Fish in Spaaaace!

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  • Fish in Spaaaace!
  • yetidave
    Member

    flattened, same momentum change as everything around them

    druidh
    Member

    Floating. As they are at the same buoyancy as the water, they have the same momentum change as everything around them.

    Fish have no plaice on a space mission.

    Unless it’s just to look at some sort of cod science or something.

    Taff
    Member

    they would die surely…. doesn’t liquid change consistency in space meaning it would float away and the fish too?

    yunki
    Member

    these puns are only just turbot to start and I’m already feeling a bit seasick..

    Premier Icon molgrips
    Subscriber

    Sink. The fish is neutrally bouyant because of the swim bladder, which is a small gas filled bladder. As the rocket accelerates, the pressure in the water increases and the bladder will shrink. Since it’s the volume of the bladder that dictates how bouyant the fish is, as the volume decreases the fish becomes less bouyant.

    Those super deep free divers experience the same thing. They have to pull themselves down using the rope at first, but the pressure shrinks their lungs after a certain depth and they start to sink.

    Oh.. just had a thought though.. The fish must be able to inflate or deflate its bladder according to its depth, mustn’t it? So if it were relatively mild acceleration it would probably actively be able to stay floating.

    druidh
    Member

    molgrips wrote:

    Oh.. just had a thought though.. The fish must be able to inflate or deflate its bladder according to its depth, mustn’t it? So if it were relatively mild acceleration it would probably actively be able to stay floating.

    That

    Oh.. just had a thought though.. The fish must be able to inflate or deflate its bladder according to its depth, mustn’t it? So if it were relatively mild acceleration it would probably actively be able to stay floating.

    fish do have some control, although considering you can make a cods swim bladder pop by reeling it up to the surface too quickly i think a rocket launch might be considered slightly more than a ‘relatively mild acceleration’ 😆

    Premier Icon molgrips
    Subscriber

    Well what’s the depth range of typical fish? Pressure goes up pretty quickly as you go down even 10m or so, and the effect of a goldfish bowl’s worth of water even under 5g isn’t going to be as much.

    In fact, since F = mgh the pressure is simply proportional to the depth, and to g which is what’s going to change in the rocket’s frame of reference. So 5g is like being under 5 times as much water. Well if a goldfish is in a tank at say 6″ depth, it’ll only be like being less than a meter under water. Well within the range of even a shallow water species I’d have thought. And the rate of change of pressure would be much lower than a quick dart to the bottom of a pond when the heron turns up.

    as much as i appreciate your maths, and would be interested in the addition of the average acceleration of a rocket being launched….

    i was merely pointing out that a rocket launch isn’t mild acceleration 🙂

    as for a ‘typical fish’ without being as straightforward as to describe the physical attributes of the species, there are a lot of different fish out there living in very different conditions and depths…

    they took frogs up into space, i’ve touched the frog pods that used to be in the ISS 😀

    mrchrispy
    Member

    no planes and no conveyer belts but…..

    what would happen to fish during a rocket launch?
    would they get flattened at the bottom of the tank or would they remain floating/swimming at the same level?

    MrSalmon
    Member

    Float. Wouldn’t the force pushing up on the bottom of the tank be transferred through the water equally?

    Premier Icon Cougar
    Subscriber

    I can’t believe how difficult we’re finding this, it’s not exactly rocket sci- oh.

    Premier Icon molgrips
    Subscriber

    And I was pointing out that even significant acceleration would not produce significant pressure in a fish tank, compared to diving to even small depths in open water.

    piemann
    Member

    Ooh, ooh, I actually met someone recently that really is sending fish up into space.

    He’s the head of Japanese research group looking at bone mineral density amongst other things. He told me that the Japanese space agency approached him with a vague idea and that it has actually turned into reality. It was originally planned for sometime in October, launching aboard a Russian Soyuz (sp?) craft which will transport a container (tank?) of fish to the International Space Station.

    The experiment is designed to look at the effects of zero gravity on bone mineral density. Funnily enough, he told me that fish are actually the only animals that can feasibly (ethically) be sent into space now (without being permanently restrained the entire time).

    maxlite
    Member

    Is this a sequel to ‘Pigs in Space’?

    piemann
    Member

    Found a link. They left on the 23rd.

    Fish in Spaaaaaaaaaace

    bigrich
    Member

    they would be pressed against the bottom of the tank.

    Premier Icon stats
    Subscriber

    A quick google search shows up 29.4m/s/s which is approx 3G

    The real question is; battered or breaded?

    neilforrow
    Member

    They float!

    Premier Icon molgrips
    Subscriber

    A quick google search shows up 29.4m/s/s which is approx 3G

    No, it’s approx 3g, and that’s in addition to the 1g from gravity.

    The problem with photos of fish of course is that they may be actively swimming up or down, rather than simply floating or sinking inertly.

    Anyway – how are they going to aerate the tank? Those bubbly things won’t work properly at all, they’ll just create a sort of mad foam.

    alex222
    Member

    So if it were relatively mild acceleration

    You must accelerate at a certain speed to reach escape velocity so there is no ‘mild acceleration’

    However they would float.

