Space exploration began with the launch of Sputnik and Astrophysics was born as the application of physics to the phenomena observed by Astronomy, which etymologically means laws of the stars.
There are 2759 entries in this glossary.| Term | Definition |
|---|---|
| Radiation Era |
The period from one second to one million years after the Big Bang. During this interval, the behaviour of the universe was dominated by radiation i.e. photons. The era ended with the recombination epoch, when the temperature of the expanding universe had fallen to a few thousand degrees, enabling electrons and protons to form the first stable atoms.
|