Properties of the Universe

[CanadaAotS]

one of the big mystery's of the universe is why gravity is so weak...

 

has anyone thought, if gravity wasn't weak we wouldn't be here?

 

I believe that there are many universes and that we happen to live in one that can sustain life. If gravity were strong like the other forces, electrons would fall into nucleus's, there would be no matter = no stars no nothing

 

If you take this sort of blunt force thinking to the universe, all the laws in a way were created to support a life form that could observe them.

 

I know this view has been taken by other people before, I just want to hear your thoughts on it... makes sense in my mind. Goes along with evolution as well, since life's purpose is to pass on its genetic code for the next generation. Since we are a living life form in the universe, its purpose could be seen as supporting life.

[5614]

err, well you asked for my view so here goes nothing!

 

My view is that it is a pointless thread. I'm referring more to the "if gravity wasn't here"... the "why gravity is so weak" has more of a purpose, although the only real answer is because it just is!

 

Let me explain, remember this is my personal view. I read that and think who cares because it would change everything, everything would be so different. I would put this in the same category as those who say "if we went faster than c what would happen". It's like if we change the whole universe and the way it works how would it work? I don't have a clue and it's totaly irrelevant!

 

What purpose does just taking gravity out of the universe have?

 

Just rereading your post you seem to go on about if gravity was stronger, whilst my post is more aimed at the "remove gravity" beginning of your post my point of view still holds for the stronger gravity part of your post.

 

And this is just how I feel, don't bite my head off! I'm sure some people would find it fascinating to think how everything would be if you remove certain elements of the universe, so maybe you should wait for those people to post.

 

Just rereading your post again (I really need some sleep!) you then go on about how the laws were "created to support a life form"... I'd disagree slightly and say that:

 

The laws happened to be that way and we happened to be able to live with those rules. They weren't made for us, they were made first, we came second once they were established.

 

I'd say we were created or evolved in such a way that we suit the laws of the universe.

 

I spose one could argue that God made the universe with humans in mind and so He designed it such that the laws of the universe would suit us... although I really wouldn't want to argue that point of view!

[Sisyphus]

What is life? Self-replicating patterns. I'd imagine that's possible in just about any scenario you could come up with.

[ecoli]

Let me explain' date=' remember this is my personal view. I read that and think who cares because it would change everything, everything would be so different. I would put this in the same category as those who say "if we went faster than c what would happen". It's like if we change the whole universe and the way it works how would it work? I don't have a clue and it's totaly irrelevant![/quote']

 

I completely agree. It's a pointless to discuss what-ifs and maybes. Ok, so if gravity was stronger, we wouldn't be here... maybe life would've evolved differently, etc. There are so many different possibilities that its not even worth discussing them... Unless there happens to be a particularly interesting one, of course.

[insane_alien]

i like what if questions because they are interesting. but from a scientific point of veiw i can't really be bothered with them.

[gib65]

There is the String Theorist's explanation for the weakness of gravity. They say that gravity is actually on equal par with the other forces of the universe except that 99.99% of gravitons leave our universe almost immediately after they are emitted from mass. This leaves an infinitesimal amount to account for the effects we feel from gravity.

 

String Theory is not accept by all though, and it might not even be falsifiable. So don't take this to be "the answer" to your question.

[Severian]

That is not a prediction of String theory - that is a prediction of a certain boundary condition which is sometimes used in some string theories. The boundary condition doesn't need to have anything to do with string theory though, and in fact if this is true then we would expect to see signs of it at the LHC, since the Plank mass would only be a few TeV.

[gib65]

That is not a prediction of String theory - that is a prediction of a certain boundary condition which is sometimes used in some string theories. The boundary condition doesn't need to have anything to do with string theory though, and in fact if this is true then we would expect to see signs of it at the LHC, since the Plank mass would only be a few TeV.

 

I'm not sure what "boundary condition" means in this context, but I'm sure the argument for gravitons leaving the universe is from String Theory. The argument goes: Strings that make up the matter, energy, and messenger particles that stay in our universe are open ended. Their ends "stick" to the brane that makes up our 3D space continuum and therefore can move about this brane but cannot move off it. Gravitons, on the other hand, are closed strings and therefore they are free to fly off our brane and travel into higher dimensions. Sometimes, but very rarely, they travel along our brane but only because they so happen to be going in that direction already. The incredibly small number of these gravitons is what accounts for the incredibly weak force of gravity.

[CanadaAotS]

meh I was really just musing. This is very scientifically important at all, more philisophical I'd say

[Severian]

I'm not sure what "boundary condition" means in this context, but I'm sure the argument for gravitons leaving the universe is from String Theory. The argument goes: Strings that make up the matter, energy, and messenger particles that stay in our universe are open ended. Their ends "stick" to the brane that makes up our 3D space continuum and therefore can move about this brane but cannot move off it. Gravitons, on the other hand, are closed strings and therefore they are free to fly off our brane and travel into higher dimensions. Sometimes, but very rarely, they travel along our brane but only because they so happen to be going in that direction already. The incredibly small number of these gravitons is what accounts for the incredibly weak force of gravity.

 

So the 'boundary condition' in your example is that the endpoints of the string in one case are restricted to lie on the brane, while in the other case, they are not. But saying that the graviton is restricted to the brane is not a prediction of string theory itself, since I could equally well set up the string theory with different boundary conditions. It is a prediction of the boundary condition.

 

Equally, I could have a non-string theory with a boundary condition such that the gravitons are allowed to propagate in the bulk, which would also dilute gravity. Indeed, the first suggestion of this was the Randall-Sundrum model, which is not a string theory.