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Author Topic: The "stuff" space is made of.  (Read 5799 times)

Offline OmnipotentOne

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The "stuff" space is made of.
« on: 21/08/2004 17:19:10 »
I've been confused on this for a while, like is space totally empty since it is a vacum, or is it composed of something? Is there something flying around up there?

Maybe its made of gravitons??  Or something about monopoles[?]

It's be nice if someone could clear this up![8D]

To see a world in a grain of sand.


 

Offline gsmollin

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Re: The "stuff" space is made of.
« Reply #1 on: 23/08/2004 17:15:05 »
The properties of a vacuum are serious quantum-mechanical physics. In layman's terms, it is composed of vacuum energy and virtual particles. The vacuum energy is another problem for physics, since the value predicted by the standard model seems to be about 12 orders of magnitude too large. The observable vacuum energy is very small, possibly zero. Virtual particles flit in and out of existence, borrowing energy from the vacuum until there is the "margin call" of conservation of energy. This is what allows superposed states to exist in quantum mechanics. If there is a source of real energy nearby, such as a cosmic ray striking the atmosphere, then virtual particles get real and can be detected.

String theory and membrane theory(ies) also attempt to explain the nature of space down to the Planck level. This gets pretty ugly, and many theories of quantum space and quantum gravity are littering the physical theory-space.
 

Offline gsmollin

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Re: The "stuff" space is made of.
« Reply #2 on: 23/08/2004 17:20:27 »
Oh, monopoles. Well, magnetic monopoles are predicted by GUTs, but have never been observed. This problem prompted Alan Guth to invent the inflationary-universe theory. The rapid inflation swept the monopoles out of our region of space. Inflationary theory also solved the horizon problem, the flatness problem, and successfully predicted the distribution of energy in the CBR. Made Alan's career, and he's resting comfortably at MIT, thank you.
 

Offline OmnipotentOne

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Re: The "stuff" space is made of.
« Reply #3 on: 25/08/2004 16:47:04 »
Ohh I think I understand now, kinda.  How exactly do you supercool something? I've read about it before but it boggles my mind.  I assume some streams in cold climates flow when its below freezing but does that mean otehr things "flow" as well?

To see a world in a grain of sand.
 

Offline gsmollin

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Re: The "stuff" space is made of.
« Reply #4 on: 25/08/2004 21:23:04 »
The supercooling was the major problem with inflation. A. Guth likened it the supercooling that can occur with compounds such as water. When the water is supercooled, it exists in a temporary state of less then frozen temperature, but still liquid. When it begins to freeze, the latent heat of fusion is released. This analogy is supposed to explain the sudden release of energy into the inflated universe, creating all the mass and energy we observe today. Guth originally thought bubbles formed at the phase transition, but there were too many defects, like monopoles, to explain. Andre Lindt had a similar explanation, but had the dynamics of the phase transition worked out better, so the bubbles could grow to an enormous size, and sweep away the defects from our region of space. No one has been able to detect an edge of our region, since the theory predicts each bubbles would be orders of magnitude larger that the observable universe.
 

Offline Observer101

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Re: The "stuff" space is made of.
« Reply #5 on: 31/08/2004 16:48:29 »
Current work on this very problem is underway at the Perimeter Institute for Theoritical Physics in Waterloo ONT, Canada By Fotini Markopoulou Kalamara ( newbielink:http://www.sciam.com/article.cfm?articleID=0007E95C-9597-1DC9-AF71809EC588EEDF [nonactive].  There is a slide show with her describing the fundimentals of her early work at:   newbielink:http://cgpg.gravity.psu.edu/online/Html/Seminars/Fall1998/Markopoulou/? [nonactive].  Any questions?  Intresting stuff AND she's a hottie!

Have you ever imagined a world with no hypothetical situations? (- George Carlin)
 

Offline gsmollin

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Re: The "stuff" space is made of.
« Reply #6 on: 31/08/2004 18:25:08 »
Good links. It was interesting to hear about Lee Smolin. I read one of his books, "Three Roads to Quantum Gravity". It was OK, but not great. It is hard to find good physics literature. The books are either too chatty, full of anecdotes, or they are too difficult, for the specialist. I suppose there is a problem getting an intermediate level book past the publisher. They want mass sales.
 

