A Cosmic Smashup and a Dark Matter Mystery?
"I soon became convinced... that all the theorizing would be empty brain exercise and therefore a waste of time unless one first ascertained what the population of the Universe really consists of." -Fritz Zwicky You very likely know that there are four fundamental forces in the Universe: gravity, electromagnetism, and the weak and strong nuclear forces. While only some particles experience the nuclear and electromagnetic forces, anything with mass or energy -- which is everything we know of -- is subject to gravity.
Source: scienceblogs.com