretation	(a) In quantum mechanics, the interpretation of the wave-function as a description of the probabilities that the state of the system will take on different values
continental crust	The part of the Earth's crust that comprises the continents and is typically ~45 km thick
delay time	Time lapse between the time a signal (e.g., a radar beam) is propagated out to a distant object and the time it is received after the object bounces it back.
magnetogram	A map showing the strength of the magnetic field in different locations.
absolute zero	The lowest temperature ever reachable in the Universe: 0 kelvin (0K), equivalent to minus 273.15 degrees Celsius (-273.15 °C)
metric tensor	the mathematical object that describes the deviation of Pythagoras's theorem in a curved space.
alias	A name that an entity uses in place of its real name, usually for the purpose of either anonymity or deception.
hard disk	A fast, high-capacity magnetic disk, completely enclosed in a protective case inside the computer, used for storing computer data.
larvae	The young of any insect which goes through metamorphosis (changes in body structure) before becoming an adult.
fraunhofer diffraction	Diffraction observed with incident parallel light
optic sign	If the lower index of the refractive reading does not vary when the gemstone is rotated, it is uniaxial and + optic sign, if the higher index is steady and the lower index varies the optical sign is -.
phase encoding	the process of locating an MR signal by altering the phase of spins in one dimension with a pulsed magnetic field gradient along that dimension prior to the acquisition of the signal
debye-hückel model	The standard plasma model of an ionized classical gas.
radiometric dating	Determination of the age of objects - e.g., earth and moon rocks - by means of the half-life of the unstable elements they contain.
intrinsic brightness	The amount of light an object actually emits, as opposed to how bright the object looks from Earth
holography	Holography is a technique that allows the light scattered from an object to be recorded and later reconstructed so that when an imaging system is placed in the reconstructed beam, an image of the object will be seen even when the object is no longer present...
solar wind	(a) Stream of charged particles flowing from the Sun at a speed of about 600 km sec-1
sunspot	a dark area on the sun's surface that is cooler than the area around it
cyanide	A chemical compound comprised of carbon and nitrogen
crevasse	A deep, almost vertical, crack or split in the upper part of a glacier.
pressure broadening	Line broadening caused by pressure.
moiré fringes	The pattern obtained when two regular sets of lines or points overlap
brightness	(a) Refers to the amount of light coming from an object
decrepitation	The explosive shattering of mineral grains on heating.
gravitational radius	The radius which an object should have in order that light emitted from its surface just ceases to escape from its surface
dripstone	stalagmites or stalactites
fossil record	remnants or traces of organisms of past geological ages embedded in Earth's crust
hierarchical clustering model	A model of galaxy clustering in which different patterns appear at different scales of distance and in which the "average" density of matter depends on the size of the volume over which the average is performed
serial register	The final (horizontal) row of a CCD in which the controlling electrodes are arranged at right angles to those on the rest of the CCD
1785 in science	The year 1785 in science and technology involved some significant events.-Aviation:* January 7 - Frenchman Jean-Pierre Blanchard and American John Jeffries travel from Dover, England to Calais, France in a gas balloon, becoming the first to cross the English Channel by air.-Biology:* Antoine...
birefringence	Same as double refraction
coarse-graining	an operation implementing some form of spatial averaging which smoothes out relatively small length-scale configurational structure while preserving the larger length-scale structure
formulas	For weight estimation based on measurements in millimeters to 1/10
fracture	A break with an uneven or irregular surface.
light	Electromagnetic radiation with wavelengths of or close to those detectable by the eye
solid angle	(a) A measure of the angular size of an extended object, equal to the area it subtends on the surface of a sphere of unit radius
lasp	Laboratory for Atmospheric Research in Boulder, Colorado - A research facility of the University of Colorado and the builders of the UVIS instrument.
gravity	As described first by Isaac Newton, gravity is a force that exists between bodies of any mass whatever (from particles to stars) in proportion to the product of their masses, and in inverse proportion to the square of the distance between them
selection rule	A rule whereby changes in quantum numbers can take only certain allowed values: e.g., l = ± 1 or 0 for dipole transitions
isotope	A chemical element is characterised by the number of protons in its atomic nucleus
mach's principle	The hypothesis that the inertia of bodies - that is, their resistance to acceleration by applied forces - is determined not by any absolute properties of space but by the effects of distant matter in the universe
hydrodynamics	The study of how gases and fluids flow under applied forces
attenuation	Process by which a compound is reduced in concentration over time, through adsorption, degradation, dilution, and/or transformation
whistlers	Radio waves generated by a flash of lightning, which travel along Earth's magnetic field out beyond the ionosphere and back to Earth
prebiotic	relating to the chemical or environmental precursors of the origin of life
purine	nitrogen base that forms a component (with sugar and phosphate of nucleotides and nucleic acids
accretion	Collection of material together, generally to form a single body.
butterfly effect	Any effect in which a small change to a system results in a disproportionately large disturbance
air mass	A large, widespread body of air that has the same properties of humidity, temperature, and density (with only slight variations) throughout.
fat saturation	A specialized technique that selectively saturates fat protons prior to acquiring data as in standard sequences, so that they produce negligible signal
photodetector	Photosensors or photodetectors are sensors of light or other electromagnetic energy
canal	(astronomy) an indistinct surface feature of Mars once thought to be a system of channels; they are now believed to be an optical illusion.
model	An intellectual concept of how nature works
panstellar	Pertaining to more than one star.
widmanstätten pattern	A geometric pattern found in some iron meteorites, consisting of groups of parallel lamellae crossing each other at various angles.
tidal heating	The heating of a planet or satellite because of friction caused by tides.
girdle	The wide part of a cut gemstone
adamantine	Very high luster.
supersonic	Describing a speed that is greater than the speed of sound in the medium concerned
digital planar holography	Digital Planar Holography is a new technology, developed recently, circa 2003, for fabricating miniature components for integrated optics
pulse window	see mean profile.
deciview	The unit of measurement of haze, as in the haze index (HI) defined below.
gabgue	The minerals of no value in veins with ore minerals.
diode	Semiconductor electronic component
pilot	controls and operates the shuttle
tsunami	Enormous ocean wave produced by an underwater earthquake, landslide or volcanic eruption.
climatology	The scientific study of climate.
gravity	the attractive force of a body
cno tri-cycle	Similar to the CNO bi-cycle, with the addition of the cycle 17O(p, )18F( +)18O(p, )15N.
one-standard-deviation uncertainty	An estimate of the uncertainty of a measurement which is specified so that the probability of the true value of the measured quantity lying within the uncertainty interval is two out of three
uniaxial	Minerals having single refraction, one optic axis.
night-sky light	The faint, diffuse glow of the night sky
psychophysical	the branch of psychology that deals with the relationships between physical stimuli and resulting sensations and mental states.
high-velocity star	Late type stars whose spatial velocities are greater than 100 km s-1
convection	Transport of heat through movement of a gas or liquid.
echo planar imaging	the utilization of rapid gradient reversal pulses of the readout gradient resulting in a series of gradient echo signals to reduce fast dephasing or signal loss.
day numbers	Quantities that facilitate hand calculations of the reduction of mean place to apparent place
jeans length	(a) The critical wavelength (J = cs ( / G0)1/2, where cs is the isothermal sound speed in the medium) at which the oscillations in an infinite, homogeneous medium become gravitationally unstable
critical equatorial velocity	In rotating early-type stars, that velocity at which the ratio of centrifugal force to gravity at the equator is unity
schwarzschild filling factor	Ratio of the actual density to the limiting value for a system.
vibrational pattern	The precise number of peaks and troughs as well as their amplitude as a string oscillates
diffraction fringe	Blurred fringe surrounding and image caused by wave properties of light
convective zone	Region in a stellar interior where convection dominates the heat flow
semi-convection	The partial convective mixing that takes place in a convectively unstable region where stability can be attained by the results of the mixing before the region is completely mixed
critical path	A term used in project planning to indicated a segment of the proposed work which if not completed on time will result in one or more other segments being delayed with serious "knock-on" effects for the project.
celestial mechanics	Study of the movements and physical interactions of objects in space; astrophysical mathematics
facet	Man made flat part of a mineral, a planar surface.
chapman-jouguet detonation	A detonation in which the velocity of the shock front with respect to the material behind it is equal to the corresponding sound velocity
polychromatic	The term polychromatic means having several colours.It is used to describe light that exhibits more than one color
calculus	A branch of mathematics that permits computations involving rates of change (differential calculus) or of the contribution of an infinite number of infinitesimal quantities (integral calculus).
torus	The topological name for the shape of a donut
electrophesis	A method of separating large molecules (such as DNA fragments or proteins) from a mixture of similar molecules
hypothermia	This situation occurs when the core temperature of one's body falls below normal
mammillary	rounded mineral surface
electromagnetic unit	EMU A system of electrical units based on the electromagnetic properties of an electric current
n lines	Two green forbidden lines of doubly ionized oxygen [O III]
deimos	The outer satellite of Mars, 12 × 13 km, P = 1.26 days; e = 0.003; inclination of orbit to planetary equator 1°.6
sublimation	A direct change of state from solid to vapor without melting.
covariant	An adjective applied to a set of relationships between mathematical or physical quantities if they remain unchanged after transformation to a different coordinate system
transfer function	mathematical relationship between the output of a system and its input
granule	A roughly circular region on the Sun whose bright center indicates hot gases rising to the surface, and whose dark edges indicate cooled gases that are descending towards the interior
wien's displacement law	For black body radiation the rate of energy radiation per unit area per unit wavelength range at constant kelvin temperature T1 can be plotted against wavelength
deglaciation	The uncovering of a landmass by retreat or melting of glacial ice.
irradiation	(a) An optical effect of contrast that makes bright objects viewed against a dark background appear to be larger than they really are
phase conjugation	This novel form of nonlinear mixing of optical waves generates an output wave which retraces precisely the path taken by the input wave
poss	Palomar Observatory Sky Survey
density	Mass per unit of volume.
chloroform	A substance used as an intermediate in the production of refrigerants, agrochemicals and fluoropolymers, produced mainly by the chlorination of methane
self-consistent field approach	An approach in which the density distribution and state of motion in a system are determined so as to be self-consistent with the force field (e.g., gravitational or electromagnetic) arising from the system itself.
virtual phase	A type of CCD in which only one electrode is physically outside the silicon and is such as to obscure only half of the pixel
chemical weathering	The process of breaking down rocks or minerals at or near the Earth's surface by chemical processes, including hydrolysis, hydration, ion exchange, and oxidation.
