Physics in crisis
Thomas Larsson
In the latest issue (Sept 2002) of Physics Today there was an essay with
this title by Sidney Nagel, who I think is a heavy-weight in non-equilibrium
statphys. Although he does not explicitly mention string theory, he writes that
"high-energy particle physics is no longer so healthy", a sentence that is
unlikely to be written by a true believer of M-theory. I wonder if people
here agree with Nagel's assessment. Personally I would say that there is a
lot of truth in it. In the last six months, the only physicists that have
made it into popular media seem to be
Stephen Wolfram (worse overselling than M-theory),
Hendrik Schön (the brightest nanophysics star who was fired from Bell Labs
in September for scientific fraud),
Viktor Ninov (fabrication of elements 116 and 118, see same issue of Physics
Today),
and now perhaps the Bogdanovich brothers. Moreover, the physics news in the
preceding year was dominated by
muon g-2 (deviation from the SM due to a theoretical mistake),
115 GeV Higgs (the peak that melted away),
broken lightbulbs in SuperKamiokande, and
CERN's financial overdraft.
Any thoughts?
A.J. Tolland
> In the latest issue (Sept 2002) of Physics Today there was an essay with
> this title by Sidney Nagel, who I think is a heavy-weight in
> non-equilibrium statphys.
Yes, he is. Also a really cool guy.
> Although he does not explicitly mention string theory, he writes that
> "high-energy particle physics is no longer so healthy", a sentence that
> is unlikely to be written by a true believer of M-theory.
I don't agree with your analysis. Even one of M-theory's true
believer's ought to be able to acknowledge that high energy particle
physics is unhealthy right now:
(1) There is a vast gap between theory and experiment. One could
make an argument that theory has become rather top-heavy of late. (My
personal slant is that string theory and the like should be thought of as
mathematical physics rather than particle physics, more an attempt to
generalize and understand the models we use to study the real world than
to actually create models of the real world itself.)
(2) It seems unlikely that we will be able to continue ramping up
accelerator resolution for very much longer. The cost is becoming quite
prohibitive. This makes it unlikely that we will be able to test _any_ of
our farther reaching theories within our lifetimes, strings, loop gravity,
algebras, whatever. This is, of course, a problem for anyone more
interested in physics than natural philosophy.
That said, I think you are taking Nagel's comment out of its
original context. He said, "high-energy particle physics is no longer so
healthy--particularly within the US since the demise of the
Superconducting Super Collider". He said this while arguing that physics
has become more of a bazaar than a cathedral, more focused on exploring
various aspects of the experimentally testable world than on building a
great reductionist picture. I don't think he was passing judgement on
M-theory.
I can't actually speak for Sid, but my guess is that he probably
views particle physics (theory and experiment) as having said most of what
it has to say and high energy/mathematical physics as a small and
relatively unimportant subdiscipline, relative to things like atomic
physics, astrophysics, and condensed matter. I suppose it's easy for us
to forget on this newsgroup that mathematical physicists and high energy
theorists really are a minority, and that many of our physics colleagues
probably view our debates about high energy physics as a tempest in a
teapot.
--A.J.
Danny Ross Lunsford
> In the latest issue (Sept 2002) of Physics Today there was an essay with
> this title by Sidney Nagel, who I think is a heavy-weight in
non-equilibrium
> statphys. Although he does not explicitly mention string theory, he writes
that
> "high-energy particle physics is no longer so healthy", a sentence that is
> unlikely to be written by a true believer of M-theory. I wonder if people
> here agree with Nagel's assessment.
It's hard to know what to think. Clearly NSF funding and the need to get is
has in some sense ruined the idea of patient research that may not pan out.
I used to think this was the major reason that things have gone sour because
it encourages (forces?) people to publish detritus. And, let's face it, most
published work is detritus.
However I now think the root cause is that math lives in its own world
without direct interaction or stimulation by new physical results. The
"pre-established harmony" that existed between math and physics is no longer
there. Already at mid-century Courant was decrying this trend. IMO a large
part of the fault here is in the math community itself - to give a personal
example, one of the moderators here basically dismissed an interesting
*physical* question about the singular potential in the Dirac monopole
theory by mathily stating "the theory of non-trivial U(1) bundles" explained
it perfectly - to my physicist way of thinking, all this does is rename a
potential that has two overlapping (what's the right math word?) components,
either one of which is singular, without explaining why it is possible to
describe the same thing in two completely equivalent, but fundamentally
different ways. The physicist wants to understand phenomena, not generalize
everything in sight. In the past, the great stimulus to math came from the
need to calculate - now the overall effort seems more geared toward
classifications heaped upon classifications. Physics moved beyond mere
classification with Copernicus. Until math recovers the dynamism it derives
from the effort to understand, and not simply name, phenomena, the present
situation will drag on and on.
-drl
J. J. Lodder
snip
> and now perhaps the Bogdanovich brothers. Moreover, the physics news in the
> preceding year was dominated by
>
> muon g-2 (deviation from the SM due to a theoretical mistake),
>
> 115 GeV Higgs (the peak that melted away),
>
> broken lightbulbs in SuperKamiokande, and
>
> CERN's financial overdraft.
>
> Any thoughts?
A handfull of unrelated events do not make a crisis.
On the other hand, the situation in quantum gravity
(50 years of unsuccesfull attemps to reconcile quantum and gravity,
and no beginning of an end in sight,
with theories becoming ever more baroque)
does by now have all the looks of a real Kuhnian crisis:
The crisis, and attempts to do something about
define entire fields of research,
and many have devoted their whole professional life
to doing something about it.
This is more or less Kuhn's criterion for crisis.
And in the sense of another philosopher-king of science, Lakatos:
QG by now has all the looks of a degenerating research program,
with researchers spending most of their time
solving problems generated by their own program,
rather than external ones presented by nature.
And the Bogdanovitch hoax may be seen
as proof of degeneration in the sense of Lakatos.
Where theories become closed universes in their own right,
with their own terminologogies, one can create one's own.
That's no reson to give up of course:
even degenerating research programs may get revived,
and start to progress again.
One may remember that Lakatos thought of high energy physics
(tabling resonances, just before quarks and gauge fields)
as an example of a degenerating research program.
And BTW, the mere fact that postings such as the above
stand a chance of being accepted by the spr moderators
is by itself already proof of crisis :-)
Jan
Thomas Larsson
> I can't actually speak for Sid, but my guess is that he probably
> views particle physics (theory and experiment) as having said most of what
> it has to say and high energy/mathematical physics as a small and
> relatively unimportant subdiscipline, relative to things like atomic
> physics, astrophysics, and condensed matter.
My point was not really confined neither to HEP nor to theory. The two
items in my list that are real scandals rather than bad judgement or
bad luck concern experiments in completely different areas of physics;
Schön in nanophysics and Ninov in nuclear physics. Besides, I once
started out in soft condensed matter, so I have some insight in this
field, and I think it is fair to say that essentially nothing has
happened in phase transition theory over the last decade. The 2D
theory was more or less closed with the advent of conformal field
theory and quantum groups/Yang-Baxter equation, and nobody has made
any significant progress on 3D critical phenomena.
There is some current interest in the application of Schramm-Loewner
evolution to 2D percolation, but so far it seems that the
mathematicians have mainly done rigorously what physicists did exactly
but non-rigorously 15 years ago. Valuable, but not really that
exciting to a physicist.
There were surely bad news in physics a decade ago too - cold fusion,
17 keV neutrino, demise of the SSC - but this didn't really affect
theorists. At that time, we were (or at least I was) busy absorbing
all the cool stuff that happened in the 1980s - conformal field
theory, quantum groups, knot theory, topological field theory. Maybe
it's just me getting older and grumpier, but I don't see anything new
of similar interest today. Apart from my own stuff, of course ;-)
Danny Ross Lunsford
John Baez
Danny Ross Lunsford <antima...@sbcglobal.net> wrote:
>IMO a large
>part of the fault here is in the math community itself - to give a personal
>example, one of the moderators here basically dismissed an interesting
>*physical* question about the singular potential in the Dirac monopole
>theory by mathily stating "the theory of non-trivial U(1) bundles" explained
>it perfectly -
I didn't dismiss it. I said that everyone should read the famous
paper by Wu and Yang which explains this stuff. He's a physicist -
a Nobel-prize-winning one in fact - and this work was done a long
time ago, in the heyday of particle physics. So it's a bit odd to
cite it as an example of the current "crisis", and blame it on
the math community. If you hate fiber bundles, I suppose
it makes sense to blame mathematicians for noticing that they exist.
But only the physicists are to blame for actually doing something
useful with them.
More generally, I find it rather odd to blame the math community
for a supposed crisis in physics. It seems obvious to me that
social scientists are the root cause of the problem. :-)
Anyway, the paper I'm talking about is a popularization of these two:
DIRAC'S MONOPOLE WITHOUT STRINGS: CLASSICAL LAGRANGIAN THEORY.
By Tai Tsun Wu (Harvard U.), Chen Ning Yang (SUNY, Stony Brook).
Phys. Rev. D14 (1976) 437-445.
DIRAC MONOPOLE WITHOUT STRINGS: MONOPOLE HARMONICS.
By Tai Tsun Wu (Harvard U.), Chen Ning Yang (SUNY, Stony Brook).
Nucl. Phys. (1976) B107:365.
and it shows up in this book:
Chen Ning Yang, Selected Papers, 1945-1980, W.H. Freeman, 1983.
>to my physicist way of thinking, all this does is rename a
>potential that has two overlapping (what's the right math word?) components,
>either one of which is singular, without explaining why it is possible to
>describe the same thing in two completely equivalent, but fundamentally
>different ways.
The reason it's possible to describe this same thing in two
different ways is *gauge symmetry*. The presence of gauge
symmetries always means we can describe the same physical
situation in different ways.
John Baez
Thomas Larsson <thomas....@hdd.se> wrote:
>In the latest issue (Sept 2002) of Physics Today there was an essay with
>this title by Sidney Nagel, who I think is a heavy-weight in non-equilibrium
>statphys. Although he does not explicitly mention string theory, he writes
>that "high-energy particle physics is no longer so healthy", a sentence that
>is unlikely to be written by a true believer of M-theory. I wonder if people
>here agree with Nagel's assessment. Personally I would say that there is a
>lot of truth in it. In the last six months, the only physicists that have
>made it into popular media seem to be [...]
The stuff that "makes it into popular media" is not necessarily the
best physics. If anything, the current obsession for "making it into
the popular media" is responsible for some of the notorious cases we've
been seeing lately, such as:
>Stephen Wolfram (worse overselling than M-theory),
>
>Hendrik Schoen (the brightest nanophysics star who was fired from Bell Labs
>in September for scientific fraud),
>
>Viktor Ninov (fabrication of elements 116 and 118, see same issue of Physics
>Today),
>
>and now perhaps the Bogdanovich brothers.
(Actually their name is Bogdanov, or Bogdanoff.)
There's a lot of excellent work going on in fundamental physics these
days. It doesn't usually result in *one person* becoming famous,
but it's ultimately more solid.
For example: there's been great research on neutrino oscillations,
the cosmological constant, dark matter, and the "acoustic peaks"
in the power spectrum of the anisotropy of the microwave background
radiation! All these are *experiments* pointing to a picture of
particle physics and cosmology that goes way beyond the Standard
Model and the basic no-frills big bang cosmology of yesteryear.
In other words, we're seeing experiments that go beyond what
theorists are currently able to explain. What more could we want?
(Yes, people claim to explain the acoustic peaks using inflationary
cosmology - but even if this is the right explanation, it goes beyond
today's particle physics, since we don't know what the "inflaton field"
is.)
>Any thoughts?
Ignore the popular media when you want to know what's really
cool in physics these days. There ain't no crisis. The battle
for new knowledge is a desperate struggle, as usual - but not hopeless.
(And above I've been neglecting all the really cool stuff that's
happening in "non-fundamental" physics, especially condensed matter.)
Danny Ross Lunsford
"John Baez" <ba...@galaxy.ucr.edu> wrote
> I didn't dismiss it. I said that everyone should read the famous
> paper by Wu and Yang which explains this stuff. He's a physicist -
> a Nobel-prize-winning one in fact - and this work was done a long
> time ago, in the heyday of particle physics. So it's a bit odd to
> cite it as an example of the current "crisis", and blame it on
> the math community. If you hate fiber bundles, I suppose
> it makes sense to blame mathematicians for noticing that they exist.
> But only the physicists are to blame for actually doing something
> useful with them.
Well, fiber bundles are fascinating math, as is distribution theory - but
the latter no more elucidates the physical reality of point particles than
the former does the Dirac string. You can't answer physical questions by
inventing a new category (oops) of math everytime an issue arises.
The issue here is that somehow EM has this odd potential theory that comes
in two forms, and I don't *physically* understand why that is - in fact it's
very strange and just saying "it's a nontrivial bundle" doesn't make it less
so. I certainly did not mean that non-trivial bundles are not interesting.
> More generally, I find it rather odd to blame the math community
> for a supposed crisis in physics.
In fact I don't - I was essentially repeating what I learned from Courant,
that math AND physics are better off when they stimulate each other.
> It seems obvious to me that
> social scientists are the root cause of the problem. :-)
I think bad pizza and American beer are the root of all evil.
> The reason it's possible to describe this same thing in two
> different ways is *gauge symmetry*. The presence of gauge
> symmetries always means we can describe the same physical
> situation in different ways.
I can't for the life of me see how the Dirac string and the isolated pole
can be gauged one into the other. As I remember it, the Dirac string itself
could be "pushed around" by a gauge transformation, but not magically
mutated into an isolated point particle - but now that you mention it, it's
a fascinating idea to try and make sense of that - so that there is some
intermediate stage that is part string and part isolated pole. How does that
work?
-drl
Arkadiusz Jadczyk
<antima...@sbcglobal.net> wrote:
>
>> The reason it's possible to describe this same thing in two
>> different ways is *gauge symmetry*. The presence of gauge
>> symmetries always means we can describe the same physical
>> situation in different ways.
>
>I can't for the life of me see how the Dirac string and the isolated pole
>can be gauged one into the other.
Dirac did not know about fibre bundles. He did not know that a "string"
is a typical mathematical phenomenon that is bound to show up when we
want to have global coordinate representation of a non-trivial bundle.
Nowadays we have methods of mathematically describing these situations.
One way would be, for instance, to use the well known fact that every
vector bundle (trivial or not) is a subbundle of a trivial bundle.
This is the simplest way to get rid of the string singularity. That is
how Goldhaber, Lipking, Weisberger and Peshkin removed the string
singularity.
Whether electromagnetic potentials have "real meaning" and are
"observable" - is *another* interesting, though related question.
This latter question has been discussed in the past.
IF we assume that electromagnetic potentials ARE observable.
