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Re: [GPSL] Gold Fish in Near Space

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  • L. Paul Verhage
    I think I would like to video tape (tape, does that date me?) the fish in their water bottle. I get concerned this would become a snuff film if the fish were
    Message 1 of 6 , Jul 23, 2013
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      I think I would like to video tape (tape, does that date me?) the fish in their water bottle. I get concerned this would become a snuff film if the fish were to die, but to see how they respond to the flight could be interesting.
       
      so it sounds like we want to oxygenate the water as much as possible before launch and then seal the bottle tight.
       
      Perhaps a first experiment would be to measure the dissolved oxygen before and after flight with different bottle configuations.
       
      Paul


      On Tue, Jul 23, 2013 at 9:48 AM, Michael Willett <mw@...> wrote:
      I would think all your assumptions would be right except the PBC. While it is a captive system, the acceleration forces would be transmitted in tact to the fish as water is nearly non-compressible. However, mass of the water and springy lines and air being very compressible would likely not yield enough G force to hurt the fish. The amount of air in the captive system contains the fish is not on your side however, less air space in the tank would be best. If you highly aerated the water and left very little air space in the tank, I think that would be best. 

      --Michael



      On Jul 23, 2013, at 8:42 AM, "L. Paul Verhage" <nearsys@...> wrote:

       

      Mark mentioned that our high school teachers launched goldfish in their BalloonSat. I was concerned about their survival chances, but glad to see that it ended well.
       
      This has me thinking. I was concerned that the water would lose dissolved oxygen as the balloon ascended. The bottle had an air space above the water and apparently was air tight enough that the air didn't leak out so fish could continue to breathe.
       
      I wasn't concerned about the temperature since the water has a large thermal interia and would take too long to cool down significantly. I also wasn't concerned about the BPC since the fish are nearly neutrally bouyant in water. I think that means the fish will ride out the motion of the water bottle without being slammed against the walls of the water bottle.
       
      Does my reasoning sound correct? The fish are safe from getting too cold and safe from being slammed around the bottle. Their largest risk comes from the water losing oxygen.  

      --
      Onwards and Upwards,
      Paul




      --
      Onwards and Upwards,
      Paul
    • Mike Manes
      If the fish tank were vented to local ambient pressure, then it would quite likely boil off entirely since the thermal mass of the water would keep the
      Message 2 of 6 , Jul 23, 2013
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        If the fish tank were vented to local ambient pressure, then it would
        quite likely boil off entirely since the thermal mass of the water would
        keep the temperature above the triple point above 50K'. Easy to test
        in your vacuum chamber, if you don't mind sucking water vapor thru your
        pump.

        73 de Mike W5VSI

        On 7/23/13 7:42 AM, L. Paul Verhage wrote:
        >
        >
        > Mark mentioned that our high school teachers launched goldfish in their
        > BalloonSat. I was concerned about their survival chances, but glad to
        > see that it ended well.
        > This has me thinking. I was concerned that the water would lose
        > dissolved oxygen as the balloon ascended. The bottle had an air space
        > above the water and apparently was air tight enough that the air didn't
        > leak out so fish could continue to breathe.
        > I wasn't concerned about the temperature since the water has a large
        > thermal interia and would take too long to cool down significantly. I
        > also wasn't concerned about the BPC since the fish are nearly
        > neutrally bouyant in water. I think that means the fish will ride out
        > the motion of the water bottle without being slammed against the walls
        > of the water bottle.
        > Does my reasoning sound correct? The fish are safe from getting too cold
        > and safe from being slammed around the bottle. Their largest risk comes
        > from the water losing oxygen.
        >
        > --
        > Onwards and Upwards,
        > Paul
        >
        >
        >
      • Al Wolfe
        We actually tried something like this in high school biology class in about 1959. Put a goldfish in some water in a beaker under a bell jar. Sucked it down and
        Message 3 of 6 , Jul 24, 2013
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          We actually tried something like this in high school biology class in
          about 1959. Put a goldfish in some water in a beaker under a bell jar.
          Sucked it down and noticed the goldfish burping form time to time. When we
          let the air back in the fish sank like a rock but then climbed to the
          surface and gulped air. Happy ending - the fish survived.

          Looking back it was a probably a silly experiment but we did learn
          something about how a fish attains neutral buoyancy.

          Today PETA or ASPCA would probably get rather upset about this sort of
          experiment.

          Al, K9SI



          > If the fish tank were vented to local ambient pressure, then it would
          > quite likely boil off entirely since the thermal mass of the water would
          > keep the temperature above the triple point above 50K'. Easy to test
          > in your vacuum chamber, if you don't mind sucking water vapor thru your
          > pump.
          >
          > 73 de Mike W5VSI
        • Mike Manes
          If you didn t notice the water boiling off, then you probably didn t pull the air down below 100 mbar.
          Message 4 of 6 , Jul 24, 2013
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            If you didn't notice the water boiling off, then you probably didn't
            pull the air down below 100 mbar.

            On 7/24/13 4:52 PM, Al Wolfe wrote:
            > We actually tried something like this in high school biology class in
            > about 1959. Put a goldfish in some water in a beaker under a bell jar.
            > Sucked it down and noticed the goldfish burping form time to time. When we
            > let the air back in the fish sank like a rock but then climbed to the
            > surface and gulped air. Happy ending - the fish survived.
            >
            > Looking back it was a probably a silly experiment but we did learn
            > something about how a fish attains neutral buoyancy.
            >
            > Today PETA or ASPCA would probably get rather upset about this sort of
            > experiment.
            >
            > Al, K9SI
            >
            >
            >
            >> If the fish tank were vented to local ambient pressure, then it would
            >> quite likely boil off entirely since the thermal mass of the water would
            >> keep the temperature above the triple point above 50K'. Easy to test
            >> in your vacuum chamber, if you don't mind sucking water vapor thru your
            >> pump.
            >>
            >> 73 de Mike W5VSI
            >
            >
            >
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