kill231
Toucan
Joined: 12 Jan 2012
Age: 26
Gender: Male
Posts: 289
Location: Anywhere in the quantum-verse
19 Jun 2012, 5:00 pm
Tollorin
Veteran
Joined: 14 Jun 2009
Age: 43
Gender: Male
Posts: 3,178
Location: Sherbrooke, Québec, Canada
20 Jun 2012, 7:37 am
21 Jun 2012, 9:50 pm
Jono wrote:
ruveyn wrote:
Jono wrote:
ruveyn wrote:
AstroGeek wrote:
I'm not qualified to make any statement on the various GUTs. However, as far as I know, none have made testable predictions just yet. So I'm not impressed with any of them.
Neither is Lee Smolin. Read his book -The Trouble With Physics-
He has given up on string theory and m-theory as lost causes.
See also "Not Even Wrong" by Peter Woit
ruveyn
I would be much more impressed by Lee Smolin's argument if it came from someone who did not support untested and possibly "unverifiable" theories himself. Since when has Loop Quantum Gravity ever made a testable prediction that has been confirmed by experiment? Just saying.
It hasn't. But that does not void his criticism of string theory and M-theory.
It is all Witten's fault. His dazzling mathematics has blinded the physics community.
It has also produced a perversion, when physicists start to believe that mathematical beauty is a corroboration of their theories. Nonesense! Beauty is NOT truth! Beauty is Beauty. It is commonplace to find that an elegant theory fails to describe the data and, in the words of American physicist Richard Feynman, it doesn't matter how beautiful your theory is, how smart you are or what your name is – if it doesn't agree with the data then it is wrong.
It is a question of disappointment. Neither string-theory nor M-theory has "delivered the goods". Time to go back to the drawing board.
ruveyn
Actually, that isn't true. I do not know of a single physicist, string theorists included. who believes that mathematical beauty is somehow a replacement for empirical evidence. However, the fact remains that general relativity and quantum mechanics are incompatible in each others domains and physics cannot progress beyond it's current state, one way or the other if we do not find a way to empirically test quantum gravity. I don't agree that we have to go back to the drawing board just yet because there has also never been any empirical data that I'm aware of that completely rules out string theory. Once we find such data, then I'm sure physicists will move on, same goes for alternative theories.
P.S. By the way, there actually is experimental evidence that gravity can show quantum effects. This was shown due to an experiment involving cold neutrons in gravitationally bound quantum states in the earths gravitational field:
http://www.nature.com/nphys/journal/v7/n6/full/nphys1970.html
Here are some other papers on experiments utilizing the same technique:
http://arxiv.org/abs/hep-ph/0703108
http://arxiv.org/abs/hep-ph/0301145
pay walls SUCK!! !! !! !
22 Jun 2012, 2:18 am
slave wrote:
Jono wrote:
ruveyn wrote:
Jono wrote:
ruveyn wrote:
AstroGeek wrote:
I'm not qualified to make any statement on the various GUTs. However, as far as I know, none have made testable predictions just yet. So I'm not impressed with any of them.
Neither is Lee Smolin. Read his book -The Trouble With Physics-
He has given up on string theory and m-theory as lost causes.
See also "Not Even Wrong" by Peter Woit
ruveyn
I would be much more impressed by Lee Smolin's argument if it came from someone who did not support untested and possibly "unverifiable" theories himself. Since when has Loop Quantum Gravity ever made a testable prediction that has been confirmed by experiment? Just saying.
It hasn't. But that does not void his criticism of string theory and M-theory.
It is all Witten's fault. His dazzling mathematics has blinded the physics community.
It has also produced a perversion, when physicists start to believe that mathematical beauty is a corroboration of their theories. Nonesense! Beauty is NOT truth! Beauty is Beauty. It is commonplace to find that an elegant theory fails to describe the data and, in the words of American physicist Richard Feynman, it doesn't matter how beautiful your theory is, how smart you are or what your name is – if it doesn't agree with the data then it is wrong.