IF we assume, following Ekstein, that all gauges are equal but some are
mor equal than other - THEN we can analyze the Dirac solution again and
try to come to some
other conclusion than it is standard. But then we will have to
re-examine also the foundations of quantum theory, where change of phase
of the wave function is compenstated by a gauge tranformation of EM
potential. Which opens another can of worms....
ark
--
Arkadiusz Jadczyk
http://www.cassiopaea.org/quantum_future/homepage.htm
--
Patrick Amon
A few days ago I attended a (technical) lecture by Wolfram at Courant. Much
as I previously agreed with the common wisdom that his recent work has been
mostly overblown hype, I was actually surprised by what I heard. The lecture
was not publicized and was only open to members of the NYU community i.e.
Courant, and Physics and Chemistry depts. After the end of his lecture, many
of the questions to Wolfram were about his intellectual honesty and whether
his work was hype or substance. It didn't seem anyone was inclined to try to
judge by themselves. Toward the very end, one person (OK, she deserves the
credit so I'll give a name: Glennys Farrar, from the Center from Particle
Astrophysics, with which I'm also affiliated) asked one very good question:
is your "theory" experimentally verifiable? Can it be disproven in a
reasonable amount of time at a reasonable cost? In other words, is it
physics (maybe the reasonable time/reasonable price and requirements for
physics, are they?)? Much to his credit, Wolfram seemed to have actually
thought of those questions and gave intelligent, intelligible answers.
Much to my surprise, the guy actually made sense. It seems to me that both
he and the media share blame for blowing this completely out of proportion
and making preposterous claims about the entire enterprise. I actually did
something I thought I would never do: I went out, bought his book, and
started reading it. In light of what he said, I ended up being much more
impressed that I expected (which is not to say much). Who knows whether his
work will pan out - but in general the lesson here is to try to judge for
ourselves the imporance of a piece of work by what it brings to the
equation, and not by what the popular media and trying to make it out to
be...
Just my 2 cents.
Patrick
(pa...@mailaps.org)
> In article <4b8cc0a6.02102...@posting.google.com>,
> Thomas Larsson <thomas....@hdd.se> wrote:
> >In the last six months, the only physicists that have
> >made it into popular media seem to be [...]
>
>
> >Stephen Wolfram (worse overselling than M-theory),
> >
[Moderator's note: unnecessary quoted text removed. -- KS]
Rain
writes
[unnecessary quoted text deleted]
>Ignore the popular media when you want to know what's really
>cool in physics these days. There ain't no crisis. The battle
>for new knowledge is a desperate struggle, as usual - but not hopeless.
>
>(And above I've been neglecting all the really cool stuff that's
>happening in "non-fundamental" physics, especially condensed matter.)
Yes I totally agree with the sentiments expressed above. It seems as if
we are encountering an annoying meme. They are easy to start and
propagate. First, a few people talk themselves into a corner and to make
themselves feel better they ensnare others. Secondly this becomes a
self-propagating meme which if it is not stopped soon becomes an
insidious "urban myth". The last phase is the most destructive of all -
yes, you've guessed it - it becomes ANOTHER DREADED "CONSPIRACY THEORY"!
Civilisation is finished once the final phase has taken hold. :)
--
The Physics
http://www.earthpoetry.demon.co.uk
RC
puppe...@hotmail.com
[snip]
> The issue here is that somehow EM has this odd potential theory that comes
> in two forms, and I don't *physically* understand why that is - in fact it's
> very strange and just saying "it's a nontrivial bundle" doesn't make it less
> so. I certainly did not mean that non-trivial bundles are not interesting.
"Strange" is nearly always just a question of level of experience.
The first time you experience many things is likely to be strange.
The point about a monopole being a nontrivial bundle does make it
less strange *if* you find fibre bundles non-strange. If you find
them strange, or have no experience with them, then of course it
does not help. Calling them flingle behrs would not help if you
didn't know what a flingle behr was. Never mind calling it a
nargle flingle behr.
There are at least two tricks about a non-trivial bundle
presentation of a monopole that you need to know in order
to see how it helps.
First, you need to understand how to build a non-trivial
bundle. That is a matter of patching together two or more
regions around the monopole. Say you do this in hemi-spheres
for example. On the north one, you use a gauge that the
monopole's string is in the south hemisphere. On the south
one you use a gauge that the string is in the north. Then
you sew them together with a joining function. And you
throw away the parts that are problems. So now you have a
presenation of the monopole where there is no string.
All you have is some funny business going on at the actual
monopole.
That's what trick two is. And the key there is symmetry breaking.
And that is where the "infamous" snake with a broken back comes
into the demo.
Imagine you started with a torus. And the cross section of
the torus is a symmetry. (Let me wave my hands a bit.)
Now, embed a mobius strip in the torus in the obvious way.
Let a line drawn crosswise on the mobius strip be the sub-set
of symmetry that survives at low energy.
Now, if you started with a demo of this, say two feet across,
you could see the mobius strip curling round inside the torus.
And if you imagine shrinking the torus, no matter how small
you shrink it, the kink in the mobius is still there. So
you've got a topological charge at work here. And people
were very excited about that because they hoped it would
lead to charge quantization. Lots of fun.
If you imagine that at high enough energy, where you can probe
small enough distance, the full set of symmetry comes back,
that's just like the mobius in the donut. If, as you shrank
your torus, the mobius strip eventually became able to twist
around as it liked, even unjoining and unkinking, then at
high enough energy, it could get rid of the kink. But the
assymptotic large distance parts would not be able to do
that because those symmetries are frozen out. So you could
get rid of the end of the monopole's string by having the
symmetry restored at some very small distance. But at large
distances and low energy, the monopole field would be
stable due to topology.
And the snake? Well, when I did this for my MSc, I did a
talk with just such a demo. Lots of cardboard and tape
and staples, and one side of the mobius pink, and the
other blue. But I could not get the darn thing to
curve round into a torus and still make it visible and
understandable from the back of the room. Too many strips
and slats and rings in the road. So I left it straight
and asked people to imagine this tube was a torus. And
it looked like a snake with a broken spine. Which explains
(huge big grin) how the dinosaurs died. See, when the
meteor hit the ground it made a huge *BANG!* And they
all turned very suddenly to see what the noise was and
*snap* all their spines broke.
Socks
Murray Arnow
"Patrick Amon" <pa...@earthlink.net> wrote:
>
>A few days ago I attended a (technical) lecture by Wolfram at Courant. Much
>as I previously agreed with the common wisdom that his recent work has been
>mostly overblown hype, I was actually surprised by what I heard. The lecture
>was not publicized and was only open to members of the NYU community i.e.
>Courant, and Physics and Chemistry depts. After the end of his lecture, many
>of the questions to Wolfram were about his intellectual honesty and whether
>his work was hype or substance. It didn't seem anyone was inclined to try to
>judge by themselves. Toward the very end, one person (OK, she deserves the
>credit so I'll give a name: Glennys Farrar, from the Center from Particle
>Astrophysics, with which I'm also affiliated) asked one very good question:
>is your "theory" experimentally verifiable? Can it be disproven in a
>reasonable amount of time at a reasonable cost? In other words, is it
>physics (maybe the reasonable time/reasonable price and requirements for
>physics, are they?)? Much to his credit, Wolfram seemed to have actually
>thought of those questions and gave intelligent, intelligible answers.
>
Your 2 cents is all sense. I had been wondering with the recent "hoax"
posts why this question is not asked of the Bogdanovs. The major concern
here is the nonunderstandable papers written by the brothers. Physics
requires that there be some observable result for a theory. Did any of
the papers state an observable conclusion? Even if their papers were
written in jabberwocky, a claim that they can explain known observations
and predict new ones can establish their credibility.
My opinion is that these two are not hoaxers; they believe what they
say. Their replies to criticism and other factors make me think that they
meet the definition of pathological science practitioners, as described
by Langmuir in his famous lecture at GE.
Jeffery
> make an argument that theory has become rather top-heavy of late. (My
> personal slant is that string theory and the like should be thought of as
> mathematical physics rather than particle physics, more an attempt to
> generalize and understand the models we use to study the real world than
> to actually create models of the real world itself.)
In particle physics, there was a continuous interchange and dialog
between theory and experiment, from when Oersted saw that an electric
current deflected a compass needle, to when the W+, W_, and Z bosons
were detected at CERN with the predicted mass. Theorists would predict
things that would be immediately detected, and experiments would
detect unexpected things that were then explained by theorists. Since
then, theory and experiment parted ways. Of course, there have been
great discoveries in experimental particle physics since then, such as
the discovery of the top quark and tau neutrino, but that was just
further confirmation of the Standard Model, which theoretical
particle physicists have long since left in the dust, as they
progressed beyond it to grand unification, supersymmetry, string
theory, M-theory, loop quantum gravity, brane world cosmology, etc.
However, this is not a criticism of theoretical particle physics. I
don't think there's anything unhealthy about that. This is just the
result of the fact that these other theories exist at higher energies
than we can currently reach. Right now, all experimental data in
particle physics is consistent with the Standard Model. However, it's
obviously not the final word in physics since there is so much about
it that is unexplained. Therefore the theorists do what they've always
done which is try to explain currently unexplained things in physics.
What should they do? Sit on their hands until the experimentalists
build bigger accelerators? So what is your criticism of theoretical
particle physics? Theoretical physcists have been very successful at
doing what they are supposed to do which is think up explanations for
unexplained aspects of what you observe, or unexplained aspects of
previous explanations. Even, if these theories turn out not to be
true, so what? We've never had a view of the Universe that was
actually true. For instance, Newtonian mechanics is obviously not true
since it doesn't take into account relativity or quantum mechanics.
What then is your criticism of modern theoretical particle physics,
even if the theories are later contradicted by experiment? They
haven't been contradicted yet. Superstring theory successfully
explains what it was intended to explain, namely uniting gravity with
the other forces, while remaining consistent with experimental data,
which is the most you could ask of any theory.
Jeffery Winkler
Ahmet Gorgun
news:aq4jk9$pe5$1...@e250.ripco.com...
> Your 2 cents is all sense. I had been wondering with the recent "hoax"
> posts why this question is not asked of the Bogdanovs. The major concern
> here is the nonunderstandable papers written by the brothers. Physics
> requires that there be some observable result for a theory. Did any of
> the papers state an observable conclusion? Even if their papers were
> written in jabberwocky, a claim that they can explain known observations
> and predict new ones can establish their credibility.
I agree. But the same criteria must be applied to everybody not only to
Bogdanovs. None of the following papers pass your requirement of stating an
observable conclusion. (They were all published in CQG:
http://www.iop.org/EJ/S/UNREG/Ce68lvg.t,gp.ITEK06S5w/journal/-page=extra.1/C
QG)
---------------------------------------------------------------
Homologically simple singularities
Lawrence Brenton
Mathematics Department, Wayne State University, Detroit, MI 48202, USA
Received 16 August 2000
Abstract. We discuss a family of topological models for spacetimes whose
spacelike hypersurfaces are exotic cohomology 3-spheres, and examine the
structure of their initial singularities.
Non-vacuum twisting type-N metrics
Pawel Nurowski1 and Jerzy F Plebanski2
1 Instytut Fizyki Teoretycznej, Uniwersytet Warszawski, ul. Hoza 69, 00-618
Warszawa, Poland
2 Departamento de Fisica, CINVESTAV, Apdo postal 14-740, 07000 Mexico, DF
Received 20 October 2000
Abstract. We present a number of results for twisting type-N metrics....
Supersymmetric higher-derivative actions in 10 and 11 dimensions, the
associated superalgebras and their formulation in superspace
Kasper Peeters1, Pierre Vanhove2 and Anders Westerberg3
1 CERN, TH-division, 1211 Geneva 23, Switzerland
2 SPT, Orme des Merisiers, CEA/Saclay, 91191 Gif-sur-Yvette Cedex, France
3 NORDITA , Blegdamsvej 17, DK-2100 Copenhagen Ø, Denmark
Received 14 November 2000
Abstract. Higher-derivative terms in the string and M-theory effective
actions are strongly constrained by supersymmetry. Using a mixture of
techniques, involving both string-amplitude calculations and an analysis of
supersymmetry requirements, we determine the supersymmetric completion of
the R4 action in 11 dimensions to second order in the fermions, in a form
compact enough for explicit further calculations. ...
On a general class of wormhole geometries
A DeBenedictis1 and A Das2
1 Department of Physics, Simon Fraser University, Burnaby, British Columbia,
V5A 1S6, Canada
2 Department of Mathematics and Statistics, Simon Fraser University,
Burnaby, British Columbia, V5A 1S6, Canada
Received 3 October 2000, in final form 10 November 2000
Abstract. A general class of solutions is obtained which describe a
spherically symmetric wormhole system. The presence of arbitrary functions
allows one to describe infinitely many wormhole systems of this type. The
source of the stress-energy supporting the structure consists of an
anisotropic brown dwarf `star' which smoothly joins the vacuum and may
possess an arbitrary cosmological constant. It is demonstrated how this set
of solutions allows for a non-zero energy density and therefore allows
positive stellar mass as well as how violations of energy conditions may be
minimized. Unlike examples considered thus far, emphasis here is placed on
construction by manipulating the matter field as opposed to the metric. This
scheme is generally more physical than the purely geometric method. Finally,
explicit examples are constructed including an example which demonstrates
how multiple closed universes may be connected by such wormholes. The number
of connected universes may be finite or infinite...
----------------------------------------------------------------------
The number of connected universes may be finite or infinite????? Arbitrary
cosmological constant???? infinitely many wormhole systems....
It is unfair to call Bogdanov's paper a parody, you can't parody this
stuff...
Ahmet Gorgun
John Baez
Jeffery <jeffery...@hotmail.com> wrote:
>What then is your criticism of modern theoretical particle physics,
>even if the theories are later contradicted by experiment? They
>haven't been contradicted yet. Superstring theory successfully
>explains what it was intended to explain, namely uniting gravity with
>the other forces, while remaining consistent with experimental data,
>which is the most you could ask of any theory.
I think this is a somewhat overoptimistic assessment of the
state of superstring theory. To the best of my knowledge,
nobody has a version of superstring theory that can be proved
to reduce to the Standard Model... possibly together with lots
of extra particles for which there are good reasons we shouldn't
have observed them yet.
One reason is that supersymmetry breaking is still quite mysterious.
Another is that in superstring theory vacua that correspond to spacetimes
with little curled-up extra dimensions, it's hard to show that those
little curled-up extra dimensions don't get big, or collapse down
to a singularity. Another even tougher problem is that among all
the superstring theory vacua, we don't know which one is truly stable
(or which *ones* are stable). For all we know, the stable string
theory vacua describe worlds very unlike our own!
But, despite the subject header, I don't think this is a "crisis".
Physics is very hard, and the frontiers of knowledge are precisely
where we run up against the frontiers of ignorance. I do however
think there should be more work on alternatives to string theory:
putting all your eggs in one basket is never a good idea. That's
why I work on a different approach to quantum gravity. This other
approach has problems of its own... so we need people to consider
even more approaches.
