🚀 go-pugleaf

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.

   In article <1992Nov6.232435.15628@galois.mit.edu> jbaez@riesz.mit.edu
   (John C. Baez) writes: 

   >Oh good, let's argue about this, since it is utterly contrafactual.  I'm
   >sure GR would have been developed (though not in 1906!)....

In fact, there was a fairly extensive thread on this topic about a year
ago.  Without trying to summarize, let me repeat 4 points people made:

  (1)   Pais' biography of Einstein provides much insight into the
    	convoluted intellectual history of the actual birth of GR,
    	primarily from Einstein's viewpoint of course, but also with an eye
    	towards other contemporary efforts (e.g., Nordstrom's theory).

  (2)	Other very different paths to GR exist.  MTW mentions a "graviton"
    	based approach, worked out apparently by Feynmann.  You don't get a
    	consistent unification of QM with GR, but you can somehow tweak out
    	Einstein's field equations.  This was cited as an argument that GR
    	was "inevitable", once quantum field theory was developed.

  (3)   One does have to decide what "GR would have been developed" means.
    	Would it count to have a theory equivalent to GR, not generally
    	accepted but merely one of a welter of competing theories?

  (4)   And finally, from Twain we can crib the granddaddy of
    	counter-factual assertions:  If Walter Scott hadn't written any
    	novels, there wouldn't have been a Civil War.  [OK, that's not
	exactly was Twain said.]