The application of logical principles, rigorous standards of evidence, and careful reasoning to the analysis and discussion of claims, beliefs, and issues.

A direct action event in which bicycle riders travel through city streets as a group.

(philosophy) The proposition that scientific theories, and any other claims to knowledge, can and should be rationally criticized, and, if they have empirical content, can and should be subjected to tests which may falsify them.

(physics) The amount of fissile material needed to support a self-sustaining nuclear chain reaction. / (figuratively) The tipping point.

(physics) the milky turbidity observed in a fluid as it is slowly cooled to just above its critical point, at which point two clear phases (gas and liquid) form

(thermodynamics) The temperature and pressure at which the vapour density of the gas and liquid phases of a fluid are equal, at which point there is no difference between gas and liquid.

(mathematics) Any function, in the calculus of variations, that satisfies the Euler equations

(ecology) The maximum load that a given system can sustain before it fails.

plural of critical load

(physics) The temperature at the critical point of a substance, i.e. the temperature above which the substance cannot be liquefied.