If we spread out in different directions, like ants searching for
food, someday one of the ants will find the picnic.
A.J. Tolland
> A.J. Tolland wrote:
> > (1) There is a vast gap between theory and experiment. One could
> > make an argument that theory has become rather top-heavy of late. (My
> > personal slant is that string theory and the like should be thought of as
> > mathematical physics rather than particle physics, more an attempt to
> > generalize and understand the models we use to study the real world than
> > to actually create models of the real world itself.)
On Wed, 6 Nov 2002, Jeffery wrote (repeatedly):
> What then is your criticism of modern theoretical particle physics?
My complaint, essentially, is that theoretical particle physics is
no longer really studying particle physics at all, but instead a branch of
mathematical physics. We started studying models which took gigantic
steps beyond the experimentally verified steps, and before too long, we
found ourselves studying the models we use to study the models we use to
study particle physics. Most papers on hep-th today are focused on the
analysis of various physically irrelevant toy-models. A far smaller
number of papers make any serious attempt to construct physically
realistic models.
Now don't get me wrong. I _really_ like mathematical physics. I
even left high energy physics so that I could play with pseudo-physical
mathematics without having to worry about reality. But I worry that there
are far too many would-be Einsteins out there, churning out
semi-mathematical garbage about highly speculative physics. I'd like to
see more people trying to see what's just beyond the next energy frontier.
I'd like to see more folks trying to extract precise predictions from QCD.
(I remember one theorist I knew joking that the experimentalists would
gladly kill him in exchange for a good prediction of the QCD background at
14 TeV.)
Am I suggesting that theorists sit on their hands until they have
data? No. But I would suggest that they focus their attention on
problems which are simpler and more relevant than pp-waves and
noncommutative spacetime. For instance, seeing if one can improve on
lattice techniques in QCD with ideas borrowed from matrix theory. It
seems to me that we ought to leave the hardcore theory to the handful of
people (cough cough Witten) who can do it efficiently.
Actually, I don't worry about any of this most of the time. Too
busy trying to learn how to do mathematics properly. :)
> Superstring theory successfully explains what it was intended to
> explain, namely uniting gravity with the other forces, while remaining
> consistent with experimental data, which is the most you could ask of
> any theory.
You're repeating propaganda. The real situation is far more
murky. For one thing, it's not yet clear that there exists any consistent
string model which is consistent with current experimental data. (I've
seen various "string inspired" field theories written down, but I've seen
no proof that they correspond to stable string vacua. And I've never seen
a string theory which can deal with the dark energy problem...) Nor is it
clear that string theory really does describe gravitational excitations
correctly. We can't do computations in most cases.
--A.J.
Thomas Larsson
What troubles me is that deliberate fraud does not seem to be that unusual
in physics anymore. To check that I am not making things up, you may wish to
consult e.g. the links below.
http://www.salon.com/tech/feature/2002/09/16/physics/
http://www.mindfully.org/Industry/Scientific-Integrity-Questions2aug02.htm
John Devers
> the discovery of the top quark and tau neutrino, but that was just
> further confirmation of the Standard Model, which theoretical
> particle physicists have long since left in the dust, as they
and
> than we can currently reach. Right now, all experimental data in
> particle physics is consistent with the Standard Model. However, it's
> obviously not the final word in physics since there is so much about
This has jogged my memory about a question I have had for a while, why
are not phonons in the standard model?
Is there any model (or table I can look up) that contains polaritons
or spinons or magnons or chargons etc? a compiled list as there is for
the standard model.
Steve Casselman
> steps beyond the experimentally verified steps, and before too long, we
> found ourselves studying the models we use to study the models we use to
> study particle physics.
If physics is anything like the rest of the world then the last 10% will
take 90% of the work. I would expect fundamental breakthroughs to happen
less and less as we know more and more physics. We should all fields of
physics to produce less fundamental breakthroughs and more refinement of
existing theories are time goes on.
Steve
Murray Arnow
>"Murray Arnow" <ar...@iname.com> wrote in message
>news:aq4jk9$pe5$1...@e250.ripco.com...
>> Your 2 cents is all sense. I had been wondering with the recent "hoax"
>> posts why this question is not asked of the Bogdanovs. The major concern
>> here is the nonunderstandable papers written by the brothers. Physics
>> requires that there be some observable result for a theory. Did any of
>> the papers state an observable conclusion? Even if their papers were
>> written in jabberwocky, a claim that they can explain known observations
>> and predict new ones can establish their credibility.
>I agree. But the same criteria must be applied to everybody not only to
>Bogdanovs. None of the following papers pass your requirement of stating an
>observable conclusion. (They were all published in CQG:
>http://www.iop.org/EJ/S/UNREG/Ce68lvg.t,gp.ITEK06S5w/journal/-page=extra.1/C
>QG)
[snip abstracts of Math Physics articles]
And I agree with you. I maintain that Mathematical Physics is a branch of
mathematics. The goal, as I see it, is not to produce laboratory
testable theories and solutions; it is to develop mathematically
consistent theories and solutions. This is quite all right, but it isn't
physics.
eb...@lfa221051.richmond.edu
John Devers <johnd...@froggy.com.au> wrote:
>This has jogged my memory about a question I have had for a while, why
>are not phonons in the standard model?
This is a bit like asking, "Why aren't eggplants in the standard
model?" The standard model is supposed to describe the fundamental
particles. It doesn't explicitly mention big, complicated things that
are made of those fundamental particles.
Eggplants are made of quarks and leptons, so they are in principle
described by the standard model, even though there's not an explicit
eggplant term in the equations. Phonons (and other quasiparticles) are
excitations of large collections of fundamental particles. They're
in principle described by the standard model, even though
there's not an explicit phonon term in the equations.
Gotta go -- I'm hungry!
-Ted
--
[E-mail me at na...@domain.edu, as opposed to na...@machine.domain.edu.]
Sunok Seo
Just what were the intelligent answers of Wolfram?
Danny Ross Lunsford
> >I agree. But the same criteria must be applied to everybody not only to
> >Bogdanovs. None of the following papers pass your requirement of stating
an
> >observable conclusion. (They were all published in CQG:
>
>http://www.iop.org/EJ/S/UNREG/Ce68lvg.t,gp.ITEK06S5w/journal/-page=extra.1/
C
> >QG)
>
> [snip abstracts of Math Physics articles]
>
> And I agree with you. I maintain that Mathematical Physics is a branch of
> mathematics. The goal, as I see it, is not to produce laboratory
> testable theories and solutions; it is to develop mathematically
> consistent theories and solutions. This is quite all right, but it isn't
> physics.
Perhaps a better term would be "physical mathematics".
-drl
Toby Bartels
>And I agree with you. I maintain that Mathematical Physics is a branch of
>mathematics. The goal, as I see it, is not to produce laboratory
>testable theories and solutions; it is to develop mathematically
>consistent theories and solutions. This is quite all right, but it isn't
>physics.
The problem is that much of the work that's been discussed here
isn't held to the standards of mathematics -- rigorous proof.
That can be all right in *applied* mathematics,
where the mathematics describes a theory that models
an effect in nature that is experimentally verified.
Then we know that something sensible is behind the math,
even if nobody has found a rigorous treatment of it yet.
For example, we know that Yang-Mills QFT is reasonable,
because it describes the results of particle theory experiments,
even though nobody has won the million dollar prize for proving it.
When we lack a connection to either experiment or proof, however,
then anything goes.
-- Toby
Dirk Bruere
"Thomas Larsson" <thomas....@hdd.se> wrote in message
news:4b8cc0a6.0210...@posting.google.com...
It is inevitable when papers_published = career_and_money
It is the result of the culture that has been allowed to develop where
quantity counts more than quality. A culture (presumably) being run by
people who cannot judge quality at all.
Dirk
Greg Kuperberg
In article <aqo2nc$9cn$1...@glue.ucr.edu>,
Toby Bartels <toby...@math.ucr.edu> wrote:
>When we lack a connection to either experiment or proof, however, then
>anything goes.
It is exactly this naive kind of loyalty to mathematical rigor that
led to the Bogdanov affair. Look again at the roster of rapporteuers.
Many of the rapporteuers are entirely rigorous in their own work.
But they apparently think, as you do, that once mathematical rigor is
gone, anything goes. On these grounds they had no qualms about signing
off on the Bogdanovs. As far as they were concerned, it was just another
flag to run up the flagpole.
Good theoretical physics has more to it than this. Even when theory is
neither mathematically rigorous nor directly connected to experiment, it
might well pass consistency checks or otherwise have deductive strength.
Non-rigorous deductive strength is always the hardest thing for outsiders
to understand, but often it's definitely there. For one thing, it tends
to appear spontaneously when many good scientists all think about the same
hard problem. It almost looks like a conspiracy - but of course it's not.
For example, cosmological inflation developed for 20 years without real
mathematical rigor or experimental confirmation. But now it's turning
out to be true. Was Alan Guth clairvoyant or incredibly lucky? I don't
think so.
--
/\ Greg Kuperberg (UC Davis)
/ \
\ / Visit the Math ArXiv Front at http://front.math.ucdavis.edu/
\/ * All the math that's fit to e-print *
Ralph E. Frost
Dirk Bruere <di...@neopax.com> wrote in message
news:aqf2or$9ncli$1...@ID-120108.news.dfncis.de...
> > http://www.salon.com/tech/feature/2002/09/16/physics/
> >http://www.mindfully.org/Industry/Scientific-Integrity-Questions2aug02.htm
This sounds like a recipe for disaster - or for a not too distant
futuristic sci-fi film where discovery comes from the 1000 typing monkeys
syndrome.
There is bound to be a much larger number of earnest, diligent, hardworking
researchers than the small number of brutish louts who cheat and lie badly,
isn't there?
I'd guess so but I'd also guess those folks are silent on the matter
and thus run the risk of being plowed under by an uninformed,
perturbed public backlash, the likes of which no one in this
marketplace has ever seen. The silence is also part of the problem
and the culturally heritage of the cold-war physics era. Don't think
it is not part of the problem. It is part of the culture. Who can
afford to say 'NO'?
If it is TRUE that "number of papers_published = career_and_money",
then that obviously is a central difficulty that is wildly dissociated
from the notion of moving along in science by relying upon the
scientific method -- unless we are in an age ruled by the "1000 typing
monkeys syndrome". And, if you listen to the cynical reflections
hereabouts, no one thinks that they are responsible for implementing
adjustments into the present system so that the next generation can
return to relying on the scientific method. The wave have crashed on
the shore.
But, maybe that is just the way things need to go -- a deep,
self-adaptive purge. Not a complete thermonuclear meltdown but just a
minor dark age -- a difficult transition out of the cul-de sac.
Maybe I misunderstood what you said. Are you suggesting that the
crisis in physics is CAUSED BY a crisis in culture and that physicists
(academicians, journal editors and publishers -- and should the text
book providers be exempted?), are helpless pawns of the funding
formula and massive PR thrust toward "being a World Class Research
Centre", so as to attract more raw product plus more industrial
funding?
Thank God for the crisis in physics. It is apparently long overdue.
--
Ralph Frost
Looking for a desktop model to help you ponder this topic?
http://flep.refrost.com
Use more robust symbols
Seek a thought worthy of speech.
Toby Bartels
>Toby Bartels wrote:
>>When we lack a connection to either experiment or proof, however,
>>then anything goes.
>It is exactly this naive kind of loyalty to mathematical rigor that
>led to the Bogdanov affair. Look again at the roster of rapporteuers.
>Many of the rapporteuers are entirely rigorous in their own work.
>But they apparently think, as you do, that once mathematical rigor is
>gone, anything goes. On these grounds they had no qualms about signing
>off on the Bogdanovs. As far as they were concerned, it was just another
>flag to run up the flagpole.
I think that you may have misinterpreted the point of my post.
I don't *support* an <anything goes> attitude.
I just think that it's a natural sociological consequence
when there is no independent grounding for ideas,
such as is provided by mathematical proof or experimental verification.
(Or, for analogies with other fields, correspondence with
what is actually written in the text.)
>Good theoretical physics has more to it than this. Even when theory is
>neither mathematically rigorous nor directly connected to experiment, it
>might well pass consistency checks or otherwise have deductive strength.
>Non-rigorous deductive strength is always the hardest thing for outsiders
>to understand, but often it's definitely there. For one thing, it tends
>to appear spontaneously when many good scientists all think about the same
>hard problem. It almost looks like a conspiracy - but of course it's not.
Certainly one can have deductive strength without rigour.
Most of Leonhard Euler's brilliant mathematics was based on this.
Today, mathematicians no longer consider it enough for publication,
but they still engage in nonrigourous speculation all the time,
as I assume you know from your own experience.
But the goal is in mind to find precise conjectures and prove them.
And good theoretical physics has in mind the goal
to suggest experimental tests and (let others) conduct them.
Or to put it another way, the word "directly" is yours, not mine.
I certainly don't mean to imply that every idea in
theoretical physics beyond the standard model,
or in literary criticism for that matter, is nonsense.
But that's a danger with no outside check on your ideas,
outside your own group of people following the same ideas.
You suggested that the Bogdanovs' rapporteurs thought that anything goes.
I don't agree with them, but where do you think that they got that idea?
-- Toby
Greg Kuperberg
Sure. Few mathematicians or physicists support idle speculation in
their own area.
>I just think that it's a natural sociological consequence when there is
>no independent grounding for ideas, such as is provided by mathematical
>proof or experimental verification.
Yes, many mathematicians and physicists do believe that this problem is
rampant in fields other than their own. And two responses to that are:
1) You can criticize other fields as too open-minded.
2) You can approve dubious speculation as acceptable to other fields.
You emphasize (1) as your own view, while I maintain that (2) has been a
factor in the Bogdanov affair. In one respect (1) and (2) are opposite:
One is conservative, the other permissive. But in another respect they
are consistent, because they are both based on a lack of respect for
someone else's research area. Or at the very least, a lack of
understanding.
Mark
"A.J. Tolland" <a...@math.berkeley.edu> writes:
> My complaint, essentially, is that theoretical particle physics is
>no longer really studying particle physics at all, but instead a branch of
>mathematical physics.
Well, that's because the pressing problem in theoretical physics *IS*
mathematical -- namely: how to make the fundamental tenets of GR and
QFT mathematically cohere.
You already have the information required to resolve QFT and GR -- namely,
QFT and GR, themselves. The pressing question is: what kind of mathematics
makes it fit together? So, of course, most of the basic work is being done
on mathematical end. There's a huge psychological gap, primarily of
a mathematical nature, that's blocking progress to the final resolution of
this fundamental issue, that needs to be overcome.
Robert Kolker
Murray Arnow wrote:
> And I agree with you. I maintain that Mathematical Physics is a branch of
> mathematics. The goal, as I see it, is not to produce laboratory
> testable theories and solutions; it is to develop mathematically
> consistent theories and solutions. This is quite all right, but it isn't
> physics.
