It doesn’t look like the Woodward effect (on which  “mach effect propulsion” mentioned in the comment above is allegedly based) has been widely replicated or accepted either. 

if so, what happened to N, O and P?

They were NOPerable.

Dean Drive, which supposedly provided momentary unidirectional force. If was even demonstrated on the popular TV show “I’ve Got a Secret”, where the inventor placed the device on a common bathroom scale, and as we watched the gadget would momentarily register less weight. It was highly promoted by John C. Campbell, the editor of Astounding/Analog  SF Magazine, the man who also introduced the world to Scientology.

The video listed here shows the bathroom scale trick.
http://www.youtube.com/watch?v=mtBvzCjpPcE
it seems obvious that what is really happening is that when the gadget generates is sudden shifts of momentum it is overwealming the scale’s ability to register.

Even if that were not the case, it still wouldn’t work. Various Casimir-dependent devices have been proposed over the years. They don’t work.

The Casimir effect is a weird byproduct of quantum field theory due to the face that the vacuum is simply the ground state of a field and, while it is the lowest possible energy of the field, it is not zero energy. That would violate the uncertainty principle. Furthermore, also because of the uncertainty principle, virtual particles emerge from and then vanish again into the vacuum all the time. They are called virtual because they don’t exist long enough to be observed. Again, that would violate the uncertainty principle.

So you create a Casimir force by creating boundary conditions for the vacuum. For example, you can put two plane mirrors facing each other. Since the electric field must go to zero on a reflective boundary, this reduces the number of allowed vacuum fluctuation states between the mirrors compared to the unbounded area outside. That in turn creates a tiny force pushing the mirrors together. Some clever guys in Scotland think they have come up with a way to jigger the process so that you can push things apart as well as together.

There are two problems with trying to use this for propulsion.

First, the force is truly tiny. It is proportional to Planck’s constant, which is small to begin with, and inversely proportional to the fourth power of the plate separation, which means it diminishes rapidly with distance between the mirrors. That makes it far too small to use for propulsion over anything greater than nano distances.

Second, momentum is still conserved. Whether reverse or not, each mirror experiences an equal force in opposite directions all the time. That means that it is not functionally different from a regular rocket. You use some sort of force to throw mass out the back, therefore throwing yourself forward. The total momentum of the system is still zero.

Conserving momentum doesn’t mean simply “everything has momentum.” What is means is that the total momentum of a system of interacting particles never changes. And momentum is a vector quantity. So if something acquires momentum in one direction, something else must have acquired momentum in the opposite direction. That isn’t happening here (in fact, its sort of the point) so this thing violates a major tenet of physics that underlies very nearly everything we understand about the world. In over 300 years, not one single violation of momentum conservation has ever been observed.

“In linear-accelerator applications, the EM electric-field energy is used to accelerate charged particles. After accelerating a charged particle (and increasing the charged particle’s momentum), the EM wave retains a zero net momentum”

This is wrong. The electromagnetic field has a momentum of its own (proportional to its energy). In accelerating the particle, the field has done work – so its energy must decrease, which means that its momentum must also decrease. The only way the field could retain zero  net momentum is if it also accelerates a particle in the opposite direction. Side-note: “EM electric-field energy” is a very strange thing to say.

In their device, even if the wave imparts some momentum to the cavity walls, it will be *exactly* balanced by the loss of momentum from the wave itself.  They don’t give the right numbers or anything usual enough to actually check any of their calculations.

Shame on those questioning the physics here. I believe this is already established as the practical power source of the beloved Nyan Cat.

Q is for Quack.

http://www.youtube.com/watch?v=SjxfAjAyp5k

So once we’ve determined that it must be powered, we need to determine if the thrust per kg of fuel is better than what is currently available. Since they don’t directly answer this, the answer is pretty much certainly no. If they are trying to rely on solar panels to get the power, they run into the issue of more effective ways to redirect the energy of sunlight. 

General rule about claimed new technology. If a company is talking about both inventing something thought to be impossible and making millions off of applications of that technology, it’s fake. They are looking to rip off investors.

1) Obvious
2) Trivial
3) Left as an exercise for the reader,
or my favorite: 4) Beyond the scope of this course.

:)

BUT it looks like we don’t need to pick it apart too much: amazingly, the folks at WIPO evaluated all the documentation themselves and issued a verdict in March 2008:

“The claimed systems…allegedly operate in a manner clearly contrary to well-established physical laws and thus the invention cannot be carried out.” They cite Encyclopedia Brittanica and the conservation of momentum.

See page 4 and 5: http://www.wipo.int/patentscope/search/docservicepdf_pct/id00000006155563

Whether it’s called the EM-drive or something else, this device unquestionably violates conservation of momentum.  The spontaneous acceleration of a *closed* device is not consistent with physics as it is currently understood.  If you emit something out the “tailpipe” (be it ions or electromagnetic radiation) that’s another story, but no closed system can change its own momentum simply by interacting with itself.  I should confess that there are non-standard (read: highly speculative with no evidence that they correspond to reality) mechanisms for this type of phenomenon.  However, I believe that this device is supposed to have been designed (and analyzed) according to the normal laws of physics: if so, it cannot work as claimed because it would violate conservation of momentum (and probably relativity), which are built into all standard laws of physics.I use the EM-drive as an example of a violation of Newton’s third law (the action-reaction one) in my intro physics class.  They can make the design complicated enough that no reputable physicist is willing to wade through the analysis to find their errors, but that doesn’t mean there isn’t an error in there somewhere.  That’s the beauty of a conservation law: I don’t need to examine every detail to know that momentum cannot be created out of nothing. 

Yes, this is bullshit. It is essentially a variation on the EmDrive, which Wikipedia has a minimal article on.

The trouble is that conservation of momentum is a direct consequence of translational invariance of the Lagrangian (via Noether’s Theorem), which the Lagrangian of the electromagnetic field satisfies. So no electromagnetic phenomena can possibly generate non-zero total momentum in the entire system of interacting objects if they started with zero total momentum. Translational invariance is so deeply embedded in the structure of electromagnetic theory that it is pretty well inconceivable that it would be violated. It is an essential property of Maxwell’s equations, as well as quantum electrodynamics and the electroweak unified field theory. Without it, about 200 years of physical theory and experiment falls apart.

It also violates the principle of relativity since it would require the total energy of the universe to be a frame dependent quantity. In fact, energy could only be conserved in at most one reference frame since in any other frame the kinetic energy of the ship would differ from the energy expended by the ship.

This is also an idea deeply embedded in centuries of physics theory and experiment. Conservation of energy is a consequence of time invariance of the Lagrangian (Noether again), which the electromagnetic Lagrangian does satisfy. If it did not, Maxwell’s equations would vary in form over time.

And am I the only one who thinks that Q is excessively excited?