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Can all fundamental forces be fictitious force ?

  1. Nov 21, 2014 #1
    After reading many questions, , I wonder:

    is it possible to consider also the other fundamental forces, the electroweak interaction and the strong interaction or ultimately the unification of these, to be fictitious forces like gravity in the framework of general relativity?

    If we want a final unification of all fundamental forces, hasn't this feature of gravity to become a feature of the other forces as well?
  2. jcsd
  3. Nov 21, 2014 #2


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    Staff: Mentor

    Gravity is unique among the four fundamental forces in that the magnitude of the force is proportional to the mass of the object acted on. That's what allows us to model it as a fictitious force in general relativity.

    You cannot do the same thing with, for example, the electromagnetic force. Two particles of the same mass will react differently to the same electrical field if they have different electrical charges, and two particles with the same charge will react differently if they have different masses. Only non-fictitious forces can behave that way.
  4. Nov 21, 2014 #3
    A force, as I understand it, involves the interaction of matter particles with each other via a field. An energy quantisation of the field is the force carrying particle of the field.

    In the case of gravity though, particles don't interact with one another in this way. General relativity describes how space-time is distorted by energy. So what looked to everyone before Einstein like two orbiting celestial bodies, bound by some long distance force was actually two lumps of energy distorting space-time enough to make their paths through 3D space elliptical.

    Yet theorists are still very concerned with "uniting the 4 forces".Is there a reason for this that is understandable to a recent science student like myself?
  5. Nov 22, 2014 #4


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    Staff: Mentor

    This is a known "problem" with general relativity. There are theorists who are trying to develop a theory of "quantum gravity" which would place gravity on a similar footing as the other fundamental forces. This is a work in progress. We don't yet have a complete theory of everything.
  6. Nov 22, 2014 #5
    No particle (or field) interacts directly with all other fields. Heck, gluons only barely interact with the rest of them. So why is it then that anything that has energy (e.g. everything that exists) also has a gravitational interaction? Gravity seems unique in that all particles interact through it.

    Then there's the whole issue of affecting spacetime. As far as I'm aware, properties such as charge, spin, color, etc. don't affect spacetime (only the energy related to these properties).
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