>
Are you asserting that highly mathematical theories make no testable
predictions about the world? This is clearly not the case for the
quantum theories of fields, electrodynamics and heavy particles. It is
surely not the case for either of the Relativity Theories. So what are
the theories that you claim make no testable predictions?
On the other hand if you are saying the modern theories are not
intuitive, you may be quite right, but as long as they make testable
predictions they are science, and not just pure mathematics.
Bob Kolker
A.J. Tolland
On Fri, 15 Nov 2002, Mark wrote:
> You already have the information required to resolve QFT and GR -- namely,
> QFT and GR, themselves. The pressing question is: what kind of mathematics
> makes it fit together?
I don't think there will be any reconciliation of QFT & GR using
only the ingredients of QFT & GR. It seems more likely to me that we need
to discover some new physics, not some clever way of rewriting QFT & GR.
--A.J.
Boris Borcic
Mark wrote:
>
> Well, that's because the pressing problem in theoretical physics *IS*
> mathematical -- namely: how to make the fundamental tenets of GR and
> QFT mathematically cohere.
>
> You already have the information required to resolve QFT and GR -- namely,
> QFT and GR, themselves. The pressing question is: what kind of mathematics
> makes it fit together? So, of course, most of the basic work is being done
> on mathematical end. There's a huge psychological gap, primarily of
> a mathematical nature, that's blocking progress to the final resolution of
> this fundamental issue, that needs to be overcome.
This is about the third rewording I make in s.p.r
of a question about this point. To put it vaguely
but concisely, I believe in something I call the
"jack-pot principle" : it applies in this case to
the expectation that fitting together QFT and GR
can/should bring to a theory allowing more testable
predictions that either QFT or GR alone.
What if indeed, the predictions of such a smoothly
synthetic theory were to spectacularly violate
one (or many) of physics disciplinary boundary,
by giving rise to something that's too obviously
interpretable as pertaining to matters traditionaly
excluded from the object of physics ?
IOW, what if the problem with mating QFT with GR
was not independent from one of restructuring the
system of sciences (and perhaps other disciplines),
so that trying to mate QFT and GR without any
propensity to rework the system of sciences is
in fact self-defeating ?
Up to now, I've recieved no answer to the various
forms I gave to that question. Perhaps this time
there will at least be someone who can tell me, "I
see your point, but I find such an expectation
highly implausible because..."
Regards, Boris Borcic
--
L'anthropie met un terme aux dynamiques
Mark
>IOW, what if the problem with mating QFT with GR
>was not independent from one of restructuring the
>system of sciences (and perhaps other disciplines),
>so that trying to mate QFT and GR without any
>propensity to rework the system of sciences is
>in fact self-defeating ?
You're beating around the bush. What you're really asking is
what if the mating of GR and QFT results in a theory of
alternate universes that waters down any empirical content
by asserting in effect that anything's possible?
Well, then it's not an empirical science and it's back to the
drawing board.
If the theory says anything's possible then it's impossible to
refute it. Whatever you "refute" it with, you're not actually
refuting the theory but refuting something else entirely different.
So, you're perpetually playing the game then of never refuting
the theory that says everything is possible, but something entirely
different that just happened to have been confused with the theory.
An example of this is where, in quantum theory, a prediction is make
that a process has probability 10^{-1000}. If the process is discovered
to have occurred, then it's not the theory that's been refuted, but
something entirely differently: namely the theory which said the process
was impossible. But since the theory which said the process was
impossible was not the actual theory published in the textbooks and
journals, then the test was all for nought. Meanwhile, the original
theory remained untouched, because it said the process WAS possible,
and you can't refute something by discovering something which it
said WAS possible!
Thomas Larsson
I maintain that a major breakthrough has was made in the 1990 by
algebraists,
including myself. Recall that
1. The correct symmetry of GR is the full space-time diffeomorphism
group.
2. In quantum theory, the relevant representations are of
lowest-weight type.
Combining these item, it seems obvious that one needs to understand
the
lowest-weight reps of the diff group, which on the Lie algebra level
becomes
the multi-dimensional Virasoro algebra.
This can hardly be dismissed as trivial, since it took 26 years from
the discovery of the original Virasoro algebra in 1968 until Rao and
Moody wrote
down the first reps of its higher-dimensional analogue in 1994. And as
I
described on a parallel thread, the most interesting reps involving
the
Einstein equations really only work if spacetime has four dimensions,
which is
a rather non-trivial prediction not in total disagreement with
observation.
As for the standard objection of anomalies, one can note that all
interesting
(= non-trivial, unitary and irreducible) reps of the Virasoro algebra
have
c > 0. By demanding anomaly freedom one thus axiomatically throws away
everything of mathematical interest, which does not seem like a very
good idea.
To me this seems conceptually like QFT and GR and nothing more,
although I am
not clear over the precise connection.
John Devers
Hi Ted, I hope you enjoyed that eggplant, was it fried or in a
dessert:-) I think you have helped me to broaden my understanding of
quasi-particles.
is there a major difference between quasi-particle excitations like
phonons and excitations like polaritons, polarons and excitons? Is all
of a systems excited energy devoted to just one quasi-particle or can
it be devided up between a number of quasi-particle systems?
Is there a list of all the quasi-particles observed so far by
scientists and the ones predicted also available?
I had abit of a go at compiling one in this thread at SSSF one time, I
found about 20 or so by surfing.
http://www2b.abc.net.au/science/k2/stn-old/archive2001/posts/March/topic259986.shtm
Could a phonon be regarded as an isolated quasi-particle from an
excited system at any time? When a phonon jumps from one excited
system to another can it be considered as an isolated quasi-particle
or is it just that the excited state of one system decreases and the
excited state of the interacting system increases?
Does entropy increase or dam up during aq phonon transfer?
The Quantum of Heat Flow.
Jim Jastrzebski
"A.J. Tolland" a...@math.berkeley.edu wrote
in<Pine.SOL.4.44.0211151039530.15493-100000@pub-708c-16>
>I don't think there will be any reconciliation of QFT & GR using
>only the ingredients of QFT & GR. It seems more likely to me that we need
>to discover some new physics, not some clever way of rewriting QFT & GR.
Why?
At what places you see them not fitting
together? Please name at least one.
Toby Bartels
Greg Kuperberg wrote:
>Toby Bartels wrote:
>>I don't *support* an <anything goes> attitude.
>Sure. Few mathematicians or physicists support idle speculation in
>their own area.
As neither do you, judging from your previous post.
>>I just think that it's a natural sociological consequence when there is
>>no independent grounding for ideas, such as is provided by mathematical
>>proof or experimental verification.
>Yes, many mathematicians and physicists do believe that this problem is
>rampant in fields other than their own. And two responses to that are:
I don't know what's "other" than their own.
We're talking about mathematical physics here.
>1) You can criticize other fields as too open-minded.
>2) You can approve dubious speculation as acceptable to other fields.
>You emphasize (1) as your own view, while I maintain that (2) has been a
>factor in the Bogdanov affair. In one respect (1) and (2) are opposite:
>One is conservative, the other permissive. But in another respect they
>are consistent, because they are both based on a lack of respect for
>someone else's research area. Or at the very least, a lack of
>understanding.
It does seem that (1) and (2) are the pretty natural conclusions to draw
in response to an assumption that such a problem is rampant in a field.
Either that's OK, or it isn't (although one might also be ambivalent,
or try to draw distinctions between problematic and unproblematic instances).
As for this "lack of respect/understanding" for "someone else",
I'd like some clarification of exactly what you're referring to.
Right now, you seem to be saying that mathematicians and physicists
often don't respect or understand mathematical physics,
which would be ... odd.
-- Toby
Louis M. Pecora
wrote:
> Well, that's because the pressing problem in theoretical physics *IS*
> mathematical -- namely: how to make the fundamental tenets of GR and
> QFT mathematically cohere.
I don't think that's a foregone conclusion. It assumes that there are
no experiments that could be done that show either theory is an
approximation of something even more fundamental.
Rather I would liken the current state of things (string theory and
unifying QFT and GR and all that) as an experiment in
mathematics/theory to see if there really does exist a formulation in
which both can reside comfortably (consistently) and/or both be derived
from as "special cases."
Assuming that we can now wash our hands of experiment and just
concentrate on the mathematics seems going a bit too far to me.
--
Lou Pecora
- My views are my own.
Murray Arnow
>Murray Arnow wrote:
>> And I agree with you. I maintain that Mathematical Physics is a branch of
>> mathematics. The goal, as I see it, is not to produce laboratory
>> testable theories and solutions; it is to develop mathematically
>> consistent theories and solutions. This is quite all right, but it isn't
>> physics.
>Are you asserting that highly mathematical theories make no testable
>predictions about the world?
No.
>This is clearly not the case for the
>quantum theories of fields, electrodynamics and heavy particles. It is
>surely not the case for either of the Relativity Theories. So what are
>the theories that you claim make no testable predictions?
>
>On the other hand if you are saying the modern theories are not
>intuitive, you may be quite right, but as long as they make testable
>predictions they are science, and not just pure mathematics.
Let's make this clear. My statement concerns the field identified as
Mathematical Physics. How do I know such a field exists? It is because
there are people who identify themselves as Mathematical Physicists who
claim they are doing Mathematical Physics. It seems to me that
Mathematical Physics is not primarily concerned with developing
laboratory testable theories or models. When you take the laboratory
away from physics, you are not doing physics.
The work referred to above can be indeed highly mathematical; however,
the mathematical results are also physically testable. This is doing
physics.
I am not decrying Mathematical Physics. I see it as a branch of
mathematics interested in investigating the mathematical properties of
problems stemming from physics. But again, this is mathematics not
physics.
A.J. Tolland
On Mon, 18 Nov 2002, Thomas Larsson wrote:
> [usual spiel about lowest weight reps of diff]
> ....
> And as I described on a parallel thread, the most interesting reps
> involving the Einstein equations really only work if spacetime has four
> dimensions, which is a rather non-trivial prediction not in total
> disagreement with observation.
These are, of course, tantalizing hints.
But they're also old news! You've told us this before, in almost
exactly these words. Give me a model that I can study, and I'll take this
idea seriously.
And until then, try to avoid saying things like the following...
> As for the standard objection of anomalies, one can note that all
> interesting (= non-trivial, unitary and irreducible) reps of the
> Virasoro algebra have c > 0. By demanding anomaly freedom one thus
> axiomatically throws away everything of mathematical interest, which
> does not seem like a very good idea.
Maybe this is why you've having such a hard time getting people to
pay attention to your idea? Field theories with anomalies in their gauge
symmetries are *broken*! It's difficult even to call them field theories
with a straight face!
If you must throw away all the interesting mathematical content to
get a physically consistent theory, then maybe the deep mathematics here
is not going to lead to good physics?
--A.J.
eb...@lfa221051.richmond.edu
In article <ar3q02$nb1$1...@e250.ripco.com>, Murray Arnow <ar...@iname.com> wrote:
>bobk...@attbi.com wrote:
>I am not decrying Mathematical Physics. I see it as a branch of
>mathematics interested in investigating the mathematical properties of
>problems stemming from physics. But again, this is mathematics not
>physics.
I think that this is correct. As I understand it, mathematical
physicists are mathematicians, not physicists. I'm pretty sure that
all the people I know who describe themselves as mathematical
physicists would agree with this statement. Our most visible resident
mathematical physicist here on sci.physics.research, John Baez,
certainly is a mathematician.
The name of the discipline is confusing -- it should really
be called physical mathematics or something.
Thomas Larsson
> And until then, try to avoid saying things like the following...
>
> > As for the standard objection of anomalies, one can note that all
> > interesting (= non-trivial, unitary and irreducible) reps of the
> > Virasoro algebra have c > 0. By demanding anomaly freedom one thus
> > axiomatically throws away everything of mathematical interest, which
> > does not seem like a very good idea.
Why? All non-trivial, unitary and irreducible reps of the Virasoro algebra
do have c > 0.
> If you must throw away all the interesting mathematical content to
> get a physically consistent theory, then maybe the deep mathematics here
> is not going to lead to good physics?
Good physics = complete lack of experimental support?
There are really two symmetries that are the coolest possible (not just
known, but possible, in view of classifications) from an algebraic point
of view:
1. mb(3|8) has maximal structure (maximal depth). It is also a localized
version of su(3)+su(2)+u(1), which is the correct symmetry of the standard
model.
2. vect(n) has minimal structure, and is the universal object that contains
every other algebra of vector fields as a subalgebra. Quantum reps that
involve the Einstein equations, i.e. gravity, only work out if n = 4.
So these objective algebraic criteria immediately and uniquely single out
the symmetries of quantum gravity coupled to the standard model in four
dimensions, and essentially nothing beyond that. Now, this is of course an
estethical argument that nobody needs to care about, were it not for a
minor detail usually ignored nowadays: quantum theory, gravity and the
standard model in 4D perfectly describe all observations up do date.
The choice of selection criteria is of course influenced by the known
outcome, but this is ok - good theoretical physics takes hints from
experiments. And this, of course, means that very little theory done today
is good physics.
An immediate corrollary: no phenomenon requiring new symmetries or extra
dimensions, e.g. new gauge bosons, proton decay, susy particles, new
submillimeter forces, etc. should be seen in the next generation of
experiments.
A.J. Tolland
On Tue, 19 Nov 2002, Thomas Larsson wrote:
> A.J. Tolland wrote:
> > And until then, try to avoid saying things like the following...
> >
> > > As for the standard objection of anomalies, one can note that all
> > > interesting (= non-trivial, unitary and irreducible) reps of the
> > > Virasoro algebra have c > 0. By demanding anomaly freedom one thus
> > > axiomatically throws away everything of mathematical interest, which
> > > does not seem like a very good idea.
>
> Why? All non-trivial, unitary and irreducible reps of the Virasoro algebra
> do have c > 0.
Because gauge theories with anomalies in their gauge symmetries
are broken. You can't keep proper track of all the degrees of freedom.
This leads to unfortunate behavior, like loss of unitarity. If you are
proposing to build a model which has some resemblance to ordinary quantum
field theory, your FIRST priority should be dealing with this problem.
And if you are not planning to build something resembling an
ordinary QFT.... well, good luck. Send us postcards.
> > If you must throw away all the interesting mathematical content to
> > get a physically consistent theory, then maybe the deep mathematics here
> > is not going to lead to good physics?
>
> Good physics = complete lack of experimental support?
Unitarity has plenty of experimental support
> An immediate corrollary: no phenomenon requiring new symmetries or extra
> dimensions, e.g. new gauge bosons, proton decay, susy particles, new
> submillimeter forces, etc. should be seen in the next generation of
> experiments.
Give us a cross section. Show us where your model(s) deviate from
the Standard Model.
--A.J.
Greg Kuperberg
Toby Bartels <toby...@math.ucr.edu> wrote:
>Greg Kuperberg wrote:
>>1) You can criticize other fields as too open-minded.
>>2) You can approve dubious speculation as acceptable to other fields.
...
