Parallel Universes?

[Anjruu]

What are parallel universes? Do we think they exist, or is there more proof? What is the current theory on how they form? Do we think they exist at all?

[ed84c]

No some wackos (sorry, string theorists), believe that the "extra" mass (i.e. mass we cant account for) is gravity leaking in from other universii in this infinitley big multiverse.

[Anjruu]

Why are string theorists wackos?

[ed84c]

because rather than trying to find a link between QED and GR they start inventing strings and mulitverses which are neither.

 

The whole idea sounds riduculus to me. I suspect the link is much more conceptual, like other theories, this is like a childs imganination.

[eon_rider]

The below extract is the end part of a great interview between Brian Greene and NOVA. It tells me he is intelligent, humble, cool, honest, and a million times smarter than me. LOL. (but that's not too hard )

 

Whether I, as a lay person, agree with strings or not, I wish him all the best with his research. And the cat understanding relativity analogy is great. IMO.

 

Brian Greene

Books include: The Elegant Universe,

Professor of Physics and Mathematics at Columbia.

Educated at Harvard and Oxford

 

Excerpt from interview with NOVA:

 

NOVA: Do you think there are limits to how much we can know about the universe?

 

Greene: I don't know. I'd like to think that there aren't, but I suspect that's a little optimistic. An analogy that's used in the NOVA program that I'm quite fond of is: We are certainly aware of intelligent beings on this planet whose capacity to understand the deep laws of the universe is limited. No matter how hard you try to teach your cat general relativity, you're going to fail. There we have an example of an intelligent living being that will never know this kind of truth about the way the world is put together. Why in the world should we be any different? We can certainly go further than cats, but why should it be that our brains are somehow so suited to the universe that our brains will be able to understand the deepest workings?

 

NOVA: Well, for example, most people have trouble envisioning a fourth spatial dimension. Can you?

 

Greene: No. I cannot envision anything beyond three dimensions. What I can do is I can make use of mathematics that describe those extra dimensions, and then I can try to translate what the mathematics tells me into lower dimensional analogies that help me gain a picture of what the math has told me. But the picture is certainly inadequate to the task of fully describing what's going on, because it's in lower dimensions, and in higher dimensions, things are definitely different.

 

To tell you the truth, I've never met anybody who can envision more than three dimensions. There are some who claim they can, and maybe they can; it's hard to say. But it's very hard, when your brain is involved in a world that appears to have three dimensions and is well suited to envisioning that world, to go beyond that and imagine more dimensions.

[darkkazier]

^^ i agree with him, and i think string theory will be the next big revolution in physics once it is all sorted out and proven. The ESA will luanch two satallites called LISA and LAGO (i believe that's it correct me if i'm wrong) which will detect gravity waves, and as i understand it string theory predicts a certain frequency and i guess if the two match up then we can assume that string theory is closer to being right.

[danny8522003]

There is also a theory about parallel universes being created whenever a "decision" is made. For example, the Universe before i wrote this post split into two. One Universe contains me writing this post while the other has me deciding not to write this post. Of course, on a quantum level there are infinite number of decisions being made and would therefore create an infinite number of parallel universes.

[darkkazier]

There is also a theory about parallel universes being created whenever a "decision" is made. For example, the Universe before i wrote this post split into two. One Universe contains me writing this post while the other has me deciding not to write this post. Of course, on a quantum level there are infinite number of decisions being made and would therefore create an infinite number of parallel universes.

 

 

It's certainly good to know their's a version of me out their that is the smartest man in the world

[gisburnuk]

I read a article in June 2005 issue of 'scientific american' a month ago about the possibilities of other universes that possess different constants of nature, ie the fine structure constant quantity 1/137 may be different in another universe. Physicists are currently looking for any evidence in the change of the fine structure since the early cosmic evolution.They intend to do this by observing the spectra lines from the light of a distant qauser and comparing it to laboratry data of other specta lines.

[elfstone]

I think the biggest hope for proving string theory is finding supersymmetry particles at a new accelator. It'd be a shame for a lot of people should it get disproved, there's been lots of work for years on it.

[DV8 2XL]

In his article, published in the May 2003 edition of Scientific American, Tegmark explains that scientists are currently discussing four distinct kinds of parallel universes. He refers to the Level I multiverse as “the least controversial type.” As I understand it, this level is based on the idea that space is infinite even though only a small portion of it is currently visible to us. Even though the visible universe grows by one light year each year, we will never be able to come even close to seeing it in its entirety since it is without end. Because it is so vast, some physicists now speculate there are not only universes just like ours out there, but, as Tegmark explains, they are themselves as endless as space; “There are an infinite number of other inhabited planets, including not just one but infinitely many that that have people with the same appearance, name and memories as you, who play out every possible permutation of your life choices.”4 Assuming the uniform distribution of matter indicative of our universe is typical, cosmologists go so far as to predict your closest doppelganger is 10 to the 1028 meters away, and at 10 to the 1092 meters away there exists a solar system identical to ours, and at 10 to the 10118 meters away is an entire universe just like ours.

