Feb 24, 2009

Science Scene - Can guns fire in space?

So, I have to admit, I sometimes have geeky tendencies [stop you snickering, really, stop]

Fire needs oxygen to burn, so if you're in the atmosphere less void of space [In space, no one can hear you scream, because sound needs atmosphere to propagate], can the gunpowder ignite and cause a gun to fire a bullet?

The explosion that fires a bullet does require oxygen for combustion, but it does not draw it solely from the air. Rather, some oxygen comes from an ingredient of the gunpowder itself, called saltpeter (potassium nitrate). The spark produced when the gun's hammer strikes the cartridge ignites the saltpeter and converts the oxygen in it to its gaseous state. This explosion generates a shock wave that propels the bullet out of the gun. [Note: lack of oxygen also makes explosions in space the rarity - looking more like a flash bulb as there is no atmosphere to transfer the energy to and cause the oxygen rich fireball.]

Care must be exercised though, because basic physics (Newton's Third Law) states that for every action there is an equal and opposite reaction. The kickback from firing a gun in space would send your entire body flying backward. Because there is nothing to slow the bullet in a zero-gravity vacuum, it would travel much faster and farther than it does on Earth, and so would you.

The visualization of a body hurtling backwards is what caught my minds eye while reading about this in the FYI section of the March issue of Popular Science. I just cannot get the image out of my mind of the shooter drifting out of sight :o)


  1. I loved this entry, so what does that make me? (Like you wrote, stop snickering!)

    While I loves me my science fiction flicks, it's always made me chuckle to see exploding starships. It's a great visual, but not scientifically valid.


  2. I cannot explain why this post has me thinking about the guy who just burned his colon (OUCH) with a firecracker......but it does.

  3. We love Science Fiction, but of course, we are always aware of what "wouldn't really happen that way". Movie goers want to see big fiery balls of flame. :)

  4. Well, now I have that image in my mind. And just think, he could scream for help, and no one would know!
    No, I am not a science geek, I can grasp some of the basics, but still I am a curious creature.

    :) Leigh

  5. Nothing wrong with being a geek, Ken!!! :) Very interesting post, so I guess that puts us in the same category.


  6. (Chuckles)I'll keep this in mind if I'm ever in space with a gun (raises eyebrow at the unlikeliness of that one). (Hugs)Indigo

  7. Which one of those cats did Hal lock out? That is what came to my mind ... and there was some scene in Space:1999 that is fragmented in my memory as well.

    As to whether or not anyone can here you scream ... I figured that Ridley Scott let everyone know why it woulldn't have mattered if anyone could or not, pretty conclusively!

  8. this puts a whole new spin on the death star explosion in empire...


  9. that would be a new hope.

    i just lost all my nerd cred, didnt i...

    mea culpa

  10. So you can fire a gun in space? Cool. As far as the kickback, I imagine in military applications some mechanism would be devised to provide an equal 'kick' in the opposite direction each time it's fired. Robotech used good ol' bullets in their universe, and I liked it a whole lot better than the laser/phaser rigamaroe.

    But as to the fireball problem, I always rationalized them by saying it was the crew's oxygen that made the pretty flames. The Death Star, for example, would have been chock full of the stuff, no?


  11. I'm so glad you researched this and posted it. People still believe the sun is like a burning ember in space, an object, rather than a collection of gases etc, a mini-nuke in many ways. Without fuel it'll die and to cut immediately to the good stuff, I LOVE your picture of gamma rays just at the moment they burst from a dying star, a supernova. How cool is it that this star-death initiates the whole process of creating the nebulae that will incubate new stars, galaxies to come? Great entry. Comments can sometimes be as interesting - to Big Mark I say "I just can't answer that, Dave."

  12. Very interesting stuff here Ken...now I know if space travel becomes a common thing in my lifetime I'll be sure to leave Mr Ruger at home!


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