4 ms·
It claims to provide thrust without propellant, which is a violation of the conservation of momentum. Since momentum and energy are conserved in much the same w
by contravariant 6y ago
It claims to provide thrust without propellant, which is a violation of the conservation of momentum. Since momentum and energy are conserved in much the same way this is already bad enough, however in special relativity the 4-momentum mixes momentum and energy (or rest-mass) and I believe that a well chosen Lorentz boost could turn a violation of the conservation of momentum into a violation of the conservation of energy.
- DennisP 6y agoSeems like it violates conservation of energy just because kinetic energy is proportional to the square of velocity, and thrust has to be constant for a given input energy since there's no preferred reference frame. Thus the faster you go, the more kinetic energy you get for the same input energy.
- postalrat 6y agoUnless there are physics involved we aren't aware of.
- me_me_me 6y agoChances of that are very slim. But investigating this might uncover what is causing the confusion. Some other external force unknown to us might be at play.
- contravariant 6y agoTechnically yes, but as I've been trying to get across; violating the conservation of momentum isn't just 'new physics' it shakes the whole foundation of modern physics. The very definition of momentum ensures it is conserved by the (classical) equations of motion, to be otherwise is patently absurd.
- murbard2 6y agoYour comment seems like it would rule out a photon rocket , which proves too much. I think the resolution is that the faster you go, the heavier you are and the more thrust you need to increase your dv.
- contravariant 6y agoA photon rocket still has a preferred reference frame where the total momentum is 0. Don't forget that photons still have momentum, even if they don't have mass.
- DennisP 6y agoSo you can calculate, for a given thrust/energy ratio, what velocity you have to exceed to get more energy out than you put in. For relativistic effects to make enough difference to matter, that velocity would have to be pretty close to c. That translates to an extremely low thrust. (I've been told that for a photon rocket, the threshold velocity is c, implying that a reactionless drive won't violate conservation of energy as long as it's no better than a photon rocket. I haven't done that math myself though.)
- xupybd 6y agoI agree with you in principle but the benefits here go beyond disproving one device. The engineering and experimental design required to disprove this design will no doubt have applications beyond the EM drive.