Thursday, June 9, 2011

The basic goal of physics

I believe that in all its branches, physics is still an experimental science. Even in theoretical physics, most of the great advances have been conceptual rather than mathematical. The basic goal of physics is not mathematical elegance or even the achievement of tenure, but learning the truth about the world around us. 
P.W. Anderson, Some thoughtful words (not mine) on research strategy for theorists
This whole article (just one page) is worth reading in full and contemplating.


  1. Yes!

    I remember reading this in a back issue of PT and the opening line stayed with me.

    "The principal error I see in most current theoretical work is that of imagining that a theory is really a good model for . . . nature rather than being merely a demonstration (of possibility)—a 'don't worry' theory."

    I would say that this also the error in the use of theory by experimentalists to fit their data. In many-body physics, theories are almost always too idealized to expect that they will be an excellent fit to data. Most of the time theory should be taken as a demonstration of possibility or as a clue to how analyze a set a data, but explicit fitting to data is almost always a no no.

    Exceptions of course exist when one is talking about matters of symmetry, or at asymptotically low energies, or when there is a gap in the system (It is no coincide that these are different perspectives to the same three sided coin).

  2. Peter, Thanks for your helpful comments.
    I re-read Anderson's article on the bus today.
    It is certainly worth reading regularly.
    I agree that too often experimentalists fitting their data to the predictions of many-body theories can be idealistic and problematic, except for low-energy universal behaviour.