Lev Landau once said that thick books are cemeteries for ideas. This is an idea that sometimes crosses my mind because it contrasts Landau’s approach to science with the modern cult-like obsession with productivity. I could give a few concrete examples.
A few months ago I was reading the papers of Bose and Einstein on Bose-Einstein statistics in a café, which totalled less than twenty pages. When a scientist I know inquired about what I was reading, I said that I wanted to understand an unusual state of matter and mentioned the term Bose-Einstein condensation. He then told me that based on internet searches it appeared that a rigorous and complete introduction to Bose-Einstein condensation would need at least one hundred pages. That’s when I realised how crazy we have become in our H-index obsessed world.
Bose and Einstein were the guys who actually developed the idea and that’s what really matters to me. How did the fundamental insights emerge and what were their intuitions about them? Another theoretical physicist can claim to understand the ideas better but that would not be true unless they independently came up with the idea. For similar reasons, there is a massive difference between someone who writes books on existing rocket science and rocket engineers who regularly push the limits of rocket technology. Einstein and Bose were both scientists who did not just happen to be lucky and I would argue that the reason why they managed to publish their results in under twenty pages was that they understood exactly what they were doing.
Put another way, it does not matter how many miles you run; it’s more important to travel in the right direction. And I daresay that those who value productivity above all else don’t actually know what they are doing. In many ways Landau appears to have upheld higher standards.
When a colleague of his mentioned a new and interesting result in theoretical physics, which another physicist may have toiled over for several months, Landau would typically ask for nothing more than the outline of the original problem in theoretical physics. Then within a few hours he would discover the same results using more elegant methods. As Landau would say,
All I need to know from the author is what he does; how to do it, I know better.
I won’t speculate on the percentage of scientists that have Landau’s ability. All I can say is that an obsession with running in circles and productivity metrics won’t get us anywhere. Some people may ask me whether there is anything else we can learn from Landau.
I think his entire collection of books, the Theoretical Minimum, is incredible. In twenty pages Landau can explain much more clearly what will require 200 pages from a modern scientist. To a large extent that might be because within his books were original methods and discoveries, proof that he understood the theory profoundly enough in order to make original contributions on a regular basis.
As for the value of rigour, or lack thereof, Landau had this to say:
‘No attempt has been made at mathematical rigour in the treatment, since this is anyhow illusory in theoretical physics