It is a question of disappointment. Neither string-theory nor M-theory has "delivered the goods". Time to go back to the drawing board.
ruveyn
Actually, that isn't true. I do not know of a single physicist, string theorists included. who believes that mathematical beauty is somehow a replacement for empirical evidence. However, the fact remains that general relativity and quantum mechanics are incompatible in each others domains and physics cannot progress beyond it's current state, one way or the other if we do not find a way to empirically test quantum gravity. I don't agree that we have to go back to the drawing board just yet because there has also never been any empirical data that I'm aware of that completely rules out string theory. Once we find such data, then I'm sure physicists will move on, same goes for alternative theories.
P.S. By the way, there actually is experimental evidence that gravity can show quantum effects. This was shown due to an experiment involving cold neutrons in gravitationally bound quantum states in the earths gravitational field:
http://www.nature.com/nphys/journal/v7/n6/full/nphys1970.html
Here are some other papers on experiments utilizing the same technique:
http://arxiv.org/abs/hep-ph/0703108
http://arxiv.org/abs/hep-ph/0301145
pay walls SUCK!! !! !! !
I can't access the Nature article either because our university doesn't have a subscription to it. The other two links don't require payments because those are the preprints of the actual papers. You might want to take a look at those other 2 papers because they are quite interesting.
25 Jun 2012, 4:18 pm
Jono wrote:
slave wrote:
Jono wrote:
ruveyn wrote:
Jono wrote:
ruveyn wrote:
AstroGeek wrote:
I'm not qualified to make any statement on the various GUTs. However, as far as I know, none have made testable predictions just yet. So I'm not impressed with any of them.
Neither is Lee Smolin. Read his book -The Trouble With Physics-
He has given up on string theory and m-theory as lost causes.
See also "Not Even Wrong" by Peter Woit
ruveyn
I would be much more impressed by Lee Smolin's argument if it came from someone who did not support untested and possibly "unverifiable" theories himself. Since when has Loop Quantum Gravity ever made a testable prediction that has been confirmed by experiment? Just saying.
It hasn't. But that does not void his criticism of string theory and M-theory.
It is all Witten's fault. His dazzling mathematics has blinded the physics community.
It has also produced a perversion, when physicists start to believe that mathematical beauty is a corroboration of their theories. Nonesense! Beauty is NOT truth! Beauty is Beauty. It is commonplace to find that an elegant theory fails to describe the data and, in the words of American physicist Richard Feynman, it doesn't matter how beautiful your theory is, how smart you are or what your name is – if it doesn't agree with the data then it is wrong.
It is a question of disappointment. Neither string-theory nor M-theory has "delivered the goods". Time to go back to the drawing board.
ruveyn
Actually, that isn't true. I do not know of a single physicist, string theorists included. who believes that mathematical beauty is somehow a replacement for empirical evidence. However, the fact remains that general relativity and quantum mechanics are incompatible in each others domains and physics cannot progress beyond it's current state, one way or the other if we do not find a way to empirically test quantum gravity. I don't agree that we have to go back to the drawing board just yet because there has also never been any empirical data that I'm aware of that completely rules out string theory. Once we find such data, then I'm sure physicists will move on, same goes for alternative theories.
P.S. By the way, there actually is experimental evidence that gravity can show quantum effects. This was shown due to an experiment involving cold neutrons in gravitationally bound quantum states in the earths gravitational field:
http://www.nature.com/nphys/journal/v7/n6/full/nphys1970.html
Here are some other papers on experiments utilizing the same technique:
http://arxiv.org/abs/hep-ph/0703108
http://arxiv.org/abs/hep-ph/0301145
pay walls SUCK!! !! !! !
I can't access the Nature article either because our university doesn't have a subscription to it. The other two links don't require payments because those are the preprints of the actual papers. You might want to take a look at those other 2 papers because they are quite interesting.
yeah, I did...very interesting.
thanks
25 Jun 2012, 6:34 pm
Tollorin
Veteran
Joined: 14 Jun 2009
Age: 43
Gender: Male
Posts: 3,178
Location: Sherbrooke, Québec, Canada
26 Jun 2012, 4:33 pm
