Re: Multiverse concepts in string theory
Hi Stephen,
Yes I agree. But once you have many scientists
believing in a certain paradigm, it takes radical new discoveries to overturn
it. The lack of confirmation is usually not enough.
Saibal
- Original Message -
From:
Stephen
Paul King
To: everything-list@eskimo.com
Sent: Wednesday, February 15, 2006 1:45
AM
Subject: Re: Multiverse concepts in
string theory
Hi Saibal,
Does this not lead one to suspect that
they secretly believe SUSY to be "not even wrong" and yet seek to save face?
My problem is that any scientific theory must be highly falsifiable, otherwise
we are just going back to the days of Scholastic debates...
http://clublet.com/why?AngelsOnTheHeadsOfPins
Onward!
Stephen
- Original Message -
From:
Saibal Mitra
To: Stephen Paul King ; everything-list@eskimo.com
Sent: Tuesday, February 14, 2006 6:20
PM
Subject: Re: Multiverse concepts in
string theory
Stephen,
Theorists are always a bit ahead and they have
already found ways to save SUSY from negative results from the LHC.
Saibal
- Original Message -
From:
Stephen
Paul King
To: everything-list@eskimo.com
Sent: Tuesday, February 14, 2006 1:04
PM
Subject: Re: Multiverse concepts in
string theory
Hi Norman,
It will be a wonderful thing to get a
confirmation by next year but I am afraid that the usual behavior of
theorist will occur: the theory will be re-tinkered so that the particle
masses are too massive to be created by humans. It has been happening
already in astrophysics...
Btw, have you any familiarity with
modeling the dynamics of scalar fields in relativistic situations? I need
some help. ;-)
Onward!
Stephen
- Original Message -
From:
Norman
Samish
To: Everything-list
Sent: Tuesday, February 14, 2006
1:36 AM
Subject: Re: Multiverse concepts in
string theory
Stephen,
As you say, the version of string theory with an
infinity of universes is an elegant concept. However, when
you say ". . . its most fundamental assumption, the existence
of a supersymmerty relation between bosons and fermions, has never even
come close to matching experimental observation," one could infer
that there is little likelihood that SUSY will ever be shown to
be a good theory.
This may change soon. Wikipedia says
"Experimentalists have not yet found any superpartners for known
particles, either because they are too massive to be created in our
current particle accelerators, or because they may not exist at
all. By the year 2007, the Large Hadron Collider at CERN
should be ready for use, producing collisions at sufficiently high
energies to detect the superpartners many theorists hope to
see."
So maybe, in a couple of years, there WILL be
experimental observation supporting SUSY.
I agree that the posts by Hal Finney and Wei Dai are
well said and inspirational. Thanks,
Norman
Re: Multiverse concepts in string theory
To clarify, that quote comes from John Peacock, the reviewer of The Cosmic Landscape for American Scientist. What he's saying is that physics, like art, is partly a function of the human aesthetic response, because empirical evidence only constrains theories allowed in physics, but does not determine it. I would agree with him only partly, because a large part of what Peacock includes under "aesthetics" is a common preference for simplicity, which can be formalized in various ways (e.g. Kolmogorov complexity). But even taking into account the formalizable common preference for simplicity, I think there is still a role for aesthetics to play in physics. I can think of two arguments for this. One is to say that the general preference for simplicity in our aesthetic response is a result of the limited complexity of our minds. In other words, everything we consider beautiful must be relatively simple, but not everything simple has to be considered beautiful. Thus the most beautiful theory is not necessarily the simplest one. The other argument is that all of the formalizations of complexity leave a free parameter, for example the choice of universal Turing machine in algorithmic information theory. Our aesthetic choices can therefore be encoded into this free parameter. - Original Message - From: Kim Jones To: Wei Dai Cc: everything-list@eskimo.com Sent: Tuesday, February 14, 2006 10:40 PM Subject: Re: Multiverse concepts in string theory Thankyou. So it used to be "science and religion." In fact it should have been all along "science and religion and art". Is it possible that we've been missing an important part of the discussion here? Art (painting, music - whatever) is the revelation of 1st person experience; the 'word of the creator'. Take it from there Kim Jones On 14/02/2006, at 11:06 AM, Wei Dai wrote: In short, physics is a human creative art on the same level as painting and music, and that is reason enough to be proud of what the subject has achieved.