h	Hubble's constant in units of 100 km s-1 Mpc-1
constituents	Any objects that are bound together to make larger objects
coordinate component	A component of a coordinate system, components are usually an angle or a length
chatoyancy	Cat's eye effect produced by some gemstones when cut properly in cabochon
achromatic lens	Lens (or combination of lenses) that brings different wavelenghts within a ray of light to a single focus, thus overcoming chromatic aberration
master equation	an equation describing the evolution of the probability of a state at a given time as the balance between transitions leading to this state, and transitions removing the system from this state.
selvage	The area bordering a vein.
gadolinium	gadolinium is a non-toxic paramagnetic contrast enhancement agent utilized in MR imaging
continental drift	The slow, lateral movements of continents across the surface of the Earth.
striated muscle	Striated muscle tissue is a form of fibers that are combined into parallel fibers
symmetric	Having similarity in size, shape, and relative position of corresponding parts.
world surface/world sheet	The surface traced in space-time by an extended object such as a string
indent	A notch or dent left on paper due to the force from the tip of a pen when writing.
hall effect	When an electric current is passed through a conductor and a magnetic field is applied at right angles, a potential difference is produced between two opposite surfaces of the conductor
viscosity	The internal friction of a fluid or liquid that tends to resist and dissipate its flow
ransom	An exchange or buy back for money; under threat.
abelian group	A mathematical group of transformations with the property that the end result of a series of transformations does not depend on the order in which they are performed
hydrocarbon	organic compound containing only carbon and hydrogen
tropopause	Upper boundary of the troposphere (about 15 km), where the temperature gradient goes to zero
brilliant	The cut of a gemstone that is round and has 32 facets plus the table above the girdle, (crown), and 24 facets plus any culet below the girdle, (pavilion).
tropopause	Upper boundary of the troposphere (about 15 km), where the temperature gradient goes to zero.
holocene epoch	The most recent geologic epoch of the Quaternary Period extending from the end of the Pleistocene (11,000 years ago) to the present.
natural selection	Tendency of individuals better suited to their environment to survive and perpetuate their species, leading to changes in the genetic makeup of the species and, eventually, to the origin of new species
spectrum	(a) The breakdown of light into a rainbow of colors
hydrogen alpha	Also called H-alpha
cryptoendoliths	Microscopic organisms that grow within rocks.
botryoidal	Resembling a bunch of grapes in rounded masses of a mineral.
human genome	The complete set of human genes - approximately 100,000 total - which together contain information covering every aspect of human physical development and function.
lifetime	The time it takes for a sample of identical particles to decay to 1/e of its initial population (e 2.718)
transceiver coil	an MRI surface coil that acts as both transmitter and receiver.
parallax	Change in the apparent position of objects when viewed from two widely separated positions.
circle of willis	a large network of interconnecting blood vessels at the base of the brain that when visualized resembles a circle.
gravitation	In Newtonian terms, a force between masses that is characterized by their acceleration toward each other; the magnitude of the force depends directly on the product of the masses and inversely on the square of the distance between them; in Einstein's terms, the curvature of space-time.
scattering angle	the angle between the direction of propagation of the scattered and incident light (or transmitted light)
world surface/world sheet	The surface traced in space-time by an extended object such as a string.
diffraction grating	A system of closely spaced equidistant slits or reflecting strips which, by diffraction and interference, produce a spectrum.
istp	International Solar-Terrestrial Physics Science Initiative
pentose-phosphate pathway	An anabolic pathway that uses the six carbons of glucose to generate five-carbon sugars
multicellular	consisting of many cells
cavitation	The formation of small cavities in a liquid, caused by a reduction in fluid pressure
binomial probability	The probability that a particular result will be obtained in a given number of trials
spectral bandwidth	The wavelength, or frequency range over which photons are detected at any one time; some detectors can operate in one or more bands placed within a broader range of spectral response.
organelle	specialized cellular part analogous to an organ
non-baryonic matter	Material that consists of exotic subatomic particles
trophic level	level within a food chain in which all members are equally far removed from the primary food producers
reflection	The throwing off or back, light from the surface.
clastic rock	Sedimentary rock made up of fragments of preexisting rocks and transported into the place of deposition.
barn	(a) Symbol: b A unit of area defined as 10-28 square meter
mass	The measure of the inertia of an object, determined by observing the acceleration when a known force is applied
fundamental star	Star for which coordinates have been determined to a very high degree of accuracy.
zepto-	Symbol: z A prefix denoting 10-21
laplacian determinism	Clockwork conception of the Universe in which complete knowledge of the state of the Universe at one moment completely determines its state at all future and past moments.
emission	The process of transition of an electron from an outer orbit to an inner orbit around the nucleus results in a characteristic amount of energy being radiated (as line emission) that corresponds to the lost energy of the electron
gps	Global Positioning System
tributary	A stream that flows into or joins a larger stream or another body of water.
mass	Measure of the amount of matter in an object
normalization	A mathematical technique for eliminating divergent terms or for making them converge.
gui	Graphical user interface
molecule	A combination of two or more atoms bound together electrically; the smallest part of a compound that has the properties of that substances.
velocity	The speed and the direction of an object's motion
zones	Yellow-white regions that circle Jupiter parallel to its equator; believed to be areas of rising gas.
greenhouse gases	Gases, primarily water vapor, carbon dioxide, and methane, that increase global temperatures by absorbing outgoing radiation emitted by the Earth's surface
materialism	Belief that material objects and their interactions constitute the complete reality of all phenomena, including such seemingly insubstantial phenomena as thoughts and dreams
auto-catalysis	the ability of certain chemicals to enhance by their presence the rate of their own production in a sequence of chemical reactions
elliptical	shaped like an egg, but with equal ends
hydrosphere	aqueous envelope of Earth, including bodies of water and water vapor in the atmosphere hydrothermal vent - opening in the sea floor produced by the hot magmatic emanations that are rich in water Hz - see hertz
foliated	Made up of thin leaves, like mica.
alignment	Process of mounting optical elements and adjusting their positions and orientations so that light follows exactly the desired path through the instrument and each optical element performs its function as planned.
period	The time interval for some regular event to take place; for example, the time required for one complete revolution of a body around another.
koschmeider constant	the constant in the reciprocal relationship between standard visual range and the extinction coefficient.
ultraviolet light	Radiation lying in the ultraviolet range; wave lengths shorter than light but longer than X rays.
ejecta	Pulverized rock scattered by meteorite impacts on a planetary surface.
termination shock	The boundary marking one of the outer limits of the Sun's influence
miaroles	Small cavities in granitic rocks created by volatile components.
luminance	a measure of light power refected or emitted from an object within a solid angle of one steradian per unit area area projected in a given direction
barred spiral	(in Hubble's (1936) classification, SB: in Morgan's classification, B) A spiral galaxy whose nucleus is in the shape of a bar, at the ends of which the spiral arms start.
step cut	(trap cut)..Cut with edges are parallel to those the rectangular table.
shot noise	Noise, or fluctuations in the current of a detector, due to the fact that the current is carried not by a smooth fluid, but by a large number of individual electrons (cf
null geodesic	The path of a light ray in curved spacetime
rossby waves	Cyclonic convection waves in a rotating fluid
starlink	A software environment and suite of programs for astronomical data analysis developed in the UK and supported by the Rutherford-Appleton Labs.
number of excitations	an indicator of how many times each line of k-space data is acquired during the scan.
slice	the term describing the planar region or the image slice selection region.
arc minute	Abbreviated arcmin
satellite	A body that orbits around a larger body.
emission coefficient	Radiant flux emitted per unit volume per unit solid angle.
amplitude modulation	Information is conveyed in the form of variations in the envelope of a carrier frequency
localisation	the wave-function of an electron is said to be localized if it is confined to a small region of a large system rather than being extended through the system
cosmological model	The result of the theoretical calculation of an expansion curve obtained, for the case of relativistic cosmological models, from solutions to Einstein's field equations
stratosphere	The region of Earth's atmosphere immediately above the troposphere
microwave radiation	(a) Radiation in the electromagnetic spectrum between infrared and radio waves
emission	The process of transition of an electron from an outer orbit to an inner orbit around the nucleus results in a characteristic amount of energy being radiated (as line emission) that corresponds to the lost energy of the electron.
ritual	Stereotyped behaviour.
symmetry breaking	(a) A reduction in the amount of symmetry a system appears to have, usually associated with a phase transition
schmidt camera	Telescopic camera incorporating an internal corrective lens or plate that compensates for optical defects and chromatic faults in the main mirror
transition probability	The probability that a system in one energy state will undergo a transition into another
occiput	Rear portion of crown
refractive index	A measure of the degree through which light is refracted when passing through a particular material compared to a vacuum.
solid angle	A measure of the angular size of an extended object, equal to the area it subtends on the surface of a sphere of unit radius.
breccia	A rock composed of fragments of earlier rocks bonded together.
andesite	A dark-colored, fine-grained volcanic rock that is intermediate in composition (with respect to silica, magnesium and iron) between rhyolite (high silica, low magnesium and iron) and basalt (low silica, high magnesium and iron).
trade winds	Part of one of the three major circulation cells in each hemisphere, the trade winds exist from approximately 0° to 30° north or south latitude
pigment	Organic substance found in plant and animal cells that creates colouring.
polar nephelometer	an instrument that measures the amount of light scattered in a specific direction
freezing point shift	change in the freezing point of a solution compared to that of the pure solvent
kelvin temperature scale	The temperature, in Celsius (Centigrade) degrees, measured above absolute zero.
refractive index	The measurement of the amount of change in direction of light passing through one medium to another
median	Literally the middle value in a sequence of values arranged in increasing size order
clapeyron's equation	A fundamental relation between the temperature at which an inter-phase transition occurs, the change in heat content, and the change in volume
flux	The amount of energy flowing through a given area in a given amount of time, usually expressed as counts per area per second.
mass models	Models that attempt to infer the distribution of mass in an astronomical system by comparing the observed properties of the system (such as the distribution of light) with those properties predicted by various theoretical distributions of mass.
habit	Characteristic crystal form.
grooved terrain	Regions of the surface of Ganymede consisting of parallel grooves; believed to have formed by repeated fracture and refreezing of the icy crust.
glacial period	Time when glaciers advance and engulf huge sheets of land
granite	An intrusive igneous rock, usually light-colored
dissipative structures	states of matter arising through bifurcation when a system is driven away from the state of thermodynamic equilibrium by external constraints exceeding a critical value.
prosecutor	The lawyer that represents the government.
