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Old 07-21-2017, 12:18 PM
 
Location: The Driftless Area, WI
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I have to agree with you, Mike, both on the facts and on the general concept of science. There must someday be a resolution to the conflict between QM & Relativity, ie- a" TOE." The Universe, after all, must have some universal mechanism to it. The question at this point is, is String Theory going to turn out to be true, or is it just a coincidence that the math seems to be working out? Most of us mere mortals have to struggle just to understand the qualitative concepts, let alone to actually participate in the quantitative computations.

Skeptics shouldn't base their incredulity on their own ignorance. I'm reminded of the comment one Cambridge student said to his buddy as they watched Newton, author of Phil. Nat.Principia Math..., walk across the campus- "There goes the man who wrote a book that only he can understand."

BTW- skeptics shouldn't confuse the concept of spatial dimensions with the more general mathematical concept of dimension-- a dimension is merely a parameter in a mathematical function.
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Old 07-21-2017, 02:23 PM
 
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Originally Posted by guidoLaMoto View Post
I have to agree with you, Mike, both on the facts and on the general concept of science. There must someday be a resolution to the conflict between QM & Relativity, ie- a" TOE." The Universe, after all, must have some universal mechanism to it. The question at this point is, is String Theory going to turn out to be true, or is it just a coincidence that the math seems to be working out? Most of us mere mortals have to struggle just to understand the qualitative concepts, let alone to actually participate in the quantitative computations.

Skeptics shouldn't base their incredulity on their own ignorance. I'm reminded of the comment one Cambridge student said to his buddy as they watched Newton, author of Phil. Nat.Principia Math..., walk across the campus- "There goes the man who wrote a book that only he can understand."

BTW- skeptics shouldn't confuse the concept of spatial dimensions with the more general mathematical concept of dimension-- a dimension is merely a parameter in a mathematical function.
Whether or not String theory turns out to be correct, it is at the moment the only game in town in the effort to come up with a workable TOE. Since it's not possible to directly test the theory, physicists have to be satisfied with indirect methods. According to Greene, with current technology it would take a collider the size of our galaxy to see a string. If you were to compare the size of a string to the size of an atom, if you expanded the atom to the size of the observable universe a string would be about the size of a tree. So, very small.

On the other hand, in M-theory which builds on string theory and requires an additional spatial dimension beyond those required in string theory, a particularly energetic string could expand into a membrane or 'brane' the size of our universe which is expanding. Each universe in the multiverse would be on it's own brane. Did two branes come into contact and create the brane of which our universe is part of? Was the 'big bang' the result of the point of contact between those two branes? Or, in keeping with the topic of this thread, did another brane come into contact with our brane/universe and result in a bruise which manifested as a cold spot?

Well, it's a fascinating idea.
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Old 07-21-2017, 02:59 PM
 
Location: The Driftless Area, WI
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Originally Posted by Mike555 View Post

Well, it's a fascinating idea.
..And how many angels can dance on the head of a pin?
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Old 09-08-2017, 02:18 PM
 
Location: Montreal
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If the multiverse theory from astrophysics proves to be correct, parallel universes are the real-life setting of alternate histories or counterfactual or what-if histories. In other words, such histories aren't just of what would have happened in this universe, but also what has happened in another universe. Our universe has one outcome to a given event but another universe has a different outcome. In each such universe, there are the exact same copies of us, cars, trees, etc. (assuming the dimensions are the same), just that history unfolds there differently from here in this universe.

Thus, counterfactual/alternate/what-if history isn't necessarily just a thought experiment, and the closely-related alternate history isn't necessarily confined to science fiction or similar literature/film/TV/theatre/poetry. Rather, especially if the multiverse theory proves to be correct, such history is real-life history. Not in this universe, but in another universe. It could absolutely happen, for instance, that in another universe, Napoleon did in fact win the battle of Waterloo in 1815, or the Nazis did in fact win World War II (quite a scary scenario for us in the Allied countries, of course), or JFK did in fact not get assassinated in 1963.
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Old 09-08-2017, 02:48 PM
 
Location: State of Transition
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Originally Posted by yofie View Post
If the multiverse theory from astrophysics proves to be correct, parallel universes are the real-life setting of alternate histories or counterfactual or what-if histories. In other words, such histories aren't just of what would have happened in this universe, but also what has happened in another universe. Our universe has one outcome to a given event but another universe has a different outcome. In each such universe, there are the exact same copies of us, cars, trees, etc. (assuming the dimensions are the same), just that history unfolds there differently from here in this universe.

