A new theory about the all of it:
Most cosmologists trace the birth of the universe to the Big Bang 13.7 billion years ago. But a new analysis of the relic radiation generated by that explosive event suggests the universe got its start eons earlier and has cycled through myriad episodes of birth and death, with the Big Bang merely the most recent in a series of starting guns.
How far will this theory go? Will it do to the inflationary theory what the inflationary theory did to the steady state theory, which is also known as the continuous creation theory? One theory destroys another. There is also a new and growing theory that claims the universe is flat. So many theories, so little time.