Witten replaces WMAP

Posted on October 11, 2004 by woit

Witten is giving a colloquium talk next week at Princeton on the topic of “Supersymmetry Pro or Con”. His talk is a last-minute replacement for one about “Recent Results from WMAP” by Lyman Page. WMAP was supposed to report the results from the analysis of the second year’s worth of satellite data early this year, but this has been delayed quite a bit already, and evidently is being delayed even more. Does anyone know why?

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17 Responses to Witten replaces WMAP

  1. D R Lunsford says:
    October 14, 2004 at 2:06 pm

    No – Pauli is right and Kaku – or whoever authored this quote (and I apologize in advance if Kaku was misquoted or not quoted) – is wrong.

  2. sol says:
    October 14, 2004 at 2:02 pm

    DRL,

    I was looking for specific quotes by Kaku, but immediately did not find it. I will supply when I do.

    However, since our universe obviously has 4 dimensions (3 spatial and one temporal), people were troubled by this extra 5th-dimension. Oskar Klein, a German mathematician, offered an explanation; the 5th dimension could not be seen because it was much too small. It had curled up, or compactified. For example, picture a garden hose. From far away, it appears to be a line (one-dimensional), but upon closer examination, one finds that it is a tube (a 2-D surface curled up).

    http://www.ecf.toronto.edu/~quanv/String/string4.html

    Is this a historical difference of opinion?

  3. sol says:
    October 14, 2004 at 1:57 pm

    I must apologize D.R. Lunsford for mispelling your name in post previous and ask you to click on Lubos’s name on information you quote, that you took the statement from.

    The html has to be placed in front of each paragraph to show italiced statement. This did not come about and looks like my writing, when its not. I should have previewed, and then posted.

  4. D R Lunsford says:
    October 14, 2004 at 1:56 pm

    Sol,

    It is absolutely false in every detail.

    -drl

  5. sol says:
    October 14, 2004 at 1:51 pm

    D.R Lundsford,

    You must always look to how these statements are produced. As a laymen I am at the mercy of minds better educated, so I would look at your response to further my position of understanding.

    What do you think of this statement?

    By adding a 5th-dimension, Kaluza unified in one stroke Einstein’s theory of gravity with Maxwell’s theory of electromagnetism.

    regards

  6. D R Lunsford says:
    October 14, 2004 at 1:06 pm

    Sol,

    I take strict exception to some of your statements below , viz:

    Theodor Kaluza made a shocking suggestion back in 1919 when he proposed that the electromagnetic waves are actually ripples on the shape of spacetime in the 5th dimension. This “Kaluza-Klein theory” was the first serious proposal to unify gravity and electromagnetism.

    The first (and IMO only) “serious” attempt to unify EM and gravity, in the sense of an irreducible, background free theory where Am and gmn have equal roles, is Weyl’s theory of 1918. KK theory is spurious unification, as can be seen by the simplest possible argument (given by Pauli) – *any* theory at all that can be made generally covariant, can be cast in Kaluza’s form, where the extra fields appear as part of the metric. So for example I can immediately write down a spurious “unification” of gravity and the Dirac theory, where the extra components will look like

    (psibar ym psi) (psibar yn psi)

    KK theory is *not* unification in the same sense as, say, Maxwell’s melding of electricity and magnetism.

    In all cases, electromagnetism and gravity are unified into something like “generalized geometry”.

    Not so. It’s Riemannian geometry. Weyl’s theory, on the other hand, *is* a more general geometry.

    I don’t know how these false mantras become commonplace “knowledge”, but it is not good for science. Trust but verify.

  7. sol says:
    October 14, 2004 at 11:32 am

    Is this the same CM?

    Remember we are talking about the Loop Quantum gravity article.

    Charles Matthews
    Guys, I’m completely dumb in the subject but I feel the article is simply too big. May be we should move most of it to something like Loop quantum gravity versus string theory? And let’s decide upon quantum gravity and loop quantum gravity articles — they should be something like merged with this article. Having three articles with much similar content is really strange. I believe with can do it in a bloodless way.

