The 1st Law

IMHO, the 1st law of Thermodynamics (The conversation of energy) is the most important 

scientific law articulated by man as it provides the raison d'ete as to how the quantum/relativistic reality, in which we all live, is powered. :)

Energy can be neither created or destroyed, only transformed.

Boltzmann and Wheeler are right, reality is information writ large. :)