So a gun is kind of like that, except it pushes the projectile out through a tube using gunpowder - basically something that makes a controlled explosion when you apply the right kind of heat trigger. That energy pushes out a piece of metal, which is called a bullet, very fast and with a lot of force. But with Eridium, you can make it fire out concentrated energy instead.

[WHY IS SHE FROM SO MUCH FURTHER IN THE FUTURE THAN ANYONE ELSE HERE......]