How To Build a Quantum Propulsion Machine

KentuckyFC writes "According to quantum mechanics, a vacuum will be filled with electromagnetic waves leaping in and out of existence. It turns out that these waves can have various measurable effects, such as the Casimir-Polder force, which was first measured accurately in 1997. Just how to exploit this force is still not clear. Now, however, a researcher at an Israeli government lab suggests how it could be possible to generate propulsion using the quantum vacuum. The basic idea is that pushing on the electromagnetic fields in the vacuum should generate an equal and opposite force. The suggestion is that this can be done using nanoparticles that interact with the vacuum's electric and magnetic fields, generating the well-known Lorentz force. In most cases, the sum of Lorentz forces adds up to zero. But today's breakthrough is the discovery of various ways to break this symmetry and so use the quantum vacuum to generate a force. The simplest of these is simply to rotate the particles. So the blueprint for a quantum propulsion machine described in the paper is an array of addressable nanoparticles that can be rotated in the required way. Although such a machine will need a source of energy, it generates propulsion without any change in mass. As the research puts it with magesterial understatement, this might have practical implications."

Comments

Momentum Conservation

[UnHolier than ever]

How does this preserve momentum conservation? In the Casimir effect, the force occurs between two plates; as the plates are pushed in opposite directions, total momentum is conserved. Here, it seems as though you get momentum out of thin air (although energy is reffered to as "being spent", but with no indication how).

I call shenanignans!!

Re:Momentum Conservation

[Nefarious Wheel]

It's hard for an old SF fan like me to admit it, but I think the implications of this paper on possibly how EM fields propagate might be even more interesting than its application as a drive. EM is an electric field collapsing to become a magnetic field, which collapses to become an electric field, rinse and repeat. How often this happens is the frequency of the EM wave system. Aren't we running up against some sort of frequency limit here, to get EM affect against quanta? Is there a maximum number for this? And at these higher limits, will there be some split between the E and the M portions of the wave? Jus' curious, but I suspect there's a few papers waiting to be writ along those lines.

Is this different from a photon drive

[stevelinton]

Is dumping momentum into the quantum vacuum different from emitting photons carrying the same momentum? If not, this is just a photon drive, which is a well known concept, has brilliant specific impulse but is incredibly energy-inefficient except at high relatavistic velocities.

Why did noone tell me it was the future?

[Nadaka]

Does it mean that I am old because I look around every day and it feels like I am living in a surreal sci-fi story?

Reactionless drives, energy weapons, smart phones, robotic killing machines, genetically engineered super species? At this rate I wonder if I would be surprised when practical AI or faster than light travel becomes an option.

Re:what are we talking here?!

[tylersoze]

Well technically the car is losing a slight bit of mass because of the energy change, but that's not relevant to the propulsion, a car isn't a rocket. The car is pushing against the earth and transferring that momentum to the earth.

Something to consider:

[Interoperable]

The paper is a one-author publication in a non-peer-reviewed journal and doesn't seem to be published anywhere else. The author's affiliation is an applied R&D institute not an academic institute with a strong theoretical background. I'm not saying that discredits it, but it certainly means that it should be taken with a grain of salt. I would suggest that anyone who wants to assess the merits should read through some of the references (which are good publications) and see if the present article appears plausible. Even without any technical expertise, the abstracts could probably provide a feel for the state of the art.

I couldn't be bothered to do that reading myself, but I would suggest that any momentum transfer to the vacuum would involve the production of real particles from the zero-point fluctuations. Conservation of momentum demands that there would be something carrying momentum in the opposite direction of the spacecraft and, by definition, it can't be an unexcited quantum field. There would have to be excitations of the field to carry the momentum (real particles).