There’s an interview with Andy Strominger in the Calcutta newspaper The Telegraph. Strominger was presumably in India for the string theory conference there this past week.
The thing I found interesting about the interview was how skeptical the interviewer was, repeatedly asking about whether string theory might not be wrong. Perhaps at least some members of the media are starting to get a clue.
Mr. “” said:
“Discreteness of space and time happens at much larger scale that corresponds to scale of elementary particles” Then it would be accessible experimentally and would have shown up already because we can probe these scales.”
I am discussing mistake in Lubos paper in respect to the currently established science. NOT in respect to my theory. So I really do not deviate from that topic and discuss my theory further. But since you meantioned it, you forced me to explain it one more time.
The answer is, Mr. “”, don’t you see logical inconsistency in your sentence: Basically you are saying: If there is a NATURAL limitation of the smallest possible size approximately equal to electron radius, then we already have the technology to break that natural limitation, and probe some thing much smaller already!!?!
If indeed that is the natural limitation of the smallest possible size, then, certainly, no human technology could even possibly break that limitation.
You thought you have break that limitation and probing some thing smaller, only because you have accelerated a particle to extremely high momentum. And calculation of de Broglie’s wavelength gives you a size smaller than that limitation already. But the matter is even the de Broglie’s wavelength formula breaks down near that limitation. That limit is in-accessible as much as light speed is un-breakable.
Mr. “” also said:
“And for the very last time–there are NO derivatives against position and time at all at the Planck scale in the Motl paper! It is a perturbative analysis of a classical black hole, the motivation being that the log Immirzi parameter in question can be derived from the other end…via a quasinormal mode analysis in classical general relativity. If you don’t agree with this paper then submit a comment or rebuttal to the journal it was published in. Otherwise your opinions dont mean a damn thing to anyone anywhere.”
Have you read the actual Motl paper? The very first equation, whatever you call it, takes derivatives against x (the first term) and time (the third term):
http://www.arxiv.org/abs/gr-qc/0212096
And frequency omega corresponds to a mass/energy of a black hole. We know a black hole has a mass at least one Planck Mass or more. So he was talking about derivatives below Planck Scale limit.
Quantoken
I agree with Chris Oakley on this one. Lubos I can handle without any problems. Quantoken is becoming too much to handle.
Anderson defends western science and then it would
seem is also fond of the Santa Fe Institute. That seems strange as I do not understand why the umbrella term ‘Complexity’ programme at Santa Fe is credible and ST is not. A generalisation of these new age programmes (ST, Complexity, experimental mathematics) has the common property of elevating the digital computer’s role in modern science.
http://www.physics.hku.hk/~tboyce/ss/topics/anderson.html
“Discreteness of space and time happens at much larger scale that corresponds to scale of elementary particles” Then it would be accessible experimentally and would have shown up already because we can probe these scales.
And for the very last time–there are NO derivatives against position and time at all at the Planck scale in the Motl paper! It is a perturbative analysis of a classical black hole, the motivation being that the log Immirzi parameter in question can be derived from the other end…via a quasinormal mode analysis in classical general relativity. If you don’t agree with this paper then submit a comment or rebuttal to the journal it was published in. Otherwise your opinions dont mean a damn thing to anyone anywhere.
I agree with Chris. Let him discuss his ideas on his own blog. Trouble is that no-one, not even other crackpots, will waste any time reading it. Thats why he is here.
Today I am writing a article for those less inclined to understand the overall perspective that can be formed into a intelligent framework for consideration.
The post( The Sphere is Not So Round) should materialize later, if people want to have a look at it. I also wrote it in response to living review that was offered.
The link paragraph below hopefully helps to orientate one first, to better conmprehend my article today, and answers, the living review article.
At the energy scales characteristic of the universe’s earliest moments, one can no longer approximate matter and energy using an ideal gas formulation; instead, one must use quantum field theory, and at the highest of energies, one must invoke a theory of quantum gravity, such as string theory. Cosmology is thus the pre-eminent arena in which our theories of the ultra-small will flex their muscles as we trace their role in the evolution of the universe.
At such small scales, how would mini-blackholes ever make sense?:)If gravity can work on such large scales, then how would would you interpret gravity at such small scales? One would need to know, what would drive these, at both the cosmological and quantum scales?
Is there any similarities here?
Peter,
The half-wit Quantoken is spoiling my enjoyment of your otherwise excellent web log. How about a new year’s resolution to ban him?
RT:
The argument of ITO is irrelevant because we are discussing whether Lubos’s paper was wrong or not. Lubos did not use ITO in his paper.
He was fundamentally wrong when he wrote equations involving derivatives against position and time at Planck Scale, where every one can agree continuous space time no longer exist.
Quantoken
Mr. “” said:
“Q wrote” most people agree that at the Planck scale continious space and time don’t exist”
This deduction/conclusion COMES PURELY FROM quantum gravity, string theory and noncommutative geometry, all of which you have repeatedly stated you don’t believe in and which “secretly inject G” (your words). Different approaches to QG all seem to converge on this conclusion that the Planck length is the lower bound or the cutoff and that space and time becomes “foamlike”. But you can’t condemn these theories as being wrong, as you have done, and then use their main conclusion (or one of them) to support another argument.
Again your logic seem to work the reverse way. The notion of Plank Scale did not came from and was not derived from Quantum Gravity, String Theory or Nonecommutative Geometry. The concept of Planck Scale was first proposed far earlier than any of these three. You simply stealed that existing notion and then claimed it to be yours and you derived them from your theory.
It’s not even a correct statement that you say I do not believe in those three. There is nothing to even believe in or not believe in! “Quantum Gravity” is a theory that people have been looking for and have not found yet. “String Theory” is a broad research direction on which people hope to finally propose a physics theory, again it’s not found yet. They say there are 10^123 kinds of different String theories but they have so far not found a single one, yet.
