4 ms·

That doesn't solve anything, it only shifts the violation somewhere else? Of course you can't keep the virtual particles, that's a net creation of mass-energy.

That doesn't solve anything, it only shifts the violation somewhere else? Of course you can't keep the virtual particles, that's a net creation of mass-energy. "which can also carry arbitrarily large momenta ℏω," With proportionally large energy. That's the concern here, not photon count. (For anyone confused, it's ℏω/c in conventional units. Some unit systems define c=1 for convenience)

scythe 13y ago
See: https://en.wikipedia.org/wiki/Woodward_effect#Propellantless_propulsion https://en.wikipedia.org/wiki/Woodward_effect#Propellantless... The claim appears to be that the momentum is transferred first to the local stress-energy tensor, and then to celestial bodies. It almost sounds feasible at a glance, but, well, it's quantum gravity. I would say it certainly seems like there's something to be learnt by this, though. A quantum effect with measurable gravitational consequences is... almost unheard of.
- gus_massa 13y ago
  There is not a complete Quantum Gravity Theory, so all what I will say are only educated guess, supposing that the final theory will mix gracefully with the current theories for the other forces. > [...] thereby producing a propulsive force thereon without having to expel propellant from the object. [...] Local momentum conservation is preserved by the flux of momentum in the gravity field that is chiefly exchanged with the distant matter in the universe. The gravity field should be quantized, and the associated particles are the gravitons. So in this effect they are using a jet of gravitons instead of a jet of photons (like in my example) or a jet of atoms/ions (like in a conventional rocket). The exact quote can be used to describe how the “laser motor” works: (modified quote) [...] thereby producing a propulsive force thereon “without” having to expel “propellant” from the object. [...] Local momentum conservation is preserved by the flux of momentum in the electromagnetic field that is chiefly exchanged with the distant matter in the universe. The correctness of this phrase depends on if you count the photons/gravitons as propellant or not. The graviton shold be massless, because the gravity force has unlimited range. The relation of the energy-momentum in a graviton should be a cuadrivector, or in more simple terms, the formula in my other comment should be valid, with a “rest mass” m = 0. So the formula can be simplified and you get the same p = E/c relation of the photons, with is very small as throwaway_yy2Di noted.

scythe 13y ago

See: https://en.wikipedia.org/wiki/Woodward_effect#Propellantless_propulsion https://en.wikipedia.org/wiki/Woodward_effect#Propellantless... The claim appears to be that the momentum is transferred first to the local stress-energy tensor, and then to celestial bodies. It almost sounds feasible at a glance, but, well, it's quantum gravity. I would say it certainly seems like there's something to be learnt by this, though. A quantum effect with measurable gravitational consequences is... almost unheard of.

gus_massa 13y ago
There is not a complete Quantum Gravity Theory, so all what I will say are only educated guess, supposing that the final theory will mix gracefully with the current theories for the other forces. > [...] thereby producing a propulsive force thereon without having to expel propellant from the object. [...] Local momentum conservation is preserved by the flux of momentum in the gravity field that is chiefly exchanged with the distant matter in the universe. The gravity field should be quantized, and the associated particles are the gravitons. So in this effect they are using a jet of gravitons instead of a jet of photons (like in my example) or a jet of atoms/ions (like in a conventional rocket). The exact quote can be used to describe how the “laser motor” works: (modified quote) [...] thereby producing a propulsive force thereon “without” having to expel “propellant” from the object. [...] Local momentum conservation is preserved by the flux of momentum in the electromagnetic field that is chiefly exchanged with the distant matter in the universe. The correctness of this phrase depends on if you count the photons/gravitons as propellant or not. The graviton shold be massless, because the gravity force has unlimited range. The relation of the energy-momentum in a graviton should be a cuadrivector, or in more simple terms, the formula in my other comment should be valid, with a “rest mass” m = 0. So the formula can be simplified and you get the same p = E/c relation of the photons, with is very small as throwaway_yy2Di noted.