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Old 08-06-2011, 06:23 PM
 
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Quote:
Originally Posted by Brian.Pearson View Post
LOL

BTW, I saw an article two or three days old saying:

Data from the Planck telescope should resolve the question once and for all

I don't know how long that is in people years. Might be interesting to see this resolved. It may not be resolved in a way that people think, who knows?
I saw that article as well. According to the article, "data from Planck cannot be discussed publicly before January, 2013." I'd say there's a lot of data to sift through, and a confirmation by peers would be needed to confirm or reject the findings of the data. Up to now, the only information is speculation that it's possible it might be evidence of another universe, but it's uncertain if that's what it is or not. It's possible it could be something completely different, such as a strange anomaly.

I think Dr. Hiranya Peiris makes a good point regarding 'other bubble universes'.
Quote:
Dr Peiris said that even if these bubble universes were confirmed, we could never learn anything further about them.

"It would be wonderful to be able to go outside our bubble, but it's not going to be possible," she explained.
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Old 08-06-2011, 08:04 PM
 
Location: Texas
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I was just now thinking about how things pop into and out of existence, including universes.

Nice knowing you, ahead of time... :P
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Old 08-06-2011, 08:15 PM
 
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Quote:
Originally Posted by Brian.Pearson View Post
I was just now thinking about how things pop into and out of existence, including universes.

Nice knowing you, ahead of time... :P
It's all just specula....... *POP*
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Old 02-28-2012, 06:46 AM
 
Location: Kent, Ohio
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So I wonder exactly what happens in the region of contact? Especially if the laws of physics are different in the two universes. Sounds like a good set-up for a sci-fi story: Living in a world where two universes collide.
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Old 02-28-2012, 09:24 AM
 
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It has been done, probably dozens of times.
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Old 02-29-2012, 09:34 AM
 
Location: Texas
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Quote:
Originally Posted by Gaylenwoof View Post
So I wonder exactly what happens in the region of contact? Especially if the laws of physics are different in the two universes. Sounds like a good set-up for a sci-fi story: Living in a world where two universes collide.
Maybe the physics are the same. Maybe they are all put together with the same building blocks, because they are the only way they can be.
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Old 03-01-2012, 06:27 AM
 
Location: Kent, Ohio
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Originally Posted by harry chickpea View Post
It has been done, probably dozens of times.
I suspect you're right, but I wonder what has been done specifically in light of the actual theories discussed in the article? I'd like to know the names/authors of some of these stories, if they exist.
If two universes with different laws of physics (based on different fundamental constants, as described in the article) were to collide in such as way that astronomers can detect physical evidence of the contact regions...well, are the physical consequences within this contact region even imaginable? Just curious.
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Old 03-01-2012, 11:47 AM
 
Location: Texas
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Quote:
Originally Posted by Gaylenwoof View Post
I suspect you're right, but I wonder what has been done specifically in light of the actual theories discussed in the article? I'd like to know the names/authors of some of these stories, if they exist.
If two universes with different laws of physics (based on different fundamental constants, as described in the article) were to collide in such as way that astronomers can detect physical evidence of the contact regions...well, are the physical consequences within this contact region even imaginable? Just curious.
NightBazaar gave a link showing possible places where there could be "contact" between our universe and others.
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Old 03-01-2012, 12:27 PM
 
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Quote:
Originally Posted by Gaylenwoof View Post
I suspect you're right, but I wonder what has been done specifically in light of the actual theories discussed in the article? I'd like to know the names/authors of some of these stories, if they exist.
A couple of co-authors mentioned in the article include Dr Hiranya Peiris and Dr Daniel Mortlock. Another co-author is Stephen Feeney, a PhD student at UCL, who created the computer algorithm to search for the tell-tale signatures of collisions between "bubble universes". Two papers were published in Physical Review Letters and Physical Review D.


Quote:
If two universes with different laws of physics (based on different fundamental constants, as described in the article) were to collide in such as way that astronomers can detect physical evidence of the contact regions...well, are the physical consequences within this contact region even imaginable? Just curious.
At the present time since we don't know if there are indeed other universes other than the one we live in, we can only guess about other universes in a multiverse scenario. A good part of it depends on why the Big Bang happened and why the universe exists at all. Again, we don't really know. With regard to the article which is the subject of the thread, one thought is that such collisions took place when the universe was very young, most likely during the initial inflation well before the first stars were formed.

With regard to what would happen if two universes with different constants and physics were to collide is an interesting question. The short answer is that we don't know. If the topic of the OP article is correct, then a collision would leave 'bruises' in the CMB. There's no merger. Since the article suggests such an event happened early on during the period of rapid inflation, that it might not happen after there's more development and complex structure form and settle down during the slower rate of the expansion of space which is currently observed.

It might be possible for two dissimilar universes to merge though. It depends of whether or not the rate of expansion generates a kind of 'barrier'. It also depends on just how crowded together universes are in a multiverse envronment. It also depends on whether universes are free floating and in motion, such as galaxies and galactic clusters in motion in the universe. If universes are spread apart, then collisions would be less likely.

If there's only space and no boundries of a universe, then collisions could be somewhat similar to collisions between galaxies which result on mergers resultng in a larger galaxy combining the two. All we have to compare with is based on what we know about our universe. If the constants and fundamental forces in our universe had been even slightly different, there are a few views of what could have happened based on computer simulations. It could've been that no stars, no matter, would have formed, just empty space. Another possibility is that the universe could have failed to grow at all almost immediately collapsing following the Big Bang. As it turned out, the constants were just right to produce the universe that we see today. It's thought that Gravity was perhaps the first force to emerge following the Big Bang, but was overtaken by the emergence of the other fundamental forces, thus causing Gravity to be considered the weakest force at smaller or local scales, which allowed space to continue expanding. At larger scales, Gravity plays a very important part in shaping structures in the universe.

A merger between two universes with different physics could result in a very different kind of universe, one in which we might not be able to exist in at all. However, it's also possible that if our universe happens to be the dominate one, then the physics from the other universe might become compressed, in effect causing no significant changes to the overall structure of our universe. I think it would depend on which universe has the greatest overall strength.

Max Tegmark developed a possible hierarchy of universes in a multiverse scenario.
The Universes of Max Tegmark
http://arxiv.org/pdf/0905.1283.pdf

I'd still stress the point that we don't know what would happen if two universes collided. The might just bounce off of each other. The thing is that the distances of our own universe, not to mention any other universe are so far that we'll likely never know. We have a good idea as to how far the particle horizon is from us, but we don't actually know how far the actual universe stretches out. We can't see that far. I would suggest that matter in the universe is likely to cease to exist, even if a collision took place today, unless something took place that's faster than the initial event of the Big Bang.

Collisions might indeed be taking place, carving out wedges in the universe, but are so far away that we'll never know about them. As the article below suggests, far enough away that we're essentially in a 'safe zone'.

FQXi Community

Larger version
http://www.fqxi.org/data/articles/Ga...h_Vilenkin.pdf
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Old 03-08-2012, 07:17 AM
 
Location: Matthews, NC
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Sliders.
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