Until you can present me string theory in one self-consistent integral piece, instead of just a few corners and parts, don’t even ask the question whether I believe it or not.
Now, I do disagree with the notion of Planck Scale. I believe the discreteness of space and time happen at a much larger scale, one that corresponds to the scale of elementary particles.
Logically that does NOT prevent me from agreeing with the notion that at Planck Scale time and space are discrete. Because if time and space has become discrete at large scale, then they certainly are even more discrete at the smaller Planck Scale. So there is no inconsistency in my logic.
No one sees to disagree that at Planck Scale we do not have continuous space and time. So if any one discusses differential equations where derivatives against position or time are involved, then he/she is fundamentally wrong.
Some food for thought: Assuming there are two spacetime-coordinates very close to each other. They are of the closest distance possible yet at different spacetime location. Now, how does the two observers at the two locations conclude they are at slightly different location, instead of exactly identical location? If you can understand this question, you will begin to understand QUITAR, and know why Planck Scale is wrong.
Quantoken
A stochastic Ito approach to (quantum) gravity is discussed by Hu and Vedagner
http://www.livingreviews.org/lrr-2004-3
Q wrote” most people agree that at the Planck scale continious space and time don’t exist”
This deduction/conclusion comes purely from quantum gravity, string theory and noncommutative geometry, all of which you have repeatedly stated you don’t believe in and which “secretly inject G” (your words). Different approaches to QG all seem to converge on this conclusion that the Planck length is the lower bound or the cutoff and that space and time becomes “foamlike”. But you can’t condemn these theories as being wrong, as you have done, and then use their main conclusion (or one of them) to support another argument. For a noncontinious/random process, like fluctuations in spactime you could use Ito calculas definitions of the derivative like you do for Brownian motion and stochastic analysis. (I dont know if anyone has applied this though in quantum gravity/geometry).
Dr. Lunsford said:
“Whatever Witten wants to think of himself, or what anyone thinks of him, is irrelevant. To be in his position of authority, and to allow and encourage the endless drain of talent and useless sqaundering of scarce resources represented by string theory, is behavior that amounts to scientific crime. His name doesn’t belong in the same paragraph as Einstein’s.”
“crime” is too heavy a word to use, Mr. Lunsford. Witten is not in control. He is a victim of the system himself. Really whoever want to spend his/her own lifetime on whatever subject is really one’s own choosing and no one else is responsible for it.
LC said: “If the string folks turn out to be wrong in the end, they’ll eventually disappear except for a few fanatics. As far as I’m concerned, people are going to do and say whatever they want irrespective of how legitimate or silly it is.”
Wrong LC. I do not see how you are going to prove string theory wrong. It’s neither right nor wrong. It’s just useless. It’s a mathematician’s toy that some people just love to play with. Toys are not as useful as tools but they are neither right nor wrong. The only way string folks will disappear would be when they are bored of their toys.
Right or wrong does not make certain things go away. An example is palm reading or astrology. As long as there is business, they will continue to exist for a long time. Once there is no longer any business, they would disappear over night.
That’s the ultimate universal truth Darwin discovered. Survival of the fittest. In the science community, fitting is measured by the ability of getting continued funding grant. Under the system, the ones who survive are the ones who can get funding, they may or may not be on the right track of scientific discovery, but as long as there is funding, they survive.
It is much easier to get funding for super string research. For one reason this is a majority group. For another, it does not take much to feed a string theoretician, all they need is a black board and a computer. And even a computer may be overkill, many of them probably mainly just use the computer for type-writting. If I am the one who grant fundings I would figure, what the heck, it’s just a very small slice of the pork barrel. So even if they are wrong, not much money could be wasted.
Thanks Peter for providing that link. I knew that living review site but have not got a chance to read everything there yet. Will comment after I study that material. Mean while, it is still wrong to push known QM to Planck Scale or below.
Most people agree that once you reach Planck Scale, familiar concepts like continuous spacetime etc. no longer exist. So how could you still have a legitimate differential equation which differentiate against position and time, and which hence depend on the assumption of continuous space and time for its legitimacy in physics. You can’t!
I do not know how your logic works, talking about derivative like dF/dx is simply wrong at Planck Scale where there is no continuous x. Any one care to dispute that?
Quantoken
Peter said:The best historical analogy is to his predecessor at the IAS, Einstein, who initially had good reasons to hope for a unified theory using extensions of Riemannian geometry. Einstein also made the mistake of pursuing an idea long after he should have realized it didn’t work.
How else, would you show gravitational collapse(turn things inside/out)?
Cosmologically, you say this area, is much like strings? You don’t like the math structures in string and M theory? You don’t like blackholes and mini blackholes?:)
We know GR works well in cosmological areas, so the leading geometrical principals are consistent and lead to where?:) So is there such a thing as gravity?:)Further, geometrical and topological considerations?
Is there no proof for gravity(?), so like strings, this should be avoided?
P.S. Statistically, I think, sound of music beats out, clock ticking and Money of Pink?:)
Rubbish JC! Geoffrey Chew is the man! And Saturday Night Fever still ranks as one of the best selling albums of all time…but when the Floyd come back with “Dark Side of the Moon II” and then III” they will blow “Fever” out of the water!
🙂
DR Lunsford,
If the string folks turn out to be wrong in the end, they’ll eventually disappear except for a few fanatics. As far as I’m concerned, people are going to do and say whatever they want irrespective of how legitimate or silly it is.
A silly example of this would be the folks who today still believe in the analytic S-matrix bootstrap stuff. Other less illuminating examples would be the people who still think late 1970’s “disco” music still rules the world, and/or the aging hippies who still think “acid rock” will once again rule the world.
