Koan 7

What do we see everywhere but rarely notice?

Light.

Things we see are not things, just light reflecting off things.

Moreover, the essence of things is light; for all things are energy slowed down by the speed of light squared. That is, E=M*C*C is M=E/C*C; Mass is Energy divided by the speed of light squared.

As all things are light, perceiving things as otherwise is an illusion.