>It does seem that (1) and (2) are the pretty natural conclusions to draw
>in response to an assumption that [laxity] is rampant in a field.
...
>As for this "lack of respect/understanding" for "someone else",
>I'd like some clarification of exactly what you're referring to.
You're right that at a broad level, mathematical physics has a
laissez-faire side in which anything can get published. I don't think
that this is unique to mathematical physics though - I think that you
see it in every discipline. I think that mathematical physics may have
a little bit more of it just because it's interdisciplinary.
But at a narrower level, everyone is blaming laxity on someone else.
If not someone in another discipline entirely, then at least someone in
another subdiscipline. This is a bit more likely in an interdisciplinary
area like mathematical physics, because a physicist can shrug at poor
work and say that mathematicians might like it and vice-versa.
As far as I know, none of the rapporteuers have ever coauthored or even
cited a Bogdanov paper. Most of the rapporteuers do mathematically
rigorous work themselves, none of it involving the KMS condition.
Their actions indicate that they are not personally interested in this
work, but they rationalized that someone else might be.
Aaron Bergman
In article <Pine.SOL.4.44.0211191232530.17901-100000@blue1>,
A.J. Tolland wrote:
> On Tue, 19 Nov 2002, Thomas Larsson wrote:
>> A.J. Tolland wrote:
>> > And until then, try to avoid saying things like the following...
>> > > As for the standard objection of anomalies, one can note that all
>> > > interesting (= non-trivial, unitary and irreducible) reps of the
>> > > Virasoro algebra have c > 0. By demanding anomaly freedom one thus
>> > > axiomatically throws away everything of mathematical interest, which
>> > > does not seem like a very good idea.
>> Why? All non-trivial, unitary and irreducible reps of the Virasoro algebra
>> do have c > 0.
> Because gauge theories with anomalies in their gauge symmetries
> are broken. You can't keep proper track of all the degrees of freedom.
> This leads to unfortunate behavior, like loss of unitarity. If you are
> proposing to build a model which has some resemblance to ordinary quantum
> field theory, your FIRST priority should be dealing with this problem.
When you try to quantize gauge theories anomalous or not, you get
non-unitary representations. The trick is that in non-anomalous
theories, the BRST operator is nilpotent and the BRST-cohomology
(i.e., the space of physical states) is unitary.
Aaron
[Moderator's note: I'm not sure what it means to say that a
space of states is unitary. - jb]
Thomas Larsson
> Because gauge theories with anomalies in their gauge symmetries
> are broken. You can't keep proper track of all the degrees of freedom.
> This leads to unfortunate behavior, like loss of unitarity. If you are
> proposing to build a model which has some resemblance to ordinary quantum
> field theory, your FIRST priority should be dealing with this problem.
It might be incorrect to call the multi-dimensional Virasoro cocycle an
"anomaly". As Jacques Distler kindly enlightened me about last year, there
are no gravitational anomalies in 4D. Nevertheless, the Fock modules
described below certainly have non-zero abelian charges (abelian
charge/abelian extension = central charge/central extension). So somehow
this kind of cocycle is invisible to other methods.
In http://www.arxiv.org/abs/math-ph/0210023 I start with a formulation of
classical gravity and replace Poisson brackets with commutators, which is
more or less by definition quantum gravity. Since it is also representation
theory of the diff algebra, 4D diff invariance is kept intact throughout
the process, which I don't think any other approach to quantum gravity can
boast. Moreover, the construction is manifestly consistent, in the same
sense that Fock modules of the Virasoro algebra are consistent.
However, there is a catch. To make sense of normal ordering, it is
necessary to expand all fields in a Taylor series and truncate at order p,
p finite. But this a regularization, and in the end one wants to take
p -> oo to recover the original fields. It is this limit that is tricky,
because the abelian charges diverge, but infinities can be cancelled
exactly in 4D. But you are probably not impressed by a prediction of four
spacetime dimensions...
A manifestly consistent and diff invariant formulation of quantum gravity
is a rather cool gadget. I think you are lacking in enthusiasm. After all,
what alternatives are there now that string theory has collapsed?
The formulation of classical physics is not even due to me. It is
essentially the antifield formalism described e.g. in Ch. 17 of Henneaux
and Teitelboim, except that I keep an infinite number of copies of the
physical phase space labelled by elements in the gauge group. But people do
that all the time in lattice gauge theory, so it should be ok.
> And if you are not planning to build something resembling an
> ordinary QFT.... well, good luck. Send us postcards.
You missed my point: this is essentially QFT, with point-like quanta! The
standard machinery of QFT is there: Fock spaces, fields, dynamics in the
form of Euler-Lagrange equations, etc. It resembles QFT in the same way as
CFT, i.e. essentially the representation theory of chiral algebras, does.
> > > If you must throw away all the interesting mathematical content to
> > > get a physically consistent theory, then maybe the deep mathematics here
> > > is not going to lead to good physics?
> > Good physics = complete lack of experimental support?
> Unitarity has plenty of experimental support
In the Virasoro algebra, all unitary reps except the trivial have c > 0,
and these are immediately relevant to the physically successful application
of CFT, namely 2D critical phenomena. My hope is to identify unitary reps
of its multi-dimensional generalization with physical particles, but so far
I have been unable to generalize the Kac table or the FQS construction.
Maybe someone could help here.
> > An immediate corollary: no phenomenon requiring new symmetries or extra
> > dimensions, e.g. new gauge bosons, proton decay, susy particles, new
> > submillimeter forces, etc. should be seen in the next generation of
> > experiments.
> Give us a cross section. Show us where your model(s) deviate from
> the Standard Model.
You really use double standards. Why don't you press string theorists for a
solid experimental prediction? After all, they have spent 20,000 man-years
worth of taxpayer money.
Aaron Bergman
Aaron Bergman <aber...@yuma.princeton.edu> wrote:
I meant to say that there exists a nondegenerate postive-definite inner
product on the space. The word 'unitary' is abused so much that I just
kept on using it. Who knows, maybe the usage is even common.
Aaron
--
Aaron Bergman
<http://www.princeton.edu/~abergman/>
John Baez
<eb...@lfa221051.richmond.edu> wrote:
>As I understand it, mathematical physicists are mathematicians,
>not physicists. I'm pretty sure that all the people I know who
>describe themselves as mathematical physicists would agree with
>this statement. Our most visible resident mathematical physicist
>here on sci.physics.research, John Baez, certainly is a mathematician.
Yes, insofar as I teach in a math department and publish papers
that contain proofs of theorems about physical theories, and
publish these papers in math and mathematical physics journals.
This activity is called "mathematical physics".
I also publish papers that contain theorems (as well as conjectures)
about mathematics that's only tangentially related to physics.
I do this in math journals. This activity is called "pure mathematics".
But to complicate thing further, I also publish papers that
propound and study theories of quantum gravity. I do this
in physics journals. This is "theoretical physics".
By the way, some of my theoretical physics papers contain
calculations that I have not been able to make rigorous!
That's typical of theoretical physics. Untypically, I try
to always point out when I'm doing this, because I don't want
people to get confused about when I'm doing what.
>The name of the discipline is confusing -- it should really
>be called physical mathematics or something.
Some people do call it that.
I've tried to make the divisions fairly precise above, but in
reality the different subjects bleed into each other a bit,
and there's no way to draw a perfectly sharp boundary. It's
good, however, to know when you've proved a theorem and when
you have not. It's also good to know when you've made a testable
prediction and when you have not. And if you're doing some
mix of math and physics and you spend most of your time doing
*neither* of these activities, it's probably good to ponder
what you're doing, what you hope to achieve, and how likely
it is that you'll achieve it.
You see, people sometimes fool themselves into thinking they're
so close to the ultimate Theory of Everything that there isn't
time for niceties like mathematical rigor and experimental
verification. In the long term this attitude can lead to
sloppiness and laziness. If there's any sort of "crisis"
in physics now, I think it's a buildup of this attitude in
certain quarters.
In short: it's not a crisis when physicists fail to figure out
the Theory of Everything on schedule. It is a crisis if they
become so impatient to reach the Theory of Everything that a
lot of them forget how to think clearly and carefully. It's
not too late to avoid this crisis, but we'll need to put some
work into it.
Ahmet Gorgun
"Thomas Larsson" <thomas....@hdd.se> wrote in message
news:4b8cc0a6.0210...@posting.google.com...
>
>
> What troubles me is that deliberate fraud does not seem to be that
unusual
> in physics anymore. To check that I am not making things up, you may
wish to
> consult e.g. the links below.
>
> http://www.salon.com/tech/feature/2002/09/16/physics/
[A popular article about the research of Jan Hendrik Schoen whose
published results could not be duplicated by others.]
>
>
http://www.mindfully.org/Industry/Scientific-Integrity-Questions2aug02.htm
[An article entitled "Recent Cases at UC Berkeley, Lab Raise Ethical
Concerns"]
Thanks for these links. I developed the following criteria for a physics
experiment. A set of measurements must meet these criteria before it can
be called a physics experiment.
If these rules are adopted they would set standards for refereeing, and
ethical issues will be left out of physics experiments. For instance,
Schoen paper fails rule 3 and it would never have been published.
Physics is an experimental science and every proper physics experiment
must meet the following criteria:
Definition:
Measurements of a moving part of an apparatus becomes a physics experiment
if and only if the published report contains all the necessary information
for the experiment to be repeated by others.
Rules:
1. Engineering. The published report must contain the necessary
information for the construction of the apparatus.
2. Theory and mathematics: The published report must contain a complete
description of the mathematical theory.
3. Observations: The published report must contain each and every
measurement made with the apparatus.
4. Error sources: The published report must contain the analysis of all
possible error sources
Conclusion:
A report of measurements which does not meet all these criteria is not a
physics experiment.
1. An experiment which meets the criteria:
The quintessential physics experiment is the report of the measurements of
the period of a pendulum by Henry Cavendish published in the Philosophical
Transactions for the year 1798. This report meets all the criteria for a
physics experiment. It includes the necessary information to build the
pendulum, a complete derivation of the mathematical theory, each and every
measurement made with the apparatus and analyses of every possible error
source.
2. An experiment which fails the criteria:
The experiment to determine the Newtonian constant G conducted by Gabriel
Luther and William Towler under the auspices of the United States Bureau
of Standards (Physical Review Letters, vol. 48, p.121-123, 1981) fails all
of the criteria for a physics experiment as stated above.
First of all, Luther and Towler experiment cannot be duplicated because
their published paper contains nothing more than a brief description of
the apparatus and some general formulas. No one can analyze and check
their computations, they are not available.
Luther and Towler used a torsion wire made of tungsten, which is notorious
for its secular drift. Their predecessor, Paul Heyl, also working under
the auspices of the United States Bureau of Standards (Research Paper RP
1480, 1942), tried to eliminate this drift by letting his torsion pendulum
oscillate freely for three months before starting his experiments and
still reported a residual drift. Luther and Towler do not discuss this
major error source that affects all torsion pendulum experiments.
Another important error source also goes unmentioned. They use 10.5 kg
tungsten spheres as attractors but fail to discuss the magnetic effects on
the pendulum of this most magnetic material.
To summarize their mathematical theory Luther and Towler gave the
following expression for G (unnumbered equation on p. 121, right hand
column):
G = G
This is a correct statement but it is not useful as a theory for the
computation of G from experiments.
But no one knows what was observed in this experiment anyway, the paper
lists no measurements.
Therefore, this is not a physics experiment, it is the opinion of Drs.
Luther and Towler about what the value of the constant G should be.
Let's summarize: A so-called experiment which cannot be duplicated is
presented as a proper physics experiment, published in a refereed physics
journal and its result is declared to be the official value of the
constant G.
Had physics been an exact science, this state of affairs would have caused
a major scandal. Physicists from all over the world would have sent
letters to the United States Bureau of Standards asking for further
information in order to duplicate and verify this suspicious looking
experiment which determined the most important constant in physics. There
was no such scandal.
What is the point of all this? What is the lesson to be learned?
Measurements which do not meet the criteria for a physics experiment, such
as the ones conducted by Luther and Towler, go unnoticed and unchallenged
because most individuals who occupy offices in the physics departments of
higher learning institutions are busy publishing papers about each other's
cosmogonical speculations. Furthermore, for a physicist to challenge an
experiment endorsed by the United States Bureau of Standards would be to
commit career suicide. It is better to keep quiet and set G=1.
Luther and Towler experiment cannot be duplicated in principle and no
physicist is supposed to duplicate it or even question it. Schoen at least
supplied a plot of his data, Luther and Towler not even that.
All these elements
o Softening of experimental criteria
o Academic careerism
o Doing physics by authority and precedent
o Embracing mythology as physics
o Mathematical sophistry
o Mixing scholasticism with physics
combine to transform physics into the soft science that it has become
today.
I started a page in order to restore physics to the rational science that
it once was. I intend to develop criteria also for theoretical physics,
for citations and rules to recognize metaphysical, occult and scholastic
elements in order to eliminate them from physics.
http://home.att.net/~agorgun/Restoration/RP-01.htm
Ahmet Gorgun
November 20, 2002
Ralph E. Frost
Boris Borcic <bor...@users.ch> wrote in message
news:3DD66BA1...@users.ch...
> Mark wrote:
> > Well, that's because the pressing problem in theoretical physics *IS*
> > mathematical -- namely: how to make the fundamental tenets of GR and
> > QFT mathematically cohere.
...
> What if indeed, the predictions of such a smoothly
> synthetic theory were to spectacularly violate
> one (or many) of physics disciplinary boundary,
> by giving rise to something that's too obviously
> interpretable as pertaining to matters traditionaly
> excluded from the object of physics ?
>
> IOW, what if the problem with mating QFT with GR
> was not independent from one of restructuring the
> system of sciences (and perhaps other disciplines),
> so that trying to mate QFT and GR without any
> propensity to rework the system of sciences is
> in fact self-defeating ?
>
> Up to now, I've received no answer to the various
> forms I gave to that question. Perhaps this time
> there will at least be someone who can tell me, "I
> see your point, but I find such an expectation
> highly implausible because..."
I see your point but I find such an expection quite a challenging
thought -- nearly overwhelming. If _I_ find it challengingly overly
speculative, then it not likely to be embraced by mainstream users
within the next week or two.
Listen to yourself. What you pose is a situation where there is some
rock-solid middle-ground which emerges that, once seen, invokes a
widespread re-partitioning of awareness such that the huge number of
living experts in the QFT and in the GTR concur -- ACTUALLY CONCUR --
and are able to see and admit that the real preferred framework was,
after all, somehow embedded, hidden or previously invisible within the
traditional descriptions, apparently waiting, like in some mythic
tale, for some stable boy to come along to pull the sword from the
stone. Maybe I've added a bit too much drama here, but in essence,
that is what would have to unfold. I guess you are saying that one
individual is going to scribble down a mostly whole piece of cloth and
raise up, or merely illuminate the long missing Atlantean Isle that is
located right to be or support the higher keystone in the arch
connecting the two lessor tectonic plates.