Actually Q, the first equation Lubos writes in his paper is the differential equation for the radial perturbations of a Schwarzchild black hole with a Regge-Wheeler potential. It is a Schrodinger-like equation! Even if he calls it a “schrodinger equation” anyone with a basic physics education knows what he means. The phi(r) in his first equation describes the radial perturbations! He then analyses quasinormal modes ANALOGOUS to quasistationary states in QM whose frequency is permitted to be complex. He is studying the asymptotic real parts of the quasi-normal frequencies. Quasinormal modes are PHYSICALLY well defined as well as mathematially well defined. The BH wants to settle down to a static spherical configuration just like a bell wants to stop ringing. This black hole perturbation equation has also been known for along time: J A Wheeler and T Regge, Phys. Rev. 108, 1063 (157). Schrodinger-like equations appear in many problems with spherical symmetry. The classical heat and diffusion equations are “Schrodinger-like” equations. The Schrodinger equation is just a heat equation in imaginary time
Thats why “heat kernels” are discussed in QM and QFT contexts.
JC –
In other epochs there were fads, but these fads were not followed at the expense of other ideas, did not corrupt the very idea of science, and were not bolstered by a credulous public, an ignorant military-industrial government, and a power-hungry core group of theorists. It was not fashionable to bash Einstein and Dirac, and now even Feynman, for not being faddists, or for following their own paths.
I’ve been reading Feynman’s lectures on gravitation. I can’t tell you how wonderful it is to see Feynman, who was not regarded as a relativist in particular, show his total mastery of the subject and to discuss it with a tangible physicality – one can almost feel the tension in spacetime represented by curvature, when Feynman describes it. And yet it is OK for the stringers to “excuse” the poor blighter for not “getting it”, to cast off his comments as the signs of approaching senility. Likewise Dirac – his little book on GR tells the story without BS, without hubris, and without ridiculous, boxed up, 2-tracked, egg-crated hyperbole prefaced by smart-assed, inappropriate quotes and goofy cartoons – but that sad man was, were are to believe, “misguided” because he thought of QFT as a horribly broken disaster that needed urgent repair. And Einstein – the man who invented 20th century physics – this pitiful lost soul spent his last years “pursuing a chimera”, we are to believe.
How can anyone who cares a fig about science read these things and not blow his top?
As far as I’m concerned, physics, if not the entire Western tradition in science, has lost its soul. The torch is being passed to the East. The kings are dead – long live the mandarins.
-drl
Peter –
Whatever Witten wants to think of himself, or what anyone thinks of him, is irrelevant. To be in his position of authority, and to allow and encourage the endless drain of talent and useless sqaundering of scarce resources represented by string theory, is behavior that amounts to scientific crime. His name doesn’t belong in the same paragraph as Einstein’s.
-drl
If for no other reason, folks mind as well work out the consequences of string theory just to see what it produces. As long as there’s ways of getting funding for string theory research, that is going to happen anyways. It may be a different story if there’s little to no funding sources for string theory research.
Since string theory doesn’t have many other major competitors with a large number of researchers, many of the best graduate students will be attracted to it. (In the late 1970’s the same sort of grad student “profile” seemed to have been attracted to supergravity). Whether it’s animal behavior in general, herd-like behavior seems to be a dominant human trait.
For Q: a tract on the physics of quasi-normal modes:
http://relativity.livingreviews.org/Articles/lrr-1999-2/
I completely agree with Peter’s 3 points observation of Witten. He is an absolute genius and his intelligence really deserves some respect.
But the more so, the more it makes him a pity. Look at the picture that a genius that do not come often on this planet walking and getting lost on a wrong road that is decorated with all beautiful flowers, but lead to no where, and at the end he would have wasted his intelligent lifetime, with little achieved and soo to be forgotten once the correct theory has been recognized. Don’t you want to say pity?
All other criticisms against Superstring Theory can at most be described as “skeptical”. Because no one know for absolutely sure whether it is right or wrong. They can only make a probability judgement. For me, there is no ambiguity, I know for a fact it is wrong, because I know for a fact what is the correct road.
Quantoken
Mr. Dr. Lunsford said:
“On the other hand you have the real crackpots like this Q, who think that physics amounts to dicking around with physical constants. No wonder the Bon-Motls of the world are so entrenched.”
I am sorry. I did not “dick around with physical constants”. I showed you the relationship between alpha and G. This relationship does not come from numerology coincidences.
It’s true there are bunches of crackpots playing numerology. But the relationship I pointed out are DERIVED from the fundamental principle of quantum information conservation. I have not shown any one exactly how they are derived, for obvious reasons I do not want any one to take credit for it. My caculation of universe “age”, CMB temperature, baryon density, Pioneer anormality acceleration, etc. are all derived from the same principle. They are not numerology conincidences.
You can call Paul Dirac a crackpot when he played numerology with G, without explaining why the relationship holds. But I have found out the “why” and have derived it rigorously from the quantum information conservation principle. So it’s not numerology, but real science.
“quantum information conservation” is one of the fundamental principles of my QUITAR theory. It has solid observational support.
I would not want to discuss QUITAR any more on Peter’s blog. But I have to do it this time since you attacked me first. Again I am not going to elaborate or go to details.
Quantoken
A few comments about Witten, since I think my point of view about him is slightly different than most people’s.
1. Yes, he’s a genius. It’s simply an awe-inspiring and humbling experience to read many of his QFT papers. Some of his string theory papers are also extremely impressive, even if one believes their motivation to be misguided.
