Just figured something new out, based on my original post here.
The energy/time version of the uncertainty principle says that virtual particles of any given energy can spontaneously appear—but the bigger the energy, the shorter they last. This explains why the strength of electromagnetism falls off at a distance—virtual photons with high energies last for short times and thus travel short distances, while virtual photons with low energies can last for longer times and travel longer distances. All straight from the book.
But I just recalled that other forces, the strong and weak, are described as having a range limitation. I’ve always read about that range-limit existing—but since no reason was given for it, and I couldn’t figure it out, I just shrugged my shoulders with an assumption of ‘quantum weirdness’. But now I have an idea /why/ that range limit exists: with a minimum amount of energy in any given virtual particle for those forces, in the form of those particles’ rest mass, the uncertainty principle thus also imposes a maximum lifespan, and thus a maximum range.
It’s been such a long time since I’ve had a chance to figure out something about physics that I wasn’t simply directly told, it’s a surprisingly pleasant experience. :)
(Now, I’m wondering if this particular idea implies that since gravity’s range is infinite, that implies that if gravity is transmitted by force-particles rather than space-curvature (assuming that that’s a distinction with meaning), then the virtual gravity force-carrying particles have to be able to have arbitrarily small energies, and thus no significant rest mass...)
Your insight about forces carried by massless vs. massive particles and their respective ranges is absolutely correct. Congratulations!
(Now, I’m wondering if this particular idea implies that since gravity’s range is infinite, that implies that if gravity is transmitted by force-particles rather than space-curvature (assuming that that’s a distinction with meaning), then the virtual gravity force-carrying particles have to be able to have arbitrarily small energies, and thus no significant rest mass...)
It is generally agreed that the still-to-be-constructed theory of quantum gravity will have gravitons, particles carrying the gravitational force analogous to photons for the EM field, and yes, gravitons should be massless as you argue. This is not however in conflict with the description of gravity as space-time geometry. Though the full details will have to wait till we understand quantum gravity completely, provisionally we can make unambiguous sense of gravitons at the pertrubative level: Think of a gravitational wave as a small ripple in spacetime, then one can quantize this perturbation and gravitons are to the wave as photons are to classical EM waves.
Just figured something new out, based on my original post here.
The energy/time version of the uncertainty principle says that virtual particles of any given energy can spontaneously appear—but the bigger the energy, the shorter they last. This explains why the strength of electromagnetism falls off at a distance—virtual photons with high energies last for short times and thus travel short distances, while virtual photons with low energies can last for longer times and travel longer distances. All straight from the book.
But I just recalled that other forces, the strong and weak, are described as having a range limitation. I’ve always read about that range-limit existing—but since no reason was given for it, and I couldn’t figure it out, I just shrugged my shoulders with an assumption of ‘quantum weirdness’. But now I have an idea /why/ that range limit exists: with a minimum amount of energy in any given virtual particle for those forces, in the form of those particles’ rest mass, the uncertainty principle thus also imposes a maximum lifespan, and thus a maximum range.
It’s been such a long time since I’ve had a chance to figure out something about physics that I wasn’t simply directly told, it’s a surprisingly pleasant experience. :)
(Now, I’m wondering if this particular idea implies that since gravity’s range is infinite, that implies that if gravity is transmitted by force-particles rather than space-curvature (assuming that that’s a distinction with meaning), then the virtual gravity force-carrying particles have to be able to have arbitrarily small energies, and thus no significant rest mass...)
Your insight about forces carried by massless vs. massive particles and their respective ranges is absolutely correct. Congratulations!
It is generally agreed that the still-to-be-constructed theory of quantum gravity will have gravitons, particles carrying the gravitational force analogous to photons for the EM field, and yes, gravitons should be massless as you argue. This is not however in conflict with the description of gravity as space-time geometry. Though the full details will have to wait till we understand quantum gravity completely, provisionally we can make unambiguous sense of gravitons at the pertrubative level: Think of a gravitational wave as a small ripple in spacetime, then one can quantize this perturbation and gravitons are to the wave as photons are to classical EM waves.