Thus, counterfactual/alternate/what-if history isn't necessarily just a thought experiment, and the closely-related alternate history isn't necessarily confined to science fiction or similar literature/film/TV/theatre/poetry. Rather, especially if the multiverse theory proves to be correct, such history is real-life history. Not in this universe, but in another universe. It could absolutely happen, for instance, that in another universe, Napoleon did in fact win the battle of Waterloo in 1815, or the Nazis did in fact win World War II (quite a scary scenario for us in the Allied countries, of course), or JFK did in fact not get assassinated in 1963.
This sounds like good news. So, can anybody tell me where the parallel universe is, with the planet that humanity hasn't screwed up, and caused to gradually become uninhabitable? And how do we get there?
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Old 09-09-2017, 07:52 PM
 
1,984 posts, read 685,325 times
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Originally Posted by Ruth4Truth View Post
This sounds like good news. So, can anybody tell me where the parallel universe is, with the planet that humanity hasn't screwed up, and caused to gradually become uninhabitable? And how do we get there?
Well, if they're parallel you won't be able to get there as there is no point of intersection.
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Old 09-24-2017, 02:39 PM
 
4,948 posts, read 7,701,529 times
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Originally Posted by Mike555 View Post
Whether or not String theory turns out to be correct, it is at the moment the only game in town in the effort to come up with a workable TOE. Since it's not possible to directly test the theory, physicists have to be satisfied with indirect methods. According to Greene, with current technology it would take a collider the size of our galaxy to see a string. If you were to compare the size of a string to the size of an atom, if you expanded the atom to the size of the observable universe a string would be about the size of a tree. So, very small.

On the other hand, in M-theory which builds on string theory and requires an additional spatial dimension beyond those required in string theory, a particularly energetic string could expand into a membrane or 'brane' the size of our universe which is expanding. Each universe in the multiverse would be on it's own brane. Did two branes come into contact and create the brane of which our universe is part of? Was the 'big bang' the result of the point of contact between those two branes? Or, in keeping with the topic of this thread, did another brane come into contact with our brane/universe and result in a bruise which manifested as a cold spot?

Well, it's a fascinating idea.
Branes (or Membranes) existing in a higher dimensional hyperspace (Bulk), that collide or come into contact with each other (Ekpyrotic Model) is a possibility, but somehow it just doesn't seem fully convincing. I'd be more inclined to think that bubble universes in a higher dimensional infinite hyperspace might be more likely than branes.

Fluctuations of energetic fields (hyperspace) could cause Big Bangs to happen resulting in the formation of new universes coming into existence. Contact between such "bubbles" could simply brush by in passing leaving a "bruise". Such a "bump" would likely manifest itself as a disturbance in our Universe, with clusters of radiation and matter being pushed away forming ripples with an "empty" space in the center of the disturbance.

On the other hand, if colliding universes made a direct collision, it might not be all that different than colliding galaxies that result in a merging of two galaxies, ultimately creating a much larger galaxy. In this case, a much larger "bubble" universe.

It's also fair to guess that in the initial inflation following the Big Bang, density would be extremely smooth. As the expansion continued, density could become sort of fragmented, or less dense in some spots and more dense in other spots. Just looking at the Cosmic Microwave Radiation background, it looks less smooth after the passage of nearly 13.8 billion years of expansion. As I understand it, these variations in the CMB suggest looking at the transition between the epochs of when radiant light and temperature differences began to appear. Farther back you wouldn't see anything because the "universe" was too dense for photons to move around. It was opaque. Photons began moving more freely after the expansion became large enough.
https://apod.nasa.gov/apod/ap110321.html

I think the Cold Spot is more likely just a large anomaly in the CMB. Regardless, concepts of a multiverse or parallel universes, while very interesting, are also very controversial. The bottom line is that we don't really know if there are any other universe-sized cosmogony structures or not.
https://phys.org/news/2014-03-cosmic...ackground.html
Competing claims over cause of cosmic cold spot - physicsworld.com
https://www.scientificamerican.com/a...llel-universe/
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Old 10-01-2017, 07:24 PM
 
20,143 posts, read 15,467,513 times
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Originally Posted by NightBazaar View Post
Branes (or Membranes) existing in a higher dimensional hyperspace (Bulk), that collide or come into contact with each other (Ekpyrotic Model) is a possibility, but somehow it just doesn't seem fully convincing. I'd be more inclined to think that bubble universes in a higher dimensional infinite hyperspace might be more likely than branes.

Fluctuations of energetic fields (hyperspace) could cause Big Bangs to happen resulting in the formation of new universes coming into existence. Contact between such "bubbles" could simply brush by in passing leaving a "bruise". Such a "bump" would likely manifest itself as a disturbance in our Universe, with clusters of radiation and matter being pushed away forming ripples with an "empty" space in the center of the disturbance.