2. He’s a physicist, not a mathematician. What he really cares most deeply about is making progress on understanding fundamental physics. His accomplishments towards this have been modest, probably not enough to get him a Nobel prize. But you have to keep in mind that, since 1973, no one else has made any really significant progress in this area. The standard model is just too good, and no one has yet had a successful idea about how to go beyond it.
3. His problem isn’t too little physical intuition. He decided to pursue aggressively the quite physical idea of string theory unification, based on a plausible hope in 1984 that this might work out. The reasons for believing in this were physical, not mathematical. His great failure has been an inability to recognize that, while initially plausible, this idea really doesn’t work. The best historical analogy is to his predecessor at the IAS, Einstein, who initially had good reasons to hope for a unified theory using extensions of Riemannian geometry. Einstein also made the mistake of pursuing an idea long after he should have realized it didn’t work.
Mr “” said: “The “establishment camp”? That must be the thousands of …thats why technology works…”
You are playing word games with me again. You know full well who I refer to using the “establishment camp” when I say “for 20 years”. They have nothing to do with today’s technology that we use daily, that are developed by scientists and engineers working on real problems relevant to this world. Your camp doesn’t.
You whole post did not contain a single clause disputing the physics issues I argued. The only thing you meantioned relevant to Lubos’s paper is that you say Lubos wasn’t using QM Schrodinger Equation.
http://www.arxiv.org/abs/gr-qc/0212096
You are wrong. The very first equation (1) Lubos wrote in his paper is Schrodinger Equation. And in the very first sentence right after that equation, Lubos called it the “Schrodinger Equation”. You must have came from another planet where Schrodinger Equation means something differently. Or your brain must be re-wired in such a weird way that you are no longer speaking English in its regular meaning.
Physics is a science about our observations of this universe, not about mathematics we think about in our minds. That’s a physics 101.
Quantoken
God, on the one hand we have to deal with the Witten cult, and on the other, the Qs.
Is there some way we can annihilate all the crackpots against all the string cultists? This would leave a world delightfully free of posers.
-drl
Mr. “” said: “quasi normal modes were invented by relativists back in the 60s or 70s, they have a precise MATHEMATICAL definition, if you want to say something meaningful, you don’t go around guessing what the term may mean, you make the effort and understand that precise mathematical definition. For that you may need to calm down first…”
Exactly, you can define your so called quasi normal state MATHEMATICALLY any way you want, as long as your math is self-consistent. But it’s not physics. In math, any thing self-consistent is correct and OK. But physics is more than just self-consistent. You can derive a set of self-consistent “physics” laws in a presumed 1 dimentional universe mathematically but it’s not physics.
Quantoken
Yes? And with what results? Do we know any more about the electron that post-Dirac? Neutrino post-WSG? No. Whatever Witten is doing – and frankly I don’t really care – it’s not physics. It may be math of crystalline perfection, but we have the real world to deal with.
-drl
We know. But that’s not Witten’s fault. He is the one who has most deeply thought on quantum field theory.
To {anonymous lurker} –
When in school I spent countless hours poring over the journal stacks, going back into the 1800s. In this way I got a complete overview of the actual evolution of physics as it appeared in the journals. In this time I came across a large number of physicists, both famous and obscure. One of the obscure ones I’ll mention off hand was a fellow named Jan Weysenhoff, a young Pole who died fighting the Nazis in the Warsaw uprising. Any single ONE of his physics papers is infinitely more interesting that ALL of Witten’s physics output based on strings. There simply IS no physics content in string theory – it’s a math game that does not in any way correspond to what is real. Therefore, in my mind, as a physicist, Witten is a complete bust – I find his work no more or less interesting than that of Hardy. If I had infinite time I might attempt to appreciate him from the mathematician’s standpoint, as Peter does. I’m assured by Peter that Witten is a great mathematician – and I have no reason to doubt it. But, again, Weyl was a greater one, and what HE wrote regarding physics was interesting AS PHYSICS ITSELF, because Weyl not only had a Jupiter-sized brain, he had a powerful and nearly faultless intuition. I see almost no evidence of physical intuitive genius in Witten.
Well, Witten is a very good mathematical physicist. His papers are very clear and fun to read. But, in terms of impact (no I don’t mean citations) he is by *NO MEANS* an Einstein (actually, John Schwarz likes to compare him to Newton, not mere Einstein) when it comes to physics, who actually did things which shaped the course of fundamental physics. And he is by no means the greatest mathematician, by *ANY* strech to imagination. There are plenty of other 20th century mathematicians who are also outstanding, and they would all be easily humbled by someone like Gauss who tackled several mathematical disciplines with ease (In contrast, all of Witten’s beautiful work follows from QFT).
Witten, THE pied piper of the ST camp, has been making grandiose claims about string theory for two decades now. What has string theory to show for in terms of physics??
As Anderson correctly notes “The position is called “naive reductionism” and is typified by Witten’s curious remark that “every exciting discovery in physics follows from string theory”.
String theorists like to boast a lot.”
Oh, but it is Witten saying it, so it must be true.
Now, here is somebody calling Witten pitiful.
Reminds me of the well known phenomenon that beginners tend to disproportionally overestimate their total understanding of physics. As proven by others on this blog, too.
Learning nowadays is a humbling experience.
Like that guy who recently asked: ‘How can ST have a classical limit when it makes no predictions?’
Answer: Sit down and try to understand what you are talking about and – in particular – what you are criticizing.
JC –
I don’t know what else to call it, and in fact it has in common with literary criticism that what you say is less important than to whom you say it, and with how much bravado and flair. See l’affaire Bogdanoff for an example, complete with breathless groupies.
On the other hand you have the real crackpots like this Q, who think that physics amounts to dicking around with physical constants. No wonder the Bon-Motls of the world are so entrenched.