Re: Multiverse concepts in string theory
Thankyou.So it used to be "science and religion."In fact it should have been all along "science and religion and art".Is it possible that we've been missing an important part of the discussion here?Art (painting, music - whatever) is the revelation of 1st person experience; the 'word of the creator'.Take it from thereKim JonesOn 14/02/2006, at 11:06 AM, Wei Dai wrote:In short, physics is a human creative art on the same level as painting and music, and that is reason enough to be proud of what the subject has achieved.
Re: Multiverse concepts in string theory
Hi Saibal,
Does this not lead one to suspect that they
secretly believe SUSY to be "not even wrong" and yet seek to save face? My
problem is that any scientific theory must be highly falsifiable, otherwise we
are just going back to the days of Scholastic debates...
http://clublet.com/why?AngelsOnTheHeadsOfPins
Onward!
Stephen
- Original Message -
From:
Saibal Mitra
To: Stephen Paul King ; everything-list@eskimo.com
Sent: Tuesday, February 14, 2006 6:20
PM
Subject: Re: Multiverse concepts in
string theory
Stephen,
Theorists are always a bit ahead and they have
already found ways to save SUSY from negative results from the LHC.
Saibal
- Original Message -
From:
Stephen
Paul King
To: everything-list@eskimo.com
Sent: Tuesday, February 14, 2006 1:04
PM
Subject: Re: Multiverse concepts in
string theory
Hi Norman,
It will be a wonderful thing to get a
confirmation by next year but I am afraid that the usual behavior of
theorist will occur: the theory will be re-tinkered so that the particle
masses are too massive to be created by humans. It has been happening
already in astrophysics...
Btw, have you any familiarity with
modeling the dynamics of scalar fields in relativistic situations? I need
some help. ;-)
Onward!
Stephen
- Original Message -
From:
Norman
Samish
To: Everything-list
Sent: Tuesday, February 14, 2006 1:36
AM
Subject: Re: Multiverse concepts in
string theory
Stephen,
As you say, the version of string theory with an
infinity of universes is an elegant concept. However, when you
say ". . . its most fundamental assumption, the existence of a
supersymmerty relation between bosons and fermions, has never even come
close to matching experimental observation," one could infer that
there is little likelihood that SUSY will ever be shown to be a good
theory.
This may change soon. Wikipedia says
"Experimentalists have not yet found any superpartners for known
particles, either because they are too massive to be created in our
current particle accelerators, or because they may not exist at all.
By the year 2007, the Large Hadron Collider at CERN should be ready
for use, producing collisions at sufficiently high energies to detect the
superpartners many theorists hope to see."
So maybe, in a couple of years, there WILL be
experimental observation supporting SUSY.
