Mythbusters
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Junior Member
Registered: 06-23-09 | If you fired a bullet in space, would the bullet still be lethal or would it even fire with zero oxygen, also say you were in a space shuttle WITH oxygen, would the bullet fire fast or slow? I heard that when the pin hits the bullet the recoil will make the gun jump back too far that the explosion from the bullet won't have enough pressure to fire out of the gun at a lethal speed. |
Senior Member
Registered: 01-02-08 | A gun works by creating a pressure difference with the projectile in the middle.
In a vacuum, the pressure difference is just greater.
The gun powder got its own oxidizer "built in", the reason why you can fire most guns submerged as seen on the show. |
Senior Member
Registered: 05-14-06 | First of all gunpowder, has a built in oxidizer and does not need extra oxygen to burn. So it works very well in a vacuum.
Next for how much it would push the shooter back. The bullet weighs about 1/9000th of a 180 lbs person. So the bullet would only be slowed down by 1/9000th of normal. So not enough to have any real effect.
theTroll |
Junior Member
Registered: 06-23-09 | Ok well wat about when you fire a gun in a weightless zone, you take all the recoil from the gun, would it send you flying back and if so would that make the bullet slower? |
Senior Member
Registered: 05-14-06 | It would move the shooter back at about .036 meters per second or about two meters per minute. Not much at all.
theTroll |
Junior Member
Registered: 06-23-09 | Ok thanks, one more thing, have the mythbusters ever tested one of your myths? |
Senior Member
Registered: 01-31-08 | The recoil in space would be practically identical to the recoil on Earth. The person holding the gun would move backwards with the same momentum as the bullet. |
Senior Member
Registered: 11-22-07 | The bullet would have the same velocity as, if not faster than, it would on earth, and it would still be leathal. |
Senior Member
Registered: 07-27-08 | Historical fact: The Soviet Union test fired a weapon in space. It worked. |
Senior Member
Registered: 02-28-08 | Question -- keeping this in mind, how far would the bullet travel? Let's say you where in LEO (low earth orbit), and pointing it away from the earth, and fired, how far would the bullet travel? |
Senior Member
Registered: 02-23-08 | quote: Let's say you where in LEO (low earth orbit), and pointing it away from the earth, and fired, how far would the bullet travel?
It would travel many times around the earth in an orbit just slightly different from the LEO from which it was fired. Its orbit would eventually decay, and it would fall to earth. So I guess the answer is "a VERY long way". |
Senior Member
Registered: 06-21-09 | I don't know what effect the vaccum will have on the barrel of the gun. however, upon leaving the the barrel the bullet fired in space will have the exact same speed as the bullet fired on earth, plus or minus the effect of the vaccuum in the barrel. If anything, there would be less air resistance.
How long will it travel in space? An object in motion stays in motion until a force acts upon it. So that bullet, if it fired beyond the gravitational pull of the earth, would remain traveling at the initial speed that it left the barrel on for what amounts to "forever" in human terms. |
Senior Member
Registered: 03-29-07 | Not exactly. If a bullet is fired outside the Earth's gravitational field, it will be acted on by the nearest large mass; The Sun, The Moon, one of the planets, the Milky Way, etc. The bullet will turn toward that large mass and what happens then depends on the parameters. Since no gun has ever been outside the Earth's gravity, it's kind of moot up until now. The effect of a vacuum on the bullet would probably give it a slightly higher muzzle velocity since the bullet doesn't have to expend energy pushing the air out of it's way as it leaves the barrel. You would have to measure the aerodynamic drag of the bullet in the atmosphere and add that velocity to the muzzle velocity. It won't be much, but it might be measurable withing the repeatability of loads. |
Senior Member
Registered: 02-23-08 | quote: Originally posted by Criminy:
How long will it travel in space? An object in motion stays in motion until a force acts upon it. So that bullet, if it fired beyond the gravitational pull of the earth, would remain traveling at the initial speed that it left the barrel on for what amounts to "forever" in human terms.
The person that asked how far the bullet will travel in space specified that it was fired from low earth orbit. By definition that means it's being acted on by Earth's gravity (in fact it would be similar to the gravity we feel here on Earth). Because the gun is already moving at nearly 17,000 mph, the velocity of the bullet will only perturb the orbit in a relatively small way. This is why it will continue in a similar orbit until that orbit decays. |
Senior Member
Registered: 06-21-09 | quote: Originally posted by spork: quote: Originally posted by Criminy:
How long will it travel in space? An object in motion stays in motion until a force acts upon it. So that bullet, if it fired beyond the gravitational pull of the earth, would remain traveling at the initial speed that it left the barrel on for what amounts to "forever" in human terms.
The person that asked how far the bullet will travel in space specified that it was fired from low earth orbit. By definition that means it's being acted on by Earth's gravity (in fact it would be similar to the gravity we feel here on Earth). Because the gun is already moving at nearly 17,000 mph, the velocity of the bullet will only perturb the orbit in a relatively small way. This is why it will continue in a similar orbit until that orbit decays.
Agreed - the question is, where does space begin and the earth's atmosphere begin? And then you have to take into account any posisble acceleration due to gravity - though I believe the bullet will reach terminal velocity and not accelerate too much more beyond a point. |
Senior Member
Registered: 02-23-08 | quote: the question is, where does space begin and the earth's atmosphere begin? And then you have to take into account any posisble acceleration due to gravity - though I believe the bullet will reach terminal velocity and not accelerate too much more beyond a point.
I don't see how these things come into question. We know it starts in low earth orbit. This more or less implies it starts outside of the Earth's atmosphere. And we know that satellites in LEO will orbit for quite a few orbits before degrading. As far as taking into account any acceleration due to gravity, that's what makes them orbit. Terminal velocity doesn't really come into it until the bullet is in the atmosphere - at which time it will almost certainly have burned up. Incidentally, the edge of the atmosphere is typically considered to be anywhere from about 100,000' to 400,000' depending on the question being asked. |
Junior Member
Registered: 06-24-09 | in theory NO because a conventual gun uses combustion which requires oxygen and in space there is no oxygen for a combustion reaction to occur |
Junior Member
Registered: 11-19-06 | kydavies2, see above, gunpowder/smokeless powder contains its own oxidiser, so the presence of oxygen is not required for the power to "burn". |
Senior Member
Registered: 06-14-04 | quote: in theory NO because a conventual gun uses combustion which requires oxygen and in space there is no oxygen for a combustion reaction to occur
If you had read the entire thread, or understood what gun powder actually is, you would know that it contains its own oxygen and will ignite and burn in space exactly as well as on Earth. Aside from that I don't understand how you could think oxygen could get through the sealed chamber of the gun then through the sealed and crimped cartridge to the powder in great enough quantity to cause an explosion. |
Junior Member
Registered: 06-24-09 | i kind of realized that after i posted it but anyways since we have astablished that gun powder can go boom in space then in theory the bullet would have almost no terminal velocity because there is an absence of air resistance. so the bullet would either constantly accelerate or maintain an extremly high velocity for a long period of time |
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