I watched three interviews last night in turn – Seiberg, Witten, and (what relief!) Dyson. Witten in particular is a total mystery to me. Here is a person with a staggering intellect, completely incapable of doing real physics. Compared to Dyson he seemed rather shallow and pitiful, despite his Jupiter-sized brain. He was more than willing for the interviewer (Ira Flato of NPR) to call him the “next Einstein”. What a laugh.
-drl
“The establishment camp have been playing word games in a confusing way. For 20 years you have found nothing physically significant but invent a bunch of terminologies that no-one knows what you are talking about. You have forgotton the basics and need to take physics 101”
The “establishment camp”? That must be the thousands of dedicated and hard-working physicists, engineers and scientists who have slogged their way through very difficult and demanding degree courses, sitting hundreds of exams, sitting in 4-5 hours of lectures a day and doing thousands of tutorial problems. Then went through the gruelling process of going through graduate school, learning to do research and then defending a phd thesis against very intense scrutiny. Then had to get their papers peer-reviewed and published. That is…those that actually did the work and all the hard study! Not all of them end up doing theoretical stuff you can’t prove like string theory or cosmology–many, the majority, use their knowledge in applied physics and engineering to create and extend all the technology we have today. It is not perfect by any means but is the best way there is and it gets there in the end.
Thats why science works; thats why technology works. If the universe could be understood using only “physics 101” and if all the physics-based technology that exists could be created using only “physics 101” then you simply would’nt need to be educated beyond high-school level physics and maths. The “establishment camp” also deduced and “established” all the physics basics you are so very fond of so why should you believe them at one level but not at the other? Also, you can’t condemn the “establishment camp” on the one hand and them on the other expect them to accept “your theory” and the arrogant way you present it.
The terminologies and technical jargon are usually straightforward and obvious to anyone who has done the work or who has at least done a good degree course. Terms like “quasinormal modes” for example ARE the basics! They have a precise mathematical definition. You don’t just guess what the term might mean! Also, you don’t need a black hole either to study them–just hit a bell with a hammer! This sort of math will turn up in engineering too so that suspension bridges and skyscrapers don’t collapse and so on. It is not just some made-up abstract concept.
Even if the very theoretical-type physics is in a bit of a purgatory there have been many other advances these past 20 years in applied areas like condensed matter theory, superconductors, laser physics, quantum electronics and quantum optics, computing and a whole host of other areas. Physics as done by the “establishment camp” actually works! But they are still using the same quantum theory and physics concepts that underlines the more abstract and arcane areas like string theory that can’t yet be proven.
You totally and completely misunderstood what the Motl paper was all about and the more you go on about it the more you show your ignorance.
He was’nt using a “wavefunction” or the QM Schrodinger equation. He was doing a classical analysis of black hole perturbations. Perturbation analysis of black holes and stars is a well-established area of astrophysics especially in establishing the stability of stars. I am sure there are people around this blog who would like to get one up on Lubos if he had made a mistake but I don’t see anyone rushing to support your rebuttal because even vehemenently anti-string people can see you are talking BS. Besides, this thread is about the Strominger interview in India–why are you hijacking it with all this stuff? Put it on your own blog.
quasi normal modes were invented by relativists back in the 60s or 70s, they have a precise mathematical definition, if you want to say something meaningful, you don’t go around guessing what the term may mean, you make the effort and understand that precise mathematical definition. For that you may need to calm down first…
“Postmodern” physics sounds like a cross between “new age” silliness with Beavis and Butthead. In many ways, “postmodern physics” sounds remarkably similar to economic forecasting.
“The only function of economic forecasting is to make astrology look respectable.”
… (quote by economist John K. Galbraith).
Mr. “”:
I know damped oscillation in English terms and in physics terms. But I do not know whatever a twisted alternative interpretation of terminology you may have in your camp.
Keep in mind wavefunctions in QM are different from classical definition of waves. It’s a “probability wave”. The phases in wavefunctions have NO physical significance. You can offset the Omega by a positive or negative number and it makes no difference. i.e., where is the zero point of energy is un-defined and can be set arbitrarily. That’s a fundamental reason why QM is incompatible with GR, because GR requires an absolute reference point for zero energy.
Those are basic textbook stuff so dare you not question it. Once again, recite it exactly after me:
The phase in QM wavefunctions has no physical meaning!!!!!!
So, dare you NOT call the Omega in wavefunction using the term “oscillation”!!! An oscillation would have a physically significant phase and a physically significant frequency. But the wavefunction in QM has neither. Depending on how you arbitrarily define where the zero energy point is, the “frequence” could be offset by any arbitrary positive or negative number.
How could you call something that does not have a meaningful frequency “oscillation”? Calling such thing “oscillation” is really abusing the English language and twist the meaning of the terminology beyond recognition, and brings nothing good but logical chaos.
The wavefunction in QM is interpretted as a “probability wave”. As such, the only thing that has physical meaning is the module of the wave function, i.e., the wave function multiplied by its complex conjugate. Integration of this module over all space must give a total probability of exactly 100%. That’s the normalization condition of a valid QM wavefunction.
It is allowed that it transitions from one normal state to another. Such transition could show up as an imaginary term in Omega. Maybe that’s what you call quasi-normal state. But such terminology is confusing, too. Such state transition itself is not a state, but merely a mix of two states.
In any case, the English prefix quasi- would mean something that’s close, or something that transforms gradually and slowly. “Quasi-normal state” would have meant a state that is close to a normal state but undergoes a slow transition to another state.
In Lubos’s paper, his imaginary part of Omega would be correspond to the order of Planck Mass scale. So the transition, or “damp”, would happen in a time even shorter than the Planck Time. Calling such a quick transition “Quasi” whatever, is really abusing the English language.
Furthermore, any process that happens in a time shorter than Planck Time is simply none-physical. Because continuous time ceases to exist below Planck Time scale.