I agree that the posts by Hal Finney and Wei Dai are
well said and inspirational. Thanks,
Norman
Re: Multiverse concepts in string theory
Stephen, Theorists are always a bit ahead and they have already found ways to save SUSY from negative results from the LHC. Saibal - Original Message - From: Stephen Paul King To: everything-list@eskimo.com Sent: Tuesday, February 14, 2006 1:04 PM Subject: Re: Multiverse concepts in string theory Hi Norman, It will be a wonderful thing to get a confirmation by next year but I am afraid that the usual behavior of theorist will occur: the theory will be re-tinkered so that the particle masses are too massive to be created by humans. It has been happening already in astrophysics... Btw, have you any familiarity with modeling the dynamics of scalar fields in relativistic situations? I need some help. ;-) Onward! Stephen - Original Message - From: Norman Samish To: Everything-list Sent: Tuesday, February 14, 2006 1:36 AM Subject: Re: Multiverse concepts in string theory Stephen, As you say, the version of string theory with an infinity of universes is an elegant concept. However, when you say ". . . its most fundamental assumption, the existence of a supersymmerty relation between bosons and fermions, has never even come close to matching experimental observation," one could infer that there is little likelihood that SUSY will ever be shown to be a good theory. This may change soon. Wikipedia says "Experimentalists have not yet found any superpartners for known particles, either because they are too massive to be created in our current particle accelerators, or because they may not exist at all. By the year 2007, the Large Hadron Collider at CERN should be ready for use, producing collisions at sufficiently high energies to detect the superpartners many theorists hope to see." So maybe, in a couple of years, there WILL be experimental observation supporting SUSY. I agree that the posts by Hal Finney and Wei Dai are well said and inspirational. Thanks, Norman
Re: Multiverse concepts in string theory
Hi Norman, It will be a wonderful thing to get a confirmation by next year but I am afraid that the usual behavior of theorist will occur: the theory will be re-tinkered so that the particle masses are too massive to be created by humans. It has been happening already in astrophysics... Btw, have you any familiarity with modeling the dynamics of scalar fields in relativistic situations? I need some help. ;-) Onward! Stephen - Original Message - From: Norman Samish To: Everything-list Sent: Tuesday, February 14, 2006 1:36 AM Subject: Re: Multiverse concepts in string theory Stephen, As you say, the version of string theory with an infinity of universes is an elegant concept. However, when you say ". . . its most fundamental assumption, the existence of a supersymmerty relation between bosons and fermions, has never even come close to matching experimental observation," one could infer that there is little likelihood that SUSY will ever be shown to be a good theory. This may change soon. Wikipedia says "Experimentalists have not yet found any superpartners for known particles, either because they are too massive to be created in our current particle accelerators, or because they may not exist at all. By the year 2007, the Large Hadron Collider at CERN should be ready for use, producing collisions at sufficiently high energies to detect the superpartners many theorists hope to see." So maybe, in a couple of years, there WILL be experimental observation supporting SUSY. I agree that the posts by Hal Finney and Wei Dai are well said and inspirational. Thanks, Norman
Re: Multiverse concepts in string theory
Stephen, As you say, the version of string theory with an infinity of universes is an elegant concept. However, when you say ". . . its most fundamental assumption, the existence of a supersymmerty relation between bosons and fermions, has never even come close to matching experimental observation," one could infer that there is little likelihood that SUSY will ever be shown to be a good theory. This may change soon. Wikipedia says "Experimentalists have not yet found any superpartners for known particles, either because they are too massive to be created in our current particle accelerators, or because they may not exist at all. By the year 2007, the Large Hadron Collider at CERN should be ready for use, producing collisions at sufficiently high energies to detect the superpartners many theorists hope to see." So maybe, in a couple of years, there WILL be experimental observation supporting SUSY. I agree that the posts by Hal Finney and Wei Dai are well said and inspirational. Thanks, Norman ~~ - Original Message - From: Stephen Paul King To: everything-list@eskimo.com Sent: Monday, February 13, 2006 7:29 PMSubject: Re: Multiverse concepts in string theoryDear Wei and Friends, I have been following this thread with some interest (Hal initial post was wonderful, BTW!) and echo the comments of Wei here, but I would offer a note of caution: we must be very careful that the elevation of string theory (SUSY) to almost dogmatic "Sacred Cow" status does not bode well for many of us, particularly those that have found that its most fundamental assumption, the existence of a supersymmerty relation between bosons and fermions, has never even come close to matching experimental observation. Maybe, just maybe, SUSY is a good theory or maybe it is just a very elegant bit of pure mathematics. Remember, just because a mathematical theory can be shown to be self-consistent