Guns On the MOON ? - Page 2

[ARCHIVED THREAD] - Guns On the MOON ? (Page 2 of 3)

Posted: 6/4/2008 4:15:51 PM EDT

[#1]

Quoted:
The only problem you'd have with firing a gun in outer space or on a planet or moon with no atmosphere would be keeping it from over heating.

You telling me energy transfer only occurs where there is an atmosphere?

Posted: 6/4/2008 4:16:33 PM EDT

[#2]

I'd be more worried about the impact of the cold in space on the powder.

Recoil would be the same as here on earth. BUT in lower gravity (1/6th xG on the moon), less in deep space, controlling your self is harder. It deep space, you would go into a slow backspin.

Posted: 6/4/2008 4:17:35 PM EDT

[#3]

Quoted:

Quoted:
The only problem you'd have with firing a gun in outer space or on a planet or moon with no atmosphere would be keeping it from over heating.

You telling me energy transfer only occurs where there is an atmosphere?

convection is a much more efficient means of transfering heat than radiation. this is why vacuum thermos bottles work well.

Posted: 6/4/2008 4:18:40 PM EDT

[#4]

Quoted:

Quoted:
The only problem you'd have with firing a gun in outer space or on a planet or moon with no atmosphere would be keeping it from over heating.

You telling me energy transfer only occurs where there is an atmosphere?

convection is a much more efficient means of transfering heat than radiation. this is why vacuum thermos bottles work well.

Touche.

Posted: 6/4/2008 4:19:13 PM EDT

[#5]

Quoted:

Quoted:
The only problem you'd have with firing a gun in outer space or on a planet or moon with no atmosphere would be keeping it from over heating.

You telling me energy transfer only occurs where there is an atmosphere?

Radiation is a very slow method of heat transfer. On Earth, guns typically cool by convection, a form of conduction.

Posted: 6/4/2008 4:19:53 PM EDT

[#6]

Quoted:

Quoted:
Yeah........no kidding........because gravity pulled it there Da Vinci

And . . . gravity doesn't exist in space?

Not in appreciable amounts.

Which is why the moon fails to stay in orbit a quarter of a million miles away

Posted: 6/4/2008 4:20:13 PM EDT

[#7]

Quoted:

Quoted:
There's air in a cartridge, so I don't see why not. Bullets will fire underwater. But I would think if you fired a bullet in space, it would never stop unless it hit something.

On Earth, a bullet won't stop until it hits something too. One of the laws of motion state that an object will remain at rest or continue in a straight line unless acted on by an outside force. That goes for anything, anywhere.

Um...............gravity, Einstien?

The outside force is gravity...

Yes I know ...and atmosphere too.

Posted: 6/4/2008 4:20:21 PM EDT

[#8]

Quoted:
I dont know if this question was ever posed but,I was talking with some guys at work.If you were on the moon, or actually an atmosphere with no oxygen, would you be able to fire a weapon. I thought no since there would be no oxygen to feed the combustion of the powder. Im not even sure the primer would detonate. Then My buddy said " How do you explain rocket propulsion in outer space" I said " Fuck you, get back to work or you're fired!

Well , what do you think ? guns on the moon or not?

Guns will work just fine in the vacuum of space. Now, in zero gravity the recoil would be a REAL bitch.

Another problem is that without an atmosphere, the only place for the gun to dump its heat is into the insulated glove of your spacesuit, so it's going to overheat quickly and STAY overheated.

Posted: 6/4/2008 4:21:48 PM EDT

[#9]

Quoted:
I don't know if this question was ever posed but,I was talking with some guys at work if you were on the moon, or actually an atmosphere with no oxygen, would you be able to fire a weapon. I thought no since there would be no oxygen to feed the combustion of the powder. I'm not even sure the primer would detonate. Then My buddy said " How do you explain rocket propulsion in outer space" I said " Fuck you, get back to work or you're fired!

Well , what do you think ? guns on the moon or not?

The topic of whether or not ammunition would work in space has already been addressed in previous posts.

The moon is not like being in space (zero gravity). In a zero gravity situation, you would most likely use a weapon such as the unsuccessful MBA GyroJet. This rocket propelled pistol had a number of design issues including lack of accuracy, but you get the idea.

