Slightly more believable EM engine

[Cuddles]

Shawyer also defends his ideas in the New Scientist letters this week, although he doesn't actually seem to answer any of the criticisms raised.

 

[Yllanes]

Shawyer also defends his ideas in the New Scientist letters this week, although he doesn't actually seem to answer any of the criticisms raised.

The letters are reproduced under the blog entry. Let's see if he comments there.

 

[CapelDodger]

I) A fundamental principle of his device is that it is that the waveguide is resonant with the microwaves. A change of wavelength would destroy this resonance and Q values of 50k or more should be impossible.

My first reaction was : if the thing's accelerating, how can the resonance be maintained? There seems to be mixing between the internal reference-frame of the waveguide and the space-time it's supposed to be moving through.

 

[Cuddles]

An interesting response from the technical director of the company he worked at, who turned it down.

 

[Zygar]

An interesting response from the technical director of the company he worked at, who turned it down.

I think, a well stated response. Clear, direct, and concise.

 

[Ziggurat]

The idea being that you get a greater force on the top surface than on the bottom, giving a non-0 resultant. My first thought was that there would also be a force on, and perpendicular to, the sides. As the sides slope, that force would resolve to a slight downwards force; at a guess, one the same size as the disparity between the top and bottom plates.

Yes, this is correct. You can look at the photons as a particle-in-a-box problem from quantum mechanics. Make the box bigger, and you decrease the energy of the particles. That means that the energy decreases with outwards displacement of ALL the walls of the box, which means that there's an outwards force perpendicular to ALL surfaces. The force on the slanted sides is going to cancel the imbalance at the ends.

This is the equivalent of trying to make a glass of water lighter by making its sides slope: after all, the force on the bottom of the glass will decrease if the area of the bottom is smaller. But of course, it doesn't work that way in real life, because the sides do matter, and once they aren't parallel to each other, the forces on opposite sides won't cancel out.