Monday, January 03, 2005
To answer a question I had some time back (although probably not just because of that), the text of David Politzer's Nobel Lecture is now up on his web page. The provocative title is "The Dilemma of Attribution," but the lecture itself isn't by any means outrageous. It's a look at the history of the ideas of QCD and asymptotic freedom from Politzer's personal perspective, with a strong emphasis on giving credit to absolutely everyone. It's an important task, as the actual history is inevitably messy, and there is an irresistible temptation to clean them up in the retelling.
As teachers of the next generation of scientists, we always seek to compress and simplify all the developments that have come before. We want to bring our students as quickly as possible to the frontier of current understanding. From this perspective, the actual history, which involves many variants and many missteps, is only a hindrance. And the neat, linear progress, as outlined by the sequence of gleaming gems recognized by Nobel prizes, is a useful fiction. But a fiction it is. The truth is often far more complicated. Of course, there are the oft-told priority disputes, bickering over who is responsible for some particular idea. But those questions are not only often unresolvable, they are often rather meaningless. Genuinely independent discovery is not only possible, it occurs all the time. Sometimes a yet harder problem in the prize selection process is to identify what is the essential or most important idea in some particular, broader context. So it's not just a question of who did it, i.e., who is responsible for the work, but what ``it" is. I.e., what is the significant ``it" that should stand as a symbol for a particularly important advance.Politzer explains vividly the diverse contributions that went into the discovery of asymptotic freedom. But he also believes, I think correctly, that the final result from him and Gross and Wilczek really was the event that deserved the Prize, even if it was "just getting a minus sign right" (the strong force grows weaker at short distances rather than stronger), and indeed a sign that some other people already had calculated. Putting it into the right context, and appreciating its fundamental significance, created the moment in which people finally understood that QCD was the correct theory of the strong interactions.
Update: Another line worth quoting --
I must say that I do regard theoretical physics as a fundamentally parasitic profession, living off the labors of the real physicists.