Big Bang

From Simple English Wikipedia, the free encyclopedia

The Big Bang is the scientific theory about the beginning of the universe that is accepted by almost all cosmologists. The theory says that the universe began by growing out from a single point about 13.7 billion years ago. The point was very small, dense, and hot. All space, time, and matter was created when the point got bigger.

Scientists base this cosmological theory on many observations. The most important is the redshift of very far away galaxies, which shows that the universe is getting bigger and colder. If the universe is getting bigger and colder, then it used to be smaller and hotter, so many scientists think that a long time ago, the universe was as small and hot as possible, and that is when the Big Bang happened. At that time, everything in the universe was very close together, probably as a singularity (an infinite curve in spacetime, such as the ones found in black holes).

The Big Bang theory is also supported by the distribution of light chemical elements and the cosmic microwave background radiation (very low-level radiation) in the universe.

Some, including religious leaders, argue that the Big Bang theory is wrong. They believe that God created the world. This is a very controversial subject and causes many disputes.