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Re: [usa-tesla] Compressing air with a stirling engine?

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  • jim farrer
    Ed, I need to be convinced that measuring the muzzle velocity would settle this question. In addition, I would need to measure the arrival time at the target.
    Message 1 of 193 , Apr 1, 2006
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      I need to be convinced that measuring the muzzle velocity would settle this question.
      In addition, I would need to measure the arrival time at the target.  That would convince me.
      I understand that a human without a parachute, when dumped out of a plane will reach the ground at the velocity of some 120 mph, regardless of the speed or height of the airplane out of which he was dumped.  Is this not correct?

      Ed Phillips <evp@...> wrote:
      davep@... wrote:

      >>>I'd have to dig into links on airguns to find the
      >>>article (it was an article on airguns taken on a
      >>>safari probably 10 years ago), but considering the
      >>>pressures of compressed air in scuba tanks and the
      >>>fact that even the most efficient explosive propellent
      >>>wasts a goodly proportion of it's energy (combustion
      >>>is far from complete when the projectile leaves the
      >>>gun) I don't find it hard to believe.
      >   The catch is the losses in the valves, and plumbing from
      >   tank.
      >    (Hint: I hang out on a the steam_tech list.  Similr issues.)
      >    (Hint II:
      >      Compressed Air also has energy left in the barrel
      >      after the projectile exits.)

      >>>Full pressure is available from the start of the shot with
      >>>compressed gas,
      >    If one neglects the finite time taken for the valve to
      >    open, and the losses in the air 'squeesing' thru the part open
      >    valve.

      >>>where pressure builds up along the way
      >>>with smokeless powder, and a large part of the
      >>>propellant gets converted to gas too late to do any
      >   A powder cartridge is smaller than a
      >   typical Compressed gas tank, and, likely 'safer'.

      >>    I still have problems with that.  What is the max pressure in a
      >>newly-charged Scuba tank?
      >    My recollection is 2150, but I could be wrong.

      >> Probably 3000 psi at the most whereas typical
      >> pressures from smokeless powder are of the order of three
      >>times that.
      >    There is a peak vs average factor which enters in, which would
      >    require careful measurement.
      >    Back when I took SCUBA cert, we were cautioned about the risks of
      >    knocking a vavle stem off, the resultant said to be the bottle
      >    '
      >      ...blowing itself thru a brick wall...
      >     '
      >     dunno.
      >      best
          A measurement of muzzle velocity would settle the matter and I think
      the powder would win hands down.  As for knocking a valve stem off, I
      believe that it would sure scoot around.  I was around when someone
      knockec a nitrogen bottle over in the middle of a big machine shop. 
      Something broke the regulator away from the tank as it fell to the floor
      and the tank took off and skidded around for what seemed like five
      minutes, making a terrific racket and causing people to run for cover. 
      It didn't hit a wall and eventually came to rest somewhere, but I can
      sure imagine it going through at least a brick wall, which isn't very
      puncture resistant.


    • Ed Phillips
      harsh treatment of desperate, uninformed people who are, by and large, just attempting to provide for their families isn t useful or, IMO, in keeping with the
      Message 193 of 193 , Jul 2, 2006
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        "harsh treatment of desperate, uninformed people who
        are, by and large, just attempting to provide for their families isn't
        useful or, IMO, in keeping with the spirit of the US, or at least what
        it used to be and how I would like it to be."

        Couldn't that same description be applied to any criminal stealing
        stuff for his family? Does that in any way justify the cost to the
        victim of the theft?

        "The yearly ost to every taxpayer is tremendous, and the profit is mainly to
        large corporate sectors... I am not saying that these guest workers
        don't accomplish anything good... only that they are not entitled by
        law to the same civil rights, privileges, assistance programs, as US
        citizens are. when they entered our nation illegally."

        Many of our local Southern California hospitals have been forced to
        close their emergency rooms because illegal aliens are indeed entitled
        by public law to free treatment regardles of their ability OR
        WILLINGNESS to pay [I have literally seen fairly new Cadillacs parked in
        our local ER parking lot when no one inside looked particular opulent
        and there were no other English-speaking people present other than my
        wife and me. For many of those people the nearest emergency room is
        simply regarded as a convenient free clinic. A legitimate visit to an
        ER will make that point obvious. The government doesn't cover these
        costs so the uninsured "regular patients" are forced to pick up the tab
        or else the hospital will go broke, as a number already have. Because
        the "regular patients" tend to be in the minority the costs to them are
        huge. As many of you are probably aware it's quite a common experience
        in border states that pregnant women cross the border, give birth to
        children after their free treatment in the local CR, and then claim that
        any attempt to deport them is cruel and unusual because the child is now
        a US citizen?

        Another flagrant example of such expensive nonsense is that illegals
        are allowed into the state college system but don't even pay the same
        "out of state fees" that legal citizens do.

        " There are many other communities with illegal emigrants, and I don't
        think that they are proposing violent solutions, to my knowledge."

        Just take a look at how Mexico treats illegal immigrants from the
        south of them who don't manage to sneak through on their way to the US.
        They are an even bigger problem to Mexico than to the US and are often
        dealt with summarily and without any attempt at trial or hearings.

        "I suppose that I am a racial bigot for maintaining this stance?"

        Many liberals would make that accusation but, of course, liberals
        don't spend their own money on their causes - just the money someone
        else has worked hard to earn.

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