    Disagree, having looked around. Loop quantum gravity at 42K is already longer than WP likes. It has various articles hanging off it, and I’ve done the work required to make this another of those. Further, quantum gravity is not something that should be merged into an article on a particular theory: it should be a top-level article setting the general scene. So in a sense I’m coming closer to what User:Lumidek suggested, just because this seems to be generating a great deal of interesting writing. Still needs work, of course. Charles Matthews 11:26, 10 Oct 2004 (UTC)

    http://en.wikipedia.org/wiki/Talk:Objections_to_the_theory_of_loop_quantum_gravity

    I am amazed at your credentials and I do appreciate the work that your doing. Even you do not understand the wave you are caught in:)

    Resources for accurate information does require that we support free institutions that would cater to those less informed, and requesting, more information to draw from.

    If, the Third Superstring Revolution goes ahead as it seems it is unfolding, how would “Quantum gravity” serve as a heading and these two aspects of strings and LQG under it?

    The third String Revolution would continue to undermine current positions. Can we tolerate such speculation?:)

    I recognized Lubos work early in Wiki when none were the wiser. I can show this. I found this a admirable quality to do work, where none had not considered, where laymen like myself would draw from.

    By now, you should understand how you got where you are, by your commmenting.

    To Wiki and Beyond:)

  10. sol says:
    October 13, 2004 at 5:23 pm

    Well CW, it would be hard to classify your statement, since it didn’t compute:) Not surprise eh?:)

    Lubos

    I was wondering if the string theory says that photons are actualy
    > waves in the space-time fabric.

    Photons have been quanta of electromagnetic waves since they were first proposed in the early 20th century. Theodor Kaluza made a shocking suggestion back in 1919 when he proposed that the electromagnetic waves are actually ripples on the shape of spacetime in the 5th dimension. This
    “Kaluza-Klein theory” was the first serious proposal to unify gravity and electromagnetism.

    This KK theory has become a part of string theory. In some cases (in some spacetimes that solve the constraints of string theory), the
    electromagnetism can be interpreted as curvature of spacetime (including an extra, hidden, small dimension). In all cases, electromagnetism and
    gravity are unified into something like “generalized geometry”.

    Moreover, a photon, much like a graviton, can be interpreted as a string moving in space and vibrating in a certain way. Gravitons are always
    closed strings (circle-shaped loops) while photons can be both closed strings as well as open strings (in the braneworlds).

    > Also I would like to know if their is a theory that says, instead of
    > having many tiny strings, space-time itself would be The String and
    > what appeared to be tiny strings would be ripples (interference?)in
    > the space-time fabric.

    Actually, there is one proposal that sort of matches your – otherwise a bit confusing – remark. Some authors have proposed that the whole Universe started, a very short time after the big bang, as a single string. No four-dimensional spacetime really existed at that moment; the Universe could have been interpreted using two-dimensional theory describing two dimensions of stringy worldsheets (one spatial dimension, one time).

    Moreover, in some sense, the spacetime is always made of strings – it is a condensate of strings organized in a very specific fashion.

    See CW, if we didn’t consider the spacetime fabric and its constituents, we wouldn’t understand where the Perimenter institute leaves off(background independance), and strings begin.

    Quantum entanglement(?), between gravitons and photons, and you can be sure my tones will be heard in some way, or seen in some kind of gravitational spectrum? Non?

    I am still learning the language, but once I decipher it to the simple responses given by lubos, you can be sure CW I’ll give you a key.:)

    I take the hint all around.:) I’ll be watching you CW for your contributions.

  11. CW says:
    October 13, 2004 at 2:44 pm

    Serenus,

    I think you can take that as a ‘yes’.

    (This simulator is better suited to writing some form of postmodern literary criticism.)

  12. sol says:
    October 13, 2004 at 12:12 pm

    Serenus Zeitblom
    No offense, sol, but you wouldn’t be a computer program designed to simulate a physicist, by any chance?

    You know I can read too, don’t you:)Even if Lubos is critical of others, there are issues developing around the Perimeter institute in regards to quantum entanglement?

    Maybe using glast will settle at least some of the issues of this computerization as shown in gamma ray detection.

    Yes, my quantum entanglement is not complete, but when it is, there will be no arguing as I will have mapped out the reality for you. So all you have to do is log on, and you are in the world you fellows created. 🙂

    I just have to find the right geometry(emergent reality)) that describes quantum gravity.

    Although this has been pointed out, in the Third Superstring Revolution(TSR) as possibly negated?

    Peter’s Woits Blog should recieve credit for TSR initated by one of its members,in asking a question of Lubos.