albedo	(a) The ratio of the amount of light reflected from a surface to the amount of incident light
inertial mass	The mass of an object as measured by the property of inertia
probability amplitude	In quantum mechanics, a probability amplitude is a complex number whose modulus squared represents a probability or probability density.For example, if the probability amplitude of a quantum state is \alpha, the probability of measuring that state is \|\alpha\|^2...
stippling	This is a method of paint application where the artist applies a series of dots by dabbing with the end of the brush, which is held at right angles to the picture surface.
advection	The transfer of matter such as water vapor or heat through the atmosphere as a result of horizontal movement of an air mass.
planck time	(a) About 10-43 seconds
blue-green algae	any of a class of algae (a group of mainly aquatic, simple photosynthetic plants) whose chlorophyll is marked by bluish-green pigments
cosmogony	The study of the origin of celestial systems, especially the solar system.
arthritis	A medical condition affecting a joint or joints, causing pain, swelling and stiffness
einstein equivalence principle	Foundation for curvcd space-time, it states that bodies fall with the same acceleration and that physics in freely falling reference frames is independent of the velocity and location of the frames
liquid crystal	substances intermediate in their properties between liquids and crystals
exponential expansion	An expansion described by a fixed doubling time
thermodynamic potential	a function of the state of a system which takes its extreme value on the asymptotically stable state reached by the system in the course of time
insolation	The solar radiation falling on Earth's surface or its atmosphere
rayleigh scattering	Light scattering of the natural gases in the atmosphere
microwave	Light, or electromagnetic radiation, whose wavelength ranges from millimetres to almost one metre
telephotometer	an instrument that measures the brightness of a specific point in either the sky or vista.
embezzlement	The fraudulent use of money or property which has been entrusted to one's care.
server	A computer system or program that provides service across a network
refraction	bending of a wave front when the wave encounters a medium with propagation properties different from the one in which it has been traveling
phenol	A highly poisonous, caustic crystalline chemical compound derived from coal tar or plant tar or manufactured synthetically
plastic	A material with properties of a solid but capable of flowing under pressure.
siderite	An iron (or iron and nickel) meteorite
open system	a system communicating with the environment by the exchange of energy and matter.[D89]
branching ratio	Ratio between the numbers of atoms starting from a given initial state which undergo two different types of transitions, perhaps, or between different bound states
vanadium	A silvery transition element used in alloy steels
coronene	The first ultraviolet phosphor to be tried on the surface of a CCD
host computer	The main or master computer in an instrumentation system
chaotic inflation	(a) A model in which many distinct universes form from different regions of a "mother" universe, with some inflating and others perhaps not
tektite	A small glassy body containing no crystals, probably of meteoritic origin and bearing no antecedent relation to the geological formation in which it is found
hydrodynamics	The study of how gases and fluids flow under applied forces.
sinuous rille	A narrow, winding valley on the moon caused by ancient lava flows along narrow channels.
physical weathering	The processes that mechanically break up rocks into fragments, such as the movement of water, wind and ice, and frost action
equatorial sky area	A fixed region on the sky defined using equatorial coordinates
molecule	The smallest unit of matter into which an element or a compound can be divided and still retain its chemical and physical properties
claustrophobia	a psychological reaction to being confined in a relatively small area.
peridotite	A coarse-grained igneous or metamorphic rock composed primarily of olivine, with or without other minerals such as pyroxenes, amphiboles, or micas.
infrared radiation	electromagnetic radiation with wavelengths longer than that of visible light and shorter than millimeter radio waves
faber-jackson relation	An empirically observed correlation between the speeds of stars in the center of a galaxy and the intrinsic luminosity of the galaxy - the higher the random speeds, the more luminous the galaxy
statistical equilibrium	A state in which the average density of atoms per cubic centimeter in any atomic state does not change with time and in which, statistically, energy is equally divided among all degrees of freedom if classical concepts prevail
cp violation	(a) A reaction between subatomic particles is said to be a "CP violating" reaction if the reaction produces a different result when the electrical charges of the particles are changed to their opposites and the mirror image of the particle trajectories is used
phylum	category of taxonomic classification just above class
biosphere	The part of a planet or moon (its atmosphere, waters, soil, and crustal rock) in which living organisms exist.
plate tectonics	The theory and study of plate formation, movement, interaction and destruction; the attempt to explain seismicity, volcanism, mountain-building, and paleomagnetic evidence in terms of plate motions
meteor	A small bit of matter heated by friction to incandescent vapor as it falls into the atmosphere
solar wind	Stream of plasma, mainly electrons and protons, which flows from the Sun's corona at up to 900 km/s
acetone	A colourless, highly flammable chemical compound (CH3)2CO used as an organic solvent, an ingredient in many lacquer thinner compounds and adhering liquids; used to remove lacquer adhered knife-cut stencils and lacquer type blockout from screen fabrics.
synthetic element	element which cannot be found as a mineral deposit
field of view	The patch of sky or of any image scene which can be seen by an optical system or by one picture element (pixel) of a detector system
ph level	A measure of acidity or alkalinity as of soil, water etc
subcontinent	A large, relatively distinct landmass, such as India, which is part of a continent but geographically considered an independent entity.
magnetic resonance spectroscopy	an MR technique wherein a sample is placed in a strong, very uniform, magnetic field, and stimulated with RF electromagnetic energy
ellipse	A plane curve in which the sum of the distances of each point along its periphery from two points - its "foci" - are equal.
stp	Standard Temperature and Pressure
sampling efforts	Technology
diaphragm	(a) A device used in optical instruments to reduce or control the aperture of the system
photon	a bundle of electromagnetic energy that exhibits both wave-like and particle-like characteristics.
biosphere	general term for regions in which life can exist
starlink	A software environment and suite of programs for astronomical data analysis developed in the UK and supported by the Rutherford-Appleton Labs
glycerol	A three-carbon substance that forms the backbone of fatty acids in fats
unstable equilibrium	Equilibrium such that if the system is disturbed a little, there is a tendency for it to move farther from its original position rather than to return
barometric law	The density distribution of gas in a plane-parallel, isothermal layer acted on by a uniform gravitational field: (z) = (0) exp ( - mg / kT)
specific gravity	Ratio of the mass of a given volume of a substance to that of an equal volume of water
manufactured	Made by hand or machinery, especially on a large scale.
carbon black	A form of amorphous carbon (soot) produced by incomplete combustion of gas (or other organic matter)
taylor instability	A hydrodynamic instability which occurs whenever there is a density inversion
stationary nonequilibrium state	time-independent state of a system subjected to fixed constraints
sum-over-histories	Probabilistic interpretation of a system's past, in which quantum indeterminacy is taken into account and the history is reconstructed in terms of each possible path and its relative likelihood.
advection	The transfer of matter such as water vapor or heat through the atmosphere as a result of horizontal movement of an air mass
pressure gradient	A pressure difference between two adjacent regions of fluid results in a force being exerted from the high pressure region toward the low pressure region
wavelength of maximum	The wavelength at which a perfect radiator emits the maximum amount of energy; depends only on the object's temperature.
peroxidase	Any of a group of enzymes (occurring especially in plant cells) that catalyse the oxidation of a compound by a peroxide.
baud	The baud is a unit of telegraph signalling speed; one baud is equal to one pulse per second
spinning rate	During high-resolution magic angle spinning 1H nuclear magnetic resonance spectroscopy experiments samples are spun at an angle (the so-called magic angle) to the magnetic field to reduce line-broadening effects.
open string	A type of string with two free ends.
chapman's equation	An equation expressing the velocity of a gas in terms of certain molecular constants.
geology	Scientific study of the dynamics and history of the earth, as evidenced in its rocks, chemicals, and fossils
indium	A soft silvery metallic element
fungus	plant of the Thallophyta subkingdom, which lacks chlorophyll and ranges in form from a single cell to massed bodies, including yeasts, molds, and mushrooms
radar	Radio Detection and Ranging
refraction	Deflection (or "bending") of light - or any ray as it passes from one medium into another of greater or lesser density, representing a change in overall speed of the ray
asymmetry	A violation of symmetry
inversion recovery	an imaging sequence that involves successive 180É and 90É pulses, after which a heavily T1-weighted signal is obtained
phonetics	The study of the production, transmission, and reception of speech sounds.
chapman-jouguet detonation	A detonation in which the velocity of the shock front with respect to the material behind it is equal to the corresponding sound velocity.
nucleic acids	long, chainlike molecules which, in the various combinations of constituent groups, embody the genetic code (DNA) and assist with its transmission (RNA)
shock wave	discontinuity in the flow of a fluid (including a gas or plasma) marked by an abrupt increase in pressure, temperature, and flow velocity at the shock front
light	Electromagnetic radiation with wavelengths of or close to those detectable by the eye.
richter scale	An exponential scale ranging from 1 to 9 that measures the amount of energy released during an earthquake.
optical fibre	Glass and transparent plastics can be made into a very thin wire or fiber
cpu	Central Processing Unit The part of a digital computer responsible for interpreting and executing instructions
magnetic flux	The number of magnetic field lines passing through an area.
iodine	A dark-violet volatile solid element belonging to the halogens
snell's law	For a refracted light beam, the ratio of the sine of the angle of incidence to the sine of the angle of refraction is a constant
kinetic energy	energy of a body or system with respect to the motion
vasectomy	Surgical procedure that removes all or part of the vas deferens (usually as a means of sterilization); is sometimes reversible.
b galaxy	In Morgan's Classification, a barred spiral.
line broadening	Increase in the range of wavelengths in which some characteristic emission or absorption occurs, due to a number of causes (e.g., Doppler broadening, the effects of perturbers, etc.)
larmor equation	an equation that states that the frequency of precession of the nuclear magnetic moment is directly proportional to the product of the magnetic field strength (Bo) and the gyromagnetic ratio (g)
geochemistry	The study of the distribution and amounts of chemical elements in the various systems that comprise the Earth.
strain	The fractional change in dimension produced by a stress applied to a body
field of view	The full angular extent of the sky being viewed by an instrument.
astronavigation	a type of navigation involving observations of the apparent positions of heavenly bodies
standard candle	A class of celestial objects of known luminosity, which can be used to find the distance to associated objects
schmidt	Telescopic camera incorporating an internal corrective lens or plate that compensates for optical defects and chromatic faults in the main mirror
precession	comparatively slow gyration of the axis of a spinning body so as to trace out a cone
phenocryst	Crystal that is set in a finer grained ground mass.
