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Old 02-04-2019, 04:15 PM
 
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Physicists Alejandro Corichi from Universidad Nacional Autónoma de México and Parampreet Singh from the Perimeter Institute for Theoretical Physics in Ontario suggest, based on a new study of Loop Quantum Gravity (LQG), that the 'big bang' was more of a big bounce resulting from the contraction of a mirror image of our own universe in which everything was identical to our own universe, but in reverse. When the mirror image universe contracted to a single point there was a rebound - the big bang which created our present universe.

While the idea of a pre-bounce universe has been predicted previously, nothing could be known about the characteristics of the previous universe. But the calculations of Drs. Corichi and Singh suggest to them a mirror image of our own universe prior to the big bang.
We are not talking about an alternate dimension; we are talking about an identical universe with the same space-time and quantum characteristics as our own. If we look at our universe now (13.7 billion years post-bounce), it would be identical to the universe 13.7 billion years before the Big Bounce. The only difference being the direction of time would be opposite; the pre-bounce universe would be reversed.

https://www.universetoday.com/13630/...rsed-universe/
The concept, whether right or wrong, and certainly it can never be known for sure what preceded the big bang, is interesting.

Oops. That article above is actually from 2008. But I had read another article that was, I think, a recent article on the subject.

Yes. The article below was posted on January 11, 2019.
https://www.livescience.com/64470-un...-universe.html

Physicists have a pretty good idea of the structure of the universe just a couple of seconds after the Big Bang, moving forward to today. In many ways, fundamental physics then worked as it does today. But experts have argued for decades about what happened in that first moment — when the tiny, infinitely dense speck of matter first expanded outward — often presuming that basic physics were somehow altered.

Researchers Latham Boyle, Kieran Finn and Neil Turok at the Perimeter Institute for Theoretical Physics in Waterloo, Ontario, have turned this idea on its head by assuming the universe has always been fundamentally symmetrical and simple, then mathematically extrapolating into that first moment after the Big Bang.

That led them to propose a previous universe that was a mirror image of our current one, except with everything reversed. Time went backward and particles were antiparticles. It's not the first time physicists have envisioned another universe before the Big Bang, but those were always seen as separate universes much like our own.

https://www.livescience.com/64470-un...-universe.html

Last edited by Mike555; 02-04-2019 at 04:45 PM..
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Old 02-04-2019, 04:34 PM
 
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Interesting. My only problem with the hypothesis is that it would infer that our two “mirror universes” would be intrinsically linked together. Mirror universe can create our own, and our own can create the mirror universe.

Unless I’m understanding it wrong, with the two universes having the same laws of physics, it seems kind of dependent on the Big Crunch theory being correct which isn’t what we are observing today.
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Old 02-04-2019, 05:10 PM
 
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A few years ago I saw a youtube video called "BBC Documentary - What Happened Before The Big Bang." in which the scientists mentioned above worked to challenge the Big Bang Theory. New ideas challenging old ideas is nothing new. Other the years, alternative candidates have been the brane theory, eternal inflation, the big bounce, multiverse theory, etc., etc.

Thirty years ago when I asked scientists what happened before the big bang, the answer was a resounding, "Nothing." I was not convinced, as we are wired to look for cause and effect. Now most believe something triggered it.
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Old 02-04-2019, 05:10 PM
 
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Originally Posted by Adric View Post
Interesting. My only problem with the hypothesis is that it would infer that our two “mirror universes” would be intrinsically linked together. Mirror universe can create our own, and our own can create the mirror universe.

Unless I’m understanding it wrong, with the two universes having the same laws of physics, it seems kind of dependent on the Big Crunch theory being correct which isn’t what we are observing today.
I agree. It seems to me that each time the big crunch were to occur, the mirror images would keep alternating. As you said, the evidence is that the universe will just keep expanding, and in fact the rate of expansion is increasing. Of course that doesn't necessarily mean that at some point the rate of expansion couldn't begin to slow for some reason and begin to reverse itself.

Personally, I find more interesting the eternal inflation hypothesis which predicts a multiverse. But it's all just speculation, at least for now.
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Old 02-04-2019, 05:37 PM
 
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Quote:
Originally Posted by Adric View Post
Interesting. My only problem with the hypothesis is that it would infer that our two “mirror universes” would be intrinsically linked together. Mirror universe can create our own, and our own can create the mirror universe.

Unless I’m understanding it wrong, with the two universes having the same laws of physics, it seems kind of dependent on the Big Crunch theory being correct which isn’t what we are observing today.
Hm, yes, it does seem required that they would be linked-- if it's an exact mirror image, then you would say that everything that happens *has to happen* because it had sort of already happened? (Wow, that sentence makes no sense.)

I wonder how cause-and-effect would work in a backwards-time universe?


I mean, it's sort of a version of the Big Crunch theory... it just goes one step further. (To me, Big Crunch makes more sense, where the re-compression of the universe is like wiping the slate clean, not like spacetime is just one big rebounding ball, the same thing over and over again.)

The other thing you could ask is, if we consider in a Big-Bang-only universe that nothing was 'before" the universe because time didn't exist... could we still say that was true with this theory? There may have been a reverse universe, BUT can we say it was "before" in terms of whether spacetime existed? And for that matter, if that universe was time in reverse, then would we say that our current universe was after... or also before?
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Old 02-14-2019, 03:05 PM
 
Location: Melbourne, Lake Washington
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A "Big Crunch" does not necessarily exclude a A multi-verse. In-fact that is more likely. Check theoretical phyisicist Sean Carroll's newest book. He also notes time direction. Also, the science channel is creating really good new programming on the Universe.
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Old 02-15-2019, 02:54 PM
 
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Quote:
Originally Posted by KonaGirl4FL View Post
A "Big Crunch" does not necessarily exclude a A multi-verse. In-fact that is more likely. Check theoretical phyisicist Sean Carroll's newest book. He also notes time direction. Also, the science channel is creating really good new programming on the Universe.
His latest book 'Something Deeply Hidden' is due out this year. Has it been published yet (I didn't see anything about whether it has been) or are you referring to the book he wrote in 2016 (2017 for the reprint edition) called The Big Picture?
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Old 02-19-2019, 06:02 AM
 
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How would that mirror universe work? Does it mean that on an individual level we would arise from the grave and move all the way back to a zygote?
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Old 02-20-2019, 04:46 AM
 
Location: Cebu, Philippines
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You mean I don't have free will, and everything I ever do or even think mirrors a past?

Last edited by cebuan; 02-20-2019 at 04:55 AM..
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Old 02-20-2019, 04:45 PM
 
Location: Seattle
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What is space anyway? Every time I try I can't wrap my head around it. It seems to be able to make more of itself, and every location is able to respond to the net distribution of mass in the Universe. How can it even exist?
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