What can light and other electromagnetic waves do to objects.

It can cause a reflection.

Such on, windows, Glasses, cars, rings, necklaces, and metal water bottles.

Spontaneity tell us the direction of the reaction, but not how fast it goes. gibbs free energy brings together enthalpy, entropy and temperature in one easy formula. g = h - ts. and, finally the sign of delta g is always negative for a spontaneous reaction.