The Gravitational Constant of the Universe Hasn't Changed.

There is some evidence that one of the constants in physics, known as the fine structure constant, or alpha, has not been entirely constant. Here's how michael brookes introduces alpha in his book, 13 things that don't make sense. Alpha determines what happens every time a photon hits some piece of matter. Look at the wall opposite you, whatever color you see, you see because of alphaa. Photon of light hits an atom in the paint and uses that energy to send out a photon that hits your eye. The energy of that photon determines the wave length of the light it produces,. In essence, what color you see.