Nearly 14 billion years ago, due to a random fluctuation in a completely empty void, a universe exploded into existence. Scientists call this the Big Bang theory for the origin of the universe. But there are other theories .
PHD Comics: Gravitational Waves Explained Simple explanation but really interesting for further understanding on gravitational waves. "That's one small step for man, one giant leap for mankind" Neil Armstrong quote Mehr
Dark Energy Dark Matter The two largest pieces of the Universe that we know the least about, yet nothing less than the ultimate fate of the Universe will be determined by them. (Illustration: NASA/CXC/M.Weiss) The Universe in a Jelly Bean Jar