solid

The Plasticity creator explains what a geometry kernel is and compares commercial options C3D, ACIS, and Parasolid, describing his months of research and why he chose as he did.

Wendover Productions explains why US passenger rail lags behind other countries. It covers freight companies owning most of the track, geography and population density, and the economics of competing with flying.

America's Test Kitchen tests eight carbon-steel skillets to find the best one, asking whether a single pan can replace stainless, cast iron and nonstick. It names a winner and covers how the pans perform.

Scott Manley covers how GPS works and how civilian accuracy went from a planned 100 meters to about one meter. He explains the technology and the removal of restrictions that made this possible.

Tim Dodd's hour-long deep dive on how rocket engines start, from solid motors to liquid engines. It covers thermal conditioning, spin-up, ignition methods, starting in space, and a step-by-step RS-25 startup.

Kyle Hill explains what nuclear waste actually is and how it is stored, arguing that the problem was effectively solved decades ago. It covers solid shielded waste and deep geological storage.

FortNine surveys motorcycle airbag technology and explains why airbags have not reached mainstream adoption. It breaks down gear such as the Helite Turtle, Dainese D-Air and Alpinestars Tech-Air.

Engineering Explained uses physics to show why today's electric cars, including Teslas, are poor at towing, pointing to battery energy density and weight. It examines Cybertruck and F-150 towing claims.

PBS Space Time considers whether life could be based on silicon instead of carbon, comparing the two elements' chemistry and why silicon is the most plausible alternative.