In an airless low-G situation (the moon has approximately 1/6 Earth gravity) you could either use a GyroJet like pistol, or a more conventional low-recoil gun. You would need enough terminal performance to penetrate the armored space suit and possibly do damage to the astronaut inside, although causing a serious air leak in the suit may be all you need to accomplish the mission. You need to minimize recoil by minimizing momentum where:

Momentum = mass * velocity

while maximizing:

Energy = 1/2 * mass * velocity * velocity

Without going through a whole bunch of math, maximizing energy (the second constraint) is the same as:

Minimize mass
Maximize velocity

Thus the ideal "cartridge" to use on the moon (not in zero-g) would be a very dense needle moving at as high a velocity as possible (this is why "needle guns" show up in so many sci-fi stories).

So you are likely to use a high velocity, small caliber, low mass bullet, ideally with a dense metallic penetrator. The (armored) space suit is likely to be similar to the EVA space suits used for space walks, which are lightly armored to protect against micrometeorites. One or more punctures in the space suit (unless it is a self-sealing suit) would probably disable the astronaut. An example of a low mass, high velocity bullet might be something like a .17 with a penetrator tip, or a low-mass varmint bullet loaded to moderately high velocity in... dare I say it... a .220 or .223 AR-15 modified to be usable by an armored space suited astronaut with gloves...

Posted: 6/4/2008 4:23:43 PM EDT

[#10]

Quoted:

Quoted:
The only problem you'd have with firing a gun in outer space or on a planet or moon with no atmosphere would be keeping it from over heating.

A water-cooled system would pretty much be the only way. You could have it a closed system so that the water that boiled off went through a pipe into the spacecraft, or just into some shade, condensed there, and then went back into the reservior.

already thought of
Link

Posted: 6/4/2008 4:24:37 PM EDT

[#11]

HOLY SHIT!!

Posted: 6/4/2008 4:24:54 PM EDT

[#12]

look up the gyro jet pistol

Posted: 6/4/2008 4:27:28 PM EDT

[#13]

Quoted:

Quoted:
Yeah........no kidding........because gravity pulled it there Da Vinci

And . . . gravity doesn't exist in space?

Not in appreciable amounts.

Which is why the moon fails to stay in orbit a quarter of a million miles away

And things fall down on the Moon at about 5 ft/sec^2.

Posted: 6/4/2008 4:28:05 PM EDT

[#14]

Quoted:
look up the gyro jet pistol

And?

It's a failed Vietnam-era attempt at a James Bond gun. The only possible advantage it could have compared to a conventional gun in space is reduced recoil.

Posted: 6/4/2008 4:29:35 PM EDT

[#15]

Now wee can get rid of those pesky moon bats!

Posted: 6/4/2008 4:33:54 PM EDT

[#16]

Quoted:

Quoted:
Actually, if you tried to fire a gun in zero gravity both you and the bullet would be propelled in opposite directions at the same speed.

Jesus H. Christ this thread is full of the FAIL. Are "you" and the projectile the same mass? No. You would not fly backwards at the same speed the bullet goes forward.

Jeez, not only that it would cause global warming.

ETA: Plus the bullet would just drop, because there is no air for it to fly in!

Posted: 6/4/2008 4:36:20 PM EDT

[#17]

Quoted:
Radiation is a very slow method of heat transfer. On Earth, guns typically cool by convection, a form of conduction.

And sometimes conduction itself, if you aren't careful

Posted: 6/4/2008 4:38:09 PM EDT

[#18]

Quoted:
ETA: Plus the bullet would just drop, because there is no air for it to fly in!

Yep, without air for the rifling to act as a propeller against, it's goes nowhere.

Posted: 6/4/2008 4:42:37 PM EDT

[#19]

Quoted:

Quoted:
Radiation is a very slow method of heat transfer. On Earth, guns typically cool by convection, a form of conduction.

And sometimes conduction itself, if you aren't careful

Not if you have that shoulder thing that goes up

Posted: 6/4/2008 4:47:05 PM EDT

[#20]

The only two issues that come to mind (without reading the thread, so hopefully this hasn't been covered):

1. I'm not sure how a (near) vaccuum would affect the insides of the casings while sitting in the mag and chamber.

2. I'd be willing to wager that the temperatures are extreme enough to effect function (i.e., insane heat melting plastic grips or Glock frames, or extreme cold interfereing with function or metallurgy in some way).

