Universe 250+ Times Bigger Than What Is Observable
eldavojohn writes "The universe is only fourteen billion years old so we are unable to observe anything more than fourteen billion light years away. This makes it a bit difficult for us to measure how large the universe actually is. A number of methodologies have been devised to estimate the size of the universe including the universe's curvature, baryonic acoustic oscillations and the luminosity of distant type 1A supernovas. Now a team has combined all known methods into Bayesian model averaging to constrain the universe's size and their research is saying with confidence that the universe is at least 250 times larger than the observable universe."
The key idea is that of inflation: general relativity allows for the distance between points to increase faster than the speed of light. Alan Guth's theory for inflation proposes that this in fact occured in the early universe, and the theory is now backed up by observations of fluctuations in the microwave background radiation (among others), where microscopic fluctuations were "frozen in" due to the rapid expansion. The consequence of this inflation is that much of the current universe is not within our 14 Gyr lightcone.
As a side note, the big hub-bub about dark energy is that it appears (based on current observations) that our universe may be entering a second inflationary period. Fortunately, the timescale for this is on the order 100 Gyr, so it will be unlikely to effect our lives directly.