cache efficiency

Real Engineering examines the efficiency of hydrogen as an energy carrier. It follows production, storage and fuel cell conversion losses and compares hydrogen cars with battery electric vehicles.

Minutephysics compares how efficiently different processes convert mass to energy per E=mc^2, from fire and fission to fusion, antimatter and black holes, which can convert a large fraction of mass to energy.

Wendover Productions explains why modern airliners fly no faster than they did decades ago, covering the economics of speed and fuel efficiency, and why supersonic travel faded.

CGP Grey compares airplane boarding methods, based on an arXiv paper, and shows why the intuitive back-to-front approach is slow while random or outside-in boarding does better.

Technology Connections explains why single-hose portable air conditioners are inefficient and often a poor choice compared with window units. It details how the single hose pulls in warm outside air and wastes energy.

A short animated simulation comparing how Multics and Unix were developed, showing why Unix's small composable programs and pipes gave it a efficiency advantage. It frames Unix as a moonshot achievable by a small team.

A Technology Connections video weighing LED streetlights against high pressure sodium lamps, covering efficiency, color, cost and light pollution. It is a follow-up to his earlier explanation of why street lights are orange.