Why gravity is so weak
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This I found in a forum: "This is an idea from M-theory (an extension of string theory). Standard 10 dimensional string theory is what is called a 'Kaluza-Klein compactification' of a more general 11D theory known as M-theory. Instead of strings, the fundamental components of M-theory are membranes - kind of like two-dimensional strings. To get to the point... our universe of 3+1 dimensions (as we see it) is embedded within a 'brane' - a higher dimensional surface. Three of the four fundamental forces (strong, weak and EM) are constrained within our standard spatial dimensions. However, gravity could fall into a different catagory. The predicted exchange particles of gravitational force are called gravitons. These have never been observed, but if they did exist, they would be massless spin-2 particles. The interesting thing about this is that such a field behaves in exactly the same way as a conventional EM field, when a space-like 5th dimension is introduced. In short, gravitons could propogate outside of our standard 3+1 dimensions - into the brane itself. Such a field would appear to our limited dimensional perception to be much weaker than the other forces. Thus the theory proposes a solution to the puzzling question of why gravity is indeed observed to be so much weaker than all the other forces." jhaga --------------------------------- Every generation laughs at the old fashions, but follows religiously the new. Henry David Thoreau, "Walden", 1854
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Mr.Prakash wrote: just too much physics that my head can handle. yeah, but I hear so much about these "Braneworlds" and trying to learn something about them: " Braneworlds ----------- Pretend you lived on your computer screen and could only move on that two dimensional surface. The computer exists in three space dimensions but you can only move on a two dimensional subspace made by the screen, so the spacetime that you experience would look like three dimensions (two space plus time) rather than four. That's sort of the idea in a braneworld higher dimensional theory. Our observed four dimensional spacetime is like the computer screen, a subspace of some bigger space that we can't see because all matter and forces are constrained to move (mainly) on our subspace, or brane (as in membrane).The total space is called the bulk and the subspace or brane on which we would live is called the brane. " jhaga --------------------------------- Every generation laughs at the old fashions, but follows religiously the new. Henry David Thoreau, "Walden", 1854
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Mr.Prakash wrote: just too much physics that my head can handle. yeah, but I hear so much about these "Braneworlds" and trying to learn something about them: " Braneworlds ----------- Pretend you lived on your computer screen and could only move on that two dimensional surface. The computer exists in three space dimensions but you can only move on a two dimensional subspace made by the screen, so the spacetime that you experience would look like three dimensions (two space plus time) rather than four. That's sort of the idea in a braneworld higher dimensional theory. Our observed four dimensional spacetime is like the computer screen, a subspace of some bigger space that we can't see because all matter and forces are constrained to move (mainly) on our subspace, or brane (as in membrane).The total space is called the bulk and the subspace or brane on which we would live is called the brane. " jhaga --------------------------------- Every generation laughs at the old fashions, but follows religiously the new. Henry David Thoreau, "Walden", 1854
jhaga wrote: That's sort of the idea in a braneworld higher dimensional theory. Our observed four dimensional spacetime is like the computer screen, a subspace of some bigger space that we can't see because all matter and forces are constrained to move (mainly) on our subspace :brain damage: :eek:
MSN Messenger. prakashnadar@msn.com
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This I found in a forum: "This is an idea from M-theory (an extension of string theory). Standard 10 dimensional string theory is what is called a 'Kaluza-Klein compactification' of a more general 11D theory known as M-theory. Instead of strings, the fundamental components of M-theory are membranes - kind of like two-dimensional strings. To get to the point... our universe of 3+1 dimensions (as we see it) is embedded within a 'brane' - a higher dimensional surface. Three of the four fundamental forces (strong, weak and EM) are constrained within our standard spatial dimensions. However, gravity could fall into a different catagory. The predicted exchange particles of gravitational force are called gravitons. These have never been observed, but if they did exist, they would be massless spin-2 particles. The interesting thing about this is that such a field behaves in exactly the same way as a conventional EM field, when a space-like 5th dimension is introduced. In short, gravitons could propogate outside of our standard 3+1 dimensions - into the brane itself. Such a field would appear to our limited dimensional perception to be much weaker than the other forces. Thus the theory proposes a solution to the puzzling question of why gravity is indeed observed to be so much weaker than all the other forces." jhaga --------------------------------- Every generation laughs at the old fashions, but follows religiously the new. Henry David Thoreau, "Walden", 1854