Offline tweener

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Re: The "stuff" space is made of.
« Reply #7 on: 31/08/2004 18:35:52 »
Those are good links!

And I agree that it is hard to find good scientific literature (not just physics) that is not too basic and does not require a closely related PhD to make sense of it.  Oh well.

----
John - The Eternal Pessimist.
 

Offline Observer101

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Re: The "stuff" space is made of.
« Reply #8 on: 31/08/2004 19:27:00 »
quote:
Originally posted by gsmollin

Good links. It was interesting to hear about Lee Smolin. I read one of his books, "Three Roads to Quantum Gravity". It was OK, but not great. It is hard to find good physics literature. The books are either too chatty, full of anecdotes, or they are too difficult, for the specialist. I suppose there is a problem getting an intermediate level book past the publisher. They want mass sales.



Going by your name, gsmollin, I really must ask; are you plugging YOUR book, "Three Roads..."?:D

Have you ever imagined a world with no hypothetical situations? (- George Carlin)
 

Offline gsmollin

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Re: The "stuff" space is made of.
« Reply #9 on: 01/09/2004 19:51:07 »
LOL, Observer 101! Its a coincidence, although I'll bet Smolin and I have similar ancestors. I hope when I critic my own book, I'll be able to say better than "OK, but not great!"
 

Offline OmnipotentOne

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Re: The "stuff" space is made of.
« Reply #10 on: 02/09/2004 05:13:25 »
OHHH i remember reading about her in ummm "faster than the speed of light" wow i got the impression she was old. And yes excellent links!!!

To see a world in a grain of sand.
 

Offline Observer101

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Re: The "stuff" space is made of.
« Reply #11 on: 02/09/2004 05:34:24 »
The speculation that I put forward is somewhat haunting for me.  An article in Scientific American describes what an observer would see when spireling into a black hole.  At the eventhorizon the darkness of the hole would be seen to loom as large as the rest of the universe, proceeding inward the rest of the universe would be seen as a globe that you are in orbit around.  Now, there have been hypothisis put forward by others of other dimentions that are "curled up" in such a way that we dont experience them.  Could the other three dimentions curl up "at the singularity"?  Also, when matter approaches the singularity it would have a velocity near if not at c which, in the direction of travel its length would be extreemly forshortened, so even a    l o n g    stream of matter would be seen as flat by a stationary observer and would pass the point of the singularity in the same abount of time as a single particle.  The energy output of a Quaser is astounding but we are only seeing that which escapes the eventhorizon.  This energy is a result of friction with other infalling material and appears greatest at the eventhorizon, by extention this energy output must increase past the eventhorizon where it too falls in.  This energy is a result of the gravity well which along with the mass represents near unimaginable energy.  I imagine that somehow two of the dimentions get curled up AND because of the velocity, extreemly forshortened.  Could this somehow be the mechinism by which ALL material erupts at a single time?  I know that this is just a restatment of the original question but, I just want to explore this further.  Another question that pops up, receint observations show that the expantion of the universe is accelerating, could it be that from our vantage point, no matter where we look we are seeing the eventhorizon of a black hole?

 "Black holes are where God divided by zero."
- Steven Wright

You checked out those links about LQG and Fotini Markopoulo Kalamari, isn't she a hottie?

Have you ever imagined a world with no hypothetical situations? (- George Carlin)
« Last Edit: 02/09/2004 05:35:19 by Observer101 »
 

Offline Observer101

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Re: The "stuff" space is made of.
« Reply #12 on: 02/09/2004 07:04:20 »
OOPS, posted on the wrong thread, close enough though...

Have you ever imagined a world with no hypothetical situations? (- George Carlin)
 

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Re: The "stuff" space is made of.
« Reply #12 on: 02/09/2004 07:04:20 »

 

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