I do realize that probably the whole establishment camp is indeed playing the word games in such a confusing way. That only shows how crazy things have become. For 20 years you have found nothing physically significant but just invented a bunch of terminologies that no one knows what you are talking about. You have forgotten the basics and need to take physics 101 again.
Quantoken
He may be annoying and rude, but at least he’s trying to think about things (without being willing to do any real work, it’s true). I’m watching a TV show with Witten at this moment, who is reciting the string litany like a naive schoolboy mouthing his catechism. There is plenty of foolishness going around these postmodern days, among the great and the grotesque alike.
-drl
No he has’nt heard of damped oscillations…and it is very clear from the stupidities he wrote that he does not understand black hole perturbation theory at all; nor does he understand what a quasi-normal mode actually is, and why by it’s very nature it deals with complex frequencies; nor does he understand that schrodinger-type equations can arise in other areas of physics.
Partial differential equations of the Schroedinger type are very common in classical physics, e.g the heat equation. They don’t have to do anything with quantum mechanics, for example one can study the classical dynamics of a perturbed black hole. The black hole is stable- any perturbation thereof will lead to damped oscillations, which lead to the notion of quasi-normal modes. Those are complex by their very definition.
Quantoken – ever heard of damped oscillations?
Correction. I think I remembered the formula wrong. The units do not work out. The correct formula is:
V = sqrt(gravity*height)
I did say that “Further, if he even take a hot tub bath and swimmed in a swimming pool, he should have know that the wave propagate SLOWER in SHALLOW waters.”
That’s exactly correct that at deeper water the wave propagates faster, and when it reaches the coast it slows down. That’s why the later and faster waves would push earlier but slower waves, and they pile up to create high tides that is unseen in the deep oceans.
Quantoken
Mr. “” said:
“You don’t assume G either-G is directly related to the inverse string tension alpha’.
No-one “secretly injected G”. You can get the Einstein equations out without assuming anything about G or even the Planck scale.”
That’s the whole point. That’s exactly where you secretly injects the assumption of gravity. The “string tension alpha” has got to be inverse proportion to the size of the string. The smaller the string is, the higher the tension will be. You arbitrarily set the string size to be about Planck Length, that’s where you introduced the G into the string tension, because Planck Length depends on G!!!
Tell me why strings HAVE to be of the size of Planck Length, not more and not less. Please give me a reason which does not contain the assumption of gravity. You can’t.
The situation of Einstein is different. He never claimed to have “derived gravity”. All he did is “describe” the gravity (in a way better than Newton). Since he simply answered the question of “how gravity works”, but not the question “why there should be gravity”, he is not responsible to explain where he got his G.
For string theoreticians, since you claim you have derived gravity, you have to show how you derived gravity, without prior knowing the existence of gravity. By secretly injecting G using the Planck Length, you are really not deriving gravity but simply play magic and “create” things that was never created on the stage.
Now, about Lubos’s mistake in his famous paper deriving the 4*ln(3) “quantum of area”. I now know he simply does not have the minimum level of basic physics training that one would expect for an assistant professor of any school, least to say Havard University.
This is reflected on his recent comments on his Blog, regarding Tsunami waves and large asteroid hitting earth. His physics instinctions do not seem to give him the ability to make judgements when an “Astronomy educator” gave an answer which is generally correct for very small asteroids but wrong for big ones. (the astronomy educator said stony ones would melt but metallic ones would not.)
Nor did he seem to instinctly realize that the propagation speed of ocean waves does not depend on frequence, wavelength or amplitude, but instead depends merely on the depth of water. The formula is roughly V = sqrt(density*gravity/height). It’s actually a high school physics problem that any one can do a rough calculation.
Even if he does not know the exact formula, he should have the instinction from common sense accumulated from life experience. If you throw a big stone or a small stone into a small pond, the wave propagate at the same speed. So it’s independent on amplitude, contrary to Lubos’s claim. If you tap the water slowly or in rapid pace, it makes no different in the propagation either, so it is also independent on wavelength or frequence. One with basic physics training knows a phase speed dependence on frequency means dispersion, and we clearly do not see dispersion in water waves. Further, if he even take a hot tub bath and swimmed in a swimming pool, he should have know that the wave propagate slower in shallow waters. It’s amazing that a physics Ph.D. would lack such basic physics instinctions, after receiving the basic physics training.
This lack of physics instinction is also reflected in his 4*ln(3) paper, which leads to a fatal mistake, which made his paper complete nonsense. Any one who studied the basic quantum mechanics and knows Schrodinger Equation should know, without having to look into textbook, that in the wavefunctions, the X (position) exponent coefficient can be an imaginary number, meaning it is a none confined and propagating wave. Or it can be a negative real coefficient, meaning the possibility of finding the particle at remote distance decreases exponentially, and hence it is a confined state.
Now the T (time) exponent coefficient, in exp(i*omega*T), The frequencey omega can be either positive or negative, meaning positive or negative energy, since energy = hbar*omega. But omega could never be an imaginary number or contain an imaginary part. The only exception is when you have slow transition between two states, then you may have an omega containing an imaginary part. Or, you can have an imaginary part but let that part approaches zero, just for the convenience of math calculation.
The reasons you can not have a frequence that contain an imaginary part, are two. One: The energy can be either positive or negative, but never imaginary. Two: more important, the wave function is a probability wave. At any given time T, you integrate the module of the wavefunction over the whole space, and it should give you exactly 100% probability of finding the particle. Once you introduce an imaginary part into omega, then the probability integration becomes time dependent and is not always 100%, which is not allowed.
That’s where Lubos made his big mistake. He introduced an imaginary part into the frequence Omega, thought it is OK mathematically. But that is simply not allowed in physics.