Posted: 6/4/2008 4:47:26 PM EDT

[#21]

Quoted:

Quoted:
ETA: Plus the bullet would just drop, because there is no air for it to fly in!

Yep, without air for the rifling to act as a propeller against, it's goes nowhere.

Got to guard against big farts, too. Letting a good reconstituted re-fried bean burrito fart go in a suit in vacuum could send you off in any direction at high velocity.

Exhaust velocity, temperature, nozzle dimensions all very complicated.

Posted: 6/4/2008 5:05:12 PM EDT

[#22]

well your AR would have have a range of a trillion lightyears.

Posted: 6/4/2008 5:21:51 PM EDT

[#23]

Of course, if your rifle is named "Vera" you may need oxygen to fire it. Enclosing it in a space suit has been demonstrated to work pretty well.

Posted: 6/4/2008 5:24:35 PM EDT

[#24]

Quoted:
I dont know if this question was ever posed but,I was talking with some guys at work.If you were on the moon, or actually an atmosphere with no oxygen, would you be able to fire a weapon. I thought no since there would be no oxygen to feed the combustion of the powder. Im not even sure the primer would detonate. Then My buddy said " How do you explain rocket propulsion in outer space" I said " Fuck you, get back to work or you're fired!

Well , what do you think ? guns on the moon or not?

the 20mm's at the range in the Sea Of Tranquility always fired up just fine. As did my m60 in the shuttle bay.

Any other SSDG's wanna chime in?

Posted: 6/4/2008 5:39:00 PM EDT

[#25]

Somebody kill me.

Posted: 6/4/2008 5:55:29 PM EDT

[#26]

Space is 2.7 kelvin (-454*F). How brittle would the gun metal be at the instant you fired it and what would happen to it when the first round exploded?

Also, what if there are aliens (or alien zombies) with rayguns chasing you?
Would you be able to get off more then one round before the gun shattered?
Would it start an interstellar war?

Will Obama be up there trying to grab your gun or will McCain be up there building the Death Star?

Posted: 6/4/2008 6:00:37 PM EDT

[#27]

Quoted:

Quoted:
Actually, if you tried to fire a gun in zero gravity both you and the bullet would be propelled in opposite directions at the same speed.

Jesus H. Christ this thread is full of the FAIL. Are "you" and the projectile the same mass? No. You would not fly backwards at the same speed the bullet goes forward.

Conservation of momentum FTMW.

Posted: 6/4/2008 6:22:06 PM EDT

[#28]

Quoted:
Jesus H. Christ this thread is full of the FAIL.

I think I just shat myself lollering. You are my new favorite member.

Posted: 6/4/2008 6:24:33 PM EDT

[#29]

Quoted:
Space is 2.7 kelvin (-454*F). How brittle would the gun metal be at the instant you fired it and what would happen to it when the first round exploded?

Also, what if there are aliens (or alien zombies) with rayguns chasing you?
Would you be able to get off more then one round before the gun shattered?
Would it start an interstellar war?

Will Obama be up there trying to grab your gun or will McCain be up there building the Death Star?

Temperature is almost a completely meaningless concept in space. Temperature requires matter, and there is extremely low matter in space, therefore there is no temperature.

There's a difference between heat and temperature. The outer atmosphere of the Sun is extremely hot, but has very low heat. The individual atoms are at millions of degrees, but the gas is so rarified that it wouldn't feel hot. Just like air at 120 degrees wouldn't be that bad, but water at 120 would feel hot. They're both the same temperature, but water has much more heat.

Since there's so little mass in space, the temperature of the matter that's there doesn't make any difference in the felt temperature. Warm water feels warm because when you touch it it imparts some of its energy to you. If there's almost no mass, there is almost nothing to impart energy to you, even if the matter is extremely hot or cold.

The only thing that matters in space is radiation, or direct contact with other matter (conduction). If you're in direct sunlight, you will get very hot. If you're in the shade, you'll cool off. It's as simple as that. Space is neither hot nor cold.

