Why is the Universe expanding?

Question

Is it an intrinsec proprety (a force) of the spacetime?

Answer 1

Basically, the universe has momentum since the Big Bang, and the stuff inside it doesn't have, or won't have, enough energy to stop it.

If I remember correctly.  Cosmology was never my strong point.

Answer 2

the universe is expanding because it exploded out of the big bang and it gave it the momentum to expand. However, Today it is going through inflation aka accelerated expansion which means there must be some other force at work, Scientists call this the "dark energy" and it makes up almost 85% of the universe.

Answer 3

I don't know much about what Phillip J is talking about. What he is saying might be a popular theory that I'm unfamiliar. What I do know is that the rest of the answerers are BS.

The universe was never an explosion. What we know about the universe today through the beloved Big Bang theory (which was named the big bang by an opponent of the theory because it is a complete misconception of the theory itself)  is that the matter in the universe is getting farther apart, so it must have been closer in the beginning... a lot closer. It is predicted that about 13 billion years ago all the matter in the universe was densely pact together to near infinite density. Then space began to expand, separating the densely pact matter until it formed the galaxy cluster we know today.

Physicists could not figure out why the universe was still expanding so long after the Big Bang so the concept of dark energy was thought up. It is believed to be uniformly distributed throughout space so its gravitational pull (yes energy has gravity) is not felt, constantly pushing the universe apart, and that it takes up roughly 2/3rds of all the matter-energy in the universe. Not much is known about it today and it is still merely hypothetical, but it is by far the most popular explanation of why the universe is still expanding.

Answer 4

Actually it's not...

What if just about everything you thought you knew was a lie?

Answer 5

According to my Fractal Foam Model of Universes, the expansion of our universe pops our cosmic-foam bubbles, which are the ether-foam bubbles of the next larger-scale universe, or super-universe. Time in the super-universe runs backwards compared to our time, so our popping cosmic-foam bubbles are the super-universe's un-popping ether-foam bubbles.

Likewise, expansion of sub-universe space pops the sub-universe's cosmic-foam bubbles which are our ether foam bubbles, and time reversal turns that into our un-popping ether-foam bubbles.

Distance is a matter of how many ether-foam bubbles there are between two points, and un-popping a bubble turns one bubble into two bubbles, thus increasing the amount of space and distance. So the expansion of one universe drives the expansion of the next universe in an infinite chain of sub-universes and super-universes.

When a bubble pops, pressure waves are generated; the p-waves generate s-waves; the s-waves orbit one another to form matter; the matter forms the cosmic foam. Expansion is inevitable; it even determines the direction of time.

Answer 6

Supposedly it's working off momemtum gained from the Big Bang.

What I don't get is, what is it expanding through? It has to be expanding through something to expand, and if that's the case, what's on the "other side" of the universe?