and elegant, there is no requirement that that theory have anything to do with the physical world we experience. I find that the choices presented by Weinberg and the Intelligent Design advocates are not the only possibilities. Consider that we still do not have a consistent and faithful model of observers within our physics and thus can not even start to coherently consider what the notion of "comprehensibility" means in the context of physics. ;-)Onward!Stephen ~`- Original Message - From: Wei Dai To: everything-list@eskimo.com Sent: Monday, February 13, 2006 7:06 PMSubject: Re: Multiverse concepts in string theoryHal wrote:> I also get the impression that Susskind's attempts to bring "disreputable"> multiverse models into "holy" string theory is more likely to kill> string theory than to rehabilitate multiverses. Perhaps I am getting a> biased view by only reading this one blog, which opposes string theory,> but it seems that more and more people are saying that the emperor has> no clothes. If string theory needs a multiverse then it is even less> likely to ever be able to make physical predictions, and its prospects> are even worse than had been thought. A lot of people seem to be piling> on and saying that it is time for physics to explore alternative ideas.> The hostile NY Times book review is just one example.String theory isn't going to be killed until there's a replacement available, and any replacement is likely to face the same issue of describing a large collection of universes of which only a small subset can support life. So I wouldn't be concerned about more effort being devoted to looking for alternatives to string theory. In the mean time, the multiverse meme continues to spread. Take the review of Susskind's book in American Scientist (http://www.americanscientist.org/template/BookReviewTypeDetail/assetid/49558) for example:In the end, however, good though this book is, I was left feeling that the argument was not carried to its logical conclusion. Despite his justified scorn for intelligent design, Susskind retains a hint of this worldview in his own attitude. It was Galileo who said that the book of Nature is written in mathematics, and almost all physicists subscribe to this view. When we contemplate the power and simplicity of constructions like general relativity, there is a temptation to carry intelligent design to an extreme in which God wrote the equations, from which all else follows. Frequently this perspective is quite explicit, as with Einstein (recall Bohr's admonition, "Stop telling God what to do!"). The landscape picture derails this thinking to some extent, but Susskind just transfers the quasi-religious awe to string theory, whose mathematical results he repeatedly describes as "miraculous." But if life on Earth is a random accident in a universe where only chance yielded laws of physics suitable for life, why stop there? Perhaps string theory itself is n
Re: Multiverse concepts in string theory
Dear Wei and Friends, I have been following this thread with some interest (Hal initial post was wonderful, BTW!) and echo the comments of Wei here, but I would offer a note of caution: we must be very careful that the elevation of string theory (SUSY) to almost dogmatic "Sacred Cow" status does not bode well for many of us, particularly those that have found that its most fundamental assumption, the existence of a supersymmerty relation between bosons and fermions, has never even come close to matching experimental observation. Maybe, just maybe, SUSY is a good theory or maybe it is just a very elegant bit of pure mathematics. Remember, just because a mathematical theory can be shown to be self-consistent and elegant, there is no requirement that that theory have anything to do with the physical world we experience. I find that the choices presented by Weinberg and the Intelligent Design advocates are not the only possibilities. Consider that we still do not have a consistent and faithful model of observers within our physics and thus can not even start to coherently consider what the notion of "comprehensibility" means in the context of physics. ;-) Onward! Stephen - Original Message - From: Wei Dai To: everything-list@eskimo.com Sent: Monday, February 13, 2006 7:06 PM Subject: Re: Multiverse concepts in string theory Hal wrote: > I also get the impression that Susskind's attempts to bring "disreputable"> multiverse models into "holy" string theory is more likely to kill> string theory than to rehabilitate multiverses. Perhaps I am getting a> biased view by only reading this one blog, which opposes string theory,> but it seems that more and more people are saying that the emperor has> no clothes. If string theory needs a multiverse then it is even less> likely to ever be able to make physical predictions, and its prospects> are even worse than had been thought. A lot of people seem to be piling> on and saying that it is time for physics to explore alternative ideas.