Is that what you propose, Boris?
That is the part that is highly implausible. Very highly implausible.
Don't you think? You are asking for some _really_ interesting
mathematics to burst onto a scene where the present abstract
mathematical widgets are already so interesting that it takes 3 or 4
decades for adepts to learn or centainly to extend them. And you want
someone to be successful in submitting their paper to "Modern
Mathematical Physics Monthly" that shows how all those other
interesting maths are like frilly, trivial, secondary window
decorations compared with the really interesting, wildly compressed
emergent stuff?
Boris, are you saying that this thing is a likely situation, this it is
not implausible?
Moreover, when you say, "leads to outside of the boundaries of physics",
or, verbatim: "pertaining to matters traditionally excluded from the object
of physics", WHAT are you suggesting? Put a name to it, please. Are you
referring to something more than consciousness?
Maybe it might be better to lay up this implausible option alongside the
other options -- the one of staying in the dual cul-de-sacs, or the
likelihood of the string theory and the spin network groups and the CA
folks striking a lasting compromise, or the option of sliding into a minor
dark age for a couple millennia of lack of movement or because all the
openings to the new imagery were snuffed out because they sounded too
different in their early emergent states. Get the options up there. Do
some analysis. Implausible compared with what?
I think the reason the math folks here don't respond to your proposal is
what they are silently saying here is, "Show me the math -- the cold, hard,
unreasonably effective math expressions -- not just the highly improbable
expectation value of such an observable ever occurring, but where are the
more robust, more synchronous math symbols an expressions?".
And that realistic question puts the discussion right in focus, back in
waiting for the Bohr's complementary expresion to emerge... or in another's
Doctor's book (Zeuss) : ....waiting for the train to come, waiting got the
the Sun to Sun, we're all just waiting....
Where's the math?
--
Best regards,
Ralph Frost
http://www.dcwi.com/~refrost/l_HGRPMTE.htm
"When God is about to do something great, he starts with a difficulty. When
he is about to do something truly magnificent, he starts with an
impossibility." --Armin Gesswein--
"...Love one another..." John 15:12
Mark
> Some uncited soul, presumably Mark Hopkins, wrote:
> > You already have the information required to resolve QFT and GR --
> > namely, QFT and GR, themselves. The pressing question is: what
> > kind of mathematics makes it fit together?
> I don't think there will be any reconciliation of QFT & GR
> using only the ingredients of QFT & GR. It seems more likely to me
> that we need to discover some new physics, not some clever way of
> rewriting QFT & GR.
As a matter of principle: you never need to see anything new to reconcile
what you've already seen, no matter what we're talking about.
The question of providing a consistent account of what's already known is a
question of a purely mathematical nature. In the case of GR & QFT, not
even that's been fully resolved.
It's not a matter of whether you need to see new stuff. It's a matter of
explaining stuff you've *already* seen. First things first. We haven't
even gotten that far yet.
Seeing new stuff has nothing to do with explaining old stuff. Even
more, the extent which it might help *clarify* old stuff is precisely
the extent you DON'T need to see it, since that's also the extent that
it pertains to the reconciliation and is therefore implictly known
already, just by the logical sum of all observations made to date.
A good example of this was Quantum Physics and Boltzmann. We already
knew in the 19th Century that a physical system in Newtonian Physics
has infinite entropy since pure states in Newtonian Physics require
infinite amounts of information to specify. So, we *already* knew --
solely on account of the very deep principle that physical systems
should possess finite information capacity -- that Newtonian Physics
breaks down and that there is some kind of quantization in the state
space of pure states (i.e., in phase space). This was acknowledged
implictly by Boltzmann who was the first to pose the expedient of
phase space quantization (without recognizing the full significance of
his expedient as a decisively non-classical hypothesis) -- all well in
advance of Planck's discovery.
The information was already there. You didn't need the new discovery
to see it. On the contrary, knowing it, you could PREDICT the new
discovery. Which is what you're supposed to do. Not wait around
for new stuff to appear.
Matthew Donald
> This is about the third rewording I make in s.p.r
> of a question about this point.
> What if indeed, the predictions of such a smoothly
> synthetic theory were to spectacularly violate
> one (or many) of physics disciplinary boundary,
> by giving rise to something that's too obviously
> interpretable as pertaining to matters traditionaly
> excluded from the object of physics ?
> what if the problem with mating QFT with GR
> was not independent from one of restructuring the
> system of sciences (and perhaps other disciplines),
> so that trying to mate QFT and GR without any
> propensity to rework the system of sciences is
> in fact self-defeating ?
Personally, I believe that even just quantum theory by itself gives
rise, through the problem of its interpretation, to ideas that
pertain to matters traditionally excluded from the object of
physics.
Nevertheless, we can always work around this because we do
apparently live in a world which we can describe very well using
classical concepts. Thus we can always choose to work on the
mathematics of quantum theory, or on its small-scale empirical
applications, without having to worry about how everything fits
together or about what it all means.
Any fusion of QFT and GR would presumably allow us to perform the
Schroedinger cat experiment, not with a process of either killing or
not killing a cat, but with a process of either dropping enough
material into a star to cause collapse to a black hole, or not doing
so. The possibility of such an experiment does peculiar things to
our understanding of the nature of time.
But again, we can ignore this, by just trying to present our latest
theory of everything, as a theory which in certain limits and in
certain states can model an S-matrix with suitable scatterings.
If you do worry too much about the problem of time in quantized
general relativity, you might end up like Julian Barbour denying that
time exists at all, or you might end up a philosophical idealist like
me. In either case, even string theorists will claim that you have
gone beyond the point of legitimate speculation!
Borcic wrote
> fitting together QFT and GR can/should bring to a theory allowing
> more testable predictions than either QFT or GR alone.
The issue here is whether it is part of the ``testable'' predictions of
a theory that the theory should allow a complete and consistent
description of reality.
Matthew Donald (matthew...@phy.cam.ac.uk)
web site:
http://www.poco.phy.cam.ac.uk/~mjd1014
``a many-minds interpretation of quantum theory''
***************************************************
[Moderator's note: this post originally appeared in s.p.r.
attached to the end of another post. That was my fault.
I've made this mistake a number of times lately, and I'll
try harder to avoid it in the future. - jb]
Toby Bartels
>By the way, some of my theoretical physics papers contain
>calculations that I have not been able to make rigorous!
>That's typical of theoretical physics. Untypically, I try
>to always point out when I'm doing this, because I don't want
>people to get confused about when I'm doing what.
This is important, because it indicates the desire to strive for rigour.
Or if instead you often proposed experimentally testable ideas,
then it would be important to point out when you
proposed an idea that you couldn't see how to test,
indicating the desire to strive for experimental verification.
Of course, you're not the only person to include such disclaimers.
But they ought to be typical.
-- Toby
A.J. Tolland
>
> It might be incorrect to call the multi-dimensional Virasoro cocycle an
> "anomaly".
Yeah, it confused the heck out of me. If your models will have
diff symmetry, don't call it an anomaly! That means the opposite. Just
call it a central charge.
BTW, can you give some physical interpretation to these central
charges?
> what alternatives are there now that string theory has collapsed?
I wouldn't say it's collapsed. It's been a bit quiet, but people
are starting to do pretty incredible things with N=1 gauge theories. My
understanding is that they have their eyes on LHC physics.
> You really use double standards. Why don't you press string theorists for a
> solid experimental prediction? After all, they have spent 20,000 man-years
> worth of taxpayer money.
<Grumble> I think your idea is interesting. I have been trying to
irritate you into doing something concrete with it.
As for strings theorists... They are not claiming to be working
with something as well understood as QFT. And they can calculate cross
sections. You have a collection of ingredients. But you have no
computational apparatus. I want to see how graviton scattering works in
your models. I want the proton lifetime, the Higgs mass, etc,...
Do you think people would have gotten so excited about strings in
the 80s if they had not been able to sit down and compute observable
quantities.
--A.J.
A.J. Tolland
On 20 Nov 2002, Aaron Bergman wrote:
> When you try to quantize gauge theories anomalous or not, you get
> non-unitary representations. The trick is that in non-anomalous
> theories, the BRST operator is nilpotent and the BRST-cohomology
> (i.e., the space of physical states) is unitary.
Same difference. Unless there are theories where Q^2 = 0 "by
accident",i.e. even if there is no gauge symmetry.
--A.J.
Kevin A. Scaldeferri
>
>[about] the expectation that fitting together QFT and GR
>can/should bring to a theory allowing more testable
>predictions that either QFT or GR alone.
>
>What if indeed, the predictions of such a smoothly
>synthetic theory were to spectacularly violate
>one (or many) of physics disciplinary boundary,
>by giving rise to something that's too obviously
>interpretable as pertaining to matters traditionaly
>excluded from the object of physics ?
>
>IOW, what if the problem with mating QFT with GR
>was not independent from one of restructuring the
>system of sciences (and perhaps other disciplines),
>so that trying to mate QFT and GR without any
>propensity to rework the system of sciences is
>in fact self-defeating ?
>
>Up to now, I've recieved no answer to the various
>forms I gave to that question. Perhaps this time
>there will at least be someone who can tell me, "I
>see your point, but I find such an expectation
>highly implausible because..."
I can't entirely say that I see your point, but as best I understand
what you are saying, I find it highly implausible based on our
understanding of the ideas of effective field theories.
Briefly, what I mean is that we usually think that when there are
regions of parameter space where "nothing interesting happens", then
we can provide an adequate ("effective") description of what happens
on one side of that region without having to know the precise nature
of what happens on the other side.
So, the idea that what goes on in the regime where QM and GR are both
relevant should have material impact on, say, condensed matter or
biology, seems rather unlikely. You'd have to argue to me why you
think the standard arguments about separation of scales, etc. don't
hold.
--
======================================================================
Kevin Scaldeferri Calif. Institute of Technology
The INTJ's Prayer:
Lord keep me open to others' ideas, WRONG though they may be.
Thomas Larsson
> On 21 Nov 2002, Thomas Larsson wrote:
> > It might be incorrect to call the multi-dimensional Virasoro cocycle an
> > "anomaly".
> Yeah, it confused the heck out of me. If your models will have
> diff symmetry, don't call it an anomaly! That means the opposite. Just
> call it a central charge.
It isn't central. The technical term is abelian extension, since the
components of the extension commute among themselves but not with
diffeomorphisms. I invented the term abelian charge for the parameter
multiplying it.
However, this extension is an anomaly in the same sense as the Virasoro
central charge is a conformal anomaly. But that didn't prevent people from
studying it for two decades (most people apparently stopped in the early
1990s).
> <Grumble> I think your idea is interesting. I have been trying to
> irritate you into doing something concrete with it.
>
> As for strings theorists... They are not claiming to be working
> with something as well understood as QFT. And they can calculate cross
> sections. You have a collection of ingredients. But you have no
> computational apparatus. I want to see how graviton scattering works in
> your models. I want the proton lifetime, the Higgs mass, etc,...
I had hoped that you, or some other smart young particle theorist,
would do that for me. I construct cocycles, realizations,
representations and invariant morphisms, but I don't really understand
how to build models or extract cross-sections. As for proton lifetime,
however, it should be infinite to the extent that proton decay signals
new gauge bosons, since there is a 1-1 correspondence between mb(3|8)
and su(3)+su(2)+u(1) gauge connections.
Boris Borcic
> Boris writes:
>
>> Mark wrote:
>>
>>> Well, that's because the pressing problem in theoretical physics
>>> *IS* mathematical -- namely: how to make the fundamental tenets of
>>> GR and QFT mathematically cohere.
>>>
>>> namely, QFT and GR, themselves. The pressing question is: what
>>> the basic work is being done on mathematical end. There's a huge
>>> psychological gap, primarily of a mathematical nature, that's
>>> blocking progress to the final resolution of this fundamental
>>> issue, that needs to be overcome.
>
>>[the idea that pp(TOE)>>pp(QFT)+pp(GR), pp=predictive power]
>>
>> IOW, what if the problem with mating QFT with GR
>> was not independent from one of restructuring the
>> system of sciences (and perhaps other disciplines),
>> so that trying to mate QFT and GR without any
>> propensity to rework the system of sciences is
>> in fact self-defeating ?
>
> You're beating around the bush.
I think it's more accurate to state that we diverge on separating the
baby from the bathwater.
> What you're really asking is
> what if the mating of GR and QFT results in a theory of
> alternate universes that waters down any empirical content
> by asserting in effect that anything's possible?
I am really saying nothing of the sort, and I am confused by what I
percieve as an ex-nihilo reference to many-worlds, coordinated to what I
can't help reading (your first sentence) as the act of decorating a pun
with a metaphor under the pretext of later extending it to a lecture,
and (second sentence) as a quite ungrammatical use of a question mark.
Again, I had no idea of making a reference to many-worlds (your
"alternative universes") but otoh I feel your discussion of the
interpretation you paint as mine, does not help understanding
many-worlds - it just explains what's wrong with the most standard way
of misunderstanding it, and perhaps shows some locally irrelevant
truths in passing.
> If the theory says anything's possible
Well, it doesn't.
> then it's impossible to refute it.
> Whatever you "refute" it with, you're not actually
> refuting the theory but refuting something else entirely different.
>
> So, you're perpetually playing the game then of never refuting
> the theory that says everything is possible, but something entirely
> different that just happened to have been confused with the theory.
Reads to me a lot like a physicist dying without achieving his rigorous
version of a TOE, if you want my feeling.
> An example of this is where, in quantum theory, a prediction is make
> that a process has probability 10^{-1000}. If the process is
> discovered to have occurred, then it's not the theory that's been
> refuted, but something entirely differently: namely the theory which
> said the process was impossible.
Are you teaching me that a coin giving heads a few thousands times in a
row isn't fair, or that mass destruction weapons have an unjust edge
over victim-averaged uglyness from a distance ?
Regards, Boris Borcic
--
What hears F(Syracuse) if F(Euręka) is the = in E=mc^2 ?
-- Cosmetic, cosmic, comic, cmc, mcc, mc^2, E = Albert !
BB
Kevin A. Scaldeferri wrote:
>
> So, the idea that what goes on in the regime where QM and GR are both
> relevant should have material impact on, say, condensed matter or
> biology, seems rather unlikely. You'd have to argue to me why you
> think the standard arguments about separation of scales, etc. don't
> hold.
>
The short answer can be that if the matter is with offending
"isomorphisms" or analogies, your separation of scale argument
may work against you. Scale incommensurability does not in
principle make immune against strong analogies. If the target
is in practice isomorphic to something you that's on other side
of your scales barriers, you might find it impossible
to open lids on it for lack of effective will to do so, because
it belies your faith in scales.
A companion answer, is to point that some superstring duality implies
swapping downscale and upscale. Now if such devices are permitted
in the field, this may fool instincts on the real role of scale
boundaries.
