Re: Semi-on-topic: Sunday's Non Sequitor cartoon

Lynn Allen wrote:
On 2008-07-28 16:34:15 -0700, "Reunite Gondwanaland (Mary Shafer)" <reunite.gondwana@xxxxxxxxx> said:

On Mon, 28 Jul 2008 19:04:08 -0400, "Francis A. Miniter"
<faminiter@xxxxxxxxxxx> wrote:

Sunday's Non Sequitor poses a difficult issue for writers of
sci-fi mystery stories. If you attempt to shoot a pistol on
the moon, for instance, will it fire? The moon does not
have an atmosphere - certainly not an oxygen rich one like
that of earth. So, would there be combustion? Or, as the
little boy suggests, has the packing of the bullet casing
already enclosed enough oxygen to cause sufficient
combustion to fire the bullet? And, he poses a further
question, too. Given the lack of atmosphere, if the gun
does fire, would the bullet travel faster?

Gunpowder contain an oxidizer. You can fire a pistol underwater or on
the moon or anywhere else. There is no need for a surrounding
atmosphere.

Mary answered the firing question. The travelling question is also pretty easy...atmospheric braking really isn't that big a factor in how far or fast bullets go. It's not the air that stops a bullet. What happens is that they fall at the same rate they would if they were dropped from the height of the gun, so a bullet fired horizontally really has only a second or less to travel before it hits the ground. How far it goes is a factor of how fast it is ejected from the gun and how far it can travel in that fraction of a second before it hits a surface.

On the moon, bullets would fall more slowly, since gravity is 1/6 earth's. So they'd go much farther before hitting the surface. I'm not sure what it would take, but a sufficiently large gun could propel a round faster than escape velocity and put it into orbit or into a path for the outer void.


I thought D = 1/2Gt^2, where G = 32 ft/sec/sec., and that G is independent of the size of the bodies involved.


Francis A. Miniter
.

Relevant Pages

  • Re: Semi-on-topic: Sundays Non Sequitor cartoon
    ... The moon does not ... has the packing of the bullet casing ... really has only a second or less to travel before it hits the ground. ... On the moon, bullets would fall more slowly, since gravity is 1/6 ...
    (rec.arts.mystery)
  • Re: Semi-on-topic: Sundays Non Sequitor cartoon
    ... The moon does not ... has the packing of the bullet casing ... What happens is that they fall at the same rate they would if they were dropped from the height of the gun, so a bullet fired horizontally really has only a second or less to travel before it hits the ground. ... On the moon, bullets would fall more slowly, since gravity is 1/6 earth's. ...
    (rec.arts.mystery)
  • Re: Semi-on-topic: Sundays Non Sequitor cartoon
    ... The moon does not ... has the packing of the bullet casing ... really has only a second or less to travel before it hits the ground. ... On the moon, bullets would fall more slowly, since gravity is 1/6 ...
    (rec.arts.mystery)
  • Re: Semi-on-topic: Sundays Non Sequitor cartoon
    ... The moon does not ... has the packing of the bullet casing ... What happens is that they fall at the same rate they would if they were dropped from the height of the gun, so a bullet fired horizontally really has only a second or less to travel before it hits the ground. ...
    (rec.arts.mystery)
  • Semi-on-topic: Sundays Non Sequitor cartoon
    ... Sunday's Non Sequitor poses a difficult issue for writers of sci-fi mystery stories. ... The moon does not have an atmosphere - certainly not an oxygen rich one like that of earth. ... Or, as the little boy suggests, has the packing of the bullet casing already enclosed enough oxygen to cause sufficient combustion to fire the bullet? ...
    (rec.arts.mystery)