Posted: 6/4/2008 7:57:41 PM EDT

[#30]

Quoted:

Quoted:
Actually, if you tried to fire a gun in zero gravity both you and the bullet would be propelled in opposite directions at the same speed.

Jesus H. Christ this thread is full of the FAIL. Are "you" and the projectile the same mass? No. You would not fly backwards at the same speed the bullet goes forward.

You wouldn't fly backwards,but the rifling in the barrel would cause you to spin opposite of the bullet's spin!

J/K!

Posted: 6/4/2008 7:58:43 PM EDT

[#31]

Quoted:
Actually, if you tried to fire a gun in zero gravity both you and the bullet would be propelled in opposite directions at the same speed.

Posted: 6/4/2008 8:13:49 PM EDT

[#32]

That's what I'm doing right now.

Posted: 6/4/2008 10:08:05 PM EDT

[#33]

Quoted:
There's air in a cartridge, so I don't see why not. Bullets will fire underwater. But I would think if you fired a bullet in space, it would never stop unless it hit something.

Many people confuse the micro gravity environment experienced in orbit with the absence of gravity; when in fact an orbiting object is in "free fall" but still subject to the constraints of gravity.

If you were in orbit around earth and fired a bullet in the same direction in which you are traveling; it would go a considerable distance based on it's velocity (not speed which isn't the same thing) before assumining a higher orbit around the planet since no rifle round can exceed escape velocity from earth.

The higher the velocity of the bullet; the higher the eventual orbit around earth.

Orbital velocity of the shooter+velocity of round fired<escape velocity from earth.

If you fired it in the opposite direction from which you were orbiting; the bullet would also travel a considerable distance and then eventually fall to earth since the negative velocity imparted to the bullet would cause the bullet to fall below the necessary velocity to remain in orbit.

The faster the speed of the round, the greater the negative velocity of the bullet and the faster it will reenter.

That's the same principle behind reto rockets that are used to de-orbit spacecraft. They don't have to be all that powerful; they only need to impart a negative velocity sufficient to de-orbit the spacecraft.

If you were in orbit around the moon, a body with lower gravity, and therefore escape velocity, and you fired in the same direction as you are traveling, the bullet would achieve escape velocity and travel an incredible distance before it went into orbit around the earth.

A projectile fired from a rail gun would likely end up in orbit around the sun whether fired from earth or lunar orbit.

But it wouldn't travel an infinite distance before being captured by solar gravity unless it attained solar escape velocity.

A bullet fired in interstellar space would travel unimaginable distances before being captured by the gravitational well of the nearest stellar body or planet capable of grabbing it into orbit or causing it to crash into it.

But since it's on a ballistic path, it wouldn't travel for eternity.

Posted: 6/4/2008 11:04:25 PM EDT

[#34]

Quoted:
Actually, if you tried to fire a gun in zero gravity both you and the bullet would be propelled in opposite directions at the same speed.

BZZT gravity has nothing to do with it. Same laws of physics apply, with gravity you are touching the ground (assumed) so the lever arm being applied to you would tend to pivot you around your center of gravity, unless the line of the recoil force runs through your CG and then it would push you in that same axis.

And speed wise is another law, Equal and opposite Reaction, remember? F=MA, Force =MassxAcceleration, Velocity =Acceleration xTime.

Both you and the bullet have the same force applied over the same time, final velocity of the objects would be in this approximate ratio. (simplified for illustration purposes)

Bullet speed is Total mass/Bullet Mass, shooter speed = Total Mass/Shooter Mass

again the actual velocity is dependent on conservation of both lineal and rotational momentum

Posted: 6/5/2008 7:12:41 AM EDT

[#35]

Quoted:

Quoted:
Space is 2.7 kelvin (-454*F). How brittle would the gun metal be at the instant you fired it and what would happen to it when the first round exploded?

Also, what if there are aliens (or alien zombies) with rayguns chasing you?
Would you be able to get off more then one round before the gun shattered?
Would it start an interstellar war?

Will Obama be up there trying to grab your gun or will McCain be up there building the Death Star?

