© Matt Strassler [March 15, 2014]
What do we know about what happened before inflation?*
Oh, sure, there are a lot of scientifically grounded speculations about what happened before. But they are many of them, and they contradict one another; and there is currently no type of data that can distinguish which of these speculations might be right. There isn’t even a leading theory which a majority of scientists tend to think of as the most likely. It simply is not known. For all we know, inflation is a continuous process that is going on throughout most of the universe, stopping occasionally in small regions (huge, compared to our observable patch of universe, but small compared to the universe as a whole.)
*assuming inflation happened at all!
After Inflation: the Hot Big Bang.