None of the four known forces explain the expansion of the universe with accelerating speed. Is the universe really accelerating, if so what is causing it? Does the M Theory explain it reasonably?
2006-07-31 01:16:19 · 13 answers · asked by gulfarazahmed 1 in Science & Mathematics ➔ Astronomy & Space
It is called Dark Energy and is different than Dark Matter (which is around galaxies). Dark energy is mostly described by a non-zero cosmological constant. This takes some history.
When Einstein came up with his equations for gravity, he realized that they did not allow a static universe. This was a problem for him philosophically, so he added another term to his basic equations. This term had a constant part which is called the cosmological constant. Einstein showed that a particular value for this constant allowed a static universe. When the expansion of the universe was discovered by Hubble, Einstein called the constant 'his greatest mistake'. For decades after this, Einstein's original equations were used instead of the modified ones with the constant.
Now fast forward to a couple of years ago. It was found that the expansion rate is actually accelerating. This can be explained by having a non-zero cosmological constant. It just doesn't have the same value that Einstein suggested for the static universe. It turns out that the cosmological constant has the effect of a pressure which balances the effects of mass. This is why the expansion accelerates.
The big question now is whether this Dark Energy is just part of the geometry of space or whether it actually corresponds to some type of matter made out of particles. We simply don't know the answer to this question.
2006-07-31 06:01:01 · answer #1 · answered by mathematician 7 · 1⤊ 0⤋
that's an exceedingly cool question and it truly makes you think of. I consider you in that there are some "holes" interior the concept. Scientists could no longer clarify why they chanced on that the universe is increasing at an increasing value, so that they progressed a clean term talked approximately as darkish ability. we've not have been given any concept what that's, or the place that's coming from, yet as a result that our universe is increasing. i'm somebody that believes that our universe's expansion IS accelerating (this became the main precise measurement taken, and till somebody can disprove it, this is the suitable that we've). truly, is that we don't comprehend what darkish ability is, and we are able to in all probability on no account comprehend (in our lifetime that's). Who is conscious...possibly there are a number of multiverses outdoors of our universe whose gravity is truly pulling aside our universe. It advantageous could be exciting to be alive while they the two disprove or instruct of darkish remember's life!
2016-10-01 07:17:27 · answer #2 · answered by mehan 4 · 0⤊ 0⤋
Listen buddy nothing's accelerating the universe's expansion....It was just that after the Big Bang occured it started expanding and since universe is only void there isn't any force to stop it's expansion.
2006-07-31 03:11:33 · answer #3 · answered by Wolverine 3 · 0⤊ 0⤋
Its Dark energy which is slowly accelerating the expansion of universe...
for your answer about string theory refer here http://physicsweb.org/articles/world/16/11/3
2006-07-31 01:35:24 · answer #4 · answered by Prakash 4 · 0⤊ 0⤋
I believe that it is dark energy that is causing the accelerating
expansion..
I believe that dark energy and dark matter may constitute other
dimensions within our own known universe..
As gravity dimenishes as a result of our own universes natural
expansion, the gravity pressure is reduced allowing energy from
the dark side ( waited a long time to use that term ! ) to bleed over from the other dimensions which is filling empty space and pushing matter from our universe apart..
2006-07-31 04:30:06 · answer #5 · answered by Anonymous · 0⤊ 0⤋
They are not 100% sure.
But the best known explanation is due to dark matter, this produces no light, or energy,and cannot be detected, by current technology, they speculate that 90% of the matter is dark, this would explain the odd gravitational effects, on our universe, and how it affects our universe.
check out, for more info
http://news.nationalgeographic.com/news/2005/09/0928_050928_dark_matter.html
2006-07-31 01:27:28 · answer #6 · answered by Juggernaut 3 · 0⤊ 0⤋
Brute Force
2006-07-31 01:19:49 · answer #7 · answered by Raylene G. 4 · 0⤊ 0⤋
dere is no exact answer now.. the scientist are playin wid the idea of a having a mysterious energy right now named as "dark energy".. the scientist believe dat its d reason for accelerating expansion of our universe.
2006-07-31 02:02:18 · answer #8 · answered by ani 2 · 0⤊ 0⤋
Dark Energy. At least that is what they are calling it. In my opinion all that means is "some energy we don't know about".
2006-07-31 01:36:38 · answer #9 · answered by campbelp2002 7 · 0⤊ 0⤋
Didn't know it was accelerating. Are you sure? Thought it was just inertia.
'nuff said?
2006-07-31 01:20:18 · answer #10 · answered by Mr. Peachy® 7 · 0⤊ 0⤋