Oscillating Universe........

Originally posted by Bardock42
What's up with everyon loving Occam's Razor lately...isn't one of the Theories that what we seem to perceive as "time" was only created with the Universe?

Occam's principle is that the simpler something is, the less opportunity there is for error. It appeals to common sense.

"Time" is generally interpreted as meaning that dimension in which things familiar to us occur. Lately, though, as consideration of events/entites outside our particular universe take on more importance (especially with unification theories), the defintion/concept of time has been expanded to give some meaning to events outside of/prior to our universe. It's kinda like Wheeler's concept of superspace but applied to time.

Originally posted by Mindship
Occam's principle is that the simpler something is, the less opportunity there is for error. It appeals to common sense.

"Time" is generally interpreted as meaning that dimension in which things familiar to us occur. Lately, though, as consideration of events/entites outside our particular universe take on more importance (especially with unification theories), the defintion/concept of time has been expanded to give some meaning to events outside of/prior to our universe. It's kinda like Wheeler's concept of superspace but applied to time.

Maybe but it is in no way infallible.

Could you explain how you define this term time?

Originally posted by Bardock42
Maybe but it is in no way infallible.

Could you explain how you define this term time?

The entire point is that Impossible and Improbable are TIME-dependent.
Let me roll a 100-sided dice. The chances that I get, say the number 17 on the first roll, is improbable. If I roll the dice 100 times, the chance becomes probable. Because of TIME.

ED> As far as I can see, there is nothing physically to support an oscillating Universe. I know there are new theories out these days, but I feel they just push the problem with the initial matter/energy-creation backwards in time… Also, the new cyclic Universe theory is based on string-theory (M-theory to be exact), and this theory is not falsifiable nor has it given us any real new knowledge. IF it is proven next year when the LHC opens I’ll shut up 🙂 Until, then, nope…

Great vengeance> The point is not unlimited amount of time. The point is the NON-existence of time before the Big Bang.

Bardock> “Something that is impossible WILL never happen.” Never is a temporal word. It DEPENDS on the existence of time. Time AND space, the four dimensions of our Universe, were created at Big Bang, just as everything else.
TIME is a factor which is needed for CHANGE to take place. You can think of change as ENERGY going from one state to another. There seems to be a smallest time-interval for the smallest kind of change to take place, so maybe time is not continuous but discreet?

Mindship>”consideration of events/entites outside our particular universe” What do you mean by that? Nothing outside our Universe has the least bit of interest to anyone. Either our Universe can interact with “it” and it is therefore part of our Universe, or our Universe can NOT interact with “it”, and we may as well act as if “it” did not exist.

As far as I remember, superspace refers to the Universe at ALL times, no?

Originally posted by The Omega

Bardock> “Something that is impossible WILL never happen.” Never is a temporal word. It DEPENDS on the existence of time. Time AND space, the four dimensions of our Universe, were created at Big Bang, just as everything else.
TIME is a factor which is needed for CHANGE to take place. You can think of change as ENERGY going from one state to another. There seems to be a smallest time-interval for the smallest kind of change to take place, so maybe time is not continuous but discreet?

Wow, this discussion's way out of my league. Fascinating though. Omega, you have schooling in this?

Originally posted by Janus Marius
Wow, this discussion's way out of my league. Fascinating though. Omega, you have schooling in this?

She's our Super-Scientist.

Originally posted by The Omega
1. Mindship>”consideration of events/entites outside our particular universe” What do you mean by that? Nothing outside our Universe has the least bit of interest to anyone. Either our Universe can interact with “it” and it is therefore part of our Universe, or our Universe can NOT interact with “it”, and we may as well act as if “it” did not exist.

2. As far as I remember, superspace refers to the Universe at ALL times, no?

1. "Universe" currently meaning the familiar three dimensions of space and one of time. Thus, for example, the compactified dimensions discussed in string theory, or the branes discussed in M-theory, would be considered "outside" our particular universe.
As you may be aware, one current idea as to the genesis of the Big Bang is that the brane of our universe collided with the brane of another universe, the point of contact being the BB. There is another theory as to why gravity is so weak compared to the other 3 fundamental forces: because, unlike the other 3 forces, gravity is not confined just to our brane. Because it can propagate from one universe to another, it gets filtered down, like light passing through many planes of glass.

