🚀 go-pugleaf

In article <1992Nov6.232435.15628@galois.mit.edu> jbaez@riesz.mit.edu (John C. Baez) writes:
>In article <1992Nov6.042306.899@murdoch.acc.Virginia.EDU> crb7q@kelvin.seas.Virginia.EDU (Cameron Randale Bass) writes:
>
>>     Suppose, as I have been, that you *don't even have* GR.
>>     In 1906, there was no certainty that GR would be developed.
>>     In fact, if Einstein had died in 1906, I'm quite sure it 
>>     wouldn't have been.
>
>Oh good, let's argue about this, since it is utterly contrafactual.  I'm
>sure GR would have been developed (though not in 1906!).  Einstein was
>not the only person working on trying to come up with relavistic
>theories of gravity.  Other people came up with some that were getting
>sort of close (sorry, I don't have references on this - it would be fun
>to know just *how* close).  And more importantly, the mathematical
>infrastructure had already been laid by Riemann and was being studied by
>Cartan and Hilbert, who were sort of into physics.  So I am quite sure
>someone would have come up with GR after a while.

     Riemann's attempts were widely considered to be failures.  It
     is my contention that Einstein was fairly lucky to have been able
     to study Riemann before 1900.  A priori there is no reason to believe
     that riemannian geometry will be useful in that context at all.
   
     And Cartan himself once bemoaned to Einstein that he did not have
     the physical background to pursue various physical subjects.  I hardly
     think this is promising grounds for an Einsteinless GR.  

     It is also true that the fact Einstein was working on the problem
     provided some of the impetus in the 1910's for such work.  However, the
     fact that GR was basically roundly ignored from 1917 until the early 60's
     lends credence to the basic assertion that GR without Einstein would
     have not been certain.  Even nearly 70 years later, however, the number 
     of errors and contradictions in GR literature is astounding (Damour, In
     "300 Years of Gravitation" Cambridge (1987)).  It is an extremely
     difficult and complex formulation, a priori, and I feel that without
     Einstein's rather prodigious physical insight, it would still lie
     undiscovered.

     I don't think I'm alone in this.  Maybe we should ask John Wheeler
     to speculate?

                            dale bass



-- 
C. R. Bass                                          crb7q@virginia.edu        
Department of Mechanical, 
     Aerospace and Nuclear Engineering
University of Virginia                              (804) 924-7926