What Would Happen If You Shot a Gun In Space?

Life Little Mysteries ^ | 2/17/2010 | Natalie Wolchover

[U-238]

Fires can't burn in the oxygen-free vacuum of space, but guns can shoot. Modern ammunition contains its own oxidizer, a chemical that will trigger the explosion of gunpowder, and thus the firing of a bullet, wherever you are in the universe. No atmospheric oxygen required.

The only difference between pulling the trigger on Earth and in space is the shape of the resulting smoke trail. In space, "it would be an expanding sphere of smoke from the tip of the barrel," said Peter Schultz an astronomer at Brown University who researches impact craters.

The possibility of gunfire in space allows for all kinds of absurd scenarios.

Imagine you're floating freely in the vacuum between galaxies — just you, your gun and a single bullet. You have two options. You either can spend all of eternity trying to figure out how you got there, or you can shoot the damn cosmos.

If you do the latter, Newton's third law dictates that the force exerted on the bullet will impart an equal and opposite force on the gun, and, because you're holding the gun, you. With very few intergalactic atoms against which to brace yourself, you'll start moving backward (not that you’d have any way of knowing). If the bullet leaves the gun barrel at 1,000 meters per second, you — because you're much more massive than it is — will head the other way at only a few centimeters per second.

Once shot, the bullet will keep going, quite literally, forever. "The bullet will never stop, because the universe is expanding faster than the bullet can catch up with any serious amount of mass" to slow it down, said Matija Cuk, an astronomer with joint appointments at Harvard University and the SETI Institute.

[HiTech RedNeck]

I remember as a kid seeing those magic bullet cartoons. They would not dumbly pierce anything suitably soft in their path. Instead they would screech to a halt, toss a net over their target, or deploy a little mallet that conks the target over the head, or something equally cute. I tried to figure out in my little-tyke head how such a gimmicked projectile might be made to work. I figured something like air resistance acting on a deployment mechanism such that the gimmick deploys at the desired distance from the gun, and even tried to build a model out of paper and kiddie wooden blocks, but heck if I understood the physics.

[BwanaNdege]

Yo’ thutty-thutty ain’t nuttin’ compared to my old Remington 45-70!

[ThunderSleeps]

Well shucks, I’ve got Gran-dad’s 30-30 saddle gun (no BS I do) and it shoots a fair piece... I’d put it up against another, iron sights and all.