2. Superspace, at least as a term, does not seem to have caught on as well as "multiverse" seems to, again in discussing events "outside" our familiar spacetime. Wheeler's initial reference was to the spatial configuration of our universe; but more informally it can also mean the higher space in which our and other universes occur.

Originally posted by Bardock42
Yeah, but still it is saying that impossible is not applicable..not that impossible becomes possible.

“Becomes” is again temporal, Bardock. Define IMPOSSIBLE. Then remove its time dependence.

Originally posted by Janus Marius
Wow, this discussion's way out of my league. Fascinating though. Omega, you have schooling in this?

Have a degree in theoretical high-energy physics and one in communications. 😖mart: So I should be able to MAKE it your league if you’re curious?`

Originally posted by Mindship
1. "Universe" currently meaning the familiar three dimensions of space and one of time. Thus, for example, the compactified dimensions discussed in string theory, or the branes discussed in M-theory, would be considered "outside" our particular universe.
As you may be aware, one current idea as to the genesis of the Big Bang is that the brane of our universe collided with the brane of another universe, the point of contact being the BB. There is another theory as to why gravity is so weak compared to the other 3 fundamental forces: because, unlike the other 3 forces, gravity is not confined just to our brane. Because it can propagate from one universe to another, it gets filtered down, like light passing through many planes of glass.

2. Superspace, at least as a term, does not seem to have caught on as well as "multiverse" seems to, again in discussing events "outside" our familiar spacetime. Wheeler's initial reference was to the spatial configuration of our universe; but more informally it can also mean the higher space in which our and other universes occur.

Maybe we disagree on the word “outside” here. Would it be better to use the word space-time? The compactified extra dimensions (which I, btw, do not subscribe to) are part of our Universe; their interactions are merely considered to be of a somewhat hairy nature.
I also do not subscribe to the oscillating Universe theory. That’s merely attempting to fit the value of Lambda with M-theory. String-theory, at it’s core, is exceedingly un-occam if you like, and postulating oscillating Universes to fit Lambda seems very much like “entties” multiplied beyond necessity.
And if we have no closed time-like curves, that is, time-machines space-time must be 5-dimensional, where he 5th dimension is NOT microscopic actually.
I subscribe more to the idea of space-time not being a fundamental manifold, but some kind maybe of sheaf-space or other “peculiar” space.
Again OTHER Universes make me wince 🙂 What is the falsifiable evidence of other Universes and/or dimensions?

Originally posted by The Omega
Maybe we disagree on the word “outside” here. Would it be better to use the word space-time? The compactified extra dimensions (which I, btw, do not subscribe to) are part of our Universe; their interactions are merely considered to be of a somewhat hairy nature.
I also do not subscribe to the oscillating Universe theory. That’s merely attempting to fit the value of Lambda with M-theory. String-theory, at it’s core, is exceedingly un-occam if you like, and postulating oscillating Universes to fit Lambda seems very much like “entties” multiplied beyond necessity.
And if we have no closed time-like curves, that is, time-machines space-time must be 5-dimensional, where he 5th dimension is NOT microscopic actually.
I subscribe more to the idea of space-time not being a fundamental manifold, but some kind maybe of sheaf-space or other “peculiar” space.
Again OTHER Universes make me wince 🙂 What is the falsifiable evidence of other Universes and/or dimensions?

I do believe we are using "universe" and "outside" differently. I chose the definition I did because, as you alluded to, compactified dimensions are hardly proven or even "universally" 😉 accepted.

As far as I know, there has been no experimental validation of other universes. The physicists' loophole, so far, is that "we don't have the tools yet (ie, the high-energy accelerators) to do the experiments." Mathematically, positing the extra dimensions/universes works wonders with unification theories: the theories are said to be "beautiful" when factors outside our 4D spacetime are added. But "beauty" in a theory does not a reality make.

Personally, I don't buy the oscillating universe idea either, but I am intrigued with quantum cosmology's idea of treating the universe as a quantum particle, complete with its own wave function and an infinite number of probabilities. But again, it's all, at best, educated speculation.

I heard in 2000 that it was popularly supposed that the universe would simply continue expanding forever until everything winds down to background radiation and black holes... ad infinitum.

