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What happens to us/earth if the earth suddenly stops rotating?

  1. Jun 27, 2011 #1
    Okay, so I present to you three different "scenarios". I'm pretty new to physics, and I can't seem to think this out for myself. Please ask questions, and excuse my english.

    I've been wondering for some time what would happen to us (and the earth) if the earth suddenly stopped rotating, like in a blink. I understand earth has friction, and that we (humans) are held in place by inertia.

    Also I've been wondering what would happen if the earth stopped completely for, say one tenth of a second, and then accelerated instantly again to its 1000 mph rotation. (Supposed to be a question)

    And lastly, what would happen if the earth suddenly changed it's rotation and started rotating a 1000 mph to the west instead of to the east?

    I know probably none of these scenarios are very likely (if even possible).

    - Gaute Huus
  2. jcsd
  3. Jun 27, 2011 #2
    If the Earth suddenly stopped rotating, then according to Newton's first law, any object not attached to the ground would carry on travelling parrallel to the ground at an initial velocity of 1000mph.
    Last edited: Jun 27, 2011
  4. Jun 27, 2011 #3


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    Welcome to PF. There's a problem with your question; you are essentially asking "If we imagine violation of physics X what would the laws of physics have to say?" This is not a good approach to science.

    It is not possible for the Earth to just stop rotating. Some action is required to stop it and depending on what this action is will affect the answer to your question.
  5. Jun 27, 2011 #4

    Andy Resnick

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    H. G. Wells wrote a delightful short story about this scenario:

  6. Jun 27, 2011 #5
    Thank you for all of your answers. The result can be various different things, depending on which way the earth is "stopped". I'm going to try speculating more with that information in mind.

    And thanks again!
  7. Jun 28, 2011 #6
    Earth can't just stop rotating or orbiting around the Sun due to gravitational forces, unless the Sun suddenly disappears or another body 'rolls up' into our solar system in a certain area and then we would start orbiting that said body - Newton said we would straight away go off course if the sun suddenly disappears - But according to Einstein, we would have to wait 8 minutes (the time it takes for gravity to take effect at our distance from the Sun) then we would go off course. For the human part we would eventually die since it would get bloody cold.

    We wouldn't feel the 'stop and go' due to the Theory of Relativity, since we are not accelerating (but I think that only applies if the rate of speed at which we are rotating is constant).

    (Sorry if any of this is wrong, I'm only 14 :L)
  8. Jun 28, 2011 #7


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    It's not a good approach to science, but it does make for a very entertaining short story.

    As does Isaac Asimov's "The Billiard Ball". This has the entire short story collection (including the great story, "Nightfall"), but you can go to "The Billiard Ball" by scrolling up to the beginning of the document, clicking on the navigation icon and then on "The Billiard Ball".

    http://www.polvoestelar.com.mx/babilonia/Libros/Isaac%20Asimov/English/Short%20Stories/Isaac%20Asimov%20-%20The%20Best%20of%20Isaac%20Asimov.pdf [Broken]
    Last edited by a moderator: May 5, 2017
  9. Aug 2, 2011 #8
    before answering your question,there are some essential things that you should know.
    1)than due to rotation,our earth becomes an accelerated frame,so as long as we are on it we experience a pseudo force that has a value of mv2/r.here r depends on our coordinates as at defferent places on earth there are different associated radius of rotation.
    2)the resultant of the main core gravitational force and pseudo force decides the apparent g.all the buildings and architectural habituals are made on the basis of this apparent g.if the value of this g changes by a margin,then these builings may collide.

    now let us answer your questions:-
    ans1)if earth suddenly stops rotating,all objects not fixed on its place will move in outer space with a particular velocity(i.e the linear rotational velocity at that instant).this objects will be influenced bythe gravitational force.those objects facing more air drag will move towards earth and all other in outer space.as discussed in point 2,the apparent g will return it's value as normal g,and hence where this change is big,buildings and other things will break and may move out in outer space.
    ans2)in this questions those thing that move in outer space will move out with 1000mph and all fixed objects will get damaged due to actin of non constant force in small interval of time(i.e gravity+pseudo,then only pseudo,and then gravity and pseudo again).the acceleration for achieving 1000mph again will further effect the apparent g for that interval of time.
    ans3)the mixture of ans1 and ans2 will happen in this case.

    note:-as centre of mass doesn't changes due to rotation,so don't consider that concept..
    hope it might help you..
    nice question...
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