What if GRAVITY fluctuated?

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    Apr 19, 2013 5:48 AM GMT
    Not many things in life are constant, except gravity. But what would the world be like if gravity fluctuated, like the weather? Imagine walking along and, whoops, you're temporarily airborne. Or that food you ate is now rising back up. How is it that gravity is a constant?

    Discuss.
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    Apr 19, 2013 7:03 AM GMT
    wrestlervic saidHow is it that gravity is a constant?
    do you actually not know or
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    Apr 19, 2013 10:35 AM GMT
    I used to have this irrational fear as a child...that the Earth would lose its gravity while I'm out for a walk. icon_rolleyes.gif
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    Apr 19, 2013 1:47 PM GMT
    People would step on the scale ten times a day and wait for the best gravity!

    (It also would make for hilarious scenes at the grocery checkout... "What? Five bananas are 15 pounds? Let me wait five minutes!")
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    Apr 19, 2013 3:05 PM GMT
    The gravitational force does fluctuate on earth. It is inversely proportional to the distance from the core (i.e. altitude).
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    Apr 19, 2013 3:41 PM GMT
    It sounded like the earth wax and wane.... lolz anyway.
    that theory could only comes into play, if the moon's gravitation pull is about 1/3 or say 1/2 of earth's... then maybe plausible.

    We could play yo-yo not so easily...icon_mad.gif

    then again if so! we could evolve into something a little different in all circumstances and possibilities....wait

    Do I smell a Jedi in the make 39.gif or just fliping gets better icon_biggrin.gif
  • ASHDOD

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    Apr 19, 2013 3:44 PM GMT
    Evolution would be totaly diffrent, so it wouldent be us,and a banana wouldent be a banana icon_smile.gif
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    Apr 19, 2013 5:00 PM GMT
    Just get small. At the scale of microbes, other forces are much stronger than gravity, and they vary across the landscape. Things like electrostatic attraction, surface tension, hydrophobicity...
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    Apr 19, 2013 5:15 PM GMT
    mindgarden saidJust get small. At the scale of microbes, other forces are much stronger than gravity, and they vary across the landscape. Things like electrostatic attraction, surface tension, hydrophobicity...


    You could christen your boat the Gravity Wave

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    Apr 19, 2013 5:23 PM GMT
    Gravity isn't constant on Earth. There is lower gravitation force at the equator than at the poles, and the higher in altitude you travel, the less the gravitational force due to moving away from the Earth's center.

    Of course, it's a pretty small difference that we don't really notice. In order to achieve what you're discussing, the Earth would have to have much less mass.
  • MikeW

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    Apr 19, 2013 6:11 PM GMT
    Can some of you physicist types explain what gravity actually IS? I understand it is related to mass but how does it have an effect on other bodies at a distance? What is a 'gravitational field'?

    What I'm really curious about is whether 'anti-grav' is even a physical possibility.
  • Medjai

    Posts: 2671

    Apr 19, 2013 6:18 PM GMT
    MikeW saidCan some of you physicist types explain what gravity actually IS? I understand it is related to mass but how does it have an effect on other bodies at a distance? What is a 'gravitational field'?

    What I'm really curious about is whether 'anti-grav' is even a physical possibility.


    It's an attractive force, though a very weak one. I may be wrong, but I think it is the weakest intermolecular a force.

    So you know about static, right? Or magnetism? Those are two forces that exert a force on a charge. It's not exactly the same, but it is sufficient for the layperson to think of gravity in a similar way. It is an attractive force between two masses.

    As for what gravity actually is, it is theoretically related to the Higgs Boson, which is the particle responsible for matter having a mass at all. I am not qualified to talk in much more depth on that though.

    I've read some interesting work done with ferromagnetic super fluids traveling relativistically in order to repel gravity, but I don't think anything like that is going to happen in the near future. It's still very much sci fi. However, there are other things that could be done, like quantum locking in a magnetic field, to achieve a similar effect...
  • Medjai

    Posts: 2671

    Apr 19, 2013 6:37 PM GMT
    MuchMoreThanMuscle saidWhat I'm interested in is how extreme gravitational fluctuations will affect my salaciously abundant sex life.


