The high stability and ignition temperature of thermite are due to the aluminum oxide layer protecting the aluminum particles.

“The aluminum is quite stable because it's covered in aluminum oxide, and only if it gets so violently heated that that layer breaks down in a large number of particles, then the reaction can start.”

Thermite is an energetic reaction that is well-suited for controlled industrial applications rather than as an explosive.

“Now you might think, given the amount of energy given off that thermite could be used as an explosive, but it's actually not well suited for that purpose.”

Thermite's safety and utility stem from the ability to precisely control the energy release.

“What makes thermite so interesting and so important is that you can control it so well.”