On the other hand, if colliding universes made a direct collision, it might not be all that different than colliding galaxies that result in a merging of two galaxies, ultimately creating a much larger galaxy. In this case, a much larger "bubble" universe.

It's also fair to guess that in the initial inflation following the Big Bang, density would be extremely smooth. As the expansion continued, density could become sort of fragmented, or less dense in some spots and more dense in other spots. Just looking at the Cosmic Microwave Radiation background, it looks less smooth after the passage of nearly 13.8 billion years of expansion. As I understand it, these variations in the CMB suggest looking at the transition between the epochs of when radiant light and temperature differences began to appear. Farther back you wouldn't see anything because the "universe" was too dense for photons to move around. It was opaque. Photons began moving more freely after the expansion became large enough.
https://apod.nasa.gov/apod/ap110321.html

I think the Cold Spot is more likely just a large anomaly in the CMB. Regardless, concepts of a multiverse or parallel universes, while very interesting, are also very controversial. The bottom line is that we don't really know if there are any other universe-sized cosmogony structures or not.
https://phys.org/news/2014-03-cosmic...ackground.html
Competing claims over cause of cosmic cold spot - physicsworld.com
https://www.scientificamerican.com/a...llel-universe/
I agree that the bubble or pocket Universe/Multiverse scenario which is predicted by inflationary theory seems more likely than the braneworld Multiverse scenario. There are actually a number of different Multiverse concepts predicted by various theories. Some more controversial than others. Of course the possibility that any of the models may exist doesn't mean that they do exist. But many physicists are taking the idea seriously while others hate the idea.

The cold-spot anomaly in the CMB is curious. The temperature variations from blue to red on the CMB map are in the micro kelvins between 2.72500 and 2.72502 k. But the cold spot is about 0.15 micro kelvin cooler than the average surroundings. The chances of the anomaly, which is huge in expanse, of arising by chance are estimated at a 1 in 50 chance. The supervoid hypothesis in which the cold spot is caused by a lack of distribution of galaxies seems to have been ruled out. However, the hypothesis that the anomaly was caused by a collision with another bubble Universe is still considered a fringe idea and is instead just a statistical fluke.

Here is a good video on the subject for any readers that may be interested.


https://www.youtube.com/watch?v=lrS0rxX-UhA
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Old 10-01-2017, 10:14 PM
 
4,948 posts, read 7,701,529 times
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Originally Posted by Mike555 View Post
I agree that the bubble or pocket Universe/Multiverse scenario which is predicted by inflationary theory seems more likely than the braneworld Multiverse scenario. There are actually a number of different Multiverse concepts predicted by various theories. Some more controversial than others. Of course the possibility that any of the models may exist doesn't mean that they do exist. But many physicists are taking the idea seriously while others hate the idea.

The cold-spot anomaly in the CMB is curious. The temperature variations from blue to red on the CMB map are in the micro kelvins between 2.72500 and 2.72502 k. But the cold spot is about 0.15 micro kelvin cooler than the average surroundings. The chances of the anomaly, which is huge in expanse, of arising by chance are estimated at a 1 in 50 chance. The supervoid hypothesis in which the cold spot is caused by a lack of distribution of galaxies seems to have been ruled out. However, the hypothesis that the anomaly was caused by a collision with another bubble Universe is still considered a fringe idea and is instead just a statistical fluke.

Here is a good video on the subject for any readers that may be interested.
Thanks for the video. I've seen a fair number of Matt O'Dowd's presentations, and usually find them interesting as food for thought. I like his somewhat casual style that tries to bring complex subjects down to be more easily understood by people without getting too bogged down by complex language. I also find some of the comments pretty hilarious to read such as, "When I microwave anything, there is ALWAYS a cold spot." I can relate to that.

Yes, there are a LOT of multiverse concepts as I alluded to in the OP. At the moment, and perhaps for a long time to come, we don't really know all the mysteries of the Universe. But it's great to have curious minds trying to unravel some of the big questions. Inflation of space was replaced by the expansion which apparently began to gradually slow down. But then about 4 billion years ago, the expansion of space began to speed up. That almost sounds counter-intuitive. Enter the concept of Dark Energy as the suspect overtaking Gravity. Between both Inflation and the Accelerated Expansion of space, it seems to me that statistical quirks or flukes in the quantum fluctuations in the CMB could very well show up with something we see as the "Cold Spot", greatly enlarged over passage of billions of years. It would seem reasonable that at least one oddball fluke would be likely to show up. But I agree with your point that while models may exist, that doesn't necessarily mean any are true. If nothing else, it gets people talking. Nothing like a sensational topic to grab attention.