    I'm sure all you whores and floozies feel the same way.


    AMIRITEORWUT?


    I was just teasing. I've been quite chaste lately. But the rest of you are all floozies and strumpets.


    I would be bad. In states of extreme low gravity or its absence, it becomes nearly impossible to achieve or maintain an erection. Space sex isn't likely...
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    Apr 19, 2013 6:38 PM GMT
    MikeW saidCan some of you physicist types explain what gravity actually IS? I understand it is related to mass but how does it have an effect on other bodies at a distance? What is a 'gravitational field'?

    What I'm really curious about is whether 'anti-grav' is even a physical possibility.
    Newton described gravity as a force between 2 objects that was directly proportional to the product of their masses, and inversely proportional to the square of the distance between them.

    Basically, the stronger an objects mass, the stronger the force of gravity on other objects. The farther you get away from the center of the object (where the mass is greatest), the weaker the gravity.

    That's why on Earth, the higher in altitude you travel, the weaker the force of gravity because you're moving away from the Earth's center. If you drop an object off a tall building, it speeds up as it gets closer to the ground. The equator has a weaker gravitational force than the poles. And the moons gravity is much weaker than Earth because it has less mass.

    Einstein, however, claimed gravity wasn't a force, but a result of the curvature of space time. Without an external force, 2 objects will always travel in a straight line. Einstein claimed the reason objects meet is because they aren't traveling on a straight line, they are traveling along a spherical path due to the curvature of space-time and that's what causes them to interact. This was the basis of General Relativity.

    Of course, General Relativity has been modified by Quantum Mechanics, so we still don't really know the specifics of how gravity works.
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    Apr 19, 2013 6:41 PM GMT
    A slight decrease in the gravitation pull would be fun to watch on the nudie beach. All the women would suddenly be proud of their perky boobs and the men, well, I will leave that to your active imaginations.
  • MikeW

    Posts: 6061

    Apr 19, 2013 6:56 PM GMT
    Thanks, Medjai and Fiyero27.

    I'm not a 'science' type at all, although I have read 'lay person' stuff (e.g., the Tao of Physics), mostly years ago, so I'm not totally uninformed. I'm mostly an 'artist' type. Fascinated by things like, for example, how occasionally a drop of water won't instantly break the surface tension of water in a dishpan but will sort of 'roll' a bit before it disperses. Or, for another example, how bubbles floating on the surface of water will get attracted to one another and their attraction accelerate until they bond and form a new geometric shape.

    I've recently found myself thinking about adhesives. I know nothing about them but I'm sure there is a whole science/engineering realm that must study them. My mind asks questions like, "How is it that surfaces that, on the atomic and possibly even the molecular level, never actually come into contact, "adhere"? What different types of "adhesion" are there? Of course I understand electromagnetism has a lot to do with it but, still, something in me finds this stuff interesting.

    As an artist, I'm also interested in 'edges', 'boundaries', and 'focus'. Not sure I can put into words what I find interesting about them but the idea that everything is a more or less dynamic 'field of energy' is curious. Vibrations and all that.
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    Apr 19, 2013 6:57 PM GMT
    if gravity did massively fluctuate, this planet would be called 'gym'
  • tennsjock

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    Apr 19, 2013 6:59 PM GMT
    oh boy, let me get back to you after my lecture today. I'm teaching Modern Physics for science/engineering majors, and we just finished a section on general relativity (Einstein's theory of gravity)...
  • MikeW

    Posts: 6061

    Apr 19, 2013 7:01 PM GMT
    FootballHawk saidif gravity did massively fluctuate, this planet would be called 'gym'

    haha true. Gravity can be our friend.
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    Apr 19, 2013 7:01 PM GMT
    alexander7 saidA slight decrease in the gravitation pull would be fun to watch on the nudie beach. All the women would suddenly be proud of their perky boobs and the men, well, I will leave that to your active imaginations.


    Fluctuating, eh? That would mean at certain times of the day Bill and I's faces would look many years younger. icon_lol.gif

  • MikeW

    Posts: 6061

    Apr 19, 2013 7:01 PM GMT
    tennsjock saidoh boy, let me get back to you after my lecture today. I'm teaching Modern Physics for science/engineering majors, and we just finished a section on general relativity (Einstein's theory of gravity)...

