What Matter, Mass, and Energy Really Are
PBS Space Time · Explainer · YouTube title: The True Nature of Matter and Mass | Space Time | PBS Digital Studios
Why it's here
HN recommends it, and the whole channel, as a clear and deeper-than-usual physics explainer.
What it covers
A PBS Space Time episode asking what matter, mass, and energy really are, starting with inertial versus gravitational mass and what mass-energy equivalence means.