Further, how silly he is, he called that Omega with an imaginary part some sort of “damped oscillation”, “quickly brings the black hole into a SPHERICAL SHAPE”. I can’t help laughing when reading that. That omega in Schrodinger Equation has nothing to do with oscillation, and it certainly does not “damp”. “damped oscillation” would mean the oscillation would eventually come to a complete stop. What does that mean in quantum mechanics? It’s total nonsense.
Lubos does not have the “order of magnitude” instinction either. He should have realized that when talking about the black hole, the smallest mass M involved would be at least Planck Mass, in most cases it will be several times or many times more. Correspondingly the omega correspond to a time scale much shorter than the Planck Time. If it is a sort of “damped oscillation”, obviously it will damp out to complete stop in a time much shorter than the Planck Time. We know time is really meaningless when the “time interval” is smaller than Planck Scale. What hell of a relaxation process was Lubos taking about?
Actually one really should not use classical quantum mechanics methods like Schrodinger Equation to study singular blackholes the size of a few Planck Mass. The mass is too high and the corresponding frequency corresponds to a time scale even shorter than Planck Time. We know at Planck Scale both GR and QM would cease to be workable because space and time is no longer continuous. One really should not push what we know at a larger scale to the limit of Planck Scale.
I am sorry to say, I expected better from an assistant professor at Havard University. Those people are supported by tax payers like me and the public do deserve to see what their tax dollars are worth.
Lubos’s paper is at:
http://www.arxiv.org/abs/gr-qc/0212096
Quantoken
The motion of the simplest bosonic string is goverened by the generalised nonlinear sigma model action. The requirement that the theory be free of Weyl anomalies (to lowest order) leads to the renormalisation group beta functions governing the physics on the world sheet. The resulting field equations are exactly those that can be derived from an Einstein-Hilbert action (coupled to a scalar, the dilaton, and an antisymmetric tensor field, the axion). GR emerges without really looking for it. You can’t avoid it.
You don’t assume G either-G is directly related to the inverse string tension alpha’.
No-one “secretly injected G”. You can get the Einstein equations out without assuming anything about G or even the Planck scale. Even if you don’t believe in string theory as a TOE it is the only theory that makes any kind of sense as a potential quantum theory of gravity. No a-priori assumptions at all are made about what the low- energy effective theory should be like, yet you recover it; the Hilbert space appears to contain black-hole like objects, what T Banks calls “asymptotic darkness”,and you get some sort of sensible result for graviton-graviton scattering. Even when you take a basic relativistic string and quantise it the spectrum automatically contains a massless spin-2 mode.
When he realised this Witten called this “the biggest intellectual thrill of his life”.
These facts put it head and shoulders above all other candidate quantum theories of gravity. It does’nt neccesarily mean string theory is correct but makes it look a whole lot righter and natural than any alternative theory of quantum gravity that you can come up with. LQG can’t reproduce Einstein gravity in the large scale limit even though it begins with GR.
I eagerly await the comic relief “explanation” of the “mistake” of the Motl paper even though the reviewer is clearly way out of his technical depth.
Chris said:
“Repeatedly posting a crank theory after being repeatedly asked to desist. I think I now understand why Quantoken has been banned from other physics discussion groups.”
Why I was “banned” on http://www.physicsforums.com had absolutely nothing to do with repeatition. I posted there a total of exactly 3 messages, which were actually three parts of the same article since I have to partition it to limit the size of each message. There was no repeatition.
I was not even sure whether I was banned or there was a technical problem. Repeated email inquiries asking what happened to my account and why never gets any response or explanation. So I have to assume I was banned and it must be for political reasons inconvenient for the message board host to explain.
Further, I am not “repeatedly posting my theory.” Upon Peter’s request, I have stopped talking about the physics details of my theory and what it is based on and what its predictions are.
Currently the only time I ever “talk” about my theory, is simply a reference to its name and its existence. I never elaborate. Are you saying I shall refrain from even meantioning the name GUITAR, the same strict way ancient Egyptian King condemned that the name “Moses” shall not be uttered from any month of any person, or the punishment shall be death? That would be worse a cersorship than the middle age, at which time they at least allowed Galileo to publish his book.
If any PhysicsForums host is reading this message, I demand an explanation to what happened to my account. If you indeed banned me, it’s OK. But at least an explanation needs to be given to me why and what happened, and what it takes to remove the ban. Ny repeated inquiries falled into deaf ears.
Quantoken
P.S. I am not forgetting about pointing out Lubos’s fatal errors in his well known 4*ln(3) paper yet. I just have not got the time to write it yet. Once I get a little bit time I will turn around and post it here. Mean while I still want to give Lubos a little bit time to find his own mistake, so he wouldn’t lose too much face when it’s eventually disclosed.
“… My theory, the GUITAR theory, is the only theory capable of deriving gravity in this fashion. I derived the G from first principle using nothing but just known parameters of one electron, including the fine structure constant alpha and the electron mass …”
Repeatedly posting a crank theory after being repeatedly asked to desist. I think I now understand why Quantoken has been banned from other physics discussion groups.
Returning to the main topic, “the only realistic possible unified theory of all the fundamental forces” is an oft-repeated selling point for superstring theory. However, if I understand Arun’s comments correctly then although the spin 2 particle is incorporated, this does not necessarily mean that we reproduce gravity in the required way. It is a bit like saying of a lump of quartz, “There’s no reason why this should not be the most advanced microprocessor yet manufactured – it’s just that we haven’t quite done it yet.”
Sorry Arun, I did not intentionally quote your words out of context. I saw it that way in Chris’s original message and did not realize it was only portion of your original sentence.
