[calciumboy]

Hello, my name is Nathanael Turner, I am 15 years old so my analogy may not be 'correct' but you get the general picture:

My Question:

1)Will the universe carry on expanding for an infinate amount of time?

OR

2)Will its mass eventually cause it to impload under its own gravitational force?

For a period it has been calculated that the universe has enough 'thrust' to escape its own gravitation pull...

However the recent discovery of "Dark Matter" which is invisable may be enough to 'tip' the mass of the universe over the critical figure causing the universe to contract.

Therefore, is this so called 'Dark Matter' enough to impload the universe and if so, how will we know, is there a way of measuring dark matter?

This may be well known already however I am only 15 and don't know a lot so please enlighten me.

[Capuchin]

Hi Nathanael,

This is pretty much one of the biggest open questions in astrophysics, and to tell the truth, nobody knows.

The prevailing theory at the moment is that the universe will collapse into a big crunch, which is the collapse you talk about, but there is evidence for other universe deaths.

It also depends on the shape and size of the universe, which is very hard to measure because we can only see a small amount of it (or it might be a large amount of it, we can't know though). This is due to the finite speed of light.

I'm a little rushed at the moment but you can read more here: Ultimate fate of the universe - Wikipedia, the free encyclopedia

I should add that evidence suggests that we have a very flat universe, that is Ω is very close to 1 (as the universe expands, this figure moves away from 1, so at the beginning of the universe, it must have been incredibly close to 1 in order for it to be so close to 1 today).

I would also like to say that because you're 15, don't state that as an excuse for being wrong, it's so natural at that age to wonder how the universe is and come up with your own theories, don't ever assume that you are wrong.