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  1. #1 question about our solar system 
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    If Mercury vanished, would Earth come closer to the sun?


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  3. #2  
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    No.


    "A man's ethical behavior should be based effectually on sympathy, education, and social ties; no religious basis is necessary. Man would indeeded be in a poor way if he had to be restrained by fear of punishment and hope of reward after death." Albert Einstein
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    Why should it? There would be absolutely no reason for it to.
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    Since the method of vanishing has not been stipulated I have reached the following conclusion; if Mercury vanished the Earth would move further away from the sun.

    Justification: the total angular momentum of a system must be preserved. If Mercury vanishes then its angular momentum must be redistrbuted within the system. It is likely that some of this would be apportioned to the Earth which would necessarily move away from the sun.
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    Quote Originally Posted by Ophiolite
    Since the method of vanishing has not been stipulated I have reached the following conclusion; if Mercury vanished the Earth would move further away from the sun.

    Justification: the total angular momentum of a system must be preserved. If Mercury vanishes then its angular momentum must be redistrbuted within the system. It is likely that some of this would be apportioned to the Earth which would necessarily move away from the sun.
    Such a small planet shouldn't have anything to do with gravity of other planets so far away. Furthermore, what does the momentum have to do with it? Am I being ignorant here? >.>
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    He's gabbing on about the conservation of momentum, in a system it has to go somewhere that it, be re-distributed, but since the original question was what if, then mercury, wherever it dissappeared to would presumably take it's momentum with it. Since there would be no more transits of mercury, the earth might receive a few more killowatts of sunlight (on average), the orbit of the earth may be slightly# affected but other than that, your money is safe in the bank...

    # That is any perturbations of the Earth's orbit caused by interactions with mercury would 'iron out'.
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    Quote Originally Posted by Jeremyhfht
    Such a small planet shouldn't have anything to do with gravity of other planets so far away.
    Point 1:On the scale of the solar system Mercury is quite close.
    Point 2:It's gravity is sufficient to effect the Earth, although by only a small amount. The scale of the effect was not mentioned, or limited by the original poster.
    Quote Originally Posted by Jeremyhfht
    Furthermore, what does the momentum have to do with it?
    I can only repeat, the angular momentum of any system is a constant. If one component in the system loses angular momentum the other one must gain it. Typically this is done by tidal interaction. (Thus the moon moves away from the Earth because the Earth slows down on its rotational axis. The moon gains angular momentum, the Earth loses it.)

    In this example I was indirectly and implicitly pointing out that
    (a) This is a hypothetical question, since Mercury could not simply vanish.
    (b) I don't like hypothetical questions, since they focus on only a single aspect of a complex scenario.
    (c) So, to a hypothetical question I can give a hypothetical answer, focusing on only one aspect of that scenario. In this instance I chose to address conservation of angular momentum.
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    Perhaps if they constructed my length contraction satellite, it would collide with mercury, and all the goofy stuff would be splattered all over the place. I don't know any other reason for this to happen though :-D

    How about changing mercury's magnetic field, What is B?
    Not that I think we should move it.
    Could we use, perhaps, a magnetic field to move mars, terraform?
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  10. #9  
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    Quote Originally Posted by LeavingQuietly
    Perhaps if they constructed my length contraction satellite, it would collide with mercury, and all the goofy stuff would be splattered all over the place. I don't know any other reason for this to happen though :-D

    How about changing mercury's magnetic field, What is B?
    Not that I think we should move it.
    Could we use, perhaps, a magnetic field to move mars, terraform?
    I think before you ask all these questions you might like to study some of the subjects, this will enable you to refine some of your queries to a level where they might not look as though they were formed by a ball casually rolling around on your keyboard in a thunderstorm.... :wink:
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  11. #10  
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    Quote Originally Posted by Megabrain
    Quote Originally Posted by LeavingQuietly
    Perhaps if they constructed my length contraction satellite, it would collide with mercury, and all the goofy stuff would be splattered all over the place. I don't know any other reason for this to happen though :-D

    How about changing mercury's magnetic field, What is B?
    Not that I think we should move it.
    Could we use, perhaps, a magnetic field to move mars, terraform?
    I think before you ask all these questions you might like to study some of the subjects, this will enable you to refine some of your queries to a level where they might not look as though they were formed by a ball casually rolling around on your keyboard in a thunderstorm.... :wink:
    So THAT'S how you type most of your replies. :wink:
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    wetyjukm vcxdsf;[c'.jk,n bovcxdsujhejtng fcvc
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  13. #12  
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    Quote Originally Posted by Ophiolite
    Quote Originally Posted by Jeremyhfht
    Such a small planet shouldn't have anything to do with gravity of other planets so far away.
    Point 1:On the scale of the solar system Mercury is quite close.
    Point 2:It's gravity is sufficient to effect the Earth, although by only a small amount. The scale of the effect was not mentioned, or limited by the original poster.
    Quote Originally Posted by Jeremyhfht
    Furthermore, what does the momentum have to do with it?
    I can only repeat, the angular momentum of any system is a constant. If one component in the system loses angular momentum the other one must gain it. Typically this is done by tidal interaction. (Thus the moon moves away from the Earth because the Earth slows down on its rotational axis. The moon gains angular momentum, the Earth loses it.)

    In this example I was indirectly and implicitly pointing out that
    (a) This is a hypothetical question, since Mercury could not simply vanish.
    (b) I don't like hypothetical questions, since they focus on only a single aspect of a complex scenario.
    (c) So, to a hypothetical question I can give a hypothetical answer, focusing on only one aspect of that scenario. In this instance I chose to address conservation of angular momentum.
    I sort of agree with Ophiolite on this one. I think the Earth would move slightly further from the Sun if Mercury were to vanish simply because Mercury must have a slight gravitational affect on the Earth.