Regards,
Boris Borcic
--
Pour échapper à la supercorde :
réfléchir un photon fractal sur le miroir de Planck - 1987
Thomas Larsson
Danny Ross Lunsford <antima...@sbcglobal.net> wrote in message news:Kjiv9.114$n32.33...@newssvr30.news.prodigy.com...
> The article mentioned is here:
>
> http://www.aip.org/web2/aiphome/pt/vol-55/iss-9/p55.html
>
Joseph Lykken (a member of the theoretical physics department at the Fermi
National Accelerator Laboratory, and a professor at the Enrico Fermi
Institute and in the physics department at the University of Chicago)
responds:
http://www.aip.org/pt/vol-55/iss-11/p56.html
Kevin A. Scaldeferri
BB <foma...@infomaniak.ch> wrote:
>
>Kevin A. Scaldeferri wrote:
> >
> > So, the idea that what goes on in the regime where QM and GR are both
> > relevant should have material impact on, say, condensed matter or
> > biology, seems rather unlikely. You'd have to argue to me why you
> > think the standard arguments about separation of scales, etc. don't
> > hold.
> >
>
>The short answer can be that if the matter is with offending
>"isomorphisms" or analogies, your separation of scale argument
>may work against you.
I'm not talking about isomorphisms or analogies. I'm talking about
effective field theory. Forgive my bluntness, but your response makes
me think that you don't know what the "standard arguments about
separation of scales" are. I summarized this in the paragraph you
snipped from your response:
Briefly, what I mean is that we usually think that when there
are regions of parameter space where "nothing interesting
happens", then we can provide an adequate ("effective")
description of what happens on one side of that region without
having to know the precise nature of what happens on the other
side.'
For a more in-depth introduction to EFT, I'd recommend Kaplan's
lectures
http://www.arxiv.org/abs/nucl-th/9506035
Dirk Bruere
"Kevin A. Scaldeferri" <ke...@its.caltech.edu> wrote in message
news:arm74i$gku$1...@inky.its.caltech.edu...
> Briefly, what I mean is that we usually think that when there are
> regions of parameter space where "nothing interesting happens", then
> we can provide an adequate ("effective") description of what happens
> on one side of that region without having to know the precise nature
> of what happens on the other side.
>
> So, the idea that what goes on in the regime where QM and GR are both
> relevant should have material impact on, say, condensed matter or
> biology, seems rather unlikely. You'd have to argue to me why you
> think the standard arguments about separation of scales, etc. don't
> hold.
Yet I would expect a TOE to provide the definitive answer to the measurement
problem and decoherence in current QM. This itself occurs at scales and
energies that are 'everyday'.
Dirk
John Baez
Dirk Bruere <di...@neopax.com> wrote:
>[...] I would expect a TOE to provide the definitive answer to the
>measurement problem and decoherence in current QM.
I wouldn't! At least, not if "TOE" means "Theory of Everything" in the
usual physics sense. When physicists speak of a TOE, they don't really
mean a theory of *everything*. Taken literally, "Everything" covers a
lot of ground, including biology, art, decoherence and the best way to
barbecue ribs. When physicists talk about a TOE, they have less all-
embracing ambitions: they just want a set of equations describing the
fundamental laws of physics. We'll still need a TOEE - a "Theory of
Everything Else" - to answer all the other vexing questions in life.
If the Theory of Everything is at all like what most physicists are groping
for now, I doubt it'll provide a definitive answer to the measurement
problem and decoherence in QM! The reason is that most physicists are
trying to *use* quantum theory rather than *explain* it. If they
succeed in getting a Theory of Everything this way, people who think
the problems with quantum theory are already solved will continue
to think so - and people who think they're not will continue to think that!
Of course, it's possible that the Theory of Everything will be so
different from what most physicists are looking for now that it will
completely shock us: maybe it *will* solve the measurement problem,
or best-way-to-barbecue-ribs problem, or all sorts of things we can't
even imagine now. It's also possible we'll never find any "Theory of
Everything". So, ultimately, I guess we'll just have to wait and see.
Charles Francis
writes:
>If the Theory of Everything is at all like what most physicists are groping
>for now, I doubt it'll provide a definitive answer to the measurement
>problem and decoherence in QM! The reason is that most physicists are
>trying to *use* quantum theory rather than *explain* it. If they
>succeed in getting a Theory of Everything this way, [...]
I don't see how you could get a theory of everything this way. If you
are going to present a more fundamental body of laws to unify what is
know so far then those laws should certainly explain qm. Likewise if you
explain qm then it is likely that you will find in your explanations
mathematical reasons why qm is, after all, fully consistent and
unifiable with other physical theories like gr.
Regards
--
Charles Francis
Dirk Bruere
"John Baez" <ba...@galaxy.ucr.edu> wrote in message
news:asjor1$88v$1...@glue.ucr.edu...
> In article <asglar$r80er$1...@ID-120108.news.dfncis.de>,
> Dirk Bruere <di...@neopax.com> wrote:
>
> >[...] I would expect a TOE to provide the definitive answer to the
> >measurement problem and decoherence in current QM.
>
> I wouldn't! At least, not if "TOE" means "Theory of Everything" in the
> usual physics sense. When physicists speak of a TOE, they don't really
> mean a theory of *everything*. Taken literally, "Everything" covers a
> lot of ground, including biology, art, decoherence and the best way to
> barbecue ribs. When physicists talk about a TOE, they have less all-
> embracing ambitions: they just want a set of equations describing the
> fundamental laws of physics. We'll still need a TOEE - a "Theory of
> Everything Else" - to answer all the other vexing questions in life.
I was really thinking of things like Penrose's conjecture about decoherence
being linked to gravitation.
> If the Theory of Everything is at all like what most physicists are
groping
> for now, I doubt it'll provide a definitive answer to the measurement
> problem and decoherence in QM! The reason is that most physicists are
> trying to *use* quantum theory rather than *explain* it. If they
> succeed in getting a Theory of Everything this way, people who think
> the problems with quantum theory are already solved will continue
> to think so - and people who think they're not will continue to think
that!
> Of course, it's possible that the Theory of Everything will be so
> different from what most physicists are looking for now that it will
> completely shock us: maybe it *will* solve the measurement problem,
> or best-way-to-barbecue-ribs problem, or all sorts of things we can't
> even imagine now. It's also possible we'll never find any "Theory of
> Everything". So, ultimately, I guess we'll just have to wait and see.
No doubt.
It's just that as an amateur I see the measurement problem as being
fundamental rather than incidental.
Dirk
Kevin A. Scaldeferri
I see no particular reason why dealing with any of the problems of QM
or QFT should have anything to do with answering the questions one
traditionally associates with a "theory of everything" like:
why is the SM gauge group what it is?
why are the coupling constants/masses what they are?
what is the nature of the beginning and end of the universe?
I don't even know that I believe that providing a rigorous basis to
QM/QFT in flat space should help with answering questions about the
intersection of GR and QM like:
what is the exact form of Hawking radiation?
what happens in the end stages of BH evaporation?
what, if anything, is the resolution of the BH information paradox?
These seem, a priori, like unrelated issues, various people's
prejudices notwithstanding.
Matthew Donald
> I see no particular reason why dealing with any of the problems
> of QM or QFT should have anything to do with answering the
> questions one traditionally associates with a "theory of
> everything" like
> why is the SM gauge group what it is?
> why are the coupling constants/masses what they are?
There are two well-known frameworks within which such
questions can be answered.
The first is to hope for a beautiful and unique theory of everything
which predicts uniquely these features of our observations.
The second is to invoke some anthropic principle variant according
to which many gauge groups and sets of coupling constants can
exist as possibilities. What matters is then which of those
possibilities are likely to allow the existence of physical
correlates of observers.
To choose the first option only requires optimism.
The second however raises technical questions, like:
What is a possibility?
What is the physical correlate of an observer?
How likely are such correlates within any given theory?
These are questions which already arise within at least some
approaches to the interpretation of quantum theory . . .
**** begin plug ***
. . . for example, in my ``Progress in a Many-Minds Interpretation of
Quantum Theory'', quant-ph/9904001,
also available from the abstract on my web site:
http://www.poco.phy.cam.ac.uk/~mjd1014/pimmia.html
I provide a mathematical framework for a many-minds
interpretation in which, quoting the abstract,
> it is argued that the formalism can be modified to give a physics
> in which no constants are required. Instead, ``constants'' have to
> be determined by observation, and are fixed only to the extent to
> which they have been observed.
**** end plug ***
Thus an understanding of QM and QFT might at least help us limit
our ambitions as far as a TOE is concerned.
Scaldeferri's next question is
> what is the nature of the beginning and end of the universe?
Like all questions about the nature of time, this question will be
viewed quite differently if, like Julian Barbour, one denies the very
existence of time, or if, like me, one believes that time is
not absolute and observer-independent but rather is an aspect of
our structure as individual observers. In my opinion, reached
largely from studying QM and QFT, the idea of *the* beginning and
end of the universe is simply a mistake.
Scaldeferri goes on
> I don't even know that I believe that providing a rigorous basis to
> QM/QFT in flat space should help with answering questions about
> the intersection of GR and QM like:
> what is the exact form of Hawking radiation?
> what happens in the end stages of BH evaporation?
About these questions I'm inclined to agree with him, although
the first I would rephrase as
> what is the exact form of Hawking radiation for any given
> observer?
Scaldeferri's final question is
> what, if anything, is the resolution of the BH information
> paradox?
Much of the force of the black hole information paradox comes
from the belief that quantum mechanics is necessarily a theory
about wavefunctions. In my opinion, this belief is
Almost unsustainable in cosmology:
Whether a global quantum state is pure or mixed cannot be decided
by local observations, and therefore depends on unobservable facts
about the total universe (the ultimate reaches of space as well as
the interior of black holes).
Almost unsustainable in statistical mechanics:
Thermal states are always mixed.
Almost unsustainable in cosmological statistical mechanics:
Does the background radiation have a temperature or not?
Entirely unsustainable in a quantum field theory with localized
observers:
Local states in quantum field theory are always mixed, or to
put it mathematically, type III von Neumann algebras have no
pure normal states.
Entirely unsustainable for observers like us:
If you really think you have a wavefunction at each instant, then
your theory of quantum mechanics should describe your physical
boundaries and explain how the purity of your state is maintained
within those boundaries.
The rest of the force of the black hole information paradox comes
from ideas about unitarity. But these ideas in turn depend on ideas
about the totality of *our* universe and about the nature of time.
Charles Francis
<ke...@sue.its.caltech.edu> writes:
>I see no particular reason why dealing with any of the problems of QM
>or QFT should have anything to do with answering the questions one
>traditionally associates with a "theory of everything" like [...]
Before I attempt to answer your notes in order, I should answer this one
since it indicates that we are, to an extent, at cross purposes:
>I don't even know that I believe that providing a rigorous basis to
>QM/QFT in flat space should help with answering questions about the
>intersection of GR and QM like [...]
I had not intended to intimate that I think a rigorous basis for
qm/qft can be had in flat space. If it could, I think we would have
one already. I am firmly convinced that qm/qft needs first to be
formulated as a background free theory, and then a physical "metric"
needs to be introduced in some way which models physical
measurement. I place "metric" in inverted commas, because this need
not be a metric in the formal mathematical sense, although it should
give rise to a metric in the classical correspondence.
>why is the SM gauge group what it is?
I think I would expect to solve, or at least cast light on and restrict
the solution this question. It is sufficiently difficult to find
solutions to special relativity and qm that one may think that there is
a very limited class of solutions to unification, and that the gauge
group is important in describing this class.
>why are the coupling constants/masses what they are?
The only indication I have on this suggests that it has something to do
with anomalous chiral symmetry breaking which apparently leads to a
requirement for three generations, but as I don't understand any of it I
can say no more.
>what is the nature of the beginning and end of the universe?
At the very high energies and short time scales involved, I would expect
quantum effects to be important. I believe that at least a theory
unifying qm & gr would be necessary to describe the beginning and end of
the universe. Specific information about particle masses, coupling
constants, must also be necessary.
>what is the exact form of Hawking radiation?
>what happens in the end stages of BH evaporation?
>what, if anything, is the resolution of the BH information paradox?
Again I would certainly expect a theory unifying quantum theory with gtr
to be necessary to study these questions, but I don't see any answer
that involves either non-relativistic foundations of qm (why are all
books on foundations non-relativistic?), or qm/qft in flat space.
Regards
--
Charles Francis
Mike Mowbray
> > [...] why are all books on foundations non-relativistic?
Perhaps because the maths in axiomatic QFT is still rather
impenetrable for most mortals? And maybe also because
relativistic QM is still not well understood? There continues
to be a steady stream of papers appearing on LANL about RQM
(see recent ones by Peres, et al, e.g. quant-ph/0212023 and
refs therein). They're still wrestling with questions such as
understanding EPR-like situations when Alice and Bob are
in different Lorentz frames.
- MikeM.
John Devers
Imagine what science would be like if nobody ever listed the elements
and left them as a loose group of names of which each scientist had a
different assorted collection.
To start this off I'd like to form 2 lists containing all of the
theorised and all of the observed quasi-particles as there does not
seem to be one anywhere as there is for elements. I'll start with this
list, please feel free to add to this list or reorganize the list in
any way. I hope to end up seeing something like a periodic table for
quasi-particles from the experts one day:-)
phonon
exciton
biexciton
biexciton emission
one exciton (excitonic hydrogen )
The two-exciton complex (excitonic helium)
The three-exciton complex (excitonic lithium)
four excitons (excitonic beryllium),
five excitons in the quantum dot (excitonic boron),
six excitons in the quantum dot (excitonic carbon),
Polariton
polaron ,
magnon
orbiton
plasmon
graviton , (undiscovered, no sight of it yet)spin-two particles called
gravitons, there should exist another, fainter kind of gravity carried
by spin-zero particles
(sometimes called dilatons). = Equivalence Principle (EP) violation
spinons ,(carry spin of the electron)
chargons ,(carry charge of the electron) (when given energy and
momentum the electron splinters)
holons ,(carry charge in the quasiparticle)
visons ,(vortex like anomalies related to electromagnetism)
soliton ,
virtual photons ,(carry em field)
virtual gluons ,(carry strong force)
partons , (quarks or gluons)
virtual pions , (the proton and neutron are assumed to contain these)
virtual quark-antiquark pairs , (all the well known particles )
virtual phonon ,
electrinos. electrons can also be split -- into fragments
called 'electrinos'.the 'cathode rays'
phonon
squark.
Stop quark
Sbottom quark
Magnetic glue
bosenova
nanocrystal quantum dots
sleptons (are scalar left right leptons.)
Neutralinos (are the lighter supersymmetrical particle)
Gluinos
Charginos and virtual w particles
Leptoquarks ( come in scalar or vector varieties)
excited fermions
excited leptons
excited quarks
excited neutinos
higgs boson ,
My proposed
Nucliorbiton
Now I would like to propose that if journals are accepting papers on
these new particles then someone might like to submit one on what I
would assume to be a new particle. I theorise that a particle would
exist due to the breaking of symmetry of neutron orbitals in the
neucleon so would anyone like to try a paper on this and crunch the
numbers for a bit of fun and fame.