    Excellent!
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    Apr 19, 2013 8:09 PM GMT
    wrestlervic saidNot many things in life are constant, except gravity. But what would the world be like if gravity fluctuated, like the weather? Imagine walking along and, whoops, you're temporarily airborne. Or that food you ate is now rising back up. How is it that gravity is a constant?

    Discuss.


    Your body uses muscle to pull food to the stomach, you can eat upside down fine if you choose to.

    Gravity already is not constant, it is dependent on mass. There are also places on the planet where balls roll up hill but this may be the result of an effect besides gravity.
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    Apr 19, 2013 8:11 PM GMT
    Fiyero27 said
    MikeW saidCan some of you physicist types explain what gravity actually IS? I understand it is related to mass but how does it have an effect on other bodies at a distance? What is a 'gravitational field'?

    What I'm really curious about is whether 'anti-grav' is even a physical possibility.
    Newton described gravity as a force between 2 objects that was directly proportional to the product of their masses, and inversely proportional to the square of the distance between them.

    Basically, the stronger an objects mass, the stronger the force of gravity on other objects. The farther you get away from the center of the object (where the mass is greatest), the weaker the gravity.

    That's why on Earth, the higher in altitude you travel, the weaker the force of gravity because you're moving away from the Earth's center. If you drop an object off a tall building, it speeds up as it gets closer to the ground. The equator has a weaker gravitational force than the poles. And the moons gravity is much weaker than Earth because it has less mass.

    Einstein, however, claimed gravity wasn't a force, but a result of the curvature of space time. Without an external force, 2 objects will always travel in a straight line. Einstein claimed the reason objects meet is because they aren't traveling on a straight line, they are traveling along a spherical path due to the curvature of space-time and that's what causes them to interact. This was the basis of General Relativity.

    Of course, General Relativity has been modified by Quantum Mechanics, so we still don't really know the specifics of how gravity works.


    Einstein also theorized about the existence of gravity waves as well though there are no known experiments proving the existence of these waves. Considering light turned out to behave as a wave itself, it certainly is an interesting theory.
  • Medjai

    Posts: 2671

    Apr 19, 2013 8:15 PM GMT
    Animus said
    wrestlervic saidNot many things in life are constant, except gravity. But what would the world be like if gravity fluctuated, like the weather? Imagine walking along and, whoops, you're temporarily airborne. Or that food you ate is now rising back up. How is it that gravity is a constant?

    Discuss.


    Your body uses muscle to pull food to the stomach, you can eat upside down fine if you choose to.

    Gravity already is not constant, it is dependent on mass. There are also places on the planet where balls roll up hill but this may be the result of an effect besides gravity.


    Gravity hills are an optical illusion, nothing more.
  • tennsjock

    Posts: 349

    Apr 20, 2013 5:09 PM GMT
    You'd get lost -- GPS wouldn't work.

    GPS satellites work by bouncing signals off your phone and measuring the round trip time. Because those signals travel at the speed of light, they can easily convert the roundtrip time measurement into a a distance measurement. Of all that determines is your distance from a single satellite -- several satellites are needed to pinpoint your location. There are two effects that make this time measurement problematic:

    1. A consequence of Special Relativity is that a moving clock ticks slower. Because the GPS satellites move quickly with respect to us, their clocks keep slightly slower time than ours on earth.

    2. A consequence of General Relativity (Einstein's theory of gravity) is that clocks in a gravitational field tick slower. Because the GPS satellites are farther away from the center of the earth than we are (and therefore in a weaker gravitational field), they tick faster than ours.

    These two effects are not of the same magnitude, so they don't completely cancel out, and both need to be taken into account for accurate surface positioning. If we didn't account for the gravitational effects on time measurements, then GPS satellites could determine your location on the surface with an accuracy of about an acre -- for more accurate results, you need gravity.

    Thanks, Einstein!
    http://www.aip.org/success/gps.pdf
    http://www.astronomy.ohio-state.edu/~pogge/Ast162/Unit5/gps.html