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If earth stops rotating

  1. Dec 30, 2012 #1
    Dear All,

    Hi I am a teacher and also new to the forum!!!

    Can someone guide me what happens if earth stops rotating suddenly!!


  2. jcsd
  3. Dec 30, 2012 #2


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    Everything would suddenly be uprooted and flung eastward since everything had some kind of rotational velocity before the Earth stopped. (And the Earth is rotating towards the east, which is counterclockwise as viewed from above the north pole) The exact velocity depends on the latitude, with those things at the equator having far more energy and speed than near the poles.
  4. Dec 30, 2012 #3
    Alot depends how fast the rotation is stopped. Imagine driving a sports car at 600 mph and hitting a huge sponge, it would slow you down slowly. But hit a steel wall 30 feet thick and all the energy would be released suddenly and you would have neck problems. As to the earth, the oceans would surge violently and mountain ranges would be displaced along with the tectonic plates and inner molten core would crack through the crust..etc. It would just be a bad day and mess up your hair.
  5. Dec 30, 2012 #4


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    The problem is that the OP didn't say anything about how the "stopping" would occur! GIGO. I was, frankly, tempted to say that we would be up to our necks in Easter Bunnies since we are now allowing any sort of magic to happen!
  6. Dec 30, 2012 #5
    Hi All,

    Thanks for the reply.

    But can I please get some more elaborate answer considering the forces.

    I agree that the free objects would fly in to space.

    But I also think the effective g would be more because the pseudo centripetal would vanished.

    Please correct me and reply.

    And wishing you all a Happy New Year in advance.

  7. Dec 30, 2012 #6


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    The effect of gravity would be greater. One can experience this by going to one of the poles (north or south) where there is not centripetal effect.

    Stopping the earth suddently/instantly is not a realistic scenario. It would better to ask, what would we experience if the earth did not rotate, or if it rotated much more slowly, e.g., if the earth was tidally locked to the sun. Certainly there is the gravitational effect, but then there is the thermal effect from the sun. The part facing the sun would get very hot, and the part facing away from the sun would get very cold. The weather would be very different.
  8. Dec 30, 2012 #7
    All the angular momentum would go into our heads twisting them off and the human race would die off.
  9. Dec 30, 2012 #8


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    That is incorrect.

    Objects right now travelling with the rotation of the earth do not fly into space ( but stopping the earth would then fling them into space??? ) At the equator, an object is travelling at 1000mph along with the rotation of the earth. With a non-rotating earth, that same object would be travelling still at 1000mph but over a non-rotaing earth along the surface.

    Why the distinction between free and attached objects. All objects make up the earth - air, people, birds, continents, oceans, core, mantle. If the rotation of the earth stopped suddenly, then all objects of the earth would comply with the non-rotation and not just some and not others, simply because the earth is considered a sum of all of its parts. No catastophic building collapse or giant earthquakes would occur with the only consideration in mind of the earth going from the rotating to the non-rotating.

    Unless of course, in this ficticious scenario, the unknown mysterious force can distinguish between the elementary particles ( electrons, protons, quarks, etc ) of say an iron atom deep within the earth to that of an iron atom in the frame of your car, and have an affect on either one diferently.
    Last edited: Dec 30, 2012
  10. Jan 1, 2013 #9
    If the Earth slowed down slowly then yes, if it suddenly stoped then no.Imagine a skyscraper on a conveyor travelling at 1000mph over a non rotateing Earth or allmost, at the north or south pole.Stop the conveyor at once, it's doubtfull the building would remain in one peice.
  11. Jan 1, 2013 #10
    Would the average temperature be higher.The Earth rotateing allows heat to escape into space continuously.One face constantly faceing the Sun might raise the temperature of the Earth overall as the heat could not escape into space as quickly as it would have to pass through the whole Earth to do that.
  12. Jan 1, 2013 #11
    Why would this happen?

    I would have thought that without the angular momentum of rotation, gravity would be reduced...but probably not by much. Consequently I would have expected the orbit of earth to expand every so slightly around the sun. I assume there would be earthquakes galore over time as the equatorial bulge is replaced by tidal forces from the sun/earth system and the earth tries to reshape.
    Last edited: Jan 1, 2013
  13. Jan 1, 2013 #12
    There would be means of moving heat from the hot side to the cold side. Convection of air, boiling & condensation of water, and conduction. Would these processes have the effect of widening the habitable zone between the hot and cold sides or would it eliminate the habitable zone altogether due to the high rate of energy transfer through that area?
  14. Jan 1, 2013 #13


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    Sorry, this statement just bothers me. No centrifugal effect. There is no such thing as centripetal effect, but if there was, it'd be pulling things inwards.
  15. Jan 1, 2013 #14


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    In other words, are you are saying, when the earth is stopped from rotating, that anything above an arbitrary surface of the earth will still possess momentum, and anything below the surface will not possess momentum. Where should one make a distinction between above and below this arbitrary surface so that above the surface is not of the earth and below is of the earth. What is so special about sea level or the land that humans walk on that it is incorrectly assumed that we, what we build or what we can see with our eyes is not part of the earth.
    That is the problem when answering ficticiuous situations - see the post from HallsofIvy. The criteria in the question were not defined
    Last edited: Jan 1, 2013
  16. Jan 1, 2013 #15
    Well I thought they were. The OP defined the situation quite clearly, " if the earth suddenly stopped and even put in a couple of exclamation marks!!
    As for anything above or below the Earth having momentum when it is stopped.Of course they both have and that the speed of the rotation makes all the difference . It's just that everything below would be better anchored.
  17. Jan 1, 2013 #16
    The question as phrased in the OP is unrealistic. It's one of those questions that we see here quite often that asks; If we ignore the laws and theories of physics by allowing "A" to happen, then what do the laws and theories of physics predict will be the effects of "A"? Astronuc correctly rephrased the question back in post number 6.
  18. Jan 1, 2013 #17
    Sorry but Astronuc's rephraseing is no more realistic than the OP "unrealistic" phraseing of the orginal enquiry.
    He presented a possible though unlikely scenerio so what's the problem.
    Are you saying it's not possible under any cercumstances.
  19. Jan 2, 2013 #18
    I have a sneaking suspicion that the OP was trying to determine whether the rotation of the earth resulted in gravity, and that 'switching' off the rotation of the earth would result in all things not fixed to the surface to float away into 'space'.
    Some how, my brother also shared this same line of thinking through what he was taught back at school 20 years ago. Clearly he wasn't paying attention in class and completely missed the whole meaning of the lesson, and he is not alone!

    So to answer the OP, gravity on the earth IS NOT a result of the rotation of the earth, it is a result of the mass of the earth regardless of whether it is spinning or not.
    The moon has gravity which is something like a 1/6th of the earths (based on its mass and the distance of the surface to its center of mass). It spins on its axis every time it orbits the earth, but things on its surface don't float away from it due to the moon not rotating as 'quickly' as the earth.
    Stopping the earths rotation suddenly would result in having to deal with inertia of every individual 'body' that contains mass (which gets messier the close to the equator you are).

  20. Jan 3, 2013 #19
    Despite this he still managed ro become a teacher:wink:
  21. Jan 3, 2013 #20
    I must add to the above that I was regarding that statement toward my brother, not to jayeshtrivedi directly.

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