A universe after this one might very well have to have different fundamental laws which by definition is not conceivable. A pop up book on the cosmos illustrated the Big Crunch theory by showing a new type of universe that was resembled an emerald instead of alot of little galaxies. I wish I knew how the idea of multidimensional space could be fitted into this.

Originally posted by The Omega

Have a degree in theoretical high-energy physics and one in communications. 😖mart: So I should be able to MAKE it your league if you’re curious?`

Ha! Definately curious. I may take time to go over this in a bit- I've been more than a bit busy this week. I could probably make sense of a good deal of this without a simple explanation, though Dictionary.com would reach a record high of hits for that day.

Thank you for the offer though. I do love this kinda stuff, I just haven't had any in-depth classes in years.

Originally posted by Mindship
I do believe we are using "universe" and "outside" differently. I chose the definition I did because, as you alluded to, compactified dimensions are hardly proven or even "universally" 😉 accepted.

At least, among theoretical physicist, it’s finally becoming accepted to question string-theory. The LHC may give us the final answer next year.

Originally posted by Mindship
As far as I know, there has been no experimental validation of other universes. The physicists' loophole, so far, is that "we don't have the tools yet (ie, the high-energy accelerators) to do the experiments." Mathematically, positing the extra dimensions/universes works wonders with unification theories: the theories are said to be "beautiful" when factors outside our 4D spacetime are added. But "beauty" in a theory does not a reality make.

A colleague of mine once pointed out to me, that IF other Universes/spacetimes exited and ours COULD interact with it, then quantum mechanics dictates that it WOULD. We’d see energy/matter appear or disappear without any other explanation than other Universes. And you are absolutely right. String-theory as a mathematical “object” unifies. But the theory is actually a hypothesis because it makes no testable predictions and is therefore not falsifiable. So technically it should be called string-hypothesis.

Originally posted by Mindship
Personally, I don't buy the oscillating universe idea either, but I am intrigued with quantum cosmology's idea of treating the universe as a quantum particle, complete with its own wave function and an infinite number of probabilities. But again, it's all, at best, educated speculation.

I think the problem is, that too many of the great physicist minds have been spend on string-hypothesis. The work on homology and cohomology done in the early 60’s was tossed over the shoulder when QCD triumphed. I believe quantum gravity should be done canonically, but maybe we need to rethink spacetime (again, if there are no closed time-like curves spacetime is 5d), and we do not another kind of logic that can deal with the transistion from quantum-regime to classical.
We'll get there eventually... What we need is another Einstein working at a paten office and revolutionising theoretical physics... 😄

Originally posted by The Omega
... What we need is another Einstein working at a paten office and revolutionising theoretical physics... 😄

You know it's going to happen. One day, someone's going to come along and write an Equation, and it's gonna blow everything away. Even this dark energy business: what a discovery!

What was the term not too long ago: the "End of Physics?"
Not even close.

Originally posted by The Omega

I believe quantum gravity should be done canonically, but maybe we need to rethink spacetime (again, if there are no closed time-like curves spacetime is 5d), and we do not another kind of logic that can deal with the transistion from quantum-regime to classical.

I don´t know too much about topology, in fact I didn´t studied it yet, but I think the problem is that gravity and space-time cannot be viewed as a smooth topological space as it is usually viewed, when taking quantum mechanics in consideration, so maybe we need to find another kind of logic to explain the universe in another different way. i just wonder what it would be, and it would mean if this is really the case.

Originally posted by The Omega
“Becomes” is again temporal, Bardock. Define IMPOSSIBLE. Then remove its time dependence.

Impossible is something that doesn't happen and has no chance of happening.

Mindship> What’s your take on dark energy?
Personally I’m not sure yet. It’s could be some kind of zero-point energy-related thing, OR – which is maybe more likely – an effect of that “new” equation someone still needs to come up with. Someone needs to explain to me why Lambda>0 and why that didn’t begin until – what was that? – 7,5 billion years ago.
Strange and curious – and very exiting, too 🙂

Atlantis001> Bingo! Topology or even more fundamental mathematical spaces. I mean, how do you define SCALE in a topological space? Distances? You can’t. But our Universe is so clearly equipped with a scale, since quantum laws only work at quantum mechanical scales, and not at our macroscopic scales.
So you’d need a logic going “A applies from a certain point” etc.

