[Old Professer]

The whole universe was contained in the Big Bang. It's not like the debris of an explosion expanding through space, rushing away from some central point. The whole space was once confined to a small point. The whole space is expanding. The Big Bang is everywhere, which is why the Cosmic Microwave Background comes from all over the sky.

You know this is incomprehensible, don't you?

Assuming this small point was in the middle of nowhere and now it isn't in the middle of anywhere and the expansion is ongoing at an indeterminate rate, any manner of suppositions could and will be made regarding its origin, makeup and future.

The human mind isn't large enough for such a notion.

[RadioAstronomer]

You know this is incomprehensible, don't you?

Not at all. Think of dots on the surface of an expanding balloon. They appear to be rushing away from each other as the balloon expands. The further the dots are apart, the faster they separate. At the beginning, they were all at the same point. The universe can be looked at in the same way. An expansion of space-time fron a single point. Everywhere was at that point in the beginning.

[VadeRetro]

Assuming this small point was in the middle of nowhere and now it isn't in the middle of anywhere . . .

No! No! It used to not be in the middle of anywhere! Now it's in the middle of nowhere.

;)

[RightWhale]

You know this is incomprehensible, don't you?

Of course it is. Cosmologists know that. They don't usually talk about that aspect except when they are having coffee away from prying ears.

[Doctor Stochastic]

The human mind isn't large enough for such a notion.

Speaking for yourself, of course. The expansion isn't very hard to describe. What's important is that expansions (and curvatures) of a manifold can be detected locally. (Result due to Gauss) The surface of a sphere has no center (or corners). If the sphere is expanding, points will move away from each other.