[FOM] extramathematical notions and the CH

[Sam Sanders]

Dear All,

I second Nik Weaver's claim that the Mathematics used in Physics can be 
formalized in systems far weaker than ZFC.  

However, according to the FOM community, what are weak systems still sufficient to
formalize the Math used in Physics?

RCA_0 ?  

RCA_0^* ?

I\Delta_0 +EXP?

Best,

Sam

> If indispensability arguments show
> anything, it is that we have experimental confirmation of the consistency
> of the weakest formal systems in which our physics can be formalized, not
> of systems which are much stronger than what is needed.