Below is a very rare list of all the elements that I had to type out
by hand as only periodic tables are available on the web, copy, paste
and save it, it's quite useful:-)
List of elements by number, with symbols.
1 H Hydrogen
2 He Helium
3 Li Lithium
4 Be Beryllium
5 B Boron
6 C Carbon
7 N Nitrogen
8 O Oxygen
9 F Fluorine
10 Ne Neon
11 Na Sodium
12 Mg Magnesium
13 Al Aluminum
14 Si Silicon
15 P Phosphorus
16 S Sulfur
17 Cl Chlorine
18 Ar Argon
19 K Potassium
20 Ca Calcium
21 Sc Scandium
22 Ti Titanium
23 V Vanadium
24 Cr Chromium
25 Mn Manganese
26 Fe Iron
27 Co Cobalt
28 Ni Nickel
29 Cu Copper
30 Zn Zinc
31 Ga Gallium
32 Ge Germanium
33 As Arsenic
34 Se Selenium
35 Br Bromine
36 Kr Krypton
37 Rb Rubidium
38 Sr Strontium
39 Y Yttrium
40 Zr Zirconium
41 Nb Niobium
42 Mo Molybdenum
43 Tc Technetium
44 Ru Ruthenium
45 Rh Rhodium
46 Pd Palladium
47 Ag Silver
48 Cd Cadmium
49 In Indium
50 Sn Tin
51 Sb Antimony
52 Te Tellurium
53 I Iodine
54 Xe Xenon
55 Cs Cesium
56 Ba Barium
57 La Lanthanum
58 Ce Cerium
59 Pr Praseodymium
60 Nd Neodymium
61 Pm Promethium
62 Sm Samarium
63 Eu Europium
64 Gd Gadolinium
65 Tb Terbium
66 Dy Dysprosium
67 Ho Holmium
68 Er Erbium
69 Tm Thulium
70 Yb Ytterbium
71 Lu Lutetium
72 Hf Hafnium
73 Ta Tantalum
74 W Tungsten (Wolfram)
75 Re Rhenium
76 Os Osmium
77 Ir Iridium
78 Pt Platinum
79 Au Gold
80 Hg Mercury
81 Tl Thallium
82 Pb Lead
83 Bi Bismuth
84 Po Polonium
85 At Astatine
86 Rn Radon
87 Fr Francium
88 Ra Radium
89 Ac Actinium
90 Th Thorium
91 Pa Protactinium
92 U Uranium
93 Ne Neptunium
94 Pu Plutonium
95 Am Americium
96 Cm Curium
97 Bk Berkelium
98 Cf Californium
99 Es Einsteinium
100 Fm Fermium
101 Md Mendelevium
102 No Nobelium
103 Lr Lawrencium
104 Rf or Ku Proposed Name Rutherfordium (Unnilquadium )
105 Ha or Db Proposed Name Dubnium ( Unnilpentium )
106 Sg Proposed Name Seaborgium (Unnilhexium )
107 Bh Proposed Bohrium (Unnilseptium) Formally Ns Nielsbohrium
108 Hs Proposed Name Hassium (Unniloctium )
109 Mt Proposed Name Meitnerium (Unnilennium )
110 Uun Ununnilium
111 Uuu Unununium
112 Uub Ununbium
114 Uuq ununquadium
114 protons and 175 neutrons
paper retracted Uuh 116 ununhexium
116 protons and 173 neutrons.
paper retracted Uuo 118 ununoctium
118 protons and 175 neutrons
zirkus
> In http://www.arxiv.org/abs/math-ph/0210023 I start with a formulation of
> classical gravity and replace Poisson brackets with commutators, which is
> more or less by definition quantum gravity.
I'm not sure that this would be QG for the reason given below [1]. Can
you comment on this so that I might be able to tell if I want to try
reading your paper? Also, what is wrong with using one of the various
quantum-Virasoro algebras?
I don't think the particular events you mentioned constitue much of a
crisis in physics for three reasons:
1) The only one that is quite costly is the case of Hendrik Schon's
work because millions of dollars (including taxpayers' money) were
invested in such research, and because various people had been
developing their careers based upon the (assumed) validity of Schon's
work.
2) You have to judge the bad with the good and there is a variety of
good work being done in different areas of physics, and I would bet
money that the vast majority of physicists are basically honest
researchers/people.
3) You have to have a sense of historical perspective. Don't forget
that "bad science" includes a variety of experiments etc. that the
Japanese, Nazis and Soviet Union and others were doing in the previous
century. Compared to that, a few mistakes or even fudgery in something
like theoretical physics is not that big of a deal (you can just write
it off as bad sci-fi but without the robots, cheesy dialogue, babes,
aliens, ray-guns etc. that are so essential :-)
[1] from page 10 of (hep-th/0006167):
Thus, one usually considers quantisation as the result of a
process applied to an underlying classical phase space, with all
of the geometrical content there (as a Poisson manifold). But
demanding any algebra such that its commutators to lowest order
are some given Poisson bracket is clearly an illogical and
ill-defined process. It not only does not have a unique answer
but also it depends on the coordinates chosen to map over the
quantum operators. Almost always one takes the Poisson bracket in
a canonical form and the quantisation is the usual CCR or
canonical commutation relations algebra. Maybe this is the local
picture but what of the global geometry of the classical phase
space? Clearly all of these problems are putting the cart before
the horse: the real world is to our best knowledge quantum so
that should come first. We should build models guided by the
intrinsic (noncommutative) geometry at the level of
noncommutative algebras and only at the end consider classical
limits and classical geometry (and Poisson brackets) as emerging
from a choice, where possible, of `classical handles' in the
quantum system.
Thomas Larsson
> thomas....@hdd.se (Thomas Larsson) wrote in message news:
>
> > In http://www.arxiv.org/abs/math-ph/0210023 I start with a formulation of
> > classical gravity and replace Poisson brackets with commutators, which is
> > more or less by definition quantum gravity.
>
> I'm not sure that this would be QG for the reason given below [1]. Can
> you comment on this so that I might be able to tell if I want to try
> reading your paper? Also, what is wrong with using one of the various
> quantum-Virasoro algebras?
The multi-dimensional Virasoro algebra Vir(n) is an extension of vect(n),
the diffeomorphism algebra in n dimensions. Since vect(4) is the correct
symmetry of general relativity, Vir(4) can be regarded as quantum general
covariance.
I am not really familiar with quantum-Virasoro algebras, but I think that
they are quantum groups based on Vir (i.e. Vir(1)). This is a completely
different algebraic structure; a Hopf-algebra deformation within the
universal envelope of Vir(1).
The main point is that Vir(1), and its deformations, lives in 1D
(technically, has growth 1). Vir(4) lives in 4D (growth 4). It seems
unlikely to me that 1D math will suffice to describe 4D physics.
> [1] from page 10 of (hep-th/0006167):
>
> Thus, one usually considers quantisation as the result of a
> process applied to an underlying classical phase space, with all
> of the geometrical content there (as a Poisson manifold).
It sounds like this paper is voicing a minority viewpoint.
> But
> demanding any algebra such that its commutators to lowest order
> are some given Poisson bracket is clearly an illogical and
> ill-defined process. It not only does not have a unique answer
Unique, or unique up to isomorphism? Typically, it has a family of answers
depending on finitely many continuous parameters, like the central charge
in the Virasoro algebra.
> but also it depends on the coordinates chosen to map over the
> quantum operators.
The existence and value of an abelian extension in a given representation
does not depend on choice of coordinates.
> Almost always one takes the Poisson bracket in
> a canonical form and the quantisation is the usual CCR or
> canonical commutation relations algebra. Maybe this is the local
> picture but what of the global geometry of the classical phase
> space?
All my work has been local (in a single chart) and infinitesimal (Lie
algebra rather than group). It would certainly be nice if somebody
globalized it, but one should first make sure that one starts with the
right local theory. If you start out wrong locally (e.g. 1D instead of 4D),
you can't save things by going global.
> Clearly all of these problems are putting the cart before
> the horse: the real world is to our best knowledge quantum so
> that should come first. We should build models guided by the
> intrinsic (noncommutative) geometry at the level of
> noncommutative algebras and only at the end consider classical
> limits and classical geometry (and Poisson brackets) as emerging
> from a choice, where possible, of `classical handles' in the
> quantum system.
It sounds that this paper is advocating noncommutative geometry (in
configuration space and not just in phase space). There is no indication
that this should be relevant to physics.
Otherwise I completely agree with the spirit the last sentence: start with
the quantum algebra and see classical Poisson brackets appear in the
hbar -> 0 limit. However, the prefix "quantum" can mean different things:
an extension (as the Virasoro algebra), a deformation (as in quantum groups),
noncommutative geometry, etc. I think the first meaning is most
conservative, since it arises directly from normal ordering.
Maybe I should point out that I define Poisson brackets purely
algebraically. With both PBs and commutators one has a Lie algebra and
an associative algebra, such that the bracket is a derivation of the
associative product. The only difference lies in how the bracket and the
product are related:
Classical: ab - ba = 0.
Quantum: ab - ba = [a,b].
As long as the diff generators act by brackets, only the Lie algebra
structure matters and we might take the bracket to be a Poisson bracket.
When one introduces a Fock vacuum and normal order, it really matters that
the bracket is a commutator, so this is the quantization step.
Thomas Larsson
> I don't think the particular events you mentioned constitue much of a
> crisis in physics for three reasons:
You are probably right. When a wrote the post, I had recently heard about
Schˆn and Ninov, and I believed in the unfair rumours about Drs Bogdanov,
so I was in an unusually gloomy mood. Besides, I did not write Nagel's
article.
However, I do think that theoretical particle physics is in a crisis,
caused by its past success. Experimental particle physics after 1980 has
essentially been about confirmation of the standard model, slightly
modified to include massive neutrinos. This is a great triumph for
yesterday's theorists and today's experimentalists, but very few theorists
active today are old enough to have made significant contributions to this,
the main exceptions being people who did great stuff as graduate students,
e.g. 't Hooft and Wilczek.
Nor is this past triumph a good predictor for what future experimentalists
will find. I have argued from a purely algebraic point of view that quantum
gravity coupled to the standard model in 4D might be essentially the end of
physics, since the corresponding symmetries are closely related to truly
remarkable algebraic structures. What is completely uncontroversial is that
we have reached the end of symmetries, in a suitably narrow sense of the
word; this is the meaning of the word "classification".
It is true that I have not been able to construct a physical model capable
of predicting cross sections, but Nature does not care about my
shortcomings. If Nature prefers the symmetries I have described elsewhere,
i.e. the Virasoro algebra in 4D and mb(3|8), there will be very little new
physics left to discover in the next generation of accelerators. Maybe
Horgan was right anyway...
Squark
> I theorise that a particle would
> exist due to the breaking of symmetry of neutron orbitals in the
> neucleon
Can you eleborate on this one? Did you mean "neutron orbitals in the
_nucleus_? What symmetry breaking are you talking about?
Best regards,
Squark
------------------------------------------------------------------
Write to me using the following e-mail:
Skvark_N...@excite.exe
(just spell the particle name correctly and use "com" rather than
"exe")
John Devers
> Can you eleborate on this one? Did you mean "neutron orbitals in the
> _nucleus_? What symmetry breaking are you talking about?
Hi Squark, I probably did mean nucleus and I really don't know if I
understand symmetry breaking yet.
It all started when I tried to summerize exactly what a magnon was one
time, I ended up with something like this below and from there I just
applied it to the nucleus, I'm not sure if it would ever hold up but
you guys are fun to go fishing with so I left it in the list for a
bite or 2;-)
Particles are connected with a property of the ground state known as
broken symmetry this leads to new particles. Atoms can have magnetic
spin at certain temps they are random at lower temps they
spontaineously align and their rotational symmetry breaks. This
breaking allows new disturbances in the solid these are recognised as
waves or particles. Rotational inertia prevents spins from responding
instantly, wave propogation occures when restoring forces encounter
inertia. Spin disturbances propagate as spin waves, or particles
called magnons.
Magnons can be detected indirectly by scattering photons or neutrons
which may interact with the magnon causing detectable changes in the
scattered particles.
zirkus
> I am not really familiar with quantum-Virasoro algebras, but I think that
> they are quantum groups based on Vir (i.e. Vir(1)). This is a completely
> different algebraic structure; a Hopf-algebra deformation within the
> universal envelope of Vir(1).
Correct, or they can be based on sVir - the classical super Virasoro
algebra.
> It sounds that this paper is advocating noncommutative geometry (in
> configuration space and not just in phase space). There is no indication
> that this should be relevant to physics.
There is no indication so far, but the paper postulates a purely
hypothetical new effect called cogravity which astrophysical
experiments are currently looking for. There is even a paper called
"Operadic Deformations as a Tool for Cogravity":
http://arxiv.org/abs/math/0202017
If you don't constrain theorists with the pesky restraints of
empirical experimental investigation then the theorists might conjure
up almost anything !
Alfred Einstead
> > > [...] why are all books on foundations non-relativistic?
> Perhaps because the maths in axiomatic QFT is still rather
> impenetrable for most mortals?
Because they are typically cast in terms of the Schroedinger
or Interaction pictures which both require a 3+1 decomposition
of the Universe to start out with -- the essential feature of
the non-relativistic universe.
You can always write a book on foundations in a purely
relativistic setting, provided you adopt the Heisenberg
picture as your starting point. That's the one which
works directly with spacetime as is and doesn't require
you to adopt the essentially Newtonian "3-D space moving
in time" precept.
Also, Relativistic quantum theory does not mean
"axiomatic" QFT. The latter was really nothing more than
a stopgap for dealing with the non-linear systems with
singular boundary data that arise out of QFT, originally
posed before people finally figured out (in the 1980's)
how to deal with such systems.
Squark
johnd...@froggy.com.au (John Devers) wrote in message news:<2978f9d5.02121...@posting.google.com>...
> broken symmetry this leads to new particles.
When the broken symmetry is continuous, yes.
> Atoms can have magnetic spin at certain temps they are random at
> lower temps they spontaineously align and their rotational symmetry
> breaks.
I'm not that proficient in nuclear physics, so I have to ask you what
do you mean by a "temp"? Do you mean there is symmetry breaking for
certain neutron + proton number?
[Moderator's note: I'm pretty sure that "temp" is just short for
"temperature" here. -- KS]
If so, it _might_ lead to some quasiparticles, but I'm not sure
(because of the particle number fixing). This is related to my post
about SSB in a system of photons in a box.
Can you explain why the magentic moment e.v. develops?
> Magnons can be detected indirectly by scattering photons or neutrons
> which may interact with the magnon causing detectable changes in the
> scattered particles.
If you applied the principle to the nucleus, what did the original
magnons inhabit?