I read several times that the Planck scale is the energy scale at which the effects of gravity are comparable to the effects of the other fundamental forces.
How can I show that this actually happens at $10^{19}$ GeV?
I read several times that the Planck scale is the energy scale at which the effects of gravity are comparable to the effects of the other fundamental forces.
How can I show that this actually happens at $10^{19}$ GeV?
I found the answer myself: requiring that the gravitational potential $GM^2/r$ is equal to the rest mass $Mc^2$, one obtains for r equal to a natural unit of length $Mc^2=1.22\times10^{19}$ GeV that is the Planck scale.