 

The Level II multiverse is considerably different than the Level I. In this model space is thought of as a mostly endless batch of rising dough containing bubbles in which a variety of universes exist. Because the dough continues to rise these bubbles grow farther and farther apart from each other so that it is impossible for us to ever see or visit them, even if, as Tegmark calculates, “you traveled at the speed of light forever.” What is interesting about Level II universes is the speculation that many, if not most, of them may operate under different physical laws than ours does. Some physicists theorize that our universe may have initially had nine dimensions that all functioned in symmetrical proportions. As the universe developed, however, only three of these dimensions participated in the cosmic expansion, which became our visible universe. The other six dimensions remain unseen.

 

The Level III multiverse also stands out from both the Level I and the Level II. In this multiverse, scientists speculate our universe is constantly branching into multiple other universes in which every possible outcome occurs. If you role a die, for example, and get a one, there are also at least five other universes in which you rolled a two, three, four, five and six. The difference between Level I and Level III multiverses is that in Level I your doubles simply live elsewhere in three-dimensional space. But in the Level III multiverse they live in another quantum reality altogether.

 

The Level IV multiverse may at first seem rather boring as compared to these others. It is the notion that every mathematical structure “corresponds to a parallel universe.” Tegmark himself refers to this as a “radical Platonism” that asserts these mathematical structures are physically real, though they exist outside of time and space. Although, for many of us, it might not seem like it would be much fun living in one of these mathematical universes, this may be just the sort of universe we need to explore from time to time if we’re going to get the bird’s eye view of reality. Many philosophers have speculated that truth is subjective, which is to say that for the frog on the lily-pad it doesn’t really matter that the stone has created a ripple effect because the frog can only experience one ripple at a time.

[Daecon]

because rather than trying to find a link between QED and GR they start inventing strings and mulitverses which are neither.

 

The whole idea sounds riduculus to me. I suspect the link is much more conceptual' date=' like other theories, this is like a childs imganination.[/quote']

 

What would you suppose to theorise then?

 

To me, String theory seems to be a good way or reconciling the two extremes. Personally I think it could have a little bit of "tweaking" as I believe the notion of a gravity energy/particle is misguided.

 

But I think String theory is on the right track.

[timo]

I think the biggest hope for proving string theory is finding supersymmetry particles at a new accelator.

What do you think would be the implications for string theory if a supersymmetric theory is proven?

[Anjruu]

"One Universe contains me writing this post while the other has me deciding not to write this post. Of course, on a quantum level there are infinite number of decisions being made and would therefore create an infinite number of parallel universes."

 

No, I think that that is impossible. As one author put it "What comes before determines what comes after." Period. "Free Will" is just an illusion, because all of your experiences and genetic makeup cause you to write that post. You posted that post. Why? Because you knew that from reading an article. Why? Because you are interested in science. Why? Because your parents brought you up that way, or at least circumstances led you there.

 

If you knew everything, down to the quantum level, you could figure out how the universe will evolve. If you KNEW me, to the core, you could tell what I am going to do next. Of course, it is impossible to KNOW that at that level, but this cause-and-effect theory sort of rules out this doppelganger notion. I came up with this on my own, so its probably wrong, but I hope I at least explained it well...

 

"If you role a die, for example, and get a one, there are also at least five other universes in which you rolled a two, three, four, five and six."

 

See, I also disagree with that. Because when you role a die, you role it in a certain way. The way the dice bounces on the table, how much barometric pressure there is, how humid it is, all cause the die to land on a certain number. Since we cannot calculate this, there is the illusion of luck, but in reality, there isn't any such thing.

 

This means, in my view at least, that from the big bang there was no other course. The way the big bang happened, all has lead inextricably to this point, which will lead to another point, on and on, until the very end of the universe. Since what comes before determines what comes after, period, free will and luck are illusions, and rule out parallel universes of type III, and what Dany said.

[Severian]

What do you think would be the implications for string theory if a supersymmetric theory is proven?

 

Well, string theories need supersymmetry to be able to describe fermions. In fact the 'super' in 'superstrings' is the same 'super' as in 'supersymmetry'. So if supersymmetry were to be found, string theory would get an immense boost in credibility.

 

On the other hand, if supersymmetry is not found at the LHC it doesn't mean that string theory is wrong. The LHC is only probing quite low energies, so it can only say that supersymmetry doesn't exist at low energies. But it could still exist at high energies where string theory is valid.

[elfstone]

This means' date=' in my view at least, that from the big bang there was no other course. The way the big bang happened, all has lead inextricably to this point, which will lead to another point, on and on, until the very end of the universe. Since what comes before determines what comes after, period, free will and luck are illusions, and rule out parallel universes of type III, and what Dany said.[/quote']

 

Hasn't this view been outruled by quantum mechanics? The absolute newtonian determinism has been replaced with the uncertainty of QM. I think that notions like free will and luck are still safe in this context.

[Severian]

Hasn't this view been outruled by quantum mechanics? The absolute newtonian determinism has been replaced with the uncertainty of QM. I think that notions like free will and luck are still safe in this context.

