- Industry:
- Number of terms: 3726
- Number of blossaries: 0
- Company Profile:
1) Nucleus formed by the α-process (q.v.) (see even-even nuclei.) 2) Particle first discovered in radioactive α decay, and later identified as helium nuclei (two protons and two neutrons bound together.) 3) The nucleus of a 4He atom, consisting of two protons and two neutrons. Mass of α-particle 4.00260 amu.
Industry:Astronomy
A hypothetical process of nucleosynthesis, which consisted of redistributing α-particles in the region from neon 20 to iron 56 (and perhaps slightly higher). The α-process has been replaced by explosive and nonexplosive C, O, and Si burning occurring in rapidly evolving or even explosive stages of stellar evolution which at higher temperatures and densities becomes the e-process.
Industry:Astronomy
1) Unit of electric current. "The ampere is that constant current which, if maintained in two straight parallel conductors of infinite length, of negligible circular cross-section, and placed 1 meter apart in vacuum, would produce between these conductors a force equal to 2 × 10-7 newton per meter of length" CIPM 1946, Resolution 2, approved by the 9th CGPM 1948). A current of 1 A is equivalent to the passage along the filament of a light bulb of about 6 × 1018 electronic charges per second. 2) constant current which, if maintained in two straight parallel conductors of infinite length, of negligible circular cross-section, and placed 1 meter apart in vacuum, would produce between these conductors a force equal to 2 × 10-7 newton per meter of length
Industry:Astronomy
The angle subtended by an object on the sky. For example, the angular size of the moon is 30 arcminutes.
Industry:Astronomy
The weak form of the anthropic principle states that life can exist only during a brief period of the history of our universe. The strong form of the principle states that out of all possible values for the fundamental constants of nature and the initial conditions of the universe, only a small fraction could allow life to form at all, at anytime. (See boundary conditions; fundamental constants of nature..)
Industry:Astronomy
The projection of human attributes onto nonhuman entities such as animals, the planets, or the universe as a whole.
Industry:Astronomy
1) The direction of the sky opposite to that of the galactic center. 2) The point in the galactic plane that lies directly opposite the galactic center. Here we gaze toward the edge of the Galactic disk. The nearest bright star to the anticenter is El Nath, in the constellation Taurus.
Industry:Astronomy
The antiparticle of a neutron. A neutron and antineutron both have the same mass and zero electric charge, but can be differentiated by their interactions: a neutron and an antineutron can annihilate into gamma rays, while two neutrons cannot.
Industry:Astronomy
