ignition

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.

NFPA video in which wildfire researcher Jack Cohen explains that embers (firebrands), not the flame front, are the main cause of homes igniting in wildfires. He shows how landscaping and removing debris around the home reduce risk.

Thunderf00t presents high-speed camera footage of alkali metals such as sodium and NaK reacting with water. The footage shows that the explosion is not caused by hydrogen ignition, as the usual explanation says. It is a Coulomb explosion driven by electrons leaving the metal.