Force

Push or pull that changes motion.

Energy

Capacity to do work; conserved across transformations.

Entropy

Measure of disorder / number of microstates consistent with a macrostate.

Spacetime

The 4D fabric in which all events occur.

Electromagnetic wave

Self-propagating oscillation of electric and magnetic fields, including light.

Natural selection

Mechanism of adaptation via heritable variation + differential survival.

Conservation law

Statement that some quantity (energy, momentum, charge) is preserved across transformations.

Quantum

Discrete unit; the framework where particles behave probabilistically at small scales.

Power law

Relationship where one quantity varies as a power of another, producing heavy tails.

Bayes' theorem

Rule for updating probability of a hypothesis given new evidence.

Pareto principle

Roughly 80 percent of effects come from 20 percent of causes.