I thought his initial incredulity around the firing cap highlighted just how much modern electronics and the energy density (and dischargeability) of modern tec

I thought his initial incredulity around the firing cap highlighted just how much modern electronics and the energy density (and dischargeability) of modern tech has colored our expectations, even for people into older tech like the creator here. When he said the cube used no batteries in the camera, I immediately assumed that it was either going to be a firing cap like device, or he was about to talk about some obscure and forgotten "super-piezo" material. Small explosions of all sorts are the bread and butter of a lot of things from the mid-century. Your car is a rolling box of self contained explosions. Likewise any "small-engine" tool from chainsaws to weed-eaters to mowers. Children's toys like cap guns and poppers were full of them. "powder actuated tools" are another example. There's probably more, but I don't want to end up on a list googling for them