What is a railgun?

Although railguns sound like something from a science fiction movie, they are far from fictitious. Railguns are devices that can accelerate conductive objects using the electromagnetic Lorentz force. Unlike conventional gunpowder weapons, which are limited by gas expansion rates ect, railguns can accelerate objects to many times the speed of sound.

As shown in the picture above, the Lorentz force is created when a conductive projectile is placed between two conductive rails. One of the rails is connected to the positive terminal of a power source and the other is connected to the negative terminal. The current flows up one rail, through the projectile, and down the other. This creates magnetic forces that repel each other forcing the projectile forward at high speeds.