ASTR 103 - Astronomy

Glossary - W

watt (W)

 

wave

The propagation of a disturbance.

wavelength

Distance between successive crests or troughs of a wave.

wave mechanics

Mathematical theory of quantum mechanics that forms the basis of the modern concept of atomic phenomena in terms of the interactions of radiation with matter.

weak nuclear force

Basic nuclear force involved in radioactive decay. It is characterized by a slow nuclear reaction rate (for example, 17 minutes on the average for neutron decay into a proton, electron, and antineutrino) in comparison to the strong nuclear force, which reacts in a very short time (for example a neutron is ejected from a nucleus in 10^-21 second).

weight

Force of attraction experienced by an object resting on the surface of an attracting body.

white dwarf

Star that has collapsed gravitationally into a small, very dense and faint object after expending its nuclear fuel.

white hole

Hypothetical opposite of the black hole. Out of it matter and radiation emerge from another Universe into our own Universe.

Wien's (displacement) law

Simple formula stating that the wavelength at which the peak energy of a radiating blackbody occurs varies inversely with the temperature of the body. As the temperature rises, the maximum of the blackbody's energy curve is displaced toward the shorter wavelengths.

winter solstice

 

worm hole

Restricted neck joining two separate Universes in the curved space geometry around a black hole.

W Virginis star

Prototype of a special class of cepheid variables belonging to Population II.