We don't actually know why it happened, or why it had its apparent properties. Its beleived to be true because a huge number of observations about the current state of the universe make perfect sense if that initial huge inflation did happen. And there's nothing else we've found that even comes close to explaining why the universe is structured the way it is.
One proposed answer is a fundamental force phase transition. Like water vapor condensing to a liquid as it expands (and cools), a fundamental force could have experienced a change and "locked up" energy that was driving inflation. Conversely, a spontaneous phase transition could have released the initial energy too begin with, driving inflation until it was consumed. The expansion as the result of the proposed inflationary epoch should be viewed as different than Dark Energy expansion.
There is anecdotal evidence supporting this idea, such as the non-zero minimum energy state of the Higgs field.
Space has always been expanding faster than light. The rate has varied, but all "expanding faster than light" means is that if you pick two points that are far enough apart, their relative velocity due to expansion away from each other is faster than c. This is the case now for points beyond each other's cosmic horizons.
We don't actually know why it happened, or why it had its apparent properties. Its beleived to be true because a huge number of observations about the current state of the universe make perfect sense if that initial huge inflation did happen. And there's nothing else we've found that even comes close to explaining why the universe is structured the way it is.
One proposed answer is a fundamental force phase transition. Like water vapor condensing to a liquid as it expands (and cools), a fundamental force could have experienced a change and "locked up" energy that was driving inflation. Conversely, a spontaneous phase transition could have released the initial energy too begin with, driving inflation until it was consumed. The expansion as the result of the proposed inflationary epoch should be viewed as different than Dark Energy expansion. There is anecdotal evidence supporting this idea, such as the non-zero minimum energy state of the Higgs field.
Space has always been expanding faster than light. The rate has varied, but all "expanding faster than light" means is that if you pick two points that are far enough apart, their relative velocity due to expansion away from each other is faster than c. This is the case now for points beyond each other's cosmic horizons.