OCAM'S RAZOR: The simplest solution is the most likely. (The more complicated, the more variables and the more assumptions > therefore the more likely it is that the assumptions are somehow interfering/incorrect)
MURPHY'S LAW: What can go wrong, will go wrong.
THE ZEROTH LAW OF THERMODYNAMICS: Any two systems in equilibrium to a third system are in equilibrium with each other.
THE FIRST LAW OF THERMODYNAMICS: In any process, the total energy of the universe remains constant.
THE SECOND LAW OF THERMODYNAMICS: The entropy of an isolated system not in equilibrium will tend to increase over time, approaching a maximum value at equilibrium. (energy systems have a tendency to increase their entropy)
THE THIRD LAW OF THERMODYNAMICS: As temperature approaches absolute zero, the entropy of a system approaches a constant.
ENTROPY: Entropy is a measure of the uniformity of the distribution of energy. A more recent formulation describing Entropy as energy dispersal describes entropy as measuring "the spontaneous dispersal of energy — at a specific temperature." (Energy used disperses.)