The big bang theory explains how the universe began. According to it, the universe began as singularity (a very hot , small and dense superforce with no stars, atoms, or structures) and then about 13.7 billion years ago, the space expanded very quickly. This leads to formation of stars and galaxies which we know today. This expanding of universe is still happening and thus the temperature of universe is decreasing.
Therefore, the statements describing the bing bang theory are:
1) The universe is continuing to expand and
2)A massive explosion caused matter and energy to expand and form the universe.