platonic solids	The five regular polyhedrons - the tetrahedron, octahedron, hexahedron, icosahedron, and dodecahedron - esteemed by Plato as embodying aesthetic and rational ideals.
enzyme	A protein that accelerates the rate of chemical reactions
statistical weight	g: The probability that the state will appear under a given set of conditions
opacity	(a) A measure of the resistance of a medium to the transmission of visible light or other forms of radiation
psd	Pulse-Shape Discrimination
polaroid	A synthetic doubly refracting substance, that strongly absorbs polarized light in one plane, while easily passing polarized light in another plane at right angles
schottky barrier	A metal to semiconductor interface without any insulation layer produces an energy barrier in the semiconductor which can be used like a diode.
s-wave	Secondary Wave: A seismic shear wave that moves transversely through Earth
isotope	(a) An atomic nucleus having the same number of protons as a more commonly found atomic nucleus but a different number of neutrons
rhyolite	A fine-grained volcanic igneous rock usually light in color
detritus	Any loose matter derived directly from an older source by disintegration or erosion and transported from its place of origin.
evolution	change over time in the morphology and physiology of species of organisms; or of any object, such as stars; or of ideas; etc.
pallas	The second asteroid to be discovered (by Olbers in 1802)
logistic equation	models the growth of a population as a competition between self-reproduction on the one side and inhibition arising from density-dependent effects on the other side.
week	An arbitrary period of days, usually seven days; approximately equal to the number of days counted between the four phases of the Moon
decaying orbit	An unstable orbit from which the orbiting object will gradually spiral into the body it is orbiting.
labradorescence	Patchy or diffuse iridescence due to the interference of light by reflection from parallel inclusions
partial voluming	a loss of resolution due to excessively large voxels, typically caused by slices that are too thick.
clade	group of organisms all descended from a single common ancestor
patroclus	Asteroid 617, a Trojan 60° behind Jupiter
laplacian determinism	Clockwork conception of the universe in which complete knowledge of the state of the universe at one moment completely determines its state at all future and past moments.
effective theory	Each part of the physical world can be described by a sub-theory that applies over a certain distance scale or energy scale
flash gate	An ultra-thin transparent electrode across the entire back surface of certain CCDs used to control the charge on the back surface and hence the QE for blue and UV light.
ip address	The numeric address of a computer on the Internet
oviraptor	A primitive theropod dinosaur that developed from the carnivorous raptor theropods during the Late Cretaceous Period
thermalization	An atomic or molecular transition is thermalized when the Boltzmann factor for the two levels of the transition takes on the value it would have in thermodynamic equilibrium.
period	(a) The period of a wave is the time interval between the receipt of two successive peaks (often called crests) of the propagating disturbance
h and persei	A double stellar association about 2 kpc distant, visible to the naked eye as a patch of light
contrast-to-noise ratio	the ratio of signal intensity differences between two regions, scaled to image noise
cryoprobe	Nuclear magnetic resonance (NMR) probes for which the coil and pre-amplifier have been cryogenically cooled to reduce the amount of electronic noise in the NMR signal
radial velocity	The speed at which an object moves toward or away from us
kelvin scale	A temperature scale with the same divisions as the Celsius (centigrade) scale and with the zero point at 0° absolute
greenhouse effect	Retention and escalation of temperature beneath a mantle of clouds or denser atmosphere
ductility	The ability of a material to irreversibly deform without rupture.
skarn	Contact rock of igneous silicate masses with limestone.
hypostasis	The pooling of blood as it accumulates at the lowest parts of the body, being pulled down by gravity; is a method of determining the position of the body at/after death.
abiotic	Non-biological in origin.
symbiosis	intimate living together of two organisms (called symbionts) of different species, for mutual or one-sided benefit
averaging	see Signal Averaging.
mdt	Mountain Daylight Time -- The time in Boulder, Colorado, where LASP is
phase change	metamorphosis of a substance from one state to another, as from gas to liquid or from solid to gas
analog	being continuous, or having a continuous range of values.
cobalt	A lustrous silvery-blue hard ferromagnetic transition metal
energy	The capacity of a body or system to do work
prandtl number	(a) Ratio of the product of the viscosity coefficient and the specific heat at constant pressure to the thermal conductivity
cosmogony	The study of the origin of celestial systems, especially the Solar System.
swap file	A disk file or partition used to temporarily store information when system memory runs low.
exobiology	The branch of biology that deals with of the origin and distribution of possible life on other planetary bodies.
uv	Ultraviolet: wavelengths shorter than about 350 nm.
integrated circuit	A small electronic component made of semiconductor silicon on which an entire electronic circuit of numerous microscopic transistor amplifiers, diodes and resistors has been constructed
c star	A class of carbon star, defined by Morgan and Keenan to replace the Harvard R and N spectral classes.
marching subpulse	The weaker component of a pulsar pulse when its period is more than half that of the main pulse, so that the subpulse occurs at progressively later intervals between successive main pulses
symmetry	State of a system such that it has a significant quantity that remains invariant after a transformation
anorthosite	An intrusive igneous rock that consists chiefly of the mineral plagioclase feldspar.
orthorhombic crystal	A crystal in which the atoms are arranged in a rectangular solid, for which each of the three principal lengths are different
geologic time	The period of time covering the physical formation and development of Earth, as recorded within the succession of rocks.
standard deviation	The root mean square deviation from the arithmetic mean
empirical	Derived from experiment or observation.
dc	Direct Current Fixed voltages
cryostat	Container used to isolate thermally a fluid from its environment and maintain it at low temperatures.
product	The result of multiplying two numbers.
climatology	The study of climate – the prevailing atmospheric conditions of humidity, temperature, winds, etc.
latitude	A north-south coordinate on the surface of the earth; the angular distance north or south of the equator measured along a meridian passing through a place.
lower mantle	The part of the mantle that lies below a depth of 1,000 kilometers
hydrodynamic soliton	A finite-amplitude disturbance which is propagated through a fluid without any change of shape
pneumographs	Rubber tubes filled with air.
escape velocity	The speed at which an object can leave another object behind, without being recalled by its gravitational force
unstable air mass	an air mass that is vertically well mixed
boundary condition	(a) Restriction on the limits of applicability of an equation
project cyclops	a 10-week design study sponsored by NASA, Stanford University, and the American Institute for Engineering Education, of possible means for detecting extraterrestrial civilizations
theory	A rationally coherent account of a wider range of phenomena than is customarily accounted for by a hypothesis.
litmus paper	colored paper used to show whether a solution is acid or alkaline.
sheetwash	Erosion of the ground surface by thin sheets of rainwater
atmosphere	A gaseous envelope surrounding a planet, or the visible layers of a star; also a unit of pressure(abbreviated atm) equal to the pressure of air at sea level on the Earth's surface.
revolution	the orbital motion of one object around another
tesla	In the SI system, a unit of measure of magnetic flux.
metamorphic rocks	Rocks that form as the result of transformation from other rocks
standard deviation	The root mean square deviation from the arithmetic mean.
cosmogony	The study of the origin of celestial systems, especially the Solar System
reaction rate	The rate at which a chemical or nuclear reaction proceeds
root canal	Also called endodontic treatment, it is the cleaning out the inside nerve of a tooth that is heavily decayed, and replacing it with a material seals the inside of the root so infection cannot get back in.
principal quantum number	A measure of the major axis of an electronic orbital
interdune valleys	Valleys or depressions between sand dunes.
density	The amount of matter in a prescribed volume of material.
north star	Polaris.
light element	In astronomy these elements are hydrogen, helium, and lithium; sometimes also beryllium and boron.
fringing	The appearance of complex light and dark contours in a CCD image due to constructive and destructive interference effects of light reflected inside the detector.
plutonic rock	rock that has solidified deep underground.
oxygen burning	The stage when a star fuses oxygen into silicon and sulfur
dqe	Detective Quantum Efficiency The ratio of the actual number of detected photoelectrons in a detector to the number of incident photons when proper account is taken of noise and other efficiency factors.
chlorine	A green reactive gaseous element belonging to the halogens
evolution	(a) In Biology the theory that coniplex and multifarious living things developed from generally simpler and less various organisms
figure of merit	The extent to which an optical system falls short of perfection.
superconductivity	(a) A phenomenon occurring in some metals at very low temperatures, in which the resistance drops to zero and the metal shows many other anomalous properties
tantalum	A silvery transition element
verdict	The finding or answer given to the court by the jury.
preflash	The technique of illuminating the CCD with a low light level flash before beginning a long exposure in order to "fill up" any charge traps.
kinetic energy	The energy associated with motion; the work that must be done to change a body from a state of rest to a state of motion, equal to 1/2 mv2 for a body of mass m moving at velocity v.
radioactive	Emitting alpha, beta, or gamma rays.
butterfly diagram	Plot of heliographic latitude of sunspots versus time, developed by Maunder in 1904 to illustrate the solar cycle
anthropogenic	produced by human activities.
io flux tube	A tube of magnetic lines and electric currents connecting Io and Jupiter.
throughput	A measure of the efficiency of an optical system
shield volcanoes	Wide, low profile volcanic cones produced by highly liquid lava.
nuclear chronology	A method of dating an object by measuring how many atomic nuclei have disintegrated and changed into other nuclei
druse	A crystal coated surface of rock.
hydrogen density	the concentration of Hydrogen atoms in water molecules or in some groups of fat molecules within tissue
extraordinary ray	Crystals and minerals belonging to the hexagonal tetragonal systems in which the ray or refractive index varies according to its direction through the crystal.
paraxial	Describing rays incident on a surface close and parallel to the axis
systems analysis	analysis of the response to inputs of a set of interconnected units whose individual characteristics are known
nordtvedt effect	A theoretical violation of the principle of equivalence for massive, self-gravitating bodies.
markovian process	a random process in which the probability of performing a transition to a certain state at a given time depends solely on the state in which the system is found at this time.
nebular lines	Lines that originate from forbidden transitions.
entropy	(a) A thermodynamic property of a macroscopic body which corresponds intuitively to the degree of disorder
c stars	A class of carbon stars (q.v.), defined by Morgan and Keenan to replace the Harvard R and N spectral classes.
nautical mile	Equals 1.15 statute miles.
transmitter	the portion of the MR scanner that produces the RF current and delivers it to the transmitting coil (antenna)
free parameter	A number which is needed to define a theory well enough so that predictions can be made, but which must be determined by experiment or observation.
earthquake	A sudden motion or trembling of the Earth's crust caused by the passage of seismic waves radiated from a fault along which sudden movement has occurred.