> The hostile NY Times book review is just one example. String theory isn't going to be killed until there's a replacement available, and any replacement is likely to face the same issue of describing a large collection of universes of which only a small subset can support life. So I wouldn't be concerned about more effort being devoted to looking for alternatives to string theory. In the mean time, the multiverse meme continues to spread. Take the review of Susskind's book in American Scientist (http://www.americanscientist.org/template/BookReviewTypeDetail/assetid/49558) for example: In the end, however, good though this book is, I was left feeling that the argument was not carried to its logical conclusion. Despite his justified scorn for intelligent design, Susskind retains a hint of this worldview in his own attitude. It was Galileo who said that the book of Nature is written in mathematics, and almost all physicists subscribe to this view. When we contemplate the power and simplicity of constructions like general relativity, there is a temptation to carry intelligent design to an extreme in which God wrote the equations, from which all else follows. Frequently this perspective is quite explicit, as with Einstein (recall Bohr's admonition, "Stop telling God what to do!"). The landscape picture derails this thinking to some extent, but Susskind just transfers the quasi-religious awe to string theory, whose mathematical results he repeatedly describes as "miraculous." But if life on Earth is a random accident in a universe where only chance yielded laws of physics suitable for life, why stop there? Perhaps string theory itself is nothing special and only part of a wider spectrum of possible prescriptions for reality. If the search for a unique and inevitable explanation of Nature has proved illusory at every step, is it really plausible that suddenly string theory can make everything right at the last? Reading Susskind's book should make you doubt that possibility, in which case we may have reached the end of the search for underlying simplicity that has driven physics since the beginning. A comment made by Steven Weinberg in his 1977 book The First Three Minutes sums things up well: "The more the universe seems comprehensible, the more it also seems pointless." Pointless to look for meaning in our existence in the universe, and also (according to Susskind) pointless to look for meaning in physics. To a physicist, this is a pretty depressing conclusion, but there is some consolation: The beauty we perceive in the laws of physics perhaps tells us as much about the human aesthetic respo
Re: Multiverse concepts in string theory
Hal wrote: > I also get the impression that Susskind's attempts to bring "disreputable"> multiverse models into "holy" string theory is more likely to kill> string theory than to rehabilitate multiverses. Perhaps I am getting a> biased view by only reading this one blog, which opposes string theory,> but it seems that more and more people are saying that the emperor has> no clothes. If string theory needs a multiverse then it is even less> likely to ever be able to make physical predictions, and its prospects> are even worse than had been thought. A lot of people seem to be piling> on and saying that it is time for physics to explore alternative ideas.> The hostile NY Times book review is just one example. String theory isn't going to be killed until there's a replacement available, and any replacement is likely to face the same issue of describing a large collection of universes of which only a small subset can support life. So I wouldn't be concerned about more effort being devoted to looking for alternatives to string theory. In the mean time, the multiverse meme continues to spread. Take the review of Susskind's book in American Scientist (http://www.americanscientist.org/template/BookReviewTypeDetail/assetid/49558) for example: In the end, however, good though this book is, I was left feeling that the argument was not carried to its logical conclusion. Despite his justified scorn for intelligent design, Susskind retains a hint of this worldview in his own attitude. It was Galileo who said that the book of Nature is written in mathematics, and almost all physicists subscribe to this view. When we contemplate the power and simplicity of constructions like general relativity, there is a temptation to carry intelligent design to an extreme in which God wrote the equations, from which all else follows. Frequently this perspective is quite explicit, as with Einstein (recall Bohr's admonition, "Stop telling God what to do!"). The landscape picture derails this thinking to some extent, but Susskind just transfers the quasi-religious awe to string theory, whose mathematical results he repeatedly describes as "miraculous." But if life on Earth is a random accident in a universe where only chance yielded laws of physics suitable for life, why stop there? Perhaps string theory itself is nothing special and only part of a wider spectrum of possible prescriptions for reality. If the search for a unique and inevitable explanation of Nature has proved illusory at every step, is it really plausible that suddenly string theory can make everything right at the last? Reading Susskind's book should make you doubt that possibility, in which case we may have reached the end of the search for underlying simplicity that has driven physics since the beginning. A comment made by Steven Weinberg in his 1977 book The First Three Minutes sums things up well: "The more the universe seems comprehensible, the more it also seems pointless." Pointless to look for meaning in our existence in the universe, and also (according to Susskind) pointless to look for meaning in physics. To a physicist, this is a pretty depressing conclusion, but there is some consolation: The beauty we perceive in the laws of physics perhaps tells us as much about the human aesthetic response as it does about any fundamental design of the universe. In short, physics is a human creative art on the same level as painting and music, and that is reason enough to be proud of what the subject has achieved.
