When will the universe stop expanding ( if it does)?

Answer 1

First I would like to address how we can see that the universe is expanding, it is. Here is how we "see" it expanding.

First of all, for an analogy think of the universe as a giant loaf of raisin bread expanding in the oven and let’s say we are sitting on one of the raisins observing what is happening. It would appear to us that ALL the raisins are moving away from our raisin as the bread gets larger, but the important thing is that the raisins further away from us are moving away from us faster than the close raisins, THIS IS THE KEY (so read it again and really think about what is happening in the expanding bread).

Secondly, if we observe bodies producing light in the cosmos, we observe a phenomenon called Doppler shift (similar to the sound changing on a horn as train passes you, but with light rather than sound). In Doppler shift light waves moving toward us will be compressed together (this is called blue shift), and light waves that are moving away from us will be expanded (this is called red shift). The faster the light is moving toward or away from us the MORE Doppler shift is observed.

Now, looking into the cosmos we see this phenomenon really happening, and the further away from us a star, galaxy or quasar is observed the more red shift it has, hence the faster it is moving away from us. In fact if we look way toward the edge of the universe has we see light that has shifted so far that it is no longer in the visible spectrum, it has become infra red light then microwave light. This red shift was discovered in 1929 by astronomer Edwin Hubble and is called Hubble Shift.

The red shift supports the theory, with scientific observation, that the cosmos is expanding and the speed it is expanding is faster the further away from us, similarly to our analogy of raisin bread rising. (it is important to note that you would observe the same thing no matter what raisin you were observing from, there is nothing special about our raisin).


Now to answer your question:

Good question and science is not sure if the cosmos will stop expanding. The key is whether the cosmos has enough mass to provide enough gravity to overcome the velocity of its expansion. If the cosmos does have enough mass then the expansion will slowly decelerate until it stops and then the gravity of the universe start to pull it back together eventually to one point (called a singularity), this is called a closed universe. If the cosmos does not have enough mass then the expansion will continue forever, this is called an open universe.

So the key to answer your question is, “how much mass is in the universe”? The problem is that we can’t see all the mass, we can see and estimate the mass of stars, galaxies and dust, then if we add all that mass up it is not enough (it is 3 x 1055 g, which is roughly 25 billion galaxies the size of the Milky Way). Some scientists argue that there is a substance called dark matter that has the additional mass necessary to stop expansion. Dark matter is matter of unknown composition that does not emit or reflect enough electromagnetic radiation to be observed directly, but whose presence can be inferred from gravitational effects on visible matter. Currently astronomers are looking for more dark matter and some argue there will be enough others argue there is not enough. At this time no one has shown by scientist observation that there is enough dark matter to cause a closed universe, but this is a hot astronomical subject and astronomers are researching it heavily.

Finally, the only answer we can give now is, no one knows yet…

Answer 2

The universe will expand and expand
some say it expand for ever
some say it expand to certain limit...
some say it expand to certain limit and start comes back

so whatever say
it is somebody's imagination and vision
so know the right thing
u must find out yourself

According to the Buddhist philosophy
IF u don't have any thing
then best thing to search about the end of the universe
and the creation of the universe
as it never ends
the searching
and the new answers comes as the long the way

take care
Amal

http://worldofsensornetworks.blogspot.com/

http://www.taketheleadheremam.blogspot.com/
http://matabariyo.blogspot.com/

Answer 3

Granted TV is not the best source for accurate information, and that discoveries are still being made so nothing final is in yet, but the latest thinking based on a TV program I saw on the Science Channel is that the expansion of the universe is actually increasing in speed over time. Hard to fathom, isn't it? It goes against all our earthly experience, but over time it does appear that the speed of the universe expanding is actually increasing. Maybe science could find out what this force is, it might be possible to use it for transportation. Anyway, the latest thinking is that the universe will expand forever, gradually it will cool, the atomic reactions that warm it will cease, and it will simply die, but that will be many billions of years away. There does not seem to be enough matter of any kind to "close" the universe; to make it fall in on itself and continue. But like I said, the final truth is probably yet to be discovered.

Answer 4

Based on the latest observational data, the universe will never stop expanding. In fact, the data shows that the rate of expansion is increasing. This means that the ultimate end of the universe will not be a collapse. What happens beyond that is still up to some speculation. No one knows what is causing the increasing rate of expansion, but it is being referred to as "Dark energy"

Answer 5

It will never stop expanding. According to the big bang theory, the universe is expanding everyday and will conitnue to expand forever. Scientists could not predict the limit of the universe until today.

Answer 6

Nobody knows the exact time-line for that to occur, but I do know that when it does stop expanding, it will immediately start collapsing back on itself, finally resulting in a huge black hole which will explode in a "big bang".
Then the process will repeat itself all over again, and again, and again...

Answer 7

we've not yet prevalent whether our universe is OPEN or CLOSED (STUDIED IN COSMOLOGY) IF OUR universe is 'open' it won't supply up increasing and could strengthen right this moment yet while that's 'closed 'it is going to offer up increasing and crumple back and lower back there will be a huge BANG

Answer 8

An object traveling through space will remain traveling the same unless an external force changes it.

Answer 9

I don't know if anyone can answer that. Maybe it never will. Maybe all the Suns will burn out, all the black holes fall apart, and then everything will be gone.

Answer 10

All the above answers are wonderful.
the scientists are hitting the wrong nail ! ! and thats why they are not in position to answer this question at all ! ! and will never be in position to do that ! ! but.........just wait for some time till.......... strikes back........
Mahesh MSc India.