siltstone	A fine-grained rock of consolidated silt with the texture and composition of shale, but lacking its fine lamination or fissility (ability to be easily split).
midas	Munich Image Data Analysis System -- A suite of programs and a software environment developed at the European Southern Observatory for astronomy applications.
noao	National Optical Astronomy Observatory (USA).
mineral	A naturally-occurring, homogeneous inorganic element or compound having a definite chemical composition and orderly internal structure, crystal form, and characteristic chemical and physical properties.
endogenous	Generated deep in the earth by volcanism or earthquakes.
population	Sampling Efforts
ft-values	t = half-life of the -unstable nucleus, and f stands for an integral which depends on the -decay energy and the type of transition
orthogonal	a plane or section perpendicular to the xyz coordinate system.
non-destructive readout	A means of reading out an infrared array or a CCD with a skipper output in which the output voltage is sampled without resetting the detector
parity	The principle of space-inversion invariance; i.e., no experiment can differentiate between the behavior of a system and that of its mirror image
sunspot	A relatively cool, dark region on the Sun's surface (photosphere) which is created by the Sun's magnetic field
unconformity	An erosional surface representating a gap in the geologic record between rock layers of different ages indicating that deposition was not continuous.
decode	To convert a coded message into understandable form using ordinary language.
nitrate	Solid or liquid particulate matter containing ammonium nitrate [NH4NO3] or other nitrate salts
theory	(a) A rationally coherent account of a wider range of phenomena than is customarily accounted for by a hypothesis
cobble	Any rock fragment larger than a pebble and smaller than a boulder, especially one that has been naturally rounded.
bromine	A deep red, moderately reactive element belonging to the halogens
rigor mortis	The stiffening of the body muscles after death.
chromosome	a gene-containing filamentous body found in cell nuclei
transit	The passage of a smaller, nearer astronomical object across the face of a larger object in the background, as in a transit of Venus across the Sun.
archaeoastronomy	The study of astronomy by ancient peoples
wkb method	(Wentzel-Kramers-Brillouin) A method for obtaining an approximate solution to Schrödinger's equation
deflection of the vertical	The angle between the astronomical vertical and the geodetic vertical
carcinogenic	Cancer causing.
fractal	A geometric figure in which a pattern is repeated ad infinitum on smaller and smaller scales
thermohaline circulation	Circulation or movement of ocean water masses resulting from density differences caused by variation of temperature and salinity.
ecology	study of the relationship between organisms and their environment
tuning fork diagram	A system of classification for elliptical, spiral and irregular galaxies.
zodiacal light	A faint glow that extends away from the Sun in the ecliptic plane of the sky, visible to the naked eye in the western sky shortly after sunset or in the eastern sky shortly before sunrise
filling	A dental appliance consisting of any of various substances (as metal or plastic) inserted into a prepared cavity in a tooth; "when he yawned I could see the gold fillings in his teeth"; "an informal British term for `filling' is `stopping'.
allotropy	The existence of a solid substance in different physical forms
outcrop	Where the bed rock is exposed.
photosynthesis	The chemical process by which green plants use solar energy to synthesize carbohydrates from carbon dioxide and water, releasing molecular oxygen as a byproduct.
ferromagnetism	magnetic even in the absence of an external magnetic field.
microwave	electromagnetic wave roughly in the range 0.01-1 m in wavelength (ordinary broadcasting utilizes waves in the 200-600 m range; the "short waves" used in long-distance communications are rarely shorter than 10 m)
post-newtonian effects	The first nontrivial gravitational effects which go beyond the predictions of Newton's theory.
pencil beam	The main lobe of an antenna pattern, consisting of a narrow receiving beam of the type obtained with a single parabolic instrument.
oscillator strength	A measure of the probability that a transition represented by an electronic oscillator will occur
knudsen number	The ratio of the mean free path length of the molecules in a fluid to a characteristic length of the structure in the fluid stream.
longitude	An east-west coordinate measured on the surface of a sphere.
atmosphere	Mixture of gases and traces of dust, ices, and droplets gravitationally bound to a planet.
paradox	A self-contradictory proposition
space-time foam	Frothy, writhing, tumultuous character of the spacetime fabric on ultramicroscopic scales, according to a conventional point-particle perspective
spin network	A term used by Roger Penrose to denote collections or networks of quantum mechanical spinors
vein	A more or less upright sheet deposit of minerals, cutting other rocks and formed from solutions rather than from a molten magma as in a dike.
smoke trail	condensation of vaporized rock removed from the surface of a meteoroid by ablation
magnitude	An arbitrary number, measured on a logarithmic scale, used to indicate the brightness of an object
canvas	Strong heavy cloth made from cotton, hemp or flax used with clothing, bags, paintings and curtains.
inversion	See temperature inversion.
cosmonaut	the Russian term for an astronaut
macroscopic	Refers to scales typically encountered in the everyday world and larger; roughly the opposite of microscopic
achromatic objective	A lens of two or more components with different refraction indices (e.g., crown glass and flint glass), used to correct for chromatic aberration
degaussing	The neutralization of an object's magnetic field by the use of an equal and opposite field
atom	The smallest part of a chemical element which remains unchanged during all chemical reactions.
astrophysics	the branch of astronomy concerned with the origin, and the chemical and physical nature of heavenly bodies.
opacity	The property of a substance that hinders (by absorption or scattering) light passing through it; opposite of transparency.
miller indices	Group of three digits used to designate crystal faces.
photonics	The technology of generating and harnessing light and other forms of radiant energy whose quantum unit is the photon for a range of applications ranging from detection to laser energy production to communications and information processing.
activation energy	amount of energy needed to initiate a reaction
copernican revolution	The revolution in thought resulting from the acceptance of the heliocentric model of the Solar System.
ultraviolet	A region of the electromagnetic spectrum
dyad	An operator indicated by writing the symbols of two vectors without a dot or cross between them.
parallax	The difference in the direction of an object when viewed from two different locations
tr	the amount of time that exists between successive pulse sequences applied to the same slice
specific heat	Ratio of the quantity of heat required to raise the temperature of a unit mass of a substance by a unit amount to that required to raise the temperature of an equal mass of water by the same amount
dipole antenna	A type of array consisting of a system of dipoles often used with radio telescopes
absorption edge	Sudden rises superposed on the smooth decrease of the curve of the attenuation coefficient, which cause the curve to have a typical sawtooth aspect
multi-echo imaging	imaging using a series of echoes acquired as a train following a single excitation pulse
brillouin scattering	Slight changes in the frequency of radiation, caused by reflection or scattering from the high-frequency sound waves that arise from thermal vibrations of atoms in the medium.
inclusion	Any solid, liquid, or gaseous foreign substance trapped inside a mineral or rock
manganese stars	Stars with an anomalously high mn-fe ratio, which show deviations from the odd-even effect for phosphorus, gallium, and yttrium
nep	Noise Equivalent Power
meteor shower	A group of meteors which appear to radiate from the same part of the sky and which occur over a limited period of a few days or hours
secular change	A continuous, nonperiodic change in one of the attributes of the states of a system
radiation pressure	The force exerted on the surface of a body by its absorption of light
ellipse	A plane curve in which the sum of the distances of each point along its periphery from two points - its "foci" - are equal
echo time	see TE.
dynode	Intermediate surface within a photomultiplier tube which emits multiple electrons when bombarded by a single electron.
rubidium	Rubidium is a chemical element with the symbol Rb and atomic number 37
time of flight	and MRA technique relying solely on the flow of unsaturated blood into a magnetized presaturated slice
sedimentary rock	Rock formed when rock and mineral particles are deposited and then compressed
microprocessor	A very large silicon integrated circuit with essentially all the functions of a computer on a single chip.
pico-	A prefix meaning 10-12.
bar	(a) The absolute cgs unit of pressure equal to 106 dyn cm-2
cataclastic rock	A metamorphic rock produced by the crushing and grinding of preexisting rocks, which are still visible as crushed fragments.
yy orionis star	Very young, late-type, low-mass stars in the gravitationally contracting stage in which the star is still accreting matter from the protostellar cloud.
vortex flow	area within a blood vessel where the blood is suddenly accelerated, then rapidly decelerated
ultraviolet	(a) Part of the electromagnetic spectrum immediately above visible light (but below Gamma-rays and X-rays); it therefore comprises a range of radiation of shorter wavelength and higher frequency than those of visible light
principle of equivalence	a principle which states that all bodies should fall with the same acceleration; also denoted the `weak equivalence principle'.
belts	Dark bands of clouds that circle Jupiter parallel to its equator; generally red, brown, or blue-green; believed to be regions of descending gas.
reset noise	The unwanted and uncertain electrical signal transmitted to the output pin of a CCD during the process of recharging, via the reset transistor, the output storage capacitor to its preset value in readiness for the next pixel charge
biaxial	Two optic axes or double refraction
group theory	The branch of mathematics which describes symmetry
nef	Noise Equivalent Flux
slump block	A large piece of rock that has broken off from the bedrock but has not yet shattered and broken
transit	The passage of a smaller, nearer astronomical object across the face of a larger object in the background, as in a transit of Venus across the sun
quantum efficiency	QE (a) The efficiency of a counter in detecting photons; the probability that a photon will liberate an electron and thus be detected
photomultiplier	A vacuum encapsulated photocathode from which electrons are ejected by the photoelectric effect followed by multiple cathodes from which many additional electrons are emitted in a cascade
subsonic	Describing a speed that is less than the speed of sound in the medium concerned
coherent scattering	A scattering process that leaves atoms in the same energy state after the scattered photon departs in a direction different from that of the incident photon
r galaxy	In the Yerkes9 1974 system, a system showing rotational symmetry, without clearly marked spiral or elliptical structure (formerly called D galaxy)
adhesion	A force of attraction between atoms or molecules of different substances
equator	The great circle on the surface of a body formed by the intersection of the surface with the plane passing through the center of the body perpendicular to the axis of rotation
ytterbium	A soft malleable silvery element having two allotropes and belonging to the lanthanoid series of metals
cadmium	A transition metal obtained as a by-product during the extraction of zinc
potential energy	energy of a body or system with respect to position or particle arrangement
effective temperature	The temperature that a blackbody would have which emitted the same amount of energy per unit area as the star does: it is a temperature characteristic of the surface region
direction cosine	A means of specifying the direction of a celestial object
subspace	a subset of a vector space which is closed under the operations of vector addition and scalar multiplication.
secular acceleration	Apparent acceleration of the Moon and Sun across the sky, caused by extremely gradual reduction in speed of the Earth's rotation (one 50-millionth of a second per day).