 

No - you still can't have free-will, since the quantum 'decisions' which are made are by definition completely random. The probability that you perform an action can still be calculated exactly, so your 'decisions' can be predicted in a statistical sense. If you were able to influence this random choice in any way you would be in contradiction of physical law (since it would no longer be truely random).

 

I disagree with Anjruu though - the random numbers are not picked in advance - they are chosen only when a quantum collapse occurs, so this physical outcome was not fixed at the start (although one could have predicted that this outcome would happen x% of the time).

[Daecon]

I almost totally agree with what Anjruu said, as I've believed exactly the same thing myself for years, however you still to take into account the randomness that appears on the quantumn level, some of which could lead to a "Butterfly Effect" chain reaction leading to other events.

 

That's about as "random" as the Universe could ever get. But if you knew everything - every outcome as it happened, you could extrapolate infinitely.

[Daecon]

An important question regarding determinism: Is 'inspiration' a random occurence, or something that could be predicted?

[Royston]

No - you still can't have free-will' date=' since the quantum 'decisions' which are made are by definition completely random. The probability that you perform an action can still be calculated exactly, so your 'decisions' can be predicted in a statistical sense. If you were able to influence this random choice in any way you would be in contradiction of physical law (since it would no longer be truely random).

[/quote']

 

In short - we are 'the sum of our parts'.

[JPQuiceno]

The Matrix! Infinite parrallel universes!

[crAckZ]

first, i dont post alot, i just like to read. i havent gone to college so please dont bash to hard

 

i do think this is an excellent idea. i always imagined a giant sphere filled with tubes. each tube is a verion of what could be. since matter is neither created or destroyed there can only be a finite number of tubes and versions. each choice you make, the opposite is being made in another tube.

 

to add to this, what if the walls of each tube was actually C . if by jumping to C+.0000001 would this allow you to start crossing through different tubes?

 

i understand you cant accel to C but maybe a quick instant jump. slowing down would be a problem also but this is all in my little mind.

[NeoPhysics]

This means, in my view at least, that from the big bang there was no other course. The way the big bang happened, all has lead inextricably to this point, which will lead to another point, on and on, until the very end of the universe. Since what comes before determines what comes after, period, free will and luck are illusions, and rule out parallel universes of type III, and what Dany said.

 

You say that what happened before tells what will happen next. Let me suppose I agree with you for a second. Now let us go all the way back to the Big Bang. If i knew everything that happened since then, if I knew everything then I would be able to tell what is going to happen next. Now, if that is true, if everything happens because of a previous event, and if the Big Bang is the "beginning" of everything, then how could the Big Bang happen if there was nothing previous to cause it?

 

For if there was nothing to determine how the Big Bang happened then is it not true that it is safe to say that the Big Bang itself could have happened in an infinite number of ways? And could not each of these possible ways have originated a parallel universe in which every difference in how the Big Bang happened caused a different universe to be created? And that if it is so that is it not possible to say that "determinism" is a paradox since it would, as i just said, bring to the conclusion that how the Bing Bang happened could not have been determined beforehand?

 

Unless of course if we were to conceive the idea that there was something before the Big Bang that would have determined how it happened, but then there would have to be something before that, and then before that one, and it would go on infinetly, so that the only way that determinism could exist in our universe is if indeed our universe had always been here and never had a "beginning"

 

Well, this is only my idea of why determinism cannot be absolute, but of course, I could be wrong in this universe

[CanadaAotS]

You say that what happened before tells what will happen next. Let me suppose I agree with you for a second. Now let us go all the way back to the Big Bang. If i knew everything that happened since then' date=' if I knew everything then I would be able to tell what is going to happen next. Now, if that is true, if everything happens because of a previous event, and if the Big Bang is the "beginning" of everything, then how could the Big Bang happen if there was nothing previous to cause it?

 

For if there was nothing to determine how the Big Bang happened then is it not true that it is safe to say that the Big Bang itself could have happened in an infinite number of ways? And could not each of these possible ways have originated a parallel universe in which every difference in how the Big Bang happened caused a different universe to be created? And that if it is so that is it not possible to say that "determinism" is a paradox since it would, as i just said, bring to the conclusion that how the Bing Bang happened could not have been determined beforehand?

 

Unless of course if we were to conceive the idea that there was something before the Big Bang that would have determined how it happened, but then there would have to be something before that, and then before that one, and it would go on infinetly, so that the only way that determinism could exist in our universe is if indeed our universe had always been here and never had a "beginning"

 

Well, this is only my idea of why determinism cannot be absolute, but of course, I could be wrong in this universe [/quote']

 

Well, one theory on how the universe started, was that before the big bang was a completely empty vacuum, and the big bang was just a random quantum flucuation resulting in an expanding mass... So, the determinism could work, the only random thing would be the very beginning

[NeoPhysics]

Regardless of where the randomess is at, from that point on there is an infinite number of possibilities so that unless there is no beginning there cannot be determinism.