How many years before the universe stops expanding, and time starts running backwards?

Answer 1

Even if the universe were to stop expanding and start contracting that wouldn't make time run backwards.

Answer 2

Your question is intelligent, and I never saw an intelligent question I didn't like. On the other hand, all I know about science is what I read in the scientific media, mainly "Discover", "Scientific American", and the web.

These souces have given me the impression that astronomers now thnk they know how much matter there is in the universe, therefore have determined whether or not gravity will be strong enough to counterbalance the accelerating expansion of the universe.

The big brains behind the big theories and the big telescopes don't seem to think there is enough matter in the universe to stop the expansion, so that particular event has been cancelled 'til further notice. For a better answer try this link to a website with professional astronomers and physicists: http://physlink.com/index.cfm

(If I had a patron saint, he'd look like a combination of Will Rogers, James Thurber and Stephen Hawking: scarier than the Jersey Devil! And when it comes to an ultimate question like this, I think that mythical concatenation of ferocious mammals knows about as much about it as anybody else. If you see him some time when you are in New Jersey, ask him and IM me the answer. I've consulted with everybody else I can think of and am still not satisfied.)

Answer 3

First, we dont know if it even will stop. It all depends on how much matter is in the universe for gravity to slow down the rate of expansion. Second, recent observations have lead scientist to conclude that the rate of expansion is speeding up.

So based on our current knowledge, if it were to contract, we dont know when - at least 15 billion years (based on the current age of the universe, it starts contracting now, and at the same rate as when it expanded).

If it doesnt contract at all. Based on our knowledge of physics, all atoms have a lifespan of how long they last. If the universe expands forever, then eventually all the atoms in the universe would quit working and fall apart. I honestly dont know, but I think the timeframe of around 30-50 billion years is about right.

However, even from a scientific viewpoint (ignoring religious for the moment) it is more likely that the universe is repeating, and this isnt the only one that has been around. There must be something that will renew it.

Answer 4

time "can" run backwards it's in any general relativity text by Mr. E=mc2 himself (you have about a 50-50 chance it does). If the universe "does" stop expanding it will occur when the gravitational potential energy of the whole universe overcomes the momentum of the big bang. But as the universe is pretty big and the "theory of everything" hasn't been found it's almost impossible to guess when (if) time starts running backwards. But hey, Einstein's work contradicted Newtonian space so who's to say Einstein won't be proved wrong in the future

Answer 5

Time will not run backwards in any event. And all current measurements show that the universe will expand forever and never contract.

Answer 6

the hubble constant (the measure which we measure the rate of expansion) has been proven beyond doubt it is accelerating. Could it collapse and reverse? doubtful but who knows. It seem the universe is doomed to forever accelerate and eventually even the bonds of the very atoms will break away. leaving an absolute empty void.

but for your enjoyment i give you a link to a very fun article on such a subject.

Answer 7

scientists recently discovered the universe is flat...like a horizontal x axis but no vertical y-axis.Thus the universe will not collapse upon itself and keep expanding forever.

Answer 8

Critical mass.
...set in motion will continue in motion until it meets resistance.
There is no evidence that the universe will collapse in on itself or run backwards.

Answer 9

TIME DOES NOT DEPEND ON THE EXPANSION OF THE UNIVERSE! TIME IS JUST A MEASURMENT OF HOW LONG MATTER EXISTS. AND THE UNIVERSE PROBABLY WON'T STOP EXPANDING. SOME SCIENTISTS SAY IT IS ACCELERATING.

Answer 10

What in the world do you think would make them collapse back??? There is nothing scientific to say it would.