Relativity 109d: Gravitational Waves - Transverse-Traceless Gauge (Plus and Cross Polarizations)

From a channel Lumen includes in full: eigenchris posts long, derivation-first lecture series on tensor calculus, general relativity, spinors and related maths, one of the most thorough free self-study routes into these topics.

A 21-minute video from eigenchris's catalogue; the title names its topic.

Video by eigenchris, played through YouTube's embedded player.