We’re Small: The Universe Is AT LEAST 250x Larger Than It Looks.

Alasdair Wilkins over at io9 has some existential nausea for you. The universe? Apparently it is at least 250 times larger than it looks. Does that make no sense to you? Yeah, me either. Until! Until some elucidation:

So just how far can we see into the visible  universe? Since the universe is about 14 billion years old, it seems obvious that we can only see within the nearest 14 billion light-years. But that isn’t quite right, as cosmic expansion has expanded the distance between us and the most distant cosmic objects to as much as 45 billion light-years. That means that there’s just about 90 billion light-years worth of visible universe that we can see.

But even that can’t compare with the full size of the universe. Of course, if we can’t see part of the universe, then we can’t actually know anything about it, because no other information will have had time to reach us either. But the trick is that the structure of the universe we are able to see can reveal its overall size. Basically, the universe can have one of three structures: a closed shape like a sphere, a flat shape, or a completely open one. Either of the last two would mean the universe is infinite, but a closed spherical shape would mean the universe has a definite volume.


…here’s what they found – in all likelihood, the universe is flat, which means it has an infinite size. But if it  is a closed sphere, then we have a lower limit for its size, which is about 250 times the size of our visible universe. Obviously, 250 times to infinite is a pretty big range, but it’s by far the tightest constraints ever put forward, and having an actual lower limit for the universe’s size could prove hugely useful in other areas of cosmology.

The nausea! The nausea.