There is a law not yet explained in physics:

I call it the law of two.

That similar energies go to similar energies especially and predominantly in twos.  

I think this is likely with anything in the entire universe.

Our galaxy the Milky Way is similar to the Andromeda Galaxy and in the last two years shifted it's movement to an angle that has both galaxies on a collision course, but many years from now.  That is a good cosmic example don't you think?