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Does Spin Affect Gravity at the Particle Level?

  1. Sep 10, 2006 #1
    I would like to get your feedback, thoughts and answers if I may?

    If it were that the particles - re electron and nucleus - are spinning then will this have an effect on the apparent gravity?

    I reflect upon industrial floor waxers and gyroscopes.

    A gyroscope will appear to defy gravity by hanging out sideways without falling. If you try to get it to hang out sideways when it is not spinning it will fall as you would expect.

    Also an industrial floor waxer needs to be pushed sideways to go forwards and if you push it forwards it will go sideways.

    If particles spin then will they do the same for gravitational effect?

    I raise the question asking that if the spinning particles that comprise our world (if they are spinning) then whether this would decrease the apparent gravitational effect that we feel? Do we feel less gravitation then actually resides in the particles were they not spinning?

    I look at the example that if you hold a piece of metal at the exact point between two magnets then you can get it to remain stationery despite both magnets 'pulling' upon it.

    In an approximately similar fashion, could it be that the spinning particles which are spinning at different orientations be serving to divert gravitational 'pull' from totally being down and converting it to other directions that often as not oppose each other and cancel each other other in terms of gravitational effect? ie If you get attracted both ways you go nowhere.

    I don't think current science considers particle movement and its possible affect upon gravitational direction so I am asking people here what they think please?

    (Sorry the topic should be: Does Particle Spin Affect Gravity?)
    Last edited: Sep 10, 2006
  2. jcsd
  3. Sep 11, 2006 #2


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    There is no sort of gravitational effect on a floor waxer due to its rotation. Floor waxers can be handled quite adaquately by Newtonian mechanics.

    There is an extremely tiny gravitational effect in General relativity, called the Lense Thirring effect, which is caused by massive rotating bodies. This is currently being studied by gravity probe B. It is an effect so small that even with the entire Earth being the "gyroscope", it is barely measurable with the most precise gyroscopes we can make with modern technology.

    And you are not going to turn a floor-waxer into a flying saucer, if that's what your last question means.
  4. Sep 11, 2006 #3
    You say the effect is extremely tiny but is that generally the case?

    If something is spinning extremely fast the effect will be larger and do we really understand the limit since as I understand it we can only calculate it by using the weak field approximation since no exact GR calculation has been developed or might at all be possible.
  5. Sep 11, 2006 #4


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    It's possible to calculate the effect in the strong field if the problem warrants it. No problem that arises in the solar system will need anything better than the weak field approximation, though.

    As far as the magnitude of the effect goes, ask again when the GPB results are in. I do seem to recall that there are some experimental measurements that were discussed a while ago, though, which were consistent with GR.

    Meanwhile, let's try and stick to the facts and avoid "overly speculative posts", as the PF guidelines suggest.
  6. Sep 11, 2006 #5


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    Here are some references that I was trying to think of about the existing measurements of the Lense-Thiring effect, using the Lageos satellite orbits:


    It appears that at least one existing measurement already rules out extremely large magnitude effects. While some degree of caution is needed about making definte statements based on only one experiment, current data supports GR and does not support any large, unexplained effects due to spin at this time. We'll have even better results when the GP-B experimental results are analyzed, which is already underway.
  7. Sep 12, 2006 #6
    Hi Pervect

    Sorry but I think you have misunderstood me. I'm not trying to lead into any idea of floor waxers being turned into flying saucers. I am not trying to be "overly speculative". I was simply asking within what science tells us these days whether a + b possibly means c.

    I am not trying to intrude upon your Gravity Probe B experiment. I am simply asking people here a question based upon some things that we observe separately in science and asking them to tell me what they think about this at a particle level based upon what they know about these things. I would like to know what they think in relation to what they know.

    Am I not allowed to ask about particles and gravity in the same question?
  8. Sep 17, 2010 #7


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    It's not fruitful to think of gyroscopic effect as appearing to defy gravity. The part of the gyroscope setup that supports the weight is supporting the full weight of the gyroscope.

    You ask about molecular effects. Are there molecular effects that are the counterpart of macroscopic effects? To my knowledge: no. Molecules do spin of course, but to get gyroscopic effects the rotor must be constrained in particular ways.

    In the case of a gyroscope there is a housing and one axis of the rotor has a fixed orientation with respect to the housing. In other words, a gyroscope setup (housing and rotor) has bearings. You can grip the housing and exert a torque, which will elicit a response.

    Such opportunitiy to exert a torque upon the spinning object is not there in molecular motion. Therefore no opportunity to elicit the kind of gyroscopic effect that we know from gyroscopes.
    Last edited: Sep 17, 2010
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