Re: More gun questions Re: gun terminology

On 12 Sep 2005 18:55:16 -0700, Constantinople wrote:

> Bill Swears wrote:
>> David Friedman wrote:
>>> In article <4326020A.9050301@xxxxxxxxxxxxxxxxxx>,
>>> Brooks Moses <bmoses-nospam@xxxxxxxxxxxxxxxxxx> wrote:
>>>
>>>
>>>>Constantinople wrote:
>>>>
>>>>>David Dyer-Bennet wrote:
>>>>>
>>>>>>Given the practical impossibility of absolutely precise alignment,
>>>>>
>>>>>and the lack of feedback while you're positioning. We humans require a
>>>>>lot of continual feedback for stuff like balancing on a bike.
>>>>
>>>>The other trick is that you need to aim the gun -- which, in general, is
>>>>going to involve pointing it in a different direction than the one
>>>>needed for anti-spin.
>>>>
>>>
>>>
>>> I disagree.
>>>
>>> Your body isn't a rigid object. So you should be able to aim the gun
>>> while squirming your body into a position that puts the center of mass
>>> in line with the recoil.
>>>
>>> I'm not arguing that you or I could do it without training. But humans
>>> routinely do very difficult things with their bodies--consider an even
>>> moderately competent ping pong player, for instance, and the precision
>>> required to put the ball into the very narrow solid angle that will
>>> neither go into the net nor miss the table.
>>>
>> I'm almost sorry the issue of recoil came up. There are several rifles
>> with recoil dampeners. Essentially sprung weights in the stock that are
>> pushed in the opposite direction from the bullet, by the same expanding
>> gasses driving the bullet. The M-16 vibrates, but offers very little
>> kick when fired.
>
> Unless I'm mistaken about what you mean, that would not make any
> difference at all. What I think you are describing (a weight on a
> spring) is a mechanism that spreads the force felt over a longer period
> of time, reducing the force felt at a given moment. That is, rather
> than feeling (I don't know what the numbers are, I'm making this up) 50
> pounds of force for 1/10 second, the shooter feels 10 pounds of force
> spread over 1/2 second. The end result is the same, must be the same,
> because of conservation of momentum. All that's happening is that the
> recoil momentum is immediately transferred to the weight on the spring,
> and then gradually transferred to the shooter, rather than being
> transferred to the shooter immediately. Thus, less jarring, a slower
> and longer acceleration, but with the same end result in terms of
> spinning the shooter around.

It's the same reason Dean Drives and the like don't work. There are a
number of things that "make sense" or are intuitively correct that simply
don't work and aren't true. One of them is the notion of "impulse", that
somehow a short sharp acceleration has more effect than a less strong one
over a long period of time. There ain't no such animal. If the weight ever
gets back to where it started it produces no net acceleration, and thus
cannot compensate for the acceleration produced by the bullet leaving the
gun/shooter system.

In systems where there is friction and viscosity that may not be the case,
and since most of us live in systems containing friction and viscosity it's
reasonable for our preconceptions to exist. Google "vibratory feeder" and
marvel. But in zero gee it von't vork.

Regards,
Ric
.

Relevant Pages

  • Re: More gun questions Re: gun terminology
    ... in line with the recoil. ... What I think you are describing (a weight on a spring) is a mechanism that spreads the force felt over a longer period of time, reducing the force felt at a given moment. ... That is, rather than feeling 50 pounds of force for 1/10 second, the shooter feels 10 pounds of force spread over 1/2 second. ... Thus, less jarring, a slower and longer acceleration, but with the same end result in terms of spinning the shooter around. ...
    (rec.arts.sf.composition)
  • Re: More gun questions Re: gun terminology
    ... >>>recoil momentum is immediately transferred to the weight on the spring, ... >>>transferred to the shooter immediately. ... >> somehow a short sharp acceleration has more effect than a less strong one ... > have to do that in zero g, so mount it on twin shoulder mounts, and use ...
    (rec.arts.sf.composition)
  • Re: More gun questions Re: gun terminology
    ... Bill Swears wrote: ... > I'm almost sorry the issue of recoil came up. ... pounds of force for 1/10 second, the shooter feels 10 pounds of force ... recoil momentum is immediately transferred to the weight on the spring, ...
    (rec.arts.sf.composition)
  • Re: Acceleration Without Time
    ... > The equivalence principle is about weight in gravity and weight ... > in non-gravitational acceleration. ... But it doesn't for weight in gravity. ... or that the clocks higher up are moving at speeds faster than clocks ...
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  • Re: OT: Funnier Than Rush
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