We didn't start the fire

When I was young, creating sparks fascinated me. I knew fire was a hazard but sparks were less dangerous.

So how did you create sparks? I knew that lighters did it when you press a button or spun a wheel. 

And then what caused the spark? I would have said friction. I was not totally wrong but the truth about how modern devices create sparks was actually more complicated.

Firstly, not all devices used friction or a battery to generate a spark(actually an arc of electricity)

There is something call piezoelectric. Those are crystals that if you hit them, they generate an electric charge. To create the arc lightning, the charge was sent metal with small gaps in between. The electric charge did the rest.

But even if I was correct about friction devices, my understanding was incomplete. The friction did generate heat but the sparks were actually combustion of a rare earth metal cerium.