If the Cold Spot is not a supervoid, then what is it? That's the mystery. How much colder is the Cold Spot compared to other cold spots (color-coded blue) in the CMB? I would think if there was a bump or collision between our universe and another one, it would seem that the Cold Spot should show rings surrounding the site. That reminds me of the "rings" Roger Penrose claimed to see in the CMB, but by thunder and for the life of me, I've never been able to see what or where he was talking about.
https://www.space.com/25126-big-bang-theory.html

https://www.space.com/10522-controve...-universe.html

https://francisworldinsideout.wordpr...es-on-the-sky/
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Old 10-02-2017, 02:08 PM
 
20,143 posts, read 15,467,513 times
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Originally Posted by NightBazaar View Post
Thanks for the video. I've seen a fair number of Matt O'Dowd's presentations, and usually find them interesting as food for thought. I like his somewhat casual style that tries to bring complex subjects down to be more easily understood by people without getting too bogged down by complex language. I also find some of the comments pretty hilarious to read such as, "When I microwave anything, there is ALWAYS a cold spot." I can relate to that.

Yes, there are a LOT of multiverse concepts as I alluded to in the OP. At the moment, and perhaps for a long time to come, we don't really know all the mysteries of the Universe. But it's great to have curious minds trying to unravel some of the big questions. Inflation of space was replaced by the expansion which apparently began to gradually slow down. But then about 4 billion years ago, the expansion of space began to speed up. That almost sounds counter-intuitive. Enter the concept of Dark Energy as the suspect overtaking Gravity. Between both Inflation and the Accelerated Expansion of space, it seems to me that statistical quirks or flukes in the quantum fluctuations in the CMB could very well show up with something we see as the "Cold Spot", greatly enlarged over passage of billions of years. It would seem reasonable that at least one oddball fluke would be likely to show up. But I agree with your point that while models may exist, that doesn't necessarily mean any are true. If nothing else, it gets people talking. Nothing like a sensational topic to grab attention.

If the Cold Spot is not a supervoid, then what is it? That's the mystery. How much colder is the Cold Spot compared to other cold spots (color-coded blue) in the CMB? I would think if there was a bump or collision between our universe and another one, it would seem that the Cold Spot should show rings surrounding the site. That reminds me of the "rings" Roger Penrose claimed to see in the CMB, but by thunder and for the life of me, I've never been able to see what or where he was talking about.
https://www.space.com/25126-big-bang-theory.html

https://www.space.com/10522-controve...-universe.html

https://francisworldinsideout.wordpr...es-on-the-sky/
This paper Pre-BigBang Cosmology? written by Amir Hajian describes the procedure used by Penrose and Gurzadyan to find the concentric circles in the CMB map which were independently confirmed by other researchers who did not agree with the conclusion of Penrose that they were evidence of pre-big bang black hole encounters. The circles, while there, are not said to be anomalous by the independent studies in contrast with Penrose's claim that they are anomalous.
''The above authors used data from the Wilkinson Microwave Anisotropy Probe (WMAP) to look for concentric low variance circles in the CMB sky. They examined 10885 choices of center in the CMB sky after masking the galactic plane from the maps. For each choice of center, they computed the variance of the temperature fluctuations in successively larger concentric rings of 0.5 degree, at increasing radii. They found three groups of rings of low variance at various radii. They claim that the low variance circles they find are statistically very significant (6 sigma detections).''

Pre-BigBang Cosmology?
Actually, this is the first that I've heard of this and of Penrose's conformal cyclic cosmology model. I'll have to listen to some of his lectures on YouTube to better understand his views.

One of the articles you posted, I can't find now in which one it was, led me to this article in physicsworld in which Tom Shanks at Durham University in the UK states that a bump between our Universe and another Universe would produce an identifiable polarization signal in the cold spot which would make a collision with another Universe the most plausible explanation for the cold spot. But the data from Planck hasn't yet been completely analysed. So I'm curious as to how that will turn out.
''Among them is the idea that the cold spot is where our universe is bumping into another universe created by eternal inflation. This would produce an identifiable polarization signal in the cold spot. Data from the European Space Agency's Planck spacecraft that might prove or disprove this have yet to be fully analysed. If the polarization signal is there, however, then a collision with another universe would "become the most plausible explanation, believe it or not”, according to Shanks.''

Competing claims over cause of cosmic cold spot - physicsworld.com
Yeah, I like the way Matt O'Dowd makes things understandable as well. Simpler is better.

Last edited by Mike555; 10-02-2017 at 02:30 PM..
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