Could Time Run Backward if the Universe Collapses?

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AnonymousAnonymous
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02 Aug 2022, 2:59 pm

https://bigthink.com/starts-with-a-bang/time-run-backwards/


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Fnord
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02 Aug 2022, 3:06 pm

Nice concept.  Provable?



naturalplastic
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02 Aug 2022, 4:38 pm

Have wondered about that many times.

The universe is now expanding. And as it is expanding time is running in what we all consider to be "forward".

But what if we live in an oscillating universe?

But what if the arrow of time is connected to which phase (expansion or contraction) the universe is in?

According to one theory the Universe will stop expanding, and start collapsing back upon itself, and will return to a singularity in the opposite of the big bang -an event known as the big crunch.

But if there will be people in this far off 'blue shifted' future when this collapse will be happening - will time also go in reverse for them?

If so...then time will move backward...which will mean that the universe will run in reverse of...reverse... and will SEEM to run forward. So even though the Universe will be collapse it will be ...expanding! But it wouldnt expand beyond the size that was the maximum when it was ...actually expanding. It will ...well. time will go in reverse, to the moment before expansion ceased. Then the universe will start to collapse...causing time to go in reverse... back to the moment just before the Universe stopped expanding, and time will run forward...causing the universe to collapse, causing time to run backward...to the moment just before it started to collapse...

Well...expansion would cease, and in effect...time would stand still. And time and the universe would be frozen at the moment of the Universe's greatest expansion. Imagine if time went into reverse every time you put you car into reverse. You wouldnt be able to back your car. :lol:

If thats how time works.

But thats just one hypothesis about how time works.

The mainstream theory, as I understand it, is that the 'arrow of time' is about the constant steady increase in entropy. In that theory even if the expansion of galaxies ground to a halt, and the Universe stated to implode, entropy throughout the universe will still continue to increase, and continue to continue all of the way up until the Big Crunch. So the arrow of time would stay the same.



Fnord
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02 Aug 2022, 4:59 pm

What if time is already running backward right now and we do not even know it, because time would be running backward everywhere, including in our minds?  The "Big Crunch" would happen only 13.8 billion years from now, instead of the "Big Bang" happening 13.8 billion years ago.

I think I will go share this insight with some pot-heads I know and watch them freak out.



naturalplastic
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02 Aug 2022, 5:15 pm

Thats why I said "What we consider to be forward" above, because what we think of as "forward" may actually BE backward. And when the collapse starts...it will be corrected to ...running forward! :D

Except... it cant be corrected to running forward for the reasons I stated. Darn!



Matrix Glitch
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02 Aug 2022, 8:59 pm

I hope not. I'd hate to go though reverse puberty.



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02 Aug 2022, 9:32 pm

No.


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02 Aug 2022, 9:35 pm

What does it mean "universe collapses"?

If you put something into a blender the contents generally don't go back in time



naturalplastic
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03 Aug 2022, 3:51 am

cyberdad wrote:
What does it mean "universe collapses"?

If you put something into a blender the contents generally don't go back in time


The universe is now expanding. Has been expanding since the Big Bang 14 billion years ago. Thats been known since it was discovered in the 1920s that all other galaxies are 'red shifted'.

So the century long debate has been (a) will this expansion go on forever, or (b) will gravity act like a break and eventually stop galaxies from spreading outward, and stop, and then cause them to fall back towards each other.

And if the later happens then everything will become 'blue shifted', as all of the galaxies get progressively closer to each other (in reverse to what they are doing now). And finally- we will presumably have something that amounts to being the opposite of 'the Big Bang'...known as 'the Big Crunch' when all of the matter of Universe converges onto a 'singularity' and collides with itself (just like it started at a singularity with the Big Bang). Thats what I mean by 'when the universe collapses'- the next phase when the universe stops expanding (according to that theory).



cyberdad
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03 Aug 2022, 7:17 am

naturalplastic wrote:
cyberdad wrote:
What does it mean "universe collapses"?

If you put something into a blender the contents generally don't go back in time


The universe is now expanding. Has been expanding since the Big Bang 14 billion years ago. Thats been known since it was discovered in the 1920s that all other galaxies are 'red shifted'.

So the century long debate has been (a) will this expansion go on forever, or (b) will gravity act like a break and eventually stop galaxies from spreading outward, and stop, and then cause them to fall back towards each other.

And if the later happens then everything will become 'blue shifted', as all of the galaxies get progressively closer to each other (in reverse to what they are doing now). And finally- we will presumably have something that amounts to being the opposite of 'the Big Bang'...known as 'the Big Crunch' when all of the matter of Universe converges onto a 'singularity' and collides with itself (just like it started at a singularity with the Big Bang). Thats what I mean by 'when the universe collapses'- the next phase when the universe stops expanding (according to that theory).


Oh of course! yes I understand now. The universe is a like a tense spring rebounding. As the velocity of matter flinging from the big bang slows down then the gravity flings it all back to the singularity.



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03 Aug 2022, 9:04 pm

VegetableMan wrote:
No.


That is also my answer. If the universe started to shrink, black holes would have to reverse from their current path. They would have to give off gravity force to push light and matter out of the inside. Since the center of a black hole is tied to the formation of a neutron star, I do not see that as a likely proposition.

I wanted to comment on red shifting and blue shifting of light. It does not directly depend upon distance, but upon the particles of matter/antimatter that light energy interact with. Outer space is not a perfect vacuum. As light energy travels in outer space, it will come into contact with such particles. Each time this occurs, a small portion of the energy is given off to the particle. That causes the light energy to become lower in frequency (red shifted). Light energy can start off as high energy gammas from a star and over many, many interactions becomes low enough to be visible to the naked eye (or even lower). The longer the distance light energy travels just increases the amount of interactions that can take place.



collectoritis
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04 Aug 2022, 9:50 am

God almost considered collapsing it when Macho Man Randy made that rap album , he figured nothing could top that :lol: :mrgreen:



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05 Aug 2022, 1:53 pm

I've read a bunch of spacey articles lately thanks to James Webb Telescope things trending.

There are many different theories of multiverses, and some claimed evidence. Some say that in a parallel universe, time runs backwards to what we experience. Other theories say all past, present, and future events exist simultaneously. Other theories suggest our universe is one of many existing in a sort of bubble bumped up against other bubbles. Another I read theorized that our universe is in an endless cycle of expansion/contraction to a singularity/big bang re-expansion cycle again over and over in an infinite loop. Others say matter drawn into black holes spews out the other side in another dimension/universe.. although one article said there was evidence of stars forming and coming out the other side of a black hole. Apparently other universes are likely to have different arrangements of particles/atoms/matter and thus entirely different rules of physics that govern them, too.

And maybe all of these things are true at the same time.. or timelessness if time as we perceive it is a mere human experience illusion while we, a splinter of the universal consciousness that IS the thinking universe, are here observing the physical universe for ~80 "years," until we return back to the ether and rejoin the others.


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06 Aug 2022, 7:04 pm

I hope not. I wouldn't want to go through 1985 again - the worst year of my life.


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