It began to expand in size. There is a hole at that point in our knowledge of the early universe but without a doubt the universe began to expand.
Events in the Universe are often dated from the Big Bang. But the fact is, NOBODY KNOWS what (if anything) happened before the Big Bang. The Big Bang MAY have been the start of time itself; but it is possible that the Universe existed (in some form) forever in the past.
It happened in the center of the universe, for which it is still expanding on the universe.
universe started moving away
The big bang began the expansion of spacetime with great rapidity. The Universe began with the Big Bang. In other words both space and time began at the big bang. The big bang started the Universe from the point t=0.
The big bang happened then!
The matter present in the Universe began to become more and more dense and this huge density originates the big bang. That was the beginning of the Universe.
Energy and space and time all came into existence when the universe was created. It happened when the Big Bang happened 13.7 billion years ago. We have no scientific understanding of anything before the Big Bang.
If the Big Bang never took place, the universe as we know it would not exist. The universe began as a singularity and expanded rapidly from that point. Without this event, there would be no galaxies, stars, planets, or life as we know it.
Some questions about the Big Bang theory and its implications for the origin of the universe include: What caused the Big Bang? How did the universe evolve after the Big Bang? What evidence supports the Big Bang theory? What are the implications of the Big Bang for our understanding of the universe's beginning and future?
Right after the big bang happened, the universe was expanding at a speed of light. While it was expanding, it started to cool itself down since the big bang caused the universe to heat up to ridiculous temperature.
In general Big Bang theory puts our currently known universe at about 13 billion years old (that's 13,000,000,000 years.)
The universe began rapidly expanding and cooling. This expansion was NOT an explosion because there is nothing around the universe for it to explode into.For what it is worth the Big Bang never ended, it is still happening.