Big Bang and observable universe, illustration. At left is the origin of the universe in the Big Bang, the initial expansion of all the matter in the universe from an infinitely compact state 13.7 billion years ago. The initial conditions are not known, but less than a second after the beginning, temperatures were trillions of degrees Celsius and the primordial universe was much smaller than an atom. It has been expanding and cooling ever since. Matter formed and coalesced into the galaxies, which are observed to be moving away from each other. The observable universe is that region of space where light has had time to reach the Earth since the start of the universe. The observable universe is estimated to be around 93 billion light years across. | |
Lizenzart: | Lizenzpflichtig |
Credit: | Science Photo Library / Lunau, Claus |
Bildgröße: | 5414 px × 3227 px |
Modell-Rechte: | nicht erforderlich |
Eigentums-Rechte: | nicht erforderlich |
Restrictions: | - |