1. Jan 28, 2015 #1

   TimeRip496

   

   How do you obtain this equation M=Gm/c^2. What does M stand for? Is is newton law at infinity? Again what is this newton law at infinity?

    

   TimeRip496, Jan 28, 2015
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3. Jan 28, 2015 #2

   Nugatory

   

   Staff: Mentor

   M is just the mass of the black hole using units in which G and c are both equal to one.
   
   We don't have to make this substitution but if we don't we'll be schlepping factors of G and c around everywhere in our equations, and they're complicated enough already.

    

   Nugatory, Jan 28, 2015
4. Jan 28, 2015 #3

   TimeRip496

   

   Do you mind telling me a source for such derivation? Cause all the Internet gives is just the derivation of the schwarzschild radius.

    

   TimeRip496, Jan 28, 2015
5. Jan 28, 2015 #4

   PeterDonis

   

   Insights Author

   2016 Award

   Staff: Mentor

   It's just a conversion factor from mass units to length units; ##Gm / c^2## converts the mass ##m## to an equivalent length. The Schwarzschild radius corresponding to ##m## is just twice that equivalent length.

    

   PeterDonis, Jan 28, 2015

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