planck's constant	Denoted by the symbol , Planck's constant is a fundamental parameter in quantum mechanics
spreading center	A linear region on the seafloor from which adjacent crustal plates are moving apart and along which magma rises to form new oceanic lithosphere.
fet	Field Effect Transistor A tiny transistor amplifier in which the current flow between two terminals, called the source and the drain, is controlled by the electric field generated inside the silicon by an external voltage on a surface called the gate electrode
mach number	The ratio of the speed of a fluid to the speed of sound in that fluid
emissivity	A measure of the efficiency of a source to radiate like a perfect black body; 0% is perfectly black and 0% is perfectly reflecting
perseus x-1	The strongest known extragalactic X-ray source, centered on NGC 1275
pixel	acronym for a picture element, the smallest discrete two-dimensional part of a digital image display.
maggots	The larvae of flies and other insects that live on rotting food.
thermonuclear fusion	The combination of atomic nuclei at high temperatures to form more massive nuclei with the simultaneous release of energy
vesicular basalt	A porous rock formed by solidified lava with trapped bubbles.
air parcel	a volume of air that tends to be trans-ported as a single entity.
osmium	A transition metal that is found associated with platinum
volcano	A vent or fissure in the Earth's surface through which molten lava, ash, and gases are ejected
rise	come up, of celestial bodies.; "The sun also rises"; "The sun uprising sees the dusk night fled..."; "Jupiter ascends"
equilibrium	a state of balance that exists between two opposing forces or divergent forms of influence.
femur	Also called the thighbone, is the long bone between the hip and the knee.
signal-to-noise ratio	ratio of the signal power in a signal channel to the (unwanted) noise power present smectite - class of clay minerals characterized by distinct swelling properties and high cation-exchange capacities (including montmorillonite, nontronite, etc.)
paleoseismology	The study of past earthquakes.
dirac function	see Delta Function.
magnetic monopole	A magnet with an isolated north (or south) pole, rather than a pair of equal-strength north and south poles, as in conventional magnets
converging lens	A lens that can refract a parallel beam into a convergent beam
azimuth	The angle along the celestial horizon, measured eastward from the north point, to the intersection of the horizon with the vertical circle passing through an object.
string coupling constant	A (positive) number that governs how likely it is for a given string to split apart into two strings or for two strings to join together into one-the basic processes in string theory
mass	The total amount of material in a body, a measure of the amount of matter
fat suppression	the process of utilizing specific parameters , commonly with STIR (short TI inversion recovery) sequences, to remove the deleterious effects of fat from the resulting images
kelvin	The kelvin is the fundamental unit of temperature in the SI system
exponential	A process that changes at an accelerating rate, for example with a constant doubling time.
cameo	A carved shell, sometimes cut from onyx or other mineral containing bands of different colors, To cut in relief, the opposite of intaglio.
arsenates	Minerals in which AsO4 radical is an important constituent.
nasa	National Aeronautics and Space Administration US government body set up in 1958, under which the Space Center at Houston, Texas, and the Space Center at Cape Canaveral, Florida, are responsible for manned and unmanned space flights.
trauma	A physical injury or wound caused by an external force of violence, which may cause death or permanent disability
dipole	a magnetic field characterized by its own north and south magnetic poles separated by a finite distance.
resonance absorption cells	Cells filled with gas that absorbs at its atoms' resonant frequencies (same as "absorption cell")
cpu	Central Processing Unit The part of a digital computer responsible for interpreting and executing instructions.
amplitude	(a) The maximum value of a varying quantity from its mean or base value
cd-rom	Compact Disk - Read Only Memory A computer data storage technology
gauss	A unit of magnetic field strength.
beryllium oxide	(BeO) a poisonous ionic chemical substance used as an electrical insulator.
n-body simulations	Computer simulations of the behavior of a large number of bodies under their mutual interactions
channel	A specific frequency band for transmitting or receiving signals, (i.e
natural philosophy	A term widely employed in the seventeenth century to mean what today is encompassed in the word science.
smooth plain	Apparently young plains on Mercury formed by lava flows at or soon after the formation of the Caloris Basin
mos	Metal Oxide Semiconductor -- A construction used to fabricate microelectronic components
bandwidth	an all-inclusive term referring to the preselected band or range of frequencies which can govern both slice select and signal sampling.
eclipse	The total or partial obscuration of the light from a celestial body caused by its passage into the shadow of another body (cf
calendar	A system of reckoning time in which days are enumerated according to their position in cyclic patterns
p cyg stars	High-luminosity, early-type stars, in which all lines have a P Cyg type profile (an emission component on the red side of the absorption line).
thermodynamic equilibrium	(a) The state reached ultimately by an isolated system.[D89] (b) The condition of a system whose members have conformed to the principle of equipartition of energy, so that there is no net exchange of energy
eddy currents	Induced currents set up in a conductor by a changing magnetic field
byte	A group of eight "bits" or binary digits (ones or zeros)
optical fibre	A long, thin strand of glass capable of excellent transmission of light over large distances.
brightness	A measure of the amount of electromagnetic radiation from a celestial object
stationary nonequilibrium state	time-independent state of a system subjected to fixed constraints.
metastable	A state which is not stable, but which lives long enough to have significance, is called metastable.
inclination	(astronomy) the angle between the plane of the orbit and the plane of the ecliptic stated in degrees.
electromagnetic unit	EMU A system of electrical units based on the electromagnetic properties of an electric current.
science	(a) Systematic study of Nature, based upon the presumption that the Universe is based upon rationally intelligible principles and that its behavior can therefore be predicted by subjecting observational data to logical analysis
cryogen	a cooling agent, typically liquid helium or liquid nitrogen used to reduce the temperature of the magnet windings in a superconducting magnet
terminal velocity	The steady final velocity reached by a body in a fluid when the resultant force on it is zero.[DC99]
shock wave	A sudden change in pressure that travels as an intense sound wave.
wave guide	special transmission medium resembling a pipe and often having a rectangular cross section, inside of which radio waves may be propagated
dsb	Double SideBand
source function	The amount of radiant energy per unit mass per unit solid angle emitted in a specified direction
eprom	Erasable Programmable Read Only Memory A small silicon chip containing thousands of individual locations which can be set to either a low or a high voltage level; a 0 or a 1
pycnonuclear	An adjective used to describe nuclear processes (such as the proton-proton chain) that take place at relatively low temperatures and that are not strongly temperature-dependent.
field of view	defined as the size of the two or three dimensional spatial encoding area of the image
methane	Gaseous hydrogen compound, one of the alkanes, in which every carbon atom is surrounded by four hydrogen atoms
oxygen	A colourless, odourless gas that makes up about 20 percent of the air we breathe; it is essential to life because it is used for the chemical reactions that occur in the cells of the body.
coupling	An interaction between the components of a system.
oceanic element	an element contained in the ocean
point source	a source of pollution that is point-like in nature
celestial mechanics	Study of the movements and physical interactions of objects in space; astrophysical mathematics.
fresnel lens	A type of lens with one surface cut in steps so that transmitted light is refracted just as if by a much thicker (and heavier and more expensive) conventional lens
normal modes	(a) All the characteristic frequencies of an oscillating body
denudation	The progressive lowering of the Earth's surface by erosion, weathering, mass wasting, and transportation.
doping	The process of selectively adding known amounts of foreign atoms into the silicon (or other semiconductor) crystal to subtly change its electrical properties
multiplex	Combining many signals into one or a small number of signals.
complex output	multichannel spectrum analyzer (MCSA, q.v.) may be set to give complex, undetected signal amplitude streams from each output channel in the form of two orthogonal quantities (a + jb)
subspace	a subset of a vector space which is closed under the operations of vector addition and scalar multiplication
sublimation	The process by which solids are transformed directly into vapor without passing through the liquid state.
so2	See sulfur dioxide.
bessel equation	A linear second-order differential equation, the solutions to which are expressible in mathematical functions known as Bessel functions
plateau	A relatively elevated, comparatively level expanse of land with at least one abruptly steep side
density	An object's mass divided by its volume
perpendicular	Vertical or upright.
liouville's theorem	The Equation of Continuity: For a general Hamiltonian system the volume of an element of phase space is invariant with respect to the equations of motion
blackbody	body capable of absorbing energy of all wavelengths falling on it; it is also capable of radiating all frequencies in a particular ratio to its absorbing properties
eucaryote	organism composed of one or more cells with clearly formed nuclei
damping	(a) In any oscillating system, a decrease in the amplitude of an oscillation due to the dissipation of energy
polarization of light	Reduction of light, considered to travel in three-dimensional transverse waves (vibrating in all directions perpendicular to the direction in which it is traveling), to two dimensions
differential rotation	As an object rotates, different parts of it may move at different rates
view	Visibility Intensive Experiment in the West, a project of the US EPA, with cooperation of the National Park Service, to measure visibility at many stations throughout the western United States to document current visibility and examine trends.
superposition principle	A quantum mechanical principle according to which any two states can be combined (actually in infinitely many ways) to form states which have characteristics intermediate between those of the two which are combined
reset noise	The unwanted and uncertain electrical signal transmitted to the output pin of a CCD during the process of recharging, via the reset transistor, the output storage capacitor to its preset value in readiness for the next pixel charge.
dtpa	Diethylenetriaminepentaacetic acid - Gadolinium chelating (chemical bonding) agent that solves the problem of toxicity
arachnoids	On Venus, one of a number of round networks of fractures in the crust, resembles spider webs.
crossbeds	Layers that are inclined with respect to a thicker layer within which they occur.
isotropic scattering	the process of scattering light equally in all directions.
petty crime	A small crime such as minor theft, trespassing etc.
parabolic	A mirror whose surface is figured to the shape of a paraboloid, a particular form of open curve.
stress	When a system of opposing forces acts on a body the material is subject to some form of stress
frequency encoding	the process of locating an MR signal in one dimension by applying a magnetic field gradient along that dimension during the period when the signal is being received.
nuclide	A species of atomic nucleus, analogous to the word "isotope" for a species of atom
lehmann discontinuity	The boundary between the Earth's solid inner core and liquid outer core
inclusions	Solid, gaseous, or liquid material of various types incorporated in a crystal during its formation and growth.
strata	Layers of sedimentary rocks which might contain differences in texture, color, fossil content, or material type.
lodestone	A piece of naturally occurring magnetic iron oxide (Fe3O4, the mineral magnetite).
science	Systematic study of Nature, based upon the presumption that the universe is based upon rationally intelligible principles and that its behavior can therefore be predicted by subjecting observational data to logical analysis.
