From: goldenfieldquaternions@gmail.com   
      
   On Friday, November 2, 2018 at 12:24:01 AM UTC-6, ben...@hotmail.com wrote:   
   > On Thursday, November 1, 2018 at 10:21:57 PM UTC, Tom Roberts wrote:   
   >> ...   
   >> For test particles the GR prediction is unambiguous:   
   >> regardless of the test particle's mass (including sign, if any) it   
   >> "falls downward" toward a positive mass and "falls upward" away from a   
   >> negative mass.   
   >>   
   >> While there is currently no experimental evidence of antimatter's   
   >> behavior in gravity, the mass of every known antiparticle is   
   >> unequivocally positive.   
   >> ...   
   >   
   > I am not clear how it is shown that antimatter unequivocally has   
   > positive mass?  As both positive and negative test masses are attracted   
   > to the positive mass of the earth, then how can attraction to the earth   
   > be used to distinguish between a positive and a negative test mass?   
      
   It makes little sense that antimatter has negative inertial mass. The   
   particle antiparticle interaction would give mc^2 - mc^2 = E = 0, where   
   experiments measure photons. The gravitational mass is an open   
   questions, and an experiment at CERN is being set up to measure this   
   with anti-hydrogen atoms.   
      
   LC   
      
   --- SoupGate-Win32 v1.05   
    * Origin: you cannot sedate... all the things you hate (1:229/2)