Not exactly news, at least not to anyone who watches the discovery channel every now and then. Basically, observations from measurements of the redshift of objects in the observable universe tell us that everything is moving away from eachother. Objects relatively close to eachother tend to stay close due to a stronger gravitational influence but distant objects are moving away from them. And the rate that everything is moving away is accelerating.

Scientists have been puzzling over this phenomenon for quite some time. They created a word, "dark energy" (not to be confused with "dark matter" or "dark energon"), to describe the unknown force that is somehow pushing everything away. But still, even theories as to why this is happening are few and far between.

So I created this thread so we can all do a little brainstorming. Let's come up with some theories as to why the universe is expanding. I'll start us off.

So we have all these objects that are moving away from each other and are accelerating. It occurred to me a few days ago that there's a known circumstance on a smaller scale where this also happens. It has to do with elliptical orbits.

Imagine a comet or an asteroid with a trail of fragments following behind with an elliptical orbit around a star. As the comet gets closer to the star it accelerates. The fragments following behind accelerate too but there's a sort of delay because they are somewhat further from the star than the piece in front of it. This causes the fragments to expand away from eachother. As the comet whips around the star and starts moving away, it decelerates and the fragments start coming together again.

Obviously this isn't exactly what's happening with our universe. The problem is with the comet scenario it only works on a one dimensional axis. Our universe is expanding in three dimensions. But what if there was the possibility that there was an extra-dimensional object that our universe was orbiting? Some scientists have suggested that our universe is one of many. Could it be possible that our universe is somehow elliptically orbiting a much larger universe on a multi-dimensional axis? If this were true then that would mean some time in the future the universe would stop expanding and start coming together again in an endless cycle.

Easy. Just look at gas particles. They move away from each other because of diffusion despite them still being effected by gravity. And since the universe is, for all we know, infinitely big, the universe has a lot of room to diffuse into.

Yes yes universal expansion big crunch and or big freeze......do we have fully functioning power armor yet or not?

I tend not to concern myself with grandios science theroies, they are interesting, but sense we base all of these theories on other theories, it seems rather pointless to me.

For all we know there could be places in the universe where the laws of physics are topsy turvy.

Black holes might not even exist.

Its possible there is only one dimension, or there might be nine.

See what I mean?

I don't think there is much reason to try and understand the rest of the universe until we fully understand our solar system, if not that then at least Earth.

Which we know to be true.

Hubble Deep Field, bottom right corner. The big yellow galaxy. Its 8 times the size of our own, which by our current laws should not be able to exist.

Thats what I mean, we think we have so much of it figured out, when we know so little.

Not to say we shouldn't pursue these things, I just think there are more things here that need some immediate attention than in Orion's Belt.

:D I agree with Didactylos.

Because alot of our laws don't seem to apply to huge (really huge) or incredibly small things. Which is why scientists are tyring to create universal laws.

Wich is pretty fool hardy imo.

We can't base theroies upon theroies upon something we barely understand as is, or at least think we understand.

Like what? Astronomers studied to do that work. What would you have them do?

We know we don't know much, it is the uninformed and ignorant people that think they know so much.

I alaways find it odd that dark energy is described as a force thats pushing the universe apart.. rather, i would think its like a vaccuum, pulling it apart, as Echonitersaid, it diffuses.

I mean.. if indee this universe did have a big bang, what else could they expect?
I know that the outer areas are speeding up, supposedly.. but could that just be that the further they get from the central mass of the univers,e the less gravity there is to hold them back in their diffusion?

Anyway.. i had a though a while back.. dark energy supposedly keeps the same ratio compared to reg energy.. could this be because everyting is expanding, including spacetime it self?

Welcome to modern Physics and Mathematics

Well Maths not so much because if you effectively prove something in it then it always true become it is the purest subject. While physics falls pray to a very small uncertainity.