Tag Archives: L. Kadanoff

Is it really as bad as they say?

It’s been a little while since I attended A.J. Leggett’s March Meeting talk (see my review of it here), and some part of that talk still irks me. It is the portion where he referred to “the scourge of bibliometrics”, and how it prevents one from thinking about long-term problems.

I am not old enough to know what science was like when he was a graduate student or a young lecturer, but it seems like something was fundamentally different back then. The only evidence that I can present is the word of other scientists who lived through the same time period and witnessed the transformation (there seems to be a dearth of historical work on this issue).

phd100311s

It was easy for me to find articles corroborating Leggett’s views, unsurprisingly I suppose. In addition to the article I linked last week by P. Nozieres, I found interviews with Sydney Brenner and Peter Higgs, and a damning article by P.W. Anderson in his book More and Different entitled Could Modern America Have Invented Wave Mechanics? In his opinion piece, Anderson also refers to an article by L. Kadanoff expressing a similar sentiment, which I was not able to find online (please let me know if you find it, and I’ll link it here!). The conditions described at Bell Labs in David Gertner’s book The Idea Factory also paint a rather stark contrast to the present status of condensed matter physics.

Since I wasn’t alive back then, I really cannot know with any great certainty whether the current state of affairs has impeded me from pursuing a longer-term project or thinking about more fundamental problems in physics. I can only speak for myself, and at present I can openly admit that I am incentivized to work on problems that I can solve in 2-3 years. I do have some concrete ideas for longer-term projects in mind, but I cannot pursue these at the present time because, as an experimentalist and postdoc, I do not have the resources nor the permanent setting in which to complete this work.

While the above anecdote is personal and it may corroborate the viewpoints of the aforementioned scientists, I don’t necessarily perceive all these items as purely negative. I think it is important to publish a paper based on one’s graduate work. It should be something, however small, that no one has done before. It is important to be able to communicate with the scientific community through a technical paper — writing is an important part of science. I also don’t mind spending a few years (not more than four, hopefully!) as a postdoc, where I will pick up a few more tools to add to my current arsenal. This is something that Sydney Brenner, in particular, decried in his interview. However, it is likely that most of what was said in these articles was aimed at junior faculty.

Ultimately, the opinions expressed by these authors is concerning. However, I am uncertain as to the extent to which what is said is exaggeration and the extent to which it is true. Reading these articles has made me ask how the scientific environment I was trained in (US universities) has shaped my attitude and scientific outlook.

One thing is undoubtedly true, though. If one chooses to resist the publish-or-perish trend by working on long-term problems and not publishing, the likelihood of landing an academic job is close to null. Perhaps this is the most damning consequence. Nevertheless, there is still some outstanding experimental and theoretical science done today, some of it very fundamental, so one should not lose all hope.

Again, I haven’t lived through this academic transformation, so if anyone has any insight concerning these issues, please feel free to comment.

A Glimpse into the Renormalization Group

Leo Kadanoff passed away recently, and his ideas have had far-reaching consequences in many areas of physics. He took the fist important step of recognizing the role of “scale transformations”, which was embodied in his idea of “block spins“, at critical points. This visionary idea soon led to Wilson’s development of the renormalization group (RG).

On a personal level, I have found that understanding the concepts behind the renormalization group to be quite challenging. Many of the treatments are from a quantum field theoretical perspective, which to an experimentalist like me, present their own difficulties. I therefore found the short introductory article by Maris and Kadanoff entitled Teaching the Renormalization Group to be extremely valuable. It conveys (in 6 pages!) the main ideas behind the RG approach to phase transitions and critical phenomena.

Of course, the article only leaves the reader wanting more, as it is brief and to the point. However, I see this as a positive! It spurs curiosity. I see myself coming back to this article repeatedly even after having surmounted more difficult texts on the topic.