Temperature is almost a completely meaningless concept in space. Temperature requires matter, and there is extremely low matter in space, therefore there is no temperature.

There's a difference between heat and temperature. The outer atmosphere of the Sun is extremely hot, but has very low heat. The individual atoms are at millions of degrees, but the gas is so rarified that it wouldn't feel hot. Just like air at 120 degrees wouldn't be that bad, but water at 120 would feel hot. They're both the same temperature, but water has much more heat.

Since there's so little mass in space, the temperature of the matter that's there doesn't make any difference in the felt temperature. Warm water feels warm because when you touch it it imparts some of its energy to you. If there's almost no mass, there is almost nothing to impart energy to you, even if the matter is extremely hot or cold.

The only thing that matters in space is radiation, or direct contact with other matter (conduction). If you're in direct sunlight, you will get very hot. If you're in the shade, you'll cool off. It's as simple as that. Space is neither hot nor cold.

OK, so assuming that you were not in the direct path of the suns radiation (with no atmosphere to protect you), is it safe to assume that the gun would dissapate all its heat into space until it reached absolute zero?

In that case, how brittle would the gun metal be and what would happen when the round exploded in the chamber (not to mention what would happen to the gun oil)?

Posted: 6/5/2008 7:15:33 AM EDT

[#36]

Quoted:
Actually, if you tried to fire a gun in zero gravity both you and the bullet would be propelled in opposite directions at the same speed.

This defies Newton's First Law of Motion, so please explain further...

Posted: 6/5/2008 9:22:52 AM EDT

[#37]

Quoted:

Quoted:
Space is 2.7 kelvin (-454*F). How brittle would the gun metal be at the instant you fired it and what would happen to it when the first round exploded?

Also, what if there are aliens (or alien zombies) with rayguns chasing you?
Would you be able to get off more then one round before the gun shattered?
Would it start an interstellar war?

Will Obama be up there trying to grab your gun or will McCain be up there building the Death Star?

Temperature is almost a completely meaningless concept in space. Temperature requires matter, and there is extremely low matter in space, therefore there is no temperature.

There's a difference between heat and temperature. The outer atmosphere of the Sun is extremely hot, but has very low heat. The individual atoms are at millions of degrees, but the gas is so rarified that it wouldn't feel hot. Just like air at 120 degrees wouldn't be that bad, but water at 120 would feel hot. They're both the same temperature, but water has much more heat.

Since there's so little mass in space, the temperature of the matter that's there doesn't make any difference in the felt temperature. Warm water feels warm because when you touch it it imparts some of its energy to you. If there's almost no mass, there is almost nothing to impart energy to you, even if the matter is extremely hot or cold.

The only thing that matters in space is radiation, or direct contact with other matter (conduction). If you're in direct sunlight, you will get very hot. If you're in the shade, you'll cool off. It's as simple as that. Space is neither hot nor cold.

OK, so assuming that you were not in the direct path of the suns radiation (with no atmosphere to protect you), is it safe to assume that the gun would dissapate all its heat into space until it reached absolute zero?

In that case, how brittle would the gun metal be and what would happen when the round exploded in the chamber (not to mention what would happen to the gun oil)?

The gun would cool very slowly, as radiation is a slow way to transfer heat. The rate of cooling decreases with time, since a cooler object radiates less heat.

The gun will never reach absolute zero, since there is a background radiation even in deep intergalactic voids (ET's version of BFE).

Posted: 6/5/2008 9:40:24 AM EDT

[#38]

Quoted:

Quoted:
Space is 2.7 kelvin (-454*F). How brittle would the gun metal be at the instant you fired it and what would happen to it when the first round exploded?

Also, what if there are aliens (or alien zombies) with rayguns chasing you?
Would you be able to get off more then one round before the gun shattered?
Would it start an interstellar war?

Will Obama be up there trying to grab your gun or will McCain be up there building the Death Star?

Temperature is almost a completely meaningless concept in space. Temperature requires matter, and there is extremely low matter in space, therefore there is no temperature.

There's a difference between heat and temperature. The outer atmosphere of the Sun is extremely hot, but has very low heat. The individual atoms are at millions of degrees, but the gas is so rarified that it wouldn't feel hot. Just like air at 120 degrees wouldn't be that bad, but water at 120 would feel hot. They're both the same temperature, but water has much more heat.