Weak ? OK, so I can jump off a cliff safely ? :rolleyes: The tigress is here :-D
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This I found in a forum: "This is an idea from M-theory (an extension of string theory). Standard 10 dimensional string theory is what is called a 'Kaluza-Klein compactification' of a more general 11D theory known as M-theory. Instead of strings, the fundamental components of M-theory are membranes - kind of like two-dimensional strings. To get to the point... our universe of 3+1 dimensions (as we see it) is embedded within a 'brane' - a higher dimensional surface. Three of the four fundamental forces (strong, weak and EM) are constrained within our standard spatial dimensions. However, gravity could fall into a different catagory. The predicted exchange particles of gravitational force are called gravitons. These have never been observed, but if they did exist, they would be massless spin-2 particles. The interesting thing about this is that such a field behaves in exactly the same way as a conventional EM field, when a space-like 5th dimension is introduced. In short, gravitons could propogate outside of our standard 3+1 dimensions - into the brane itself. Such a field would appear to our limited dimensional perception to be much weaker than the other forces. Thus the theory proposes a solution to the puzzling question of why gravity is indeed observed to be so much weaker than all the other forces." jhaga --------------------------------- Every generation laughs at the old fashions, but follows religiously the new. Henry David Thoreau, "Walden", 1854
Variable Speed of Light theories propose a (to my mind) simpler explanation of the universe. M-theory (never actually christened as membrane theory, AFAIK) is pretty messy. You should look into it for an interesting read (or at least an interesting alternative) cheers, Chris Maunder
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This I found in a forum: "This is an idea from M-theory (an extension of string theory). Standard 10 dimensional string theory is what is called a 'Kaluza-Klein compactification' of a more general 11D theory known as M-theory. Instead of strings, the fundamental components of M-theory are membranes - kind of like two-dimensional strings. To get to the point... our universe of 3+1 dimensions (as we see it) is embedded within a 'brane' - a higher dimensional surface. Three of the four fundamental forces (strong, weak and EM) are constrained within our standard spatial dimensions. However, gravity could fall into a different catagory. The predicted exchange particles of gravitational force are called gravitons. These have never been observed, but if they did exist, they would be massless spin-2 particles. The interesting thing about this is that such a field behaves in exactly the same way as a conventional EM field, when a space-like 5th dimension is introduced. In short, gravitons could propogate outside of our standard 3+1 dimensions - into the brane itself. Such a field would appear to our limited dimensional perception to be much weaker than the other forces. Thus the theory proposes a solution to the puzzling question of why gravity is indeed observed to be so much weaker than all the other forces." jhaga --------------------------------- Every generation laughs at the old fashions, but follows religiously the new. Henry David Thoreau, "Walden", 1854
This is definitely not the thread to try and follow the day after having a migraine. :sigh:
Software Zen:
delete this; -
Weak ? OK, so I can jump off a cliff safely ? :rolleyes: The tigress is here :-D
Trollslayer wrote: I can jump off a cliff safely ? I am not totally sure about this. But if you grow alot of hair and loose some weight it should be quite safe. :rolleyes: jhaga --------------------------------- Every generation laughs at the old fashions, but follows religiously the new. Henry David Thoreau, "Walden", 1854
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Variable Speed of Light theories propose a (to my mind) simpler explanation of the universe. M-theory (never actually christened as membrane theory, AFAIK) is pretty messy. You should look into it for an interesting read (or at least an interesting alternative) cheers, Chris Maunder
I have a small little following of fellow physicists (including myself) that are still playing around with aether physics (ie variable speed of light theories). I too have never been one for all this hype about branes and n dimensional spaces. I think it is far too complicated an idea. I always get mad too when I see the Scientific American articles proclaiming this stuff as the preliminary material for a Theory of everything. Maybe it is just me...then again, I still maintain that there is a simpler alternative to quantum mechanics...:suss: John Theal Physicist at Large Got CAD? http://www.presenter3d.com[^]
