Fr.: extinction atmosphérique
The decrease in the intensity of light from a celestial body due to absorption and scattering by Earth's atmosphere. It increases from the zenith to the horizon and affects short wavelengths more than long wavelengths, so that objects near the horizon appear redder than they do at the zenith.
Fr.: continuum de Balmer
A continuous range of wavelengths in the Balmer spectrum of
hydrogen corresponding to transitions between the energy levels
Fr.: discontinuité de Balmer
An abrupt decrease in the intensity of the continuum at the limit of the → Balmer series of hydrogen (at about 3650 Å), caused by the energy absorbed when electrons originally in the second → energy level are ionized. Same as → Balmer jump.
Fr.: effet de couverture
Fr.: effet de couverture
Fr.: réseau échelette
Turi, noun from tur "a net, a fishing net;" belizi adj. from beliz, → blaze.
Fr.: continuum bleu
The → continuum emission of an astronomical source with wavelengths between about 492 and 455 nm.
Fr.: co-orbitage; c-orbitant, co-orbiteur
The action or quality of a → co-orbiting asteroid.
Fr.: astéroïde co-orbiteur
An asteroid having a → co-orbital motion.
Fr.: vol d'accostage
The unpowered flight of a spacecraft or missile after propulsion cutoff or between the burnout of one stage and the ignition of the next.
Fr.: Univers à densité critique
A Universe whose density is just less than or equal to the critical value and expands forever with no change in the expansion rate.
Fr.: surface collectrice
Of an interferometric telescope made up of several mirrors, the hypothetical mirror created by the combination of the individual mirrors.
→ collect; → area.
Fr.: chauffage par collisions
turi-ye kâv (#)
Fr.: réseau concave
A → diffraction grating ruled on a concave spherical mirror that eliminates chromatic aberration and transmits regions of the spectrum, such as the ultraviolet, which is not transmitted by glass lenses.
Any of the large, continuous land areas of the Earth. They are usually considered to be seven: Europe, Asia, Africa, North America, South America, Australia, and Antarctica.
Contraction of L. terra continens "continuous land," from continens, pr.p. of continere "to hold together," from → com- "together" + tenere "to hold, to keep, to maintain" from PIE root *ten- "to stretch;" → tension.
Qâré, from Ar. qârrat.
Of or of the nature of a continent.
puste-ye qâre-yi (#)
Fr.: croûte continentale
The part of the → Earth's crust which underlies the → continents. Continental crust is more silica-rich and thicker than → oceanic crust, and is on average older. However, it is highly variable in all of these respects. The average thickness of the continental crust is about 40km, but beneath parts of the Andes and the Himalaya mountain ranges the crust is more than 70 km thick. Continental crust is continuously being eroded and turned into sediment. Some of this sediment ends up on the ocean floor where it can be returned to the → Earth's mantle at → subduction zones. The oldest parts of the continental crust include some rocks that are nearly 4 billion years old. New continental crust is produced by the destruction of oceanic crust at subduction zones, a process that continues today.
Fr.: dérive de continents
A hypothesis proposed by Alfred Wegener (1912) suggesting that the → continents are not stationary, but drift through time. Wegener's hypothesis has since been developed and included in a new theory called → plate tectonics.
In logic, a → proposition that may be either true or false, and is not necessarily one or the other.
Noun of → contingent.