I understand the difference between detonation and deflagration but isn't black powder considered an explosive? Yet it's been used as a muzzleloading propellant for centuries. I can't figure out how he's setting it off in the breach of a cannon
Deflagration is still an explosion.
for reference, here's the CFR that defines some of the terms folks are throwing around:
27 CFR § 555.11 - Meaning of terms.
Explosives. Any chemical compound, mixture, or device, the primary or common purpose of which is to function by explosion. The term includes, but is not limited to, dynamite and other high
explosives, black powder, pellet powder, initiating
explosives, detonators, safety fuses, squibs, detonating cord, igniter cord, and igniters.
Propellant actuated device.
(a) Any tool or special mechanized device or gas generator system that is actuated by a propellant or which releases and directs work through a propellant charge.
(b) The term does not include -
(1) Hobby rocket motors consisting of ammonium perchlorate composite propellant, black powder, or other similar low
explosives, regardless of amount; and
(2) Rocket-motor reload kits that can be used to assemble hobby rocket motors containing ammonium perchlorate composite propellant, black powder, or other similar low
explosives, regardless of amount.
High-order Explosives (HE) detonate, even in open air; i.e. their pressure front moves faster than the speed of sound, resulting in a shock wave. Common examples are nitroglycerine, ANFO, flash powder.
Low-order Explosives (LE) deflagrate, even in a container; i.e. they develop gas pressure quickly, but not quickly enough to outrun sound. Common examples are gunpowder, [unpressurized] gasoline, model rocket motors.
Black powder is LE, so yes it is an explosive. I haven't been able to (quickly) find a source that gives me confidence on the classification of Tannerite, though its patent language includes the word detonate, so I'd be willing to believe that it is HE.
It's certainly possible to use HE to drive a projectile. Maybe this makes me a coward, but I'd stand far away and wear a cup.