Einstein's theory of Special Relativity has at its core the notion of an "inertial reference frame". Unfortunately this is an overblown concept which immediately distorts our understanding of our position in the world, and does not jive with the reality of our experience as galactic observers.

This is especially relevant when applied to cosmological issues involving spaceships travelling at uniform velocities with respect to each other and measurements that such inertial observers can make, and deductions they can infer about the relations between these measurements.

We need to think a bit more carefully, and be prepared to reconsider some fundamental assumptions here.

This video is part of the Sociology of Physics playlist. A big thanks to all my Patreon supporters!