    However, I admit I know little about all this jumble. But let me pose a question that may help:

    If Jupiter were to disappear, would the Earth move closer to the SUN?
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    It would make sense that planets of varying gravity would sort of cause an equilibrium effect. This is probably why we've yet to find planets similar to earth in habitat, since it'd require an equilibrium in order to be within a certain orbit range for a good temperature. However, would someone here better versed in physics care to explain it? in ENGLISH would be preferred, rather than obscure jargon.
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    I have seen it written that the effect of jupiter on the earth's orbit is to cause a pertubation of around 100,000 miles. This means that if at the moment Jupiter were exactly the other side of the sun, the earth were 93million miles from the sun, then on a subsequent orbit Jupiter was opposite the sun, the earth would then be 93,100,000 miles from the sun - however the slight eccentricity of the natural orbit of the earth is around 20-30 times greater than this. Jupiter therefore 'pulls' the earth the extra 0.1M miles. If Big J dissappeared therefore the earth's orbit would merely lose one of the forces that contribute to eccentricity. The important factor would be whether J dissappeared during a perturbation, as the earth would be further from than the sun than it's natural orbital velocity dictated. The earth wold then keep this extra eccentricity of orbit in the form of a pure ellitical orbit (ignoring affects of other planets), over the whole year rather than a minor deviation for part.

    Well you said In English without quoting Keplar, newton...
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    Quote Originally Posted by Megabrain
    I have seen it written that the effect of jupiter on the earth's orbit is to cause a pertubation of around 100,000 miles. This means that if at the moment Jupiter were exactly the other side of the sun, the earth were 93million miles from the sun, then on a subsequent orbit Jupiter was opposite the sun, the earth would then be 93,100,000 miles from the sun - however the slight eccentricity of the natural orbit of the earth is around 20-30 times greater than this. Jupiter therefore 'pulls' the earth the extra 0.1M miles. If Big J dissappeared therefore the earth's orbit would merely lose one of the forces that contribute to eccentricity. The important factor would be whether J dissappeared during a perturbation, as the earth would be further from than the sun than it's natural orbital velocity dictated. The earth wold then keep this extra eccentricity of orbit in the form of a pure ellitical orbit (ignoring affects of other planets), over the whole year rather than a minor deviation for part.

    Well you said In English without quoting Keplar, newton...
    Ok. So would Mercury have some sort of effect on the Earth if it vanished?
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  17. #16  
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    The effects would be identical, but the amount of effect on the earth I have no idea of, Jupiter is large but far away, mercury is relatively nearer and smaller, the effect could be either way.
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  18. #17  
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    Quote Originally Posted by Megabrain
    The effects would be identical, but the amount of effect on the earth I have no idea of, Jupiter is large but far away, mercury is relatively nearer and smaller, the effect could be either way.
    I believe the effect would be less. since the size factor is too great for it to be an equal effect. The distance is too small, as well.

    Furthermore, citing newton and other sources isn't jargon, since jargon in physics wasn't invented (for wide-spread use) until sometime around after the golden age of science. >.>
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  19. #18  
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    Well it should be a straight forward equation, the ratio of the distance vs the ratio of their mass's ie if you double the distance & quadruple the mass, the gravitational effect will be the same.

    Mercury nearest approach = approx 90million KM
    Jupiter = 591million KM

    Distance Ratio = 6.6:1

    Mass Mercury = 3.303 * 10^23 Kgs

    Mass of Jupiter = 1.9 * 10^27 Kgs

    Mass ratio = 5700

    Which I think means Jupiter has a pull about 130 times the pull of mercury.

    By that reckoning mercury perturbs the earth's orbit by around 769km out of an orbit of 150,000,000Km
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  20. #19  
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    according to theory each unit in the total of solar system mass has an effect on the others. the loss of that very small mass pulling in conjunction with the sun would cause a lesser pull from that direction and increase the orbit, fractionally.
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    Quote Originally Posted by jackson33
    according to theory each unit in the total of solar system mass has an effect on the others. the loss of that very small mass pulling in conjunction with the sun would cause a lesser pull from that direction and increase the orbit, fractionally.
    Globaly that is essentially true, but being a dynamic system it is much more sosphisticated, the point at which the earth was, when mercury dissappeared would be a point to which the earth would return on every subsequent orbit [ignoring the effects of other bodies], it would be the point diametrically opposite the sun where the earth would trace a new path.

    If you put a satellite into a low earth orbit and then apply thrust for a few seconds the orbit changes but becomes elliptical returning to the point in space where the thrust was initialised [this becomes the periapsis]. Orbital mechanics requires two thrusts to change an orbit, the first to produce an eliptical orbit and the second [at apoapsis] to make the orbit circular. In the same way the dissappearance of mercury may be considered as thrust ie a pull or push, the orbit would become elliptical.
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    i have a question about the unviverse, how many known starts are directly below us and above us?

    -if it was asked, SORRY
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    Quote Originally Posted by johnny
    i have a question about the unviverse, how many known starts are directly below us and above us?

    -if it was asked, SORRY
    Look carefully at what you have written 'starts' ? - do you mean stars? explain a bit more, maybe that cauliflower is affecting your brain..
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    yea stars, do they map stars beloew the earth as much as the ones out across from us?
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    Below the earth?

    Up Down above below are only terms relevent when subject to gravity, unless you think the earth is flat...

    They are mapped in all directions, starfield charts exist for every portion of the sky - as viewed from any point on earth.
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