Shut up and Calculate!
Should one ignore the foundational issues of quantum mechanics when learning the topic for the first time?
During yesterday’s session, I mentioned that I once heard a professor say that the best way to learn quantum mechanics without losing sleep is to focus first on learning how to use it as a toolkit i.e. not worry too much about what it all means in the foundational sense! This is of course a bit controversial, indeed from my point of view, thinking about foundational issues whether in physics or mathematics, is a very important part of advancing the knowledge in both fields.
Anyway, as we go through the axioms of quantum mechanics one by one, I thought it would cool to share some resources on both sides of the debate. This week I will share resources relevant to the ‘Shut and Calculate’ philosophy.
‘Shut up and Calculate’ by Max Tegmark:
I advocate an extreme "shut-up-and-calculate" approach to physics, where our external physical reality is assumed to be purely mathematical. This brief essay motivates this "it's all just equations" assumption and discusses its implications.
2. ‘Could Feynman Have Said This?’ by N. David Mermin:
But while “shut up and calculate” sounded dimly familiar to me as a characterization of a certain interpretive stance, I couldn’t recall where Feynman had written it. Mulling this over, a terrible thought began to dawn on me. Could it be that I myself had once used the phrase? If so, then it would appear that I had picked it up from something by Feynman, forgotten the source, and presented it as my own. Devastating!
It was devastating because I have a horror of writing or uttering any witticism that is not original with me, unless I make it absolutely clear where and (if known) from whom I got it. I don’t even like to tell jokes unless I’ve made them up myself.
(I digress to offer you my favorite:
Question: What is the difference between theoretical physics and mathematical physics?
Answer: Theoretical physics is done by physicists who lack the necessary skills to do real experiments; mathematical physics is done by mathematicians who lack the necessary skills to do real mathematics.
Mathematical physicists tend not to like this joke, but other physicists seem to. Nonphysicists, of course, are entirely immune to its charms.)
3. ‘Three Cheers for "Shut Up and Calculate" in Fundamental Physics’ (slides only) by Nima Arkani-Hamed:
The famous Cornell physicist David Mermin once said that the standard approach to understanding Quantum Mechanics was to "Shut Up And Calculate!", a quote also often (mis)attributed to Richard Feynman. Over the years, "Shut Up And Calculate" has become something of a pejorative characterization of an approach to physics, said by some to be intellectually lazy and philosophically unsophisticated, the method of philistines merely "solving equations" rather than "Asking Profound Questions".
In this talk I will explain why this is utter nonsense, giving a full-throated three cheers for "Shut Up And Calculate" in fundamental physics. I will describe, through both historical and contemporary examples, how the very experience of grappling with the most conceptual issues in physics forces the "Shut Up and Calculate" approach on us. Far from being the product of an unwillingness to think about big questions, "Shut up and Calculate" is born of the deepest thinking about, and the greatest respect for, such questions, coupled with a desire to find concrete paths to attacking them, rather than gaping at them in perpetual awe. I will also argue that the "Shut Up And Calculate" philosophy is certain to grow in influence over time, as we draw ever closer to uncovering laws of physics governing the most fundamental elements of reality.
As we approach the final sessions of this module, I may start inviting volunteers onstage for 5 - 10 minutes before the session starts to share their comments or any criticism of the above resources.
Best wishes,
Bambordé