1. at astronomical observatories capture this light even better, providing a clearer picture of our galaxy.
2. waves are the only waves, besides visible light, to reach Earth's surface.
3. telescopes can reveal the existence of pulsars in space.
4. measure the temperature variations in the universe.
5. waves show the heat emitted by celestial bodies.
6. rays are used to study hot stars.

Aparticle of mass m is placed in a one-dimensional box of length l. the box is so small that the particle’s motion is relativistic, so that e p2/2m is not valid. (a) derive an expression for the energy levels of the particle using the relativistic energy–momentum relation and the quantization of momentum that derives from connement. (b) if the particle is an electron in a box of length l 1.00 1012 m, nd its lowest possible kinetic energy. by what percent is the nonrelativistic formula for the energy in error?