    Premier Icon molgrips
    Subscriber

    You must accelerate at a certain speed to reach escape velocity

    Not so. Escape velocity is the speed at which a ballistic projectile would need to be launched from Earth’s surface to break out of its gravitational pull. You could reach space at 1mph if that’s what your rocket did. Just keep going up.

    The real question is; battered or breaded?

    You can’t ask that! What if it was something like trout, and those were the only two options? People would be floundering around for ages, trying to work out which was the least horrid on their scale of taste.

    logical
    Member

    But what would happen if the rocket was on an escalator?

    alex222
    Member

    Yes you wouldn’t have to reach escape velocity if you wanted to orbit the earth. But you still have to overcome the acceleration due to gravity to leave the earths surface surely?

    Premier Icon richmars
    Subscriber

    Just going up at 1mph isn’t getting into orbit, it’s like the chap in the balloon last week.

    Premier Icon portlyone
    Subscriber

    We should ask…

    Premier Icon stats
    Subscriber

    No, it’s approx 3g, and that’s in addition to the 1g from gravity.

    Yeah, the acceleration of the rocket is 3g. However the force exerted by the rocket is equivalent to 4g acceleration to overcome gravitational pull, hence the reduction in thrust as the rocket escapes earths atmosphere and gravitational pull. Any mass connected to the rocket will be exerted to 4g.

    alex222
    Member

    But that is buoyancy in a fluid and can only work within a fluid.

    The question is if you put a fish on a rocket and fired it into space would it be squashed or continue to float?

    Show me a rocket that uses buoyancy to fly.

    Premier Icon molgrips
    Subscriber

    But you still have to overcome the acceleration due to gravity to leave the earths surface surely?

    Only by a tiny amount. And you need to consider forces, because acceleration is as a result of force.

    F = ma

    So for a 85kg person, you need 85 * 9.81 Newtons of force ie 834N So if your rocket motor provides 835N of force, you’ll accelerate upwards, pretty slowly. At 0.011 m/s/s, meaning that after 5 mins of that you’d be going upwards at 3.5m/s or roughly 8mph.

    Just going up at 1mph isn’t getting into orbit

    Define up!

    To get into AN orbit around the earth you need to end up moving in an ellipse or a parabola, which will involve some sideways motion. What happens to you (ie if you fall back down, continue into space, swing around one or more times, end up in a stable elliptical orbit, or a nice circular one) depends on how much sideways and how fast you were going up.

    alex222
    Member

    Don’t you also have to take into account the mass of the rocket.

    cupra
    Member

    This thread sums up why I enjoy this forum so much. The science related randmoness of it all doesn’t half put a smile on my face. I know, I’m easy pleased.

    As you were…

    Premier Icon richmars
    Subscriber

    hence the reduction in thrust as the rocket escapes earths atmosphere and gravitational pull.

    The gravitational pull doesn’t reduce much even when in orbit.

    Premier Icon stats
    Subscriber

    The gravitational pull doesn’t reduce much even when in orbit.

    No, but if you’re taking your goldfish to Mars it will.

    EDIT: wrote your instead of you’re, pedantry corner.

    Premier Icon richmars
    Subscriber

    Is that a deep fried mars to go with the fish?

    Premier Icon molgrips
    Subscriber

    The gravitational pull doesn’t reduce much even when in orbit.

    He is right. In orbit, you are falling to Earth same as if you fell out of a window. It’s just that you are moving forward so fast that the ground is always falling away from you at the same rate. You are falling around the Earth.

    mrchrispy
    Member

    I knew this thread would be a winner 🙂
    it was that story about the Russians that got me thinking, I wondered if they’d need little seats for the cosmofish.

    personally i reckon they stay where they are butI can’t prove it, I’m banned from keeping fish. rockets…. I have a plenty in the underground lair but after the incident with the sharks and the lasers, no more fish!!!

    Premier Icon scaredypants
    Subscriber

    I don’t mean to carp, but this thread started so promisingly and then began to flounder when you got all “scientific”

    Premier Icon 40mpg
    Subscriber

    Just to recap, so are fish unaffected by acceleration because they are floating in a liquid?

    If so, why don’t they fill fighter pilots cockpits with water (apart from the fact they would drown)?

    Observation:
    Those fish are all the same way up. Why is that in (next to) zero gravity?

    Premier Icon molgrips
    Subscriber

    No-one’s said they are ‘unaffected’.

    The pressure in the water increases. And their blood would flow down to their.. er.. belly.. just the same as with fighter pilots.

    Premier Icon richmars
    Subscriber

    Why is that in (next to) zero gravity?

    It’s not an answer, but it’s not zero gravity. It’s nearly the same as on earth.

    magowen100
    Member

    The acceleration acts only on the water not on the fish so as long as the fish is neutrally bouyant (or able to maintain bouyancy) then it will feel little in the way of an effect.
    Maybe I’m missing something but why look at the effects of weightlessness on fish when they inhabit a zero gravity habitat on earth?

    Premier Icon molgrips
    Subscriber

    The acceleration acts only on the water not on the fish so as long as the fish

    Rubbish.

    Maybe I’m missing something but why look at the effects of weightlessness on fish when they inhabit a zero gravity habitat on earth?

    Floating is not the same as zero gravity. Take a hot air balloon ride, then pour a glass of champagne, see which way the drink falls.

    The water around the fish supports it, but gravity still affects it.

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