Another hoax in physics?

Ask to a physicist working with gravitational waves to write some questions about his area and then ask another physicist and a social scientist to answer those questions. Deliver the answers to a group of physicists and researchers in human sciences and ask them to find out which is the real physicist. Surprisingly, the physicists group could not recognize his real partner while the human scientists did much better. This was a front page matter of Folha de São Paulo (in Portuguese and subscription required) today. It reminds the Sokal affair, when the physicist Alan Sokal published a pseudo-scientific paper in a humanities journal, and the Bogdanov affair, a controversy about some papers on the Big Bang published by the Bogdanov brothers in respectable physics journals. They all raise serious questions about the strength of the peer-review system that selected the research for publication.

Fortunately the gravitational wave affair is not a hoax but the result of a study made by Harry Collins and collaborators at the Cardiff School of Social Sciences. Collins is a sociologist which works on the nature of scientific knowledge and has some interest in physics. He wrote the book Gravity’s Shadow , where he presents a sociological view of the search for gravitational waves, discusses the nature of knowledge, the processes of scientific discovery and the nature of sociological research (as stated in his website; I did not read the book). In his paper , which he says is to be published in Studies in History and Philosophy of Science 37A, 4 (2006), he reports on his new work described above. The questions made by the gravitational wave physicist are not trivial. Some of them are:

Is a spherical resonant mass detector equally sensitive to radiation from all over the sky?

State if after a burst of gravitational waves pass by, a bar antenna continues to ring and mirrors of an interferometer continue to oscillate from their mean positions? (only motion in the relevant frequency range is important).

Imagine that the end mirrors of an interferometer are equally but oppositely (electrically) charged. Could the result of a radio-wave incident on the interferometer be the same as that of a gravitational wave?

Of course, if you know some physics you can justify any answer, be it right or wrong. The questions were answered by a physicist and by Collins himself. Then 9 physicists were asked to see the answers and to point out who was the real physicist. Just one chose the real physicist, 7 chose Collins and one could not reach any conclusion. In the other group, 8 researchers, mainly from humanities, analyzed the answers. Five of them chose the real physicist, 2 chose Collins and one could not decide among the two.

So what can we learn from all this? This is similar to a Turing test where you have to decide if a computer has intelligence. You ask questions to a computer and to a person, without knowing who is who, and analyze the answers. If you can not decide who is the person then the computer has developed intelligence. What Collins is showing is that even if you have a general knowledge of some area but are not completely immersed in it, you can make comments and even give suggestions as if you were a specialist. In fact, sometimes we do that when refereeing papers or proposals in areas close to ours. This is what happened in the Sokal and Bogdanov affairs. Folha de São Paulo reports that Sokal said that he is strike by Collins work. I can understand why.

I have now found out that this was also published in Nature. A subscription is needed and I can not read it from home. Anyway, here is the link.

UPDATE: Folha de São Paulo article (in Portuguese) can be accessed here. There is also some comments by Marcelo Leite (in Portuguese) published yestarday which can be accessed here. Nature is not accessible unless you have a premium subscription (my instituion doesn't have one).

O carro de som da USP

Uma das piores coisas que existem na USP é o carro de som do SINTUSP, o sindicato dos trabalhadores da universidade. Com greve ou sem greve, quando menos se espera, ele aparece fazendo suas pregações por mais uma greve ou por melhores salários ou por melhorias na educação. Entretanto, o volume extremamente alto e a voz estridente e irritante da "tia da greve", a locutora oficial do carro de som, interrompe aulas e impede o trabalho de professores e funcionários.

Um grupo bem humorado de estudantes da Poli fez um video durante a pseudo-greve do ano passado. Lembro-me bem que houve um tumulto na Poli e o SINTUSP acusou professores da Poli de agressão. O video é bastante revelador e engraçado. Veja A Greve do Veto. Bom divertimento.

(Grato ao Oscar pelo link do vídeo)

Effective Field Theories

There is nice review on effective field theories, by C. P. Burgess, even though the title, Quantum Gravity and Precision Tests, does not reveal it. It starts with a scalar field theory and shows how to get the effective theory for the light modes. The great advantage over other papers is that it does not pay attention to the technicalities but rather to the ideas involved. It is ideal for those who are starting to study the subject. Of course, once you get this bird eye view of the subject you must then work out the technical details looking at other papers in the reference. The second part, which is much shorter than the first one, is dedicated to show how quantum effects can be computed in general relativity even though it is not renormalizable. It is really a good starting point.

Strings 2006 - Day 5

Today is the last day I will blog from Beijing even though there are 5 more talks programmed for tomorrow. We again had 11 talks today. The more interesting one was given by Kapustin. He detailed a little bit the first two points of his work with Witten on the Langlands program. Gauntlett gave a nice review on Einstein-Sasaki and presented his new solutions for AdS_3 in 10 and 11 dimensions. Horowitz talked about a black holes and how tachyons are related to the evaporation process. And that is it. I am really tired and this last post is written telegraphically. I also lost my voice almost completely because of the air-conditioning. Hope Varig still has its planes flying otherwise I may stay in Germany for a while.

I just heard a rumor that CERN will not host Strings 2008. It will be postponed by one year and Rome will take it in 2010. I don't know the reason and maybe it is still the same: if supersymmetry is found in 2008 then we all will be together to celebrate it and if it is not found we will be together for a collective suicidal.

Strings 2006 – Day 4

Yesterday I wrote that an alternative B. Greene gave a talk on cosmology at Strings 2006. In fact it was Koenraad Schalm who gave the talk. He belongs to the group of the real Brian Greene at Columbia. So what happened is that when I arrived the talk had already started. I went to the back of the room because the air-conditioning is better there. From there I could see that the speaker was not Brian Greene. He looked like Koenraad but it couldn't be him. After all, I met him when he was at Stony Brook and we discussed some calculations involving path integrals and anomalies. And this talk was on cosmology! Definitely it couldn't be Koenraad. So I was taken by surprise when he told me this afternoon that he had given the talk. He also commented that when he started the talk he said he was giving the talk in the place of the real Brian. I really have to change my glasses before I get into trouble. I mentioned Koenraad talk because it was really good. And now knowing that he went to cosmology makes it more valuable. Congratulations Koenraad and sorry for not having recognized you.

Besides that today was a heavy day. We had 5 talks in the morning and 6 in the afternoon. It is too much! Shiraz Minwalla gave an energetic talk as always. He reviewed the calculation of the partition function of N=4 gauge theories for 1/8 BPS states and the connection with giant gravitons. The next talk was by Schnabl and he described his solution of the open string field theory and the new advances. M. Green gave a nice talk about the new results for the four graviton amplitude. Stephan Hawking talked about the semi-classical birth of the universe. At the end there was a question and it took several minutes before he could make his computer answer it. It was a bit embarrassing. Some of the other talks were about emergent geometry and stringy phenomenology. The banquet at night was uneventful. Tomorrow there will be 11 lectures again. I will probably skip some of them.