Re: Multiverse concepts in string theory
Le 13-févr.-06, à 09:44, Hal Finney wrote (in part): In many of our discussions of multiverse models, we have explicitly or implicitly included the notion of measure, that some universes would be more "common" or more "prominent" than others. This is often linked to extensions of Occam's Razor, so that universes with relatively simple models would have higher measure than those that are more complex. The necessity of "simplicity" could perhaps be a consequence of comp, but this remains to be shown. But even if that is the case, I don't see how "simplicity" would make the model having a higher measure, unless you attach consciousness to particular individuals in particular universe, but this can be done only by identifying the first person and some arbitrary particular third person description. And the UDA shows this cannot be done (with comp). Physics is a science, and that means it needs to work with theories that can be tested and disproven. We are a long way from being able to come up with any experiment that a working physicist in his lab could run to see whether multiverse models are correct. (And no, quantum suicide doesn't count!) The day physicists will understand the logician's sense of model and theories, things will be pretty much clear. If we agree that physicists obey the same laws as the particles they describe, then, even just the two slits experiment entails mutiverses, and confirms QM which is literally a mutiverse theory (even with the collapse, which is just an invention for cutting on the typical quantum contagion of the superpositions). Also, note that the 0-universe, 1-universe, infinity-of-universes are all on the same par. Nobody has ever tested the existence of a primitive physical universe nor of the existence of Aristotelian Prime Matter, and other common sense idea on which those physicalist ideas derive. Note also that the theory of Matter given by the loebian (introspective) machine is 100% testable. I also get the impression that Susskind's attempts to bring "disreputable" multiverse models into "holy" string theory is more likely to kill string theory than to rehabilitate multiverses. String theory relies entirely on QM and so inherits all its interpretation problems. Except that in String Theory, like Quantum Cosmology, the "wave collapse" is still more unintelligible. Witten makes the points in a conference some years ago. According to him String Theory is still very fuzzy on the whole wave aspect of strings, above its traditional role as computation tool. Perhaps I am getting a biased view by only reading this one blog, which opposes string theory, but it seems that more and more people are saying that the emperor has no clothes. If string theory needs a multiverse then it is even less likely to ever be able to make physical predictions, and its prospects are even worse than had been thought. A lot of people seem to be piling on and saying that it is time for physics to explore alternative ideas. The hostile NY Times book review is just one example. To be sure I disagree that string theory is not testable, and I think the multiverse idea is testable and already indirectly tested and that it is the most certain consequence of QM. Now, as a theory of everything, string theories, like QM and actually the whole physics enterprise, are flawed at the start, because those approach relies (consciously or not) on a hardly clear or coherent theology inherited mainly from Aristotle, and which tends to put the mind-body problem under the rug. Bruno http://iridia.ulb.ac.be/~marchal/
RE: Multiverse concepts in string theory
Hal wrote: > I also get the impression that Susskind's attempts to bring "disreputable" > multiverse models into "holy" string theory is more likely to kill > string theory than to rehabilitate multiverses. Perhaps I am getting a > biased view by only reading this one blog, which opposes string theory, > but it seems that more and more people are saying that the emperor has > no clothes. If string theory needs a multiverse then it is even less > likely to ever be able to make physical predictions, and its prospects > are even worse than had been thought. A lot of people seem to be piling > on and saying that it is time for physics to explore alternative ideas. > The hostile NY Times book review is just one example. Two words: Continental drift. Ok, continental drift is observable, whereas multiverses aren't, but it is worth remembering the ridicule heaped (up until not so very long ago) on those who dared to suggest what is now known as plate techtonics. Jonathan Colvin
