Question: Where is the universe ? It gives me a headache each time I think about this question ...

David Freeborn answered on 20 Jun 2013:

Hi Pauline,

This is a great question. But I’m not surprised it gives you a headache: there are no easy answers!

When we ask where something is, we normally want to know “where” it is against some other object or system. We can say “the computer is on the table” or “the North Pole is at the top of the earth”, because we are giving some other system to compare the location against. In other words, we give the location of an object relative to some other system to measure against.

We can only give objects a point in space, relative to other objects.

But the Universe doesn’t have a point in space. The Universe contains all of space and time in itself.

We think that space isn’t flat like a carpet, but curved in on itself, like the surface of ball. If you reached the “edge” of space, you would end up back where you started. But the Universe isn’t sitting “inside” anything else- all of space is contained within the Universe itself. So there’s no way of saying “where” the Universe is- it contains all of space in itself.

So the Universe isn’t anywhere really! We can say where things are “inside” the Universe, but we can’t ever say the Universe is anywhere!

I hope that makes some sort of sense and that isn’t causing any more headaches: it’s a really difficult concept!