I've got a limited understanding of physics, but what I understood from the em drive website, was that basically it did not violate ths conservation of energy, the em-drive was more of a direct energy-momentul convetsion tool.
So, supposedly, if em drive worked, you could produce a flying car that could hover without new energy input (it was supposed to use superconducting materials in the cavity). As soon as you started mooving the energy in the cavity started to decrease - so you would be transfering the energy/momentum of photons in the cavity to your ship?
Anyway, my physics gut told me this was all bullshit, but I wanted to believe sooo much, if this worked, it would have been the greatest invention in human history.
One problem is that we actually already have a direct energy to momentum generating "EM" drive. It is called a laser; light possesses momentum (in some sense, it is nothing but momentum) and emitting light asymmetrically produces thrust. The "EMDrive" claims to be orders of magnitude more efficient than laser propulsion (as well as not incinerating anything in it's wake), which is why it was both interesting and probably impossible.
Conservation of momentum is almost as important as conservation of energy, and indeed, if you have a reactionless drive you can extract unlimited energy:
"applying a constant force results in a constant acceleration, the kinetic energy of a mass driven by such a device increases quadratically with time, while the energy input increases only linearly with time. Thus, at some point, the kinetic energy of the device-driven mass exceeds the energy input, and if this energy is collected via decelerating the mass (via regenerative electromagnetic braking, for example), then there would be a net gain in energy."
So, supposedly, if em drive worked, you could produce a flying car that could hover without new energy input (it was supposed to use superconducting materials in the cavity). As soon as you started mooving the energy in the cavity started to decrease - so you would be transfering the energy/momentum of photons in the cavity to your ship?
Anyway, my physics gut told me this was all bullshit, but I wanted to believe sooo much, if this worked, it would have been the greatest invention in human history.