Who knew gun-building could be such a dangerous yet humorous activity? I'm not talking about a regular gun, no, the sort of weapon I'm thinking about is a coil gun, constructed of wire, electricity and thin metal slugs. Between exploding circuits, smoking wires and a case of always checking which end is the pointy one, putting one together is not the safest of endeavours.
In the video above, self-described "professional" engineer Mehdi Sadaghdar explains the principles behind a coil gun before proceeding to construct one in his workshop... well, one he constructed earlier. It's a simple device and while its lethality is questionable, it's definitely neat to see in action.
Sadaghdar plays the role of a bumbling electrician, though it's clear from reading his blog detailing the concept (and the obviously comedic tone of the video) that it's all for laughs:
Basically as we all know, when we turn on or energise a coil, it starts attracting ferromagnetic material, in my case a steal bullet I made.
The issue is that if we keep the coil on, it keeps attracting the bullet. So what happens is that the bullet accelerates towards the coil and as soon as the magnetic centre of the bullet reaches the magnetic centre of the coil, the force of the coil over the bullet becomes zero. But as the bullet has momentum, it passes the centre, at which point the coil starts pulling it back and decelerating the bullet, or accelerate it back towards the centre.
Now, this is a great way to present science to the masses. Just don't got building one of your own unless you know what you're doing. Who knows how many poor cardboard boxes might suffer your misdirected metal wrath?