Regarding background dependence/independence. It is true that super string theory violates the GR’s background independence principle. But that can not be interpret as evidence that they did not secretly inject gravity in the first place to derive the result of “predicted the existence of gravity.” They can pick and choose just part of GR as their input.
The fact remains that they assumed the existance of gravity in the first place (by merely using Planck Length) in their theory. So how could they later claim they derived gravity?
They surely have not derived the GR, at least the GR we known from Einstein. How could a theory start with background dependence, and end up with a background independent result?
Neither the super string camp nor the LQG camp is very honest in that both secrectly injected gravity by using Planck Length in the first place, and both later claim they derived gravity.
You can bet your money that when you see a magician “created” (or “derived”, for that matter) something on the stage, it must be something previously brought to the stage before the performance, even though you may not know the detail how the magic works.
Quantoken
Since what I wrote was:
“I guess the SuperStringers’ attitude would be – we know that General Relativity is correct, because it emerges out of string theory”
I don’t know what all the arguments are about. The string theorist would almost certainly say that General Relativity was not an input into string theory; that in fact, starting the study of string propagation on a fixed background space-time goes against the spirit of General Relativity, and is one argument that LQGers use against string theory.
Chris asked:
“we know that General Relativity is correct, because it emerges out of string theory”
Is this true? How can a theory that makes no predictions have a classical limit?
I say: the statement in quotations is incorrect because it states an incorrect causal relationship. It’s the other way around. GR emerged PRIOR to string theory. The correctness of GR has nothing to do with string theory. GR is what it is, regardless whether string theory is right or not.
On the opposite, the correctness of string theory has to depend on GR. That is to say, since GR is so far believed to be correct, the string theory MUST derive GR as a necessary but not sufficient condition to be a correct theory. That is to say, if string theory can not lead to GR, it is then definitely wrong. But if string theory does lead to GR, it still may not be sufficient to say it is correct.
Now, to explain what it means string theory predicted GR in layman’s term. It is indeed true that you will get GR out of string theory. It is also true LQG also leads to GR. Actually it is true that ANY theory that works on discrete space-time at Planck Scale, would necessarily leads to GR.
Because GR was a secret input parameter to those theories in the first place. Certainly you will get GR at the printout end if you have entered GR on the input end in the first place.
To put it this way, string theory suggests there exists such little tiny stringy ringy thingym in addition to the regular 3 space dimention and 1 time dimention. That little ringy is only one Planck length in size. Thouse little rings would necessarily have some effect of curving the regular 4-D spacetime in large scales. And that is what we call gravity.
But because the rings are small, the gravity is also weak. The smaller the rings are, the weaker the gravity will be. Needless to say, if the rings are infinitely small, then gravity will be zero. Let’s say the gravity effect strenth will be roughly proportional to the area of those rings. That happen to be about one Planck Area, which is roughly the square of Planck Length, i.e., G*hbar/C^3. So gravity is exactly proportional to G.
Surprise! Surprise?!
You see where GR is secretly punched into the keyboard in the first place to get the GR output? To obtain the correct gravity, string theoreticians have to make their stringy ringy’s not too small and not too big. And the size just have to be about one Planck Length. And the definition of Planck Length happen to contain a G. And the G, of course, came from GR in the first place.
I really do not think that can be called “predicted gravity” if you secrectly entered G in the first place.
To really predict GR, you have to start with absolutely no knowledge of G and at the end you have to be able to derive G out of your theory. It should NOT be allowed that you secretly enter a known G into your formula some where in the middle.
My theory, the GUITAR theory, is the only theory capable of deriving gravity in this fashion. I derived the G from first principle using nothing but just known parameters of one electron, including the fine structure constant alpha and the electron mass.
Next time you see a theory working on Planck Scale to start with, and claim to have derived GR at the end. You know they are cheating since G was enter secretly using Planck Scale.
If any stringy theoretician has a different opinion, then I want to ask, Do you have a legitimate reason you have to make your stringy thingy no bigger and no smaller than one Planck Length, other than just to cheat the computation and get the correct GR output?
Quantoken
we know that General Relativity is correct, because it emerges out of string theory”
I was taken back by this as well.:)
I see Arun is answering, but the conceptual framework just does not seem to be clicking for some:) I have been incubating this for a couple of days and will be posting tomorrow, respective of the positions, Peter and Lubos have exemplified about the knowledge base that allows further developement by competent indivuduals in their respective areas. I’ll be more specific then.
Just let me say that the quantum harmonic oscillator, if thought of as, in referrence to the holographical point on the brane, the relevance of Gr would have found value to me in the quoted statement above. I’ll be more specific to this as well tomorrow.
Some might pre-empt me here if they wanted too, and expand on that point:)If both Peter and Lubos have a basis from which to speak, then what would happen if such manifestation of this thinking expanded into our world?:) How would we see the new concepts show theselves in the physics as some fractorial representation(Ramanujan) that would suit the common people?
I ‘ll answer this as well:)
Chris O.,
If one studies the propagation of strings in a background space-time metric then one finds a consistency requirement that the metric must follow the Einstein equations in vacuum ( R_{mu,nu} = 0 ) at the one-string-loop level. There are stringy corrections at the 2-loop level, which are not relevant in ordinary conditions.
String theory is capable of subsuming our current theories, and also describing the limits of applicability of current theories. The problem is that where its predictions are firm (10 dimensions or stringy corrections to GR) they are inaccessible experimentally; and where its predictions are (potentially) accessible (e.g., low energy Super Symmetry) they are not necessary; i.e., if low energy SUSY is not found, then that does not invalidate string theory, because almost certainly string theory can accomodate not having low energy SUSY.
The to-us-experimentally-accessible-universe is not uniquely determined by string theory; and there perhaps is no experimental finding in our current capabilities that can rule out string theory.