2006-08-14 08:26:57 · 13 answers · asked by forthursdaynight 2 in Science & Mathematics ➔ Astronomy & Space
...and how is it expanding?
2006-08-14 08:27:15 · update #1
The shape of the universe is determined by a struggle between the momentum of expansion and the pull of gravity. The rate of expansion is expressed by the Hubble Constant, Ho, while the strength of gravity depends on the density and pressure of the matter in the universe. If the pressure of the matter is low, as is the case with most forms of matter we know of, then the fate of the universe is governed by the density. If the density of the universe is less than the "critical density" which is proportional to the square of the Hubble constant, then the universe will expand forever. If the density of the universe is greater than the "critical density", then gravity will eventually win and the universe will collapse back on itself, the so called "Big Crunch". However, the results of the WMAP mission and observations of distant supernova have suggested that the expansion of the universe is actually accelerating which implies the existence of a form of matter with a strong negative pressure, such as the cosmological constant. This strange form of matter is also sometimes referred to as the "dark energy". If dark energy in fact plays a significant role in the evolution of the universe, then in all likelihood the universe will continue to expand forever.
2006-08-14 17:12:01 · answer #1 · answered by Astromajor 1 · 2⤊ 0⤋
The universe is not expanding. There is just movement that was caused by the vacuum.
As the movement slows, gravitaional forces will begin to try to compress everything but then, this will be trying to create a vacuum which will pull everything apart again and cause more movement. Assuming that there could be no more star implosions and explosions, things would oscillate back and forth until everything is just still. However, there will be star explosions until the universe is all used up causing more stars and planets to be formed and adding more gravity all of which adds movement. Considering that the universe is infinite and matter never disappears, it just changes form, it will be a pretty long time before it is used up and there is no movement.
All in all, it was a pretty good feat of engineering to design something so self sustaining.
The universe is proof of the vacuum and only exists as it is because the infinite vacuum existed.
2006-08-14 16:18:12 · answer #2 · answered by Anonymous · 0⤊ 2⤋
The universe cannot be static. The basic laws of physics require that it either expand of contract. Because there is gravity between any two objects (see Newton) they will be drawn together unless there is a force acting to counteract the pull of gravity, e.g. the momentum of the Big Bang. The question is whether or not there is enough matter in the cosmos to reverse the expansion. If so, there will be a Big Crunch; if not, endless expansion.
2006-08-14 15:48:48 · answer #3 · answered by x 7 · 0⤊ 1⤋
Expansion is a proven fact. It is also a proven fact the universe is expanding faster. (God or someone has stepped on the gas).
Why the universe is expanding at a faster and faster rate noone knows for sure.
When it stops it may just stop. No contracting, Or it may contract.
No one knows that either It seems the total mass/energy of the universe is to close to call
2006-08-14 15:42:30 · answer #4 · answered by Jeff C 2 · 0⤊ 1⤋
I think it would contract. My personal theory (which others probably share, too) is that it's expanding because of the heat generated by the big bang, and once it cools off it will contract and eventually fall into itself. As it falls into itself, the components of the universe will create friction, creating more heat, and then creating another big bang.
Most everything observed in life is cyclical. I think it's the nature of the universe as well.
2006-08-14 15:35:29 · answer #5 · answered by Cassie 3 · 0⤊ 1⤋
When the universe stops expanding, it is going to start contracting again untill everything is squished together like it was before the big bang and then there is going to be another big bang and the whole thing is going to start overt again.
2006-08-14 15:31:37 · answer #6 · answered by Nieds 2 · 0⤊ 1⤋
some say if some sort of gravitational pull of powerful proporsion stop the expansion it most likely create a reverse effect. and the universe would shrink till it would collapse on itself often refered as the big crunch.
2006-08-14 15:31:30 · answer #7 · answered by Amer O 2 · 0⤊ 1⤋
Nothing. The effect will not be felt here for sure. The contraction is only a suggestion not proof that will ever happen
2006-08-14 15:30:50 · answer #8 · answered by Dr M 5 · 0⤊ 1⤋
the universe is not expanding in my opinion
it has infinite dimensions 'length x width x height'
there is "no creation of new space"
2006-08-14 15:34:47 · answer #9 · answered by gjmb1960 7 · 0⤊ 1⤋
The force from the Big Bang is still in effect.
Once it stops, it could contract.
2006-08-14 15:30:46 · answer #10 · answered by Anonymous · 0⤊ 1⤋