heat capacity	Also known also as thermal capacity
cartridge case	A cylindrical case of pasteboard, metal or the like, for holding a complete charge of powder, and often, also the bullet for a rifle, machine gun or small arm.
equilibrium	A condition of balance between the forces operating on or within a physical system, so that no accelerated motions exist among the parts of a system
strangulation	The condition of having respiration stopped by compression of the air passage.
surface brightness	The measure of the amount of light that an object, especially a galaxy, emits per area of the sky
c stars	A class of carbon stars ( q.v.), defined by Morgan and Keenan to replace the Harvard R and N spectral classes
index of refraction	ratio of the speed of light in a vacuum to its speed in a given medium
pha	Pulse Height Analyzer
geodesic	a path or line of shortest distance joining two points in space (or space-time)
ozone layer	A layer in the lower part of Earth's stratosphere (about 20-60 km above sea level) where the greatest concentration of ozone (03) appears
existence theorems	these are the theorems that assert the existence of mathematical objects satisfying a specific set of axioms
anomaly	An angular value used to describe the position of one member of a binary system with respect to the other
thought experiment	An experiment that cannot be or is not carried out in practice, but can, given sufficient imagination and rigor, be reasoned through by thought and intuition alone
dyne	(a) The cgs unit of force equal to the force necessary to give an acceleration of 1 cm sec-2 to a mass of 1 gram
probable error	The error which will not be exceeded by 50 percent of the cases
longitude	An east-west coordinate on the earth's surface; the angular distance, measured east or west along the equator from the Greenwich meridian, to the meridian passing through a place.
ore	A mineral occurring in sufficient amounts to permit its recovery at a profit.
liquid metal hydrogen	A form of hydrogen under high pressure that is a good electrical conductor.
saturation recovery	a little-used pulse sequence that generates a predominately proton density dependent signal, basically employing a 90° RF excitation pulse, with a very long repetition time
latitude	Imaginary lines that allow measurement of position north or south of the equator ("horizontal")
non-euclidean geometry	Geometry that does not follow the postulates and results of Euclidean geometry
day	An interval of 86400.51 seconds (see second, Système International), unless otherwise indicated.
abelian group	A mathematical group of transformations with the property that the end result of a series of transformations does not depend on the order in which they are performed.
traps	Irregularities in the silicon crystal lattice which can absorb free charges created in the semiconductor by, for instance, the absorption of light.
argon	A chemical element, (symbol Ar, atomic number 18).
diffraction	A wave-like property of light which allows it to curl around obstacles whose size is about that of the wavelength of the light
fabry-perot interferometer	(a) A type of interferometer wherein the beam of light is passed through a series of pairs of partly reflecting surfaces set at various angles to it and spaced at certain prechosen numbers of the wavelength to be examined
mass models	Models that attempt to infer the distribution of mass in an astronomical system by comparing the observed properties of the system (such as the distribution of light) with those properties predicted by various theoretical distributions of mass
asymmetric	Not similar in size, shape, form or arrangement of parts on opposite sides of a line, point or plane.
p cygni star	High-luminosity, early-type star, in which all lines have a P Cyg type profile (an emission component on the red side of the absorption line).
relative age	The age of a geological feature referred to other features
critical speed	In fluid flow, the speed at which the behavior of the fluid switches from that of laminar flow to that of turbulent flow or vice versa
center of mass	Two bodies revolve around a common center, called the balance point of the system.
law	A theory of such wide and invariable application that its violation is thought to be impossible.
haze	an atmospheric aerosol of sufficient concentration to be visible
volatile organic compounds	class of organics that is easily vaporizable at low temperatures and pressures
standard error	The standard deviation of a distribution of means or any other statistical measure computed from samples
einstein equivalence principle	Foundation for curvcd space-time, it states that bodies fall with the same acceleration and that physics in freely falling reference frames is independent of the velocity and location of the frames.
equilibrium	A balance: equality of distribution.
velocity	The speed and direction of an object’s motion.
superfluidity	A phenomenon occurring in liquid helium-4 below about 2.17 degrees, in which the liquid flows through thin capillaries without apparent friction and displays many other anomalous properties
buried channel	A construction in a silicon CCD which results in a collection zone for photo-generated electrons which is buried well below the surface of the silicon
twisted-pair	A form of wiring consisting of two strands of single wire twisted together to form a transmission line
arcminute	One sixtieth of a degree of angular measure
tsytovitch effect	An effect wherein the index of refraction of a medium is much less than unity so that the phase velocity of electromagnetic waves is greater than the speed of light in the medium
pole star	The star - Polaris - that lies near the direction in the sky toward which the North Pole of the Earth points.
jumbled terrain	Strangely disturbed regions of the moon opposite the locations of the Imbrium basin and Mare Oriental
blooming	A method of coating lenses to reduce back-reflection from their surfaces
bolometer	A kind of detector mainly used to measure infrared radiation
tektite	A small glassy body containing no crystals, probably of meteoritic origin and bearing no antecedent relation to the geological formation in which it is found.
stratosphere	The layer of the atmosphere above the troposphere
point	(diamonds).
http	Hyper-Text Transfer Protocol.
planetocentric coordinates	Coordinates for general use, where the z-axis is the mean axis of rotation; the x-axis is the intersection of the planetary equator (normal to the z-axis through the center of mass) and an arbitrary prime meridian; and the y-axis completes a right-hand coordinate system
vacuum expectation value	The value of the Higgs field (a constant value different from zero) is called a system's Vacuum Expectation Value.
symmetry	The property of being unchanged after some transformation
ray tracing	Computer simulation of light ray paths through an optical system.
relative humidity	Partial pressure of water vapor at the atmospheric temperature divided by the vapor pressure of water at that temperature, expressed as a percentage.
atom	(a) The smallest component of matter that retains its chemical properties
plume	A rising column of gas over a maintained source of heat.
nitrous oxide	A colorless gas or liquid (N2O), soluble in water or alcohol
bohrium	A synthetic radioactive element first detected by bombarding a bismuth target with chromium nuclei
lumogen	Fluorescent UV coating which improves the blue sensitivity of a CCD by emitting light at approximately 540 to 580 nm when excited with light of wavelengths shorter than 450 nm.
dara	Deutsche Agentur Fur Raumfahrt Angelegenheiten (Germany).
chlorophyll	A group of green, light-collecting pigments found in green plants, algae, and some bacteria that in the presence of sunlight convert CO2and H2O into carbohydrates.
neon burning	The stage in which a star burns neon into oxygen and magnesium.
noether's theorem	A mathematical theorem that states that for every symmetry of the Lagrangian of a physical system (i.e
biconcave	Describing a lens with two concave faces
epitaxial	A thin layer of differently doped semiconductor used in the construction of solid-state devices such as the CCD
closed string	A type of string that is in the shape of a loop.
acoustic wave	A wave for which pressure is the restoring force
molecule	The smallest unit of a chemical compound
p-l relation	See Period-Luminosity relation.
dynamic range	The ratio of the maximum possible signal, the saturation level, to the system noise floor.
sessile	attached directly by the base (rather than being raised on a stalk)
hestia	Unofficial name for Jupiter VI
diagnosis	To process of testing to identify other problems.
redox potential	voltage difference at an inert electrode immersed in a reversible oxidation-reduction system
crêpe ring	(a) Rather transparent inner ring (Ring C) of the saturn ring system
paleothermometer	The method or substance used to determine temperatures at a given time in the past.
complex number	A type of number that is the sum of two parts, the first of which produces a positive number when multiplied by itself (like ordinary numbers), and the second of which produces a negative number when multiplied by itself (unlike ordinary numbers)
attitude control	The act of controlling the position of a spacecraft relative to the direction in which it's moving.
alkali metal	Any of the monovalent metals of group I of the periodic table (lithium or sodium or potassium or rubidium or cesium or francium); "the hydroxides of the alkali metals are strongly alkaline".
green's theorem	An identity that connects line integrals and double integrals
gallium	A soft silvery low-melting metallic element
gradient coils	three paired orthogonal current-carrying coils located within the magnet which are designed to produce desired gradient magnetic fields which collectively and sequentially are superimposed on the main magnetic field (Bo) so that selective spatial excitation of the imaging volume can occur
crown	An enamel cover (on teeth).
ray tracing	Computer simulation of light ray paths through an optical system
bel	A number used mainly in English-speaking countries to express the ratio of two powers as a logarithm to the base ten
abiotic	not involving or not produced by living organisms
methane	Gaseous hydrogen compound, one of the alkanes, in which every carbon atom is surrounded by four hydrogen atoms.
geodynamics	The study of processes, such as the movement of material, in the Earth's interior.
strangeness	(a) A property of hadrons which may have a zero or non-zero value, depending on their rate of decay
lyot division	In Saturn's rings, the gap between rings B and C
detailed balance	cancellation of the effect of a process by a simultaneously operating `inverse' process.
chromosphere	(a) The part of the Sun's atmosphere immediately above the surface (the photosphere) and beneath the corona
line	A geometrical object with one dimension
zener diode	A semiconductor diode with high doping levels on each side of the junction
visual range	the distance at which a large black object just disappears from view.
ridge	A long narrow natural elevation or striation.
accretion	(a) Collection of material together, generally to form a single body
decay constant	for an atom that undergoes radioactive decay, the decay constant is the proportionality factor between the time rate of decay and the total number of atoms present; it is the inverse of the mean lifetime of an atom
optical axis	An optical axis is a line along which there is some degree of rotational symmetry in an optical system such as a camera lens or microscope.The optical axis is an imaginary line that defines the path along which light propagates through the system...
deduction	Process of reasoning in which a conclusion is derived from a given premise or premises, without a need for additional information
long path measurement	an atmospheric measurement process that is made over distances in excess of a few hundred meters.
string	(a) Fundamental one-dimensional object that is the essential ingredient in string theory
rich galaxy cluster	A cluster containing over 1000 galaxies, mostly elliptical, scattered over a volume about 3 Mpc in diameter.
nucleus	A part of the cell containing DNA and RNA and responsible for growth and reproduction.
electrocution	Death brought about by electricity.
hyperbolic	Having the shape of a hyperbola, a particular form of curve whose two 'arms' diverge and never rejoin.
coarse-graining	an operation implementing some form of spatial averaging which smoothes out relatively small length-scale configurational structure while preserving the larger length-scale structure.
budget	See light extinction budget.
base si unit	a unit assumed to be mutually independent from which all other units are derived
photodissociation	The breakup of a molecule by the absorption of light with enough energy to break the molecular bonds.
