[FOM] Question about theoretical physics

[Timothy Y. Chow]

On Tue, 2 Jul 2013, Joe Shipman wrote:
> That's a good distinction, but what I said, and what Professor Neumaier 
> said, and what Lubos Motl said, all apply to the most fundamental and 
> canonical experiments of all, such as the measurements of the Lamb shift 
> and the magnetic moment of the electron, so the issues I raise are 
> unaffected by this point.

But I think they are affected, because the mere act of asking for an 
*algorithm* means that you're asking for a precise specification of an 
infinite family of inputs and a systematic procedure for treating all 
those inputs.  I don't think that physics operates that way.

The analogy in mathematics might be asking for an "algorithm" for 
generating a computer-verifiable proof of, say, the Poincare conjecture, 
from Perelman's preprints.  There isn't any such algorithm.  What we do is 
to hope that a bunch of experts will get together and study the proof and 
then tell everyone else that they understand how it works.  When this 
happens, we generally declare the problem solved.  It's nice if there is a 
beautifully written exposition that any random mathematician can use to 
confirm the result independently, without the need to talk to any experts 
in order to pick up the tricks of the trade that are needed to fill in the 
"obvious" steps of the proof that the experts don't bother to write down. 
But it's hardly a "scandal" if no such exposition exists.  We trust that 
the experts know what they're doing and that if someone were to take the 
time to become an expert, they would be able to reproduce the same 
results.  That's the only "algorithm" in most cases.

Tim