    Lubos has revealled this unconscious desire of reform, so you Serenus Zeitblom are caught in a “new wave“, and don’t even know it.:)

    LOL:)

  13. serenus zeitblom says:
    October 13, 2004 at 5:41 am

    “That they might have extended the vision of what the cosmo is capable of, when they regarded strings as a quantum mechanical discritpion of that same universe?”

    No offense, sol, but you wouldn’t be a computer program designed to simulate a physicist, by any chance?

  14. Matti Pitkanen says:
    October 13, 2004 at 12:27 am

    Dear All,

    If I would be allowed to dream freely I would guess that Witten with his full authoricity would summarize briefly the same that I try to summarize below.

    During last 25 years I have developed a unification that I call Topological Geometrodynamics based on the assumption
    that space-times are representable as 4-surfaces in H= M^4xCP_2 (Cartesian product of Minkowski space and CP_2).

    TGD can be regarded either as a generalization of string model by replacing string world sheet with space-time 4-surface or as a fusion of special and general relativities to obtain a Poincare invariant theory of gravitation.

    In contrast to Kaluza-Klein theories, classical gravitation and gauge fields are unified in terms of induction of M^4xCP_2 metric and spinor structure. Standard model quantum numbers are understood in terms of isometry and holonomy groups apart from family replication. Color is not spinlike quantum number at fundamental level but analogous to rotational degrees of freedom of
    rigid body. Baryon and lepton numbers correspond to different chiralities for H-spinors induced to space-time surface and quark and lepton numbers are separately conserved.

    The basic (not the only one) conformal invariance is naturally associated with metrically 2-dimensional light like causal determinants (call them X^3_l) which by the general coordinate invariance can be selected as representatives of 3-spaces. This conformal invariance implies effective 2-dimensionality: the physics is coded by certain 2-dimensional sections X^2 of X^3_l so that a formalism reduces to a form very reminiscent of conformal field theories. Family replication corresponds to the different genera (sphere, torus, etc.) for X^2 and there is an argument explaining why only the 3 lowest genera are realized.

    Super-conformal symmetry is a pure gauge symmetry and does not have imbedding space counterpart: no sparticles. There is Higgs which gives a dominant contribution to intermediate gauge boson masses but only a small contribution
    to fermion masses: the rate for producing Higgs is about one percent from that predicted by standard model since Higgs-fermion couplings giving the dominant modes are weak.

    The construction of S-matrix leads to a generalization of the notion of Feynman diagram. By the above mentioned conformal invariance all Feynman diagrams represented as light like 3-surfaces connecting initial and final states
    are equivalent and fermions are “on mass shell” but not with respect to four momentum which does not appear at space-time level at all. Any generalized Feynman diagram is equivalent to a tree diagram. The notions of functional
    integral and virtual particle become obsolete and S-matrix can be seen as a generalization of S-matrix associated with braids with braiding induced by hydrodynamical flow defined
    by energy momentum tensor at the light like causal determinants.

    Particle massivation can be understood as a
    loss of correlations due to the ergodicity of this flow and p-adic thermodynamics constructed for a decade ago expresses this quantitatively and reduces the understanding of the ratios of elementary particle mass scales to Planck
    mass scale to number theory.

    There are four books about TGD and its applications at http://www.physics.helsinki.fi/~matpitka/ . The chapter “Overview about the Evolution of Quantum TGD” explains the evolution of the ideas can be found at http://www.physics.helsinki.fi/~matpitka/tgd.htlm#tgdevo .

    With Best Regards,
    Matti Pitkanen

  15. sol says:
    October 12, 2004 at 6:13 pm

    QM is not only acceptable from a pragmatic point of view for describing:

    #4 thermo-dybnamical properties of material and light

    That they might have extended the vision of what the cosmo is capable of, when they regarded strings as a quantum mechanical discritpion of that same universe?

    Sort of brings the clumping issue in line, or Andrey Kravtsov computer models.

    They had to see past Smolin(Glast indications), in order to bring something new to the table:)

  16. Alejandro Rivero says:
    October 12, 2004 at 2:23 pm

    Something about fractality?

  17. Sean says:
    October 12, 2004 at 12:49 pm

    They’ve been repeatedly delaying for quite a while now, and have been extremely good at not leaking any info. The simple explanation would just be that they have a lot of work to do and want to get it right; more exciting to imagine that they’ve discovered something unexpected, but we’ll just have to wait until they tell us.

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