equatorial telescope	The classic type of telescope mount with one axis parallel to the Earth's polar axis (i.e
ankylosaurus	A genus of squat, quadrupedal, armored dinosaurs of the Cretaceous Period.
measurements	Measurements made in a place to sample the local environment.
alfvén number	A dimensionless number characterizing steady fluid flow past an obstacle in a uniform magnetic field parallel to the direction of flow
background noise	All the interference effects in a system which is producing, measuring, or recording a signal
coronene	The first ultraviolet phosphor to be tried on the surface of a CCD.
density	The ratio of the weight of a substance to its volume expressed in g/cm 3, and numerically equal to the specific gravity.
flux	(a) Total radiation going out from the 2 solid angles of a hemisphere
multi-dimensional hole	A generalization of the hole found in a doughnut to higher-dimensional versions
oesophagus	A tube connecting the back of the mouth to the stomach; a part of the digestive system.
excitation	The process of raising an atom to a higher energy level.
epizone	In regional metamorphism, the depth level nearest the surface to approx
antenna temperature	A term used to describe the strength of a signal received from a radio source
igneous	Rock formed by solidification from a molten or partially molten state.
population	see stellar population.
helioseismology	The study of the interior of the Sun by the analysis of its natural modes of oscillation.
sunspot radiation	Intense, variable, circularly polarized radio waves in a noise storm
double refraction	Ability of certain crystals to split incident light into two rays with different refractive indices.
ntt	New Technology Telescope
duty cycle	The fraction of time a pulsed beam is on.
disjoint	An adjective applied in mathematics to two or more sets which have no members in common.
fifo	First-In-First-Out buffer
bedrock	The solid rock that underlies soil, sand, gravel, or other loose material.
magnetization vector	the integration of all the individual nuclear magnetic moments which have a positive magnetization value at equilibrium versus those in a random state.
stromatolite	laminated sedimentary fossil formed from layers of blue-green algae
mass spectrometry	This technique can be used to both measure and analyze molecules under study
pressure	The force exerted over a surface divided by its area.
granules	Convective cells (about 1000 km in diameter) in the solar photosphere
accelerometer	Oscillatory mechanical system measuring the acceleration of the body to which it is attached.
nucleoside	compound consisting of a sugar and a purine of pyrimidine base
emissivity	A measure of the efficiency of a source to radiate like a perfect black body; 0% is perfectly black and 0% is perfectly reflecting.
commutation relations	in quantum mechanics, if one has two operators A and B, then it is often the case that the action of the product operator AB is not the same as that of BA
critical angle	Critical angle can refer to:Critical angle the angle of incidence above which total internal reflection occursCritical angle of attack, in aerodynamics; the angle of attack which produces the maximum lift coefficient...
gauge symmetry	Symmetry principle underlying the quantum-mechanical description of the three nongravitational forces; the symmetry involves the invariance of a physical system under various shifts in the values of force charges, shifts that can change from place to place and from moment to moment.
inversion layer	a very thin layer of electrons trapped on an interface between a semiconductor and an insulator, or between two different semiconductors
deferred charge	There are a number of phenomena in CCDs which result in charges becoming "trapped" during the charge-coupling process
noble gas	one of a group of rare but extremely stable gases with low reaction rates (helium, neon, argon, krypton, xenon, radon)
channel stops	Narrow, heavily doped strips in a silicon CCD which act like walls to prevent sideways movement of charge in a pixel
palladium	A silvery white ductile transition metal occurring in platinum ores
extrusive rock	Igneous rock that solidifies on the surface of the earth.
boule	The form and shape of a synthetic stone when created by the inverted blowpipe of a Verneuil furnace, somewhat carrot shaped.
cryptocrystalline	....The structure of a substance as chalcedony, that consist of very small crystals but show no external sign of crystal structure.
gravitational instability	The process by which fluctuations in an infinite medium of size greater than a certain length scale (the Jeans length) grow by self-gravitation
adiabatic index	The ratio of the fractional change in pressure to the fractional change in density as an element of fluid expands (or contracts) without exchange of heat with its surroundings
refractor	A device for gathering and amplifying light by means of a lens.
self-consistent field approach	An approach in which the density distribution and state of motion in a system are determined so as to be self-consistent with the force field (e.g., gravitational or electromagnetic) arising from the system itself
quadratic detection model	model used to predict the amount of change in equivalent contrast or perceived landscape structure required to evoke a single noticeable change in landscape appearance.
dissociation	When a compound separates into two or more parts.
tunnel diode	A highly doped p-n junction diode that has a large reverse current, and, in the forward direction, a negative slope resistance over part of the voltage-current characteristic
photons	Packets of radiant energy: quanta of light.
closed string	A type of string that is in the shape of a loop
tidal coupling	The locking of the rotation of a body to its revolution around another body.
payload specialist	professionals from life sciences or physical sciences fields
tissue	A part of an organism consisting of an aggregate of cells having a similar structure and function.
vibrational pattern	The precise number of peaks and troughs as well as their amplitude as a string oscillates.
batholith	A huge body of plutonic rock that has been intruded deep into the earth's crust and latter exposed by erosion.
closed orbit	A circular orbit, one which returns back on itself.
spectral series line	A spectral line belonging to a series of lines of a given atom arising from transitions with a common lower energy level.
south atlantic anomaly	A disturbance in the geomagnetic field (a region of intense charged-particle fluxes) over the south part of the Atlantic Ocean
country rock	The older, preexisting rock that encloses or is traversed by an igneous intrusion or a mineral deposit.
chemical element	Matter composed of atoms of only one chemical type which cannot be decomposed into simpler substances by chemical methods.
figure of merit	The extent to which an optical system falls short of perfection
dendrites	Skeletal crystals that develop from supersaturated solutions, often in small cracks, often resembling plant or trees.
perturbation method	A system of successive approximations to the solution of a problem, by starting with a closely similar problem whose solution is known, applying small departures from equilibrium, and then calculating their consequences.
salinity	The amount of dissolved salts in water.
subduction	The process of one tectonic plate moving beneath another tectonic plate at a convergent margin (where two plates collide)
cno tri-cycle	Similar to the CNO bi-cycle, with the addition of the cycle 17O(p, )18F( +)18O(p, )15N
radial velocity	Velocity along the line of sight toward (-) or away from (+) the observer.
long period variable	A variable star with a period ranging from 100 days to over 400 days.
molybdenum	A transition element used in alloy steels, lamp bulbs and catalysts
brightness contrast	The ratio of the difference in brightness between two objects to the brightness of the brighter of the two
continuity of mass law	One of the basic laws of stellar structure
intermediate water	Layer of ocean water above the deep water and immediately below the mixed layer of water at the ocean surface.
internet	A global spider-web-like network of computers and computer systems with no central hub or single point of control.
dike	In the forming of rocks, when intruding sedimentary rocks in a vertical or nearly vertical position.
ring of fire	The name of the extensive area of volcanic and seismic activity that roughly coincides with the borders of the Pacific Ocean.
albedo	the fraction of total light incident on a reflecting surface that is reflected back omnidirectionally.
phase difference	Two identical waves of the same wavelength are said to be "in phase" when the peaks and troughs coincide perfectly
gauss	(a) The cgs unit of magnetic flux density
debye	Unit of electric-dipole moment, equal to that existing between a unit of positive charge and a unit of negative charge separated by a distance of 1 cm
null line	The path, in space-time, of a light ray or other massless object
detrital	Occurrence of minerals in gravels that came from a mineral deposit
oblate spheroid	A sphere flattened such that its polar diameter is smaller than its equatorial diameter.
carat	Unit of weight used to weigh gemstones, equal to 200 milligrams, or .200 grams
differentiation	The process by which a magma changes composition, for example, by crystal fractionation
convolution	A mathematical combination of two functions which involves multiplying the value of one function at a given point with the value of another function, the weighting function, for a displacement from that point and then integrating over all such displacements
viscous	Characterized by resistance to flow due to internal friction within a fluid.
light	Electromagnetic radiation that is visible to the eye.
emission coefficient	Radiant flux emitted per unit volume per unit solid angle
euclidean	Characterizing the “flat” geometry developed by the ancient Greek mathematician Euclid, in which parallel lines never cross and the angles of a triangle sum to 180 degrees
frequency	(a) The frequency of a periodic or harmonic motion which repeats itself in equal time units is the number of oscillations or cycles per unit of time
presaturation	a specialized technique employing repeated RF excitation of structures adjacent to the ROI for the purpose of reducing or eliminating their phase effect artifacts.
polytrope	A mathematical model of an inhomogeneous, compressible configuration in equilibrium under its own gravitation in which the relation between the pressure and the density satisfies the relation p = K(n+1)/n, where K is a constant and n is the polytropic index.
selection rule	A rule whereby changes in quantum numbers can take only certain allowed values: e.g., l = ± 1 or 0 for dipole transitions.
tip angle	angle between the net magnetization vector before and after an RF excitation pulse
metastable state	(a) A condition of a system or body in which it appears to be in stable equilibrium but, if disturbed, can settle into a lower energy state
noise	an undesirable background interference or disturbance that affects image quality
hypothesis	A tentative theory or supposition, advanced to explain certain or phenomena, which is subject to further tests and verification.
planck tension	About 1039 tons
delta function	also called Dirac Function
astronomical twilight	The period from sunset to the time that the Sun is 18° below the horizon; or the corresponding period before sunrise
habit	An established custom.
synthetic stones	Man made stones which have approx
rubidium	A soft silvery highly reactive element
planar imaging	a method of scanning in which the data is collected simultaneously from an entire layer.
fringes	(a) The light and dark bands obtained by interference or diffraction of light
copernican revolution	The revolution in thought resulting from the acceptance of the heliocentric model of the Solar System
digestion	The act or process by which food is digested i.e
tail	The long streamer (about 107 km long; density about 10-18 atm) behind the comet head
absolute zero	(a) The zero value of thermodynamic temperature; 0 kelvin or -273.15°C
data	The outcome of a set of measurements from which inferences may be drawn, theories constructed, and so forth.
horizontal parallax	The difference between the topocentric and geocentric positions of an object, when the object is on the astronomical horizon.
black body radiation	Radiation emitted by a hypothetical perfect radiator
actinium	A soft silvery-white radioactive metallic element that is the first member of the actinoid series
neptune	(a) Eighth major planet out from the Sun, discovered in 1846 by Johann Galle and Louis d'Arrest following predictions calculated by Urbain Le Verrier