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I have a small little following of fellow physicists (including myself) that are still playing around with aether physics (ie variable speed of light theories). I too have never been one for all this hype about branes and n dimensional spaces. I think it is far too complicated an idea. I always get mad too when I see the Scientific American articles proclaiming this stuff as the preliminary material for a Theory of everything. Maybe it is just me...then again, I still maintain that there is a simpler alternative to quantum mechanics...:suss: John Theal Physicist at Large Got CAD? http://www.presenter3d.com[^]
John Theal wrote: I still maintain that there is a simpler alternative to quantum mechanics I suspect you're right, though I gave up keeping current with physics a long time ago. It was while learning physics that I learned about Occam's Razor, and my teachers impressed upon me that, when there are multiple ways to explain an observation, the simpler is most likey to be correct. So why do physicists continue to propose ever more complex and convoluted theories about the nature of things? There must be a simpler explanation - preferably one I'll be capable of understanding.:-O Will Build Nuclear Missile For Food - No Target Too Small
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This is definitely not the thread to try and follow the day after having a migraine. :sigh:
Software Zen:
delete this;The book The Elegant Universe by Brian Greene is a very good one for the more simple minded of us (although I recomend still a university degree in nuclear physics to understand most of it). It covers all up to date theories especially the string theories (yes there is more than one around). He explains things in a very clear way without any formulas (ok in the appendix are a few ones). Nonetheless the ideas presented there show clearly that our universe is not so simple as many of us may think. Amazon
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The book The Elegant Universe by Brian Greene is a very good one for the more simple minded of us (although I recomend still a university degree in nuclear physics to understand most of it). It covers all up to date theories especially the string theories (yes there is more than one around). He explains things in a very clear way without any formulas (ok in the appendix are a few ones). Nonetheless the ideas presented there show clearly that our universe is not so simple as many of us may think. Amazon
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Weak ? OK, so I can jump off a cliff safely ? :rolleyes: The tigress is here :-D
Trollslayer wrote: Weak ? OK, so I can jump off a cliff safely ? ;P Err... No. But, next time you stand on your tip-toes, realize that your calf muscles can very casually counteract the graviational force exerted on you by the entire bazillion kilos of dirt and water called 'Earth'. Physics is so cool :) -- Russell Morris "So, broccoli, mother says you're good for me... but I'm afraid I'm no good for you!" - Stewy
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I have a small little following of fellow physicists (including myself) that are still playing around with aether physics (ie variable speed of light theories). I too have never been one for all this hype about branes and n dimensional spaces. I think it is far too complicated an idea. I always get mad too when I see the Scientific American articles proclaiming this stuff as the preliminary material for a Theory of everything. Maybe it is just me...then again, I still maintain that there is a simpler alternative to quantum mechanics...:suss: John Theal Physicist at Large Got CAD? http://www.presenter3d.com[^]
I'm with you on the divergence of theoretical physics from experiment over the past few years, but what could be simpler then quantum mechanics? It's just simple complex linear algebra. It's always been my opinion that the hard part is the mapping back to quantities that we consider physical. That and the measurement stuff. Personally that is the hardest part of QM to handle. That there are 2 laws for time evolution of a system watched and unwatched. -Andy Brummer
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I have a small little following of fellow physicists (including myself) that are still playing around with aether physics (ie variable speed of light theories). I too have never been one for all this hype about branes and n dimensional spaces. I think it is far too complicated an idea. I always get mad too when I see the Scientific American articles proclaiming this stuff as the preliminary material for a Theory of everything. Maybe it is just me...then again, I still maintain that there is a simpler alternative to quantum mechanics...:suss: John Theal Physicist at Large Got CAD? http://www.presenter3d.com[^]
John Theal wrote: I have a small little following of fellow physicists (including myself) that are still playing around with aether physics (ie variable speed of light theories). Any new evidences besides the old, refuted ones? Is there any website you can recommend as a starting point for reading? Thank you in advance
"We trained hard, but it seemed that every time we were beginning to form up into teams we would be reorganised. I was to learn later in life that we tend to meet any new situation by reorganising: and a wonderful method it can be for creating the illusion of progress, while producing confusion, inefficiency and demoralisation." -- Caius Petronius, Roman Consul, 66 A.D.