From: dr.paul.g.ellis@gmail.com   
      
   On Wednesday, 24 April 2019 11:53:13 UTC+1, J.B. Wood  wrote:   
      
   > Hello, and I wasn't inquiring about the effects of gravity or whether   
   > it's a "true" force or not.  I'm trying to understand its origin and why   
   > it should exist in curved space-time.  Examples showing its effect(s) on   
   > masses don't address its genesis.   
      
   J.B. Thank you for your reply.   
      
   I wonder whether this is more of a linguistic/mental-modelling problem   
   than anything else.   
      
   You wrote " I'm trying to understand its origin and why it should exist   
   in curved space-time."   
      
   It seems to me that you're coming from a mental model based in Newtonian   
   ideas and consequently the essential point is eluding you: that gravity   
   doesn't "exist in" curved space-time, but rather it *is* curved   
   space-time.   
      
   You must have often seen a quote like "Matter tells spacetime how to   
   curve, spacetime tells matter how to move”, which is John Wheeler's   
   succinct summary of Einstein's theory of general relativity (from Geons,   
   Black Holes, and Quantum Foam (2000), p. 235.)   
      
   That's it, in a nutshell!   
      
   May I suggest that you try to let go of the idea of gravity as an   
   existing 'thing/force/whatever' and try instead to envision a mental   
   model that sees only matter curving spacetime so that toboggans   
   free-fall down snowy hills...?   
      
   Best regards - Pellis   
      
   PS: Incidentally, I had a conversation with Wheeler while walking around   
   the gardens of the Niels Bohr Institute, during a conference in about   
   1973. He never got a Nobel prize himself but at least two of his many   
   doctoral students did: Richard Feynman, and recently Kip Thorne   
      
   https://en.wikipedia.org/wiki/John_Archibald_Wheeler   
      
   --- SoupGate-Win32 v1.05   
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