John Baez’s latest This Week’s Finds is out. As in other recent issues, he starts with some of the most fantastic astronomical pictures around. He also links to his recent non-technical talk Fundamental Physics: Where We Stand Today, which also has fantastic pictures. In the talk he describes how, since the 80s, “many physicists feel stuck”, and “continue to make predictions but they are usually wrong or not yet testable. This has led to a feeling of malaise. Why are they failing?” He partially answers this question with
But when their theories made incorrect or untestable predictions, many theorists failed to rethink their position. It is difficult to publicly retract bold claims. Instead, they focus more and more attention on the mathematical elegance of their theories… some becoming mathematicians in disguise. (There are worse fates).
Someone who was at the talk reports that afterwards Carlo Rovelli asked Baez “whether what he had just presented didn’t imply that the theoretical physics of the last 25 years was ‘junk'”, and that Baez “replied after some hesitation ‘You said it'”.
A physicist who has been concerned for quite a while about the sociological changes in how particle theory is done and the ever more critical situation that the field finds itself in is theorist Bert Schroer. His specialty is in the area of algebraic approaches to QFT, especially conformally invariant ones. More than a decade ago he was writing review articles on QFT well-worth reading that included warnings about what has been going on. For some examples, see his Reminiscences about Many Pitfalls and Some Successes of QFT Within the Last Three Decades and Motivations and Physical Aims of Algebraic QFT.
Schroer has just posted three new articles on the arXiv. One of these is entitled String theory and the crisis in particle physics and is well worth reading if you have any interest in the ongoing controversy over string theory. Schroer has many interesting points to make on the subject, and one of his main concerns is that a great deal of knowledge developed about QFT during the last century may be effectively lost as the training of young theorists focuses on string theory. This article has already drawn Lubos Motl’s trademark rant accusing anyone skeptical about string theory of being an incompetent crackpot.
The second of his new articles is called Physicists in times of war and begins with comments on the Iraq war and Schroer’s profound disappointment at the refusal of Witten and others to join him in a public campaign against the war before it began. The second part of the article tells the story of Pascual Jordan, one of the founders of quantum mechanics who joined the Nazi party. Schroer’s politics are diametrically opposite to those of Jordan, but he is highly sympathetic to Jordan’s scientific point of view, from the earliest years of quantum mechanics, that it is necessary to think about quantum systems in a way which doesn’t depend on starting with a classical Lagrangian and “quantizing”.
The last of Schroer’s new articles should appear on hep-th tonight and is entitled Positivity and Integrability. It tells some of the history of the QFT group at the Free University in Berlin and has a lot of interesting things to say about reflection positivity and the Euclidean approach to quantum field theory.
Update: I haven’t heard anything at all back from the arXiv about the trackback issue, but just noticed that trackbacks to the two recent Schroer articles mentioned here have appeared. The ways of the arXiv are highly mysterious….
Update: Baez has a clarification here of his response to Rovelli.