(physics) The angle of incidence beyond which light traveling through a medium experiences total internal reflection upon encountering a boundary with a less refractive medium.

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

(operations) The sequence of dependent steps that determine the minimum time needed to carry out an operation.

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

(programming) A piece of code that accesses a shared resource that must not be concurrently accessed by more than one thread of execution.

plural of critical mass

Of a system: capable of causing serious injury or damage if it fails or malfunctions.

Of a system: capable of causing death if it fails or malfunctions.

plural of critical period

(psychology, biology) A maturational stage in the lifespan of an organism during which the nervous system is especially sensitive to certain environmental stimuli.