Bardock> When you say something HAPPENS (or does not) or has a chance of happening you depend on time.
Will you agree with me, that for something improbable to happen, you’d have to wait a long time?

Originally posted by The Omega
Bardock> When you say something HAPPENS (or does not) or has a chance of happening you depend on time.
Will you agree with me, that for something improbable to happen, you’d have to wait a long time?

Certainly. I just mean it is part of the definition of impossible that it just doesn't happen...as soon as it happens it wasn't impossible in the first place. So I think if you look at an endless amount of time you can say that there is nothing impossible....but the impossible doesn't become possible...

Originally posted by The Omega
Mindship> What’s your take on dark energy?
Personally I’m not sure yet. It’s could be some kind of zero-point energy-related thing, OR – which is maybe more likely – an effect of that “new” equation someone still needs to come up with. Someone needs to explain to me why Lambda>0 and why that didn’t begin until – what was that? – 7,5 billion years ago.
Strange and curious – and very exiting, too 🙂

Honestly? I'm not 100% convinced yet that this is a real force. I'm still keeping in mind the ever-so-teeny possibility that this observation may be an effect of our measuring process (basically, I'm just trying to anticipate the next curve ball). That aside...to think that there has been discovered a fifth fundamental force...wow...

Scientists seem to be differentiating between dark energy being some kind of ZPE, or "quintessence," this (as best as I understand it) a kind of cosmic wave/field phenomenon. Sounds like the difference between a quantum interpretation and a relativity one, much like the problem with understanding gravity. If that's the case, we may not be able to even start understanding dark energy until we grasp quantum gravity.

BTW, what're your thoughts on zero point energy? Is there really enough energy in a cup of coffee to boil all the Earth's oceans? Or is it a pipe dream energy source?

Originally posted by Bardock42
Certainly. I just mean it is part of the definition of impossible that it just doesn't happen...as soon as it happens it wasn't impossible in the first place. So I think if you look at an endless amount of time you can say that there is nothing impossible....but the impossible doesn't become possible...

But the point exactly is, that the probability of something happening IS time (and energy) dependent. OUR definition of impossible is time-dependent, meaning that we say something will NEVER ever ever happen. But if you remove TIME from the equation of probabilities and possibilities you’re left with “something will”.

Originally posted by Mindship
Honestly? I'm not 100% convinced yet that this is a real force. I'm still keeping in mind the ever-so-teeny possibility that this observation may be an effect of our measuring process (basically, I'm just trying to anticipate the next curve ball). That aside...to think that there has been discovered a fifth fundamental force...wow...

A wise thing to keep in mind. It may be, that we are really seeing some as of yet unknown gravitational and/or causal effects and the supernova’s may be closer than we think. I’m not sure it’s a fifth force… It seems to act like “anti-gravity”, based on exotic matter like what is needed to open a wormhole mouth. So we ARE dealing with maybe some kind of negative energy-density. I mean, maybe our idea that matter and energy are always greater than or equal to zero is wrong?

Originally posted by Mindship
Scientists seem to be differentiating between dark energy being some kind of ZPE, or "quintessence," this (as best as I understand it) a kind of cosmic wave/field phenomenon. Sounds like the difference between a quantum interpretation and a relativity one, much like the problem with understanding gravity. If that's the case, we may not be able to even start understanding dark energy until we grasp quantum gravity.

I’m not too keen on “quintessence”. It’s too un-occamian, if you like. If ZPE can explain dark energy, why postulate more (like my beef with string-theory)? If we somehow canonically quantized gravity (which I believe is the way on 5d space-time, which may not be the fundamental space, but a “higher space”, perhaps a tangent/phase-space of the underlying quantum-world?) I think we’d maybe see dark energy since both Dirac, Schrödinger and Feynmann are time-reversal equations, if you catch my drift?

Originally posted by Mindship
BTW, what're your thoughts on zero point energy? Is there really enough energy in a cup of coffee to boil all the Earth's oceans? Or is it a pipe dream energy source?

Simply writing that off as “nothing” seems unwise to me. It’s this ZPE that I actually hold responsible for “dark energy” effects. Imagine the PRESSURE in the vacuum stress-energy tensor from ZPE??