Since there's so little mass in space, the temperature of the matter that's there doesn't make any difference in the felt temperature. Warm water feels warm because when you touch it it imparts some of its energy to you. If there's almost no mass, there is almost nothing to impart energy to you, even if the matter is extremely hot or cold.

The only thing that matters in space is radiation, or direct contact with other matter (conduction). If you're in direct sunlight, you will get very hot. If you're in the shade, you'll cool off. It's as simple as that. Space is neither hot nor cold.

OK, so assuming that you were not in the direct path of the suns radiation (with no atmosphere to protect you), is it safe to assume that the gun would dissapate all its heat into space until it reached absolute zero?

In that case, how brittle would the gun metal be and what would happen when the round exploded in the chamber (not to mention what would happen to the gun oil)?

It worked for the russians with a 23mm cannon.

Posted: 6/5/2008 11:07:04 AM EDT

[#39]

Quoted:
Actually, if you tried to fire a gun in zero gravity both you and the bullet would be propelled in opposite directions at the same speed.

FAIL!!!!!

Posted: 6/5/2008 11:08:43 AM EDT

[#40]

Quoted:

Quoted:
Actually, if you tried to fire a gun in zero gravity both you and the bullet would be propelled in opposite directions at the same speed.

Oh, holy crap, again.

You're not serious, are you? What kind of diet are you on that got you down to 55 grains of weight?

And damn, the gun weighs nothing?!

Posted: 6/5/2008 11:14:15 AM EDT

[#41]

The only reason you think that there is no gravity in space, is that you forgot that you are in free fall.

There is tons of gravity in space, you are just submitting to it.

Posted: 6/5/2008 11:17:16 AM EDT

[#42]

I read threads like this, and I think "Now I understand the political opinions expressed around here a little bit better."

Posted: 6/5/2008 11:20:16 AM EDT

[#43]

Quoted:
I read threads like this, and I think "Now I understand the political opinions expressed around here a little bit better."

I hate to break this to you... But people here tend to be considerably smarter than the general populace.

Considering that factoid, and having read this thread, I conclude we, as a nation, are completely fucked.

Posted: 6/5/2008 11:28:01 AM EDT

[#44]

Keep in mind that the gun would have to be designed to fire perfectly horizontally and sighted the same. Guns normally fire in an arc....

Posted: 6/5/2008 11:30:17 AM EDT

[#45]

Quoted:
Actually, if you tried to fire a gun in zero gravity both you and the bullet would be propelled in opposite directions at the same speed.

Only if it's a really heavy bullet or you're a very tiny person.

Posted: 6/5/2008 11:31:42 AM EDT

[#46]

Quoted:
This came up last week... They would work. Everything is self contained.

+1

Posted: 6/5/2008 11:33:34 AM EDT

[#47]

Quoted:
Keep in mind that the gun would have to be designed to fire perfectly horizontally and sighted the same. Guns normally fire in an arc....

Well, the bullet would still interact with any local gravity wells... But not nearly at the rate we are accustomed to on Earth... So for any realistic engagement distance, you are correct.

Posted: 6/5/2008 11:39:06 AM EDT

[#48]

Quoted:

Quoted:
Keep in mind that the gun would have to be designed to fire perfectly horizontally and sighted the same. Guns normally fire in an arc....

Well, the bullet would still interact with any local gravity wells... But not nearly at the rate we are accustomed to on Earth... So for any realistic engagement distance, you are correct.

No.

There is still significant gravity anywere near a planet (i.e. orbit). This has been covered several times in this thread.

Posted: 6/5/2008 11:44:45 AM EDT

[#49]

Quoted:
I hate to break this to you... But people here tend to be considerably smarter than the general populace.

Considering that factoid, and having read this thread, I conclude we, as a nation, are completely fucked.

I unfortunatley have to agree with you.

Posted: 6/5/2008 11:55:16 AM EDT

[#50]

Quoted:
Somebody kill me.

pkill -9 Deadeye_Jack
Yes, I am a nerd.

[ARCHIVED THREAD] - Guns On the MOON ? (Page 2 of 3)

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