If the universe were to collapse, would time go backwards?

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Jitro
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06 Feb 2013, 4:33 pm

If the universe were to collapse, would time go backwards? Would people start walking backwards, uneating, undrinking etc.?



Fnord
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06 Feb 2013, 4:35 pm

If the universe were to collapse into a singularity, time would eventually slow down and stop, according to general relativity.


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ruveyn
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06 Feb 2013, 4:45 pm

Jitro wrote:
If the universe were to collapse, would time go backwards? Would people start walking backwards, uneating, undrinking etc.?


No.

If the universe were to collapse (a big bang in reverse) things would get hot.

ruveyn



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06 Feb 2013, 7:17 pm

Jitro wrote:
If the universe were to collapse, would time go backwards? Would people start walking backwards, uneating, undrinking etc.?


Well, I won't say it's impossible, because humanity hardly know anything about the universe as a whole. For a long time, humanity thought that the Earth was the center of the universe, and that everything revolved around it. Then we thought the Sun was the center of the universe. Then we thought the entire universe was just the Milky Way. Then we came up with the Big Bang theory.
Then we thought the universe was shrinking, and it would eventually collapse in on itself. Then we found out that the universe was not only growing, but speeding up in growth. And now we have all of these theories about dark matter and dark energy. And we discovered black holes. We also discovered pulsars and quasars. Within the past couple decades, we've found planets around other stars. And even more recently, we found a planet that had two suns.
Simply put, we don't really know to much about what's out there. Scientists think they know a whole lot about the universe, but they're finding new things almost constantly. We don't know if the universe has the ability to collapse or not. And if the universe did collapse, who knows what would happen?



naturalplastic
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06 Feb 2013, 9:36 pm

Its already happening!

The universe passed its prime a couple billion years ago.

As we speak it is- at this very moment -collapsing!

Has been for a couple billion of its 13 billion years.

Because its collapsing time is -at this moment- running backwards.

But since time is running backward- we are also running backwards- so our perception of time is backward. So we precieve time as running forward.

So- to us- time APPEARS to be running forward.
But its running backward.

Beings in the forward outward expanding phase of the universe have a forward perception of time running forward- so they correctly percieve that time is running forward- when it is in running forward.

But beings in the contracting phase have the illusion that time is running forward when it is really running backward they perceive the backward progress of time in a backward way- so to them- its time runnng forward.

So beings who live in the universe- can never tell whether they are coming or going. Because it looks the same either way! It always appears that we are expanding regardless of which phase your in.

Or, thats my theory.



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06 Feb 2013, 10:00 pm

naturalplastic wrote:
Its already happening!

The universe passed its prime a couple billion years ago.

As we speak it is- at this very moment -collapsing!

Has been for a couple billion of its 13 billion years.

Because its collapsing time is -at this moment- running backwards.

But since time is running backward- we are also running backwards- so our perception of time is backward. So we precieve time as running forward.

So- to us- time APPEARS to be running forward.
But its running backward.

Beings in the forward outward expanding phase of the universe have a forward perception of time running forward- so they correctly percieve that time is running forward- when it is in running forward.

But beings in the contracting phase have the illusion that time is running forward when it is really running backward they perceive the backward progress of time in a backward way- so to them- its time runnng forward.

So beings who live in the universe- can never tell whether they are coming or going. Because it looks the same either way! It always appears that we are expanding regardless of which phase your in.

Or, thats my theory.


I have two things to say.

1. Where did you hear that the universe is collapsing?

2. What do you mean by "Or thats my theory"?



VIDEODROME
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07 Feb 2013, 12:50 am

I thought it would speed up?

It seems like I read somewhere that is what it would look like if you fell toward a Black Hole so I figure that would relate to the Big Crunch.



Apple_in_my_Eye
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07 Feb 2013, 1:30 am

I don't think so, but also -- backwards from whose point of view? You could say that we're all going backwards in time right now, but we can't tell because we're all doing it at the same time. You'd have to have some people going 'backwards' while others go 'forward' in order to perceive 'backwards in time." I think that that might lead to thermodynamic problems or impossibilities, though.



MCalavera
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07 Feb 2013, 1:42 am

I don't know why the idea of the universe itself collapsing is more disturbing to me than my eventual and relatively imminent death.



ripped
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07 Feb 2013, 1:49 am

You first must have the definitive account of what time is.
If time is simply a measurement of motion, then no, time would not have to go 'backwards'.



Jitro
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07 Feb 2013, 11:00 am

ruveyn wrote:
Jitro wrote:
If the universe were to collapse, would time go backwards? Would people start walking backwards, uneating, undrinking etc.?


No.

If the universe were to collapse (a big bang in reverse) things would get hot.

ruveyn


Well, since space would be going backwards (collapsing), wouldn't time do the same?



JNathanK
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07 Feb 2013, 12:30 pm

How would we know whether its going backwards or not? I kind of wonder if this is why history seems to repeat itself.



ruveyn
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07 Feb 2013, 1:51 pm

Jitro wrote:
ruveyn wrote:
Jitro wrote:
If the universe were to collapse, would time go backwards? Would people start walking backwards, uneating, undrinking etc.?


No.

If the universe were to collapse (a big bang in reverse) things would get hot.

ruveyn


Well, since space would be going backwards (collapsing), wouldn't time do the same?


Are you saying that there would be A Hot Time In The Old Town Tonight?

ruveyn



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07 Feb 2013, 8:39 pm

Jitro said:
"Well, since space would be going backwards (collapsing), wouldn't time do the same?"

Well, space would be going inwards on itself, not backwards, if it was collapsing. And since we don't know what time really is we can't predict what it would do.
Besides, how do we know that time is connected to the universe? You can say, "50 billion years ago, before the Big Bang ..." and that would still be part of humanity's general definition of time. You can also say "After the universe collapses" and that would still be part of our general definition of time. But is that definition of time a true representation of what time is? I don't know - and that proves my point.



naturalplastic
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07 Feb 2013, 9:29 pm

If the universe stopped expanding this moment.

And then started to collapse back to the big crunch.

We would have several billion years before it got noticeably warmer.

But- probably causes would still precede effects. And things would still degenerate toward entropy ( more order to more disorder). So the the arrow of time would be the same. So time would still move foreward.

Then at the moment of the big crunch- time would actually stop altogether because when the whole universe collapses to a point its the equivalent of a black hole. And time stops at black holes.

But then we would have another big bang and time would start up again -moving forward.



ripped
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08 Feb 2013, 4:16 am

JNathanK wrote:
How would we know whether its going backwards or not? I kind of wonder if this is why history seems to repeat itself.

I heard a theory that time was comprised of cycles which conform a loop, except there is progression from each cycle to the next. More like a spiral.
Have I lost you there?