Scale invariance in cosmology and physics

Understand

The fundamental laws of physics are required to be invariant under local spatial scale change.

• In 3-dimensional space, this leads to a variation in Planck constant \hbar and speed of light c.
• They vary as \hbar ~ a^(1/2) and c ~ a^(-1/2), a is the local scale.
• A direct consequence is that the expanding universe progressively alters the values of c which in turn affects the evolution of the universe itself.