Why fundamental forces change their strength?

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Discussion Overview

The discussion revolves around the question of why fundamental physical forces change their strength with distance. Participants explore various theories and concepts related to this phenomenon, including classical and quantum mechanics, and the implications of different mathematical formulations.

Discussion Character

  • Exploratory
  • Technical explanation
  • Debate/contested

Main Points Raised

  • Some participants note that every fundamental force changes its strength with distance, citing examples such as the 1/r² dependency in classical gravity and electromagnetism.
  • Others suggest that the explanation for these changes depends on the theoretical framework being used, with some theories treating it as an axiom that aligns with experimental observations.
  • One participant explains that in quantum mechanics, the concept of 'force' is derived from more fundamental quantities like energy and potentials, raising questions about the form of the Lagrangian or Hamiltonian that leads to these derived forces.
  • Another participant discusses the 1/r² case as a result of the density of radiated fields and mentions ongoing research into extra dimensions that might alter this relationship.
  • There is mention of how the nature of force carriers in Quantum Chromodynamics (QCD) leads to a different understanding of force strength, with color-charged particles influencing the force experienced.
  • Weak forces are described as having a Yukawa potential shape due to the mass of their force carriers, indicating a different mechanism at play compared to other forces.
  • A later reply questions whether the discussion pertains to the form of the force law itself or the behavior of parameters like the charge in Quantum Electrodynamics (QED) that may change with distance.

Areas of Agreement / Disagreement

Participants express a range of views on the topic, with no consensus reached. Different theoretical frameworks and interpretations are presented, indicating ongoing debate and exploration of the subject.

Contextual Notes

Limitations include the dependence on specific theoretical frameworks and the unresolved nature of certain mathematical formulations related to force strength and distance.

heartless
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Yeah, same as above, Why do fundamental physical forces change their strength with distance? Shouldn't the force be the same everywhere? Why or Why not? :-p (how do you know, and what did you get the answer from)

Thanks,
 
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Every fundamental force changes its strength with distance, for instance 1/r^2 and so forth.

Why? Well it depends on which formalism you want to take, certain theories posit it as a sort of axiom that fits experiment. For instance classical Newtonian gravity and classical electromagnetism (well you can derive it from Maxwells laws but that's sort of trivial enough that it means more or less the same thing).

In quantum mechanics, the notion of 'force' becomes somewhat of a derived quantity, whereas energy and 'potentials' are enforced as more fundamental and natural to the theory. There again, you might ask, why that particular lagrangian/hamiltonian that gives such and such a derived force concept that varies with distance? Again, the ultimate justification is experiment, but in some instance you can argue that such and such a fundamental lagrangian *has* to be in that form b/c of various symmetries and so forth.
 
1/r^2 is an easy case actually, because it is just from the density of radiated field, decreasing as the surface of the sphere increases. In fact the people searching extra dimensions look for 1/r^{2+something}.

Constant force in QCD is understood because the force carriers are themselves colour-charged particles, reinforcing the charge. Well, that is one naive explanation, but one needs a lot of CPU time to get the tubular string force field (the "QCD string").

Weak forces are understood because the force carriers are massive, thus they get a yukawian potential shape.
 
heartless said:
Yeah, same as above, Why do fundamental physical forces change their strength with distance? Shouldn't the force be the same everywhere? Why or Why not? :-p (how do you know, and what did you get the answer from)

Thanks,
Do you mean something like e^2/r^2, or the QED result that e^2 itself changes with distance?
 

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