Wednesday, December 20, 2006

This and That

Some random things put together:
  • The arxiv will change its identifier scheme for new submissions beginning January 1st 2007. For more info, see here.

  • The well known German radio station 'Deutschlandfunk' (DLF) had a long report on Dec. 17th about 'Strings in the Crisis' (Strings in der Krise). This information was kindly provided by my husband, who actually listens to DLF. I like to call this station 'Depri-Funk', because no matter what they talk about, it's always depressing.

    If you know German, you can read the transcript on this site

    Strings in der Krise -- Physiker streiten um den rechten Weg zur Weltformel

    And if you really want, you can listen to the mp3 here.

    Be warned, if you do so, you'll have to endure a female voice intoning poems of the form "A Cosmos of slowness, Time is creeping, [...] Living in slow-motion. Dying in slow-motion [...] A Cosmos in reverse. The end is the beginning. Zebras are spitting grass to the ground. Men are dying [...] A cosmos of darkness [...]"

    ('A Kosmos der Langsamkeit.Zeit kriecht [...] Leben in Zeitlupe. Sterben in Zeitlupe [...] Ein Kosmos im Rückwärtsgang. Das Ende ist der Anfang [...] Zebras spucken Grashalme auf den Boden [...] Menschen sterben [...] Der Anfang ist das Ende [...] Ein Kosmos der Dunkelheit.')

    Jan Loius and Hermann Nicolai come to briefly express their excitement about string theory, and it is reported that: 'The Canadian physicist Lee Smolin finds in his book 'Zee Trobble Wiz Physiks' that strings are a failed thought experiment'. Later Nicolai says about the string debate caused by Smolin and Woit: "I wouldn't call that trouble, I perceived it somewhat as an amusement" ('Als Ärger würde ich das nicht bezeichnen. Ich habe das zum Teil etwas amüsiert zur Kenntnis genommen.') There is also the to-be-expected mentioning of L. Susskind and the anthropic principle, which is summarized stating that for Susskind it is 'a logical result of the mysterious six extra dimensions' ('eine logische Folge jener ominösen sechs Extradimensionen') that there exist 'universes that are inhabited only by speaking plants'.

    Quite interesting though is Thomas Thiemann's contribution in the end, where he briefly talks about his work on Loop Quantum Gravity. 'To describe the area of an A4* paper, it would take 1068 of these loops'. ('[...] um z. B. den Flächeninhalt von einem DIN-A4-Blatt zu beschreiben, bräuchte man 1068 von diesen Schleifen.')

    Since it is Depri-Funk, they finally come to the conclusion 'The situation [in LQG] is similar as it is in string theory. Researchers were able to properly write down the theory mathematically, but they aren't able to explain the world consistently. Both theories - strings as well as loops - are pure constructs. And both might remain speculations forever'

    ('Die Situation ist wie bei den Strings: Den Forschern ist es zwar gelungen, eine Theorie mathematisch sauber aufzuschreiben. Aber beide Theorien scheinen noch längst nicht in der Lage, die Welt schlüssig zu erklären. Beide Theorien - Strings wie Loops - sind bislang pure Konstrukte. Und beiden droht das Schicksal, für immer spekulativ zu bleiben.')

  • Weird Google searches that lead people to this blog:

    I also noticed with astonishment that my blog is currently the 4th hit for 'Peter Woit'. How did that happen?

  • Tomorrow morning, I'm stepping into a metal box in Toronto. It will make funny noises for too many hours, and when I step out of it, I'm hopefully in Frankfurt. That is, you are facing a slow-motion time on this blog.

  • And in the absence of anything more interesting to say, I'd like to point you towards this interesting blog, which I stumbled across today:

    Aaron in Afrika

* For the US visitors: A4 paper is used in the rest of the world, but is roughly the same size as letter format.


  1. Sticking my neck out a bit, I think it's safe to say 'There are no strings in nature.' An achievement of LHC will be to confirm it.

    What about branes? Probably not under the umbrella of 10D strings. But probable under a different foundation.

    Are there loops? Since loops result from direct mathematical application of QFT on GR, both of which are real enough, it stands a better chance of being real. I.e. spacetime is quantized.

    How about matter arising ONLY from a quantized spacetime under the umbrella of LQG? Probably not. My take is matter arise from both a quantized spacetime plus an element yet to be discovered. A third 'dark'.

  2. What about branes?

    What about brains?


    I am not sure that I agree on your statement 'There are no strings in nature.' I am pretty sure string theory will at least in some limit turn out to be the right way. Also, it might very well be that it becomes of utmost importance for heavy ion collisions. This has nothing to do with string theory being the theory of quantum gravity, but it has quite a lot to do with nature.

    I have my problems with LQG as well, the largest problem probably being that we don't know whether gravity has a quantized version at all. I personally favour the idea that there just is no quantum gravity. But don't tell anybody, as I found out recently I'm a member of the quantum gravity group...





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