Re: Can you solve my gravity-maths problem in Mathematica?

*To*: mathgroup at smc.vnet.net*Subject*: [mg62853] Re: [mg62828] Can you solve my gravity-maths problem in Mathematica?*From*: "Carl K. Woll" <carlw at wolfram.com>*Date*: Tue, 6 Dec 2005 23:10:28 -0500 (EST)*References*: <200512060504.AAA02783@smc.vnet.net>*Sender*: owner-wri-mathgroup at wolfram.com

Paul wrote: > Hello, I have been working on a simple model of quantum gravity. Like > atoms have a minimum electron shell distance caused by the quantisation > of the electromagnetic force my approximation for the average distance > between particles held together by a graviational force, using my > model, becomes : > > "Find r at the maximum value of: > > f(r) = exp( m*r ) * integrate( exp(-2*m*r)/r^2 , r ) > > (r>0) " > You really need to distinguish between r the integration variable, and r the argument to f. Also, if the r^2 in the denominator is the integration variable, then the integral over r>0 does not converge. So, change the name of the integration variable, and spell out the limits of the integration. Then, maybe someone can help you. Carl Woll Wolfram Research > Where we use constants such that c=h=G=1. In this system for example > electron mass is something like 10^(-23) I believe. (The graviational > bond enegy in this model becomes m^5 in my units.) > > So I need to find f'(r)=0. > > Can anyone find a good way to solve this for r, maybe as a series in > terms of m? Also, I would be interested in seeing a graph of f(r).

**References**:**Can you solve my gravity-maths problem in Mathematica?***From:*"Paul" <paulbird@whsurf.net>