How long is the universe`s longevity ?

Question

13.3 (7) billion years as present. But how long? Dose time go on ever?

Answer 1

While our own sun is a third generation star (that metallicity thingy) there are vast clouds of hydrogen throughout the galaxies that have yet to coelesce into 1st generation stars, so writing the universe off after the equivalent of 6 times the expected life of our own sun is, perhaps, somewhat premature.

Our sun is a yellow dwarf with an expected life of double its present 5 billion year age, so the writer is proposing a universe longevity of around 60 billion years. This surely far too short!

Vincent G thinks that when the number of protons has fallen to 1 in 1000 of its current number that that would effectively be the end and that this would be after 10^37 years, the half life of protons being 10^36. 10^36 is 10, billion, billion,billion,billion years; a bit longer than 60 billion years. Unfortunately his maths is a bit out because after 10^36 years the number of proton would halve but it would be another 10^36 yrs before the number halved again to 25%. Halving the number 5 times is equal to 10^37 years but at this point there would still be more than 3 in 100 stars left not 1 in 1000, so I don't set too much store by this answer!

I would also like to know, Kmc; if the giant black hole at the centre of our galaxy has not destroyed our galaxy, how could micro-black holes created by CERN destroy the Universe? Could this be a misunderstanding too?

Some scientists believe that the universe will expand for a period then collapse, toni, however, other scientists believe that it will go on expanding for ever. Why do you only quote the collapser theory?

Let's be honest you can choose any number you like from 60 billion to 10^37 years and they are all based on someone's guess, or someone's belief or someone's misunderstanding.

We can make a best estimate based on current understanding of astro-physics but every advance in that science will change the estimate, so until we know EVERYTHING it's like betting on a 100 horse race run over ten years. The only people who would give you odds on that would be William Hill, the bookies!

Answer 2

There are a few things that could qualify for the end of the universe.

Should it mean the end of matter as we know it? 10^36 years is considered to be the half-life of the proton. So, in 10^37 years, only on proton out of one thousand would still be around.
That pretty much signals the end of it, unless some mechanism replenishes proton.

Perhaps the end would be when stars stop shining. At the big bang, the metallicity of the stars was about one millionth what third generation stars (like the sun) have -- the sun is about 1.6%.
So, if we assume that metallicity progresses at 1.6% per ten billion year (10 billion years being the age of the universe when the sun was born), then perhaps 5 or 6 cycles and a metallicity of 10% or more for the average star would be unbearable to allow stellar fusion (so perhaps another 70 billion years). There would still be stars shining, but less.

Then, you may consider the current rate of cosmic expansion. How much time before galaxies get so far away from one another as to feel completely lost?

But who know what secrets and surprises the dark matter holds.
We only have conjectures. The future may not be so bleak just yet.

Answer 3

There has been a discovery lately that the universe is expanding and it is picking up speed. Up until now it is 13 to 14 billion years. But unless something else comes up, the universe might loose energy and freeze over, but it will go on forever.

Answer 4

About 80 - 100 billion years until there is nothing left..

Answer 5

Nobody knows for sure.

The Universe as we know and understand it is constantly expanding and speeding up its expansion.

Scientists believe that eventually, once it has reached its maximum expansion, that it will contract back and eventually crash back into one point - the same point that was the site of the "big bang."

picture a rubber band that is expanding until it can't go anyfurther and then letting it go and allowing it to come back to its original size.

only difference is that scientists believe that the original size of the universe was as small as the point of a needle.

Answer 6

it is infinite, but if the scientists at C.E.R.N. have anything to do with it not much longer. they are making tiny black holes that could destroy the universe... something must be done about this??

Answer 7

Don't know really the expectancy of the universe really probably infinity...

Answer 8

There is only one universe, it has always been and will always be.
Simple!

Answer 9

It would take forever to answer that question !