Strong gravity

Discussion in 'Science and Technology' started by Supreme Admiral, May 26, 2009.

  1. Supreme Admiral

    Supreme Admiral Captain

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    Out of my curiosity..how does that effect strong gravity on humans on other planets? Could we possible to survive on other planets with strong gravity or not?
     
  2. RobertVA

    RobertVA Fleet Captain Fleet Captain

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    "Strong" isn't very specific. Would that be 1.5 G, 2G, 3G or more?

    The ability to function for long periods would probably be influenced by the individual's age, their amount of experience in the high G environment and their physical fitness. I would expect animal tests in centrifuges before humans were exposed to such conditions.

    Even healthy adults might need some assistance getting blood back up to the heart from the feet with more than marginally stronger gravity.

    I'm not aware of any place in this solar system with higher surface gravity than Earth other than the gas giants, where gravity is so strong human survival would probably be impossible.
     
  3. Maurice

    Maurice Snagglepussed Admiral

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    In the old book "Habitable Planets for Man" they discuss G-force stress tests and hypothesize that 1.5Gs is the maximum a human could tolerate, but that it would have negative effects because the heart would have to work harder for one thing. Alos, falling could be potentially fatal because the higher acceleration under higher gravity means you'd hit the ground with more speed and more force. I can dig out the book if you want some specifics.
     
  4. Deckerd

    Deckerd Fleet Arse Premium Member

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    I love the idea that there's an old book called Habitable Planets for Man. It's just funny.
     
  5. All Seeing Eye

    All Seeing Eye Admiral

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    I thought Earths Gravity was 9G. :confused:
     
  6. Jadzia

    Jadzia on holiday Premium Member

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    You're thinking of the average gravitational acceleration on the earth's surface surface, which is 9.8 metres per second per second, which defines 1G.
     
  7. JoeZhang

    JoeZhang Vice Admiral Admiral

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    There was a really interesting BBC documentary a couple of years ago about the effects of gravity on evolution. Even a little stronger or a little weaker would have resulted in some radically different animals.
     
  8. backstept

    backstept Rear Admiral Rear Admiral

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    maybe you were thinking of how fast things accelerate when they fall, which is 9.81m/s
     
  9. Maurice

    Maurice Snagglepussed Admiral

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    TGT pointed out to me that Stephen Dole's "Planets for Man" (aka "Habitable Planets for Man") is available as a free download from Rand.org. I first learned about the book because it is cited in the TNG Writer's Technical Guide. I used it in designing the solar system builder portion of the computer game Rules of Engagement back in 1991.

    [​IMG]
    From page 105.

    The book is out of date in some ways, particularly related to theories about planet arrangement around stars, but a lot of the underlying logic and research still stands especially concerning the human animal in different gravities, why planets have to have short day-night cycles, etc.
     
    Last edited: May 27, 2009
  10. Meredith

    Meredith Vice Admiral Admiral

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    I know people who already weigh 2x times as much as they should and they don't have any problems getting around. It would be like serious weight training with weights on all of the time. I think 2X gravity would be livable, though it would either strain your heart, or you would have really good cardio health because of it!
     
  11. Asbo Zaprudder

    Asbo Zaprudder Admiral Admiral

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    Terraform the settlers by using genetic engineering, or select colonists from the existing tails of the gene pool distribution in the appropriate phenotype dimensions.
     
  12. Maurice

    Maurice Snagglepussed Admiral

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    Weighing twice as much as you should isn't the same as the increased acceleration of higher gravity, which means impacts are more severe, etc.
     
    Last edited by a moderator: May 29, 2009
  13. Jadzia

    Jadzia on holiday Premium Member

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    Also in a 2G environment, your blood pressure might be doubled in order to pull it up from your feet and get enough flowing to your brain. 240/160 would be a bit of a worry.
     
  14. oponda2009

    oponda2009 Guest

    Gravity dictates the orbits of the planets around the sun. By measuring those orbits, you can calculate the planet's gravity. Here on earth, we have a normal gravitational force.
    By the way, the earth's gravitational pull does not "twist" something in orbit - the force it exerts is directly toward the center of the earth, and would be the same whether the earth was rotating or not.
     
  15. RobertVA

    RobertVA Fleet Captain Fleet Captain

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    No. the velocity and orbital radius of planets orbiting the Sun has MUCH more to do with the mass of the Sun. The mass of the planets does create small but detectable shifts in the the orbital trajectories of other planets. If two planets had overlapping apogees and perigees, over a multi-million year period they would probably have occasions when they pass within a few million miles of each other, producing major shifts in their orbits.
     
  16. Myasishchev

    Myasishchev Rear Admiral Rear Admiral

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    At the very least, it would be an issue going immediately from Earth to a 2G planet. People who weigh 320 pounds didn't gain the surplus 160 overnight. Their muscles were conditioned to accept the extra weight incrementally.

    Forgetting the other circulatory effects for a moment, I wonder what effects even comparatively slight increases in gravity (2, 3Gs) for extended periods would have on air pressure. Would going back immediately to a 1G environment cause problems, i.e. bends and such?
     
  17. Daedalus12

    Daedalus12 Rear Admiral Rear Admiral

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    I could see tons of potential physiological damages which can result from stronger gravity. We have already have a large knowledge base of physiological damages resulting from experiencing micro-gravity. Skylab was the first to provide extensive data on that subject. I am sure the physiological deterioration resulting from stronger gravity will just as broad and extensive as it is for low gravity.

    [​IMG]

    Source: Human Physiology in Space, BioEssays 1996 Volume 18 Issue 12.
     
  18. Christopher

    Christopher Writer Admiral

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    No, that's not true at all. The mass, and therefore the gravitational pull, of a planet (unless it's a giant planet) is so infinitesimally small compared to that of its primary star that it basically goes to zero in the equation. The only significant factors defining a planet's orbit are the mass of its primary star and its distance from that star.

    A planet's surface gravity is calculated from its own mass and radius. Its orbital parameters have nothing to do with that computation.


    No, here on Earth we have an Earth-sized gravitational force. We think of that as "normal" because it's what we're used to, but there's nothing intrinsically more "normal" about Earth's gravity than that of any other body.