## Dialog on Dark Matter

Here are equations explaining the force between photons or photon and mass:

F=Y_1 (f_1 f_2)/r^2 (gravity force between photon and photon)

F=Y_2 f m/r^2 (gravity force between photon and mass)

F=Y_1 (f_1 f_2)/r^2 (gravity force between photon and photon)

F=Y_2 f m/r^2 (gravity force between photon and mass)