[Semiapies]

"This is essentially the same mechanism used by sailboats tacking against the wind, and despite being counterintuitive at first is well-established."

Tacking is different from this. This is using ground-speed to generate thrust, as even the shills acknowledge.

"The speed is limited only by gearing and mechanical efficiency--an idealized device could accelerate arbitrarily."

Arbitrary magic acceleration inside an atmosphere should be your first clue that something's extremely wrong here.

And yes, I looked at the various forum links that turned up, which made very clear the very typical full-court astroturf press going on (like the argument above with someone who registered only to argue with unbelievers in this thread). You might take a look.

"Sticking with a knee-jerk reaction against something while ignoring further information that supports it gives "skeptics" a bad name."

Skeptics get a bad name because they don't join in the squee.

All I ask is that you look at the further information. Check back on this story in months and years and see whether it pans out.

[camccann]

Arbitrary magic acceleration

...in other words, either you didn't actually read the explanations or you didn't understand them. The energy is being extracted from a velocity difference between two media. And no, tacking works on exactly the same principles in order to sail upwind. Some manner of mechanical linkage decelerates one or both media with respect to the other, extracting usable energy. In the case of a boat it's the combination of the keel and sail; for this vehicle, it's clever fixed gearing between the fan and wheels. In either case, the velocity of the vehicle relative to either medium is nearly irrelevant.

Check back on this story in months and years and see whether it pans out.

The idea behind this vehicle has been floating around the internet for at least three years, by the way.

If you're really so confident that you're correct, I'm sure one of the "shills" would be happy to make a wager with you, mediated by a neutral third party. What kind of odds would you accept for a wager that the vehicle doesn't work?

[Semiapies]

You don't get infinite acceleration from one velocity difference. End of story.

"If you're really so confident that you're correct, I'm sure one of the "shills" would be happy to make a wager with you"

Funny; demands to make a bet seem pretty common around this whole matter. No, I'm not going to waste my time dickering over the terms of a bet with shills or true believers. I'm going to wait for this farce to fall apart.

[camccann]

You don't get infinite acceleration from one velocity difference. End of story.

Given a steady source of energy, you can accelerate as much as you like, up to the limit of losses due to friction. What do you think is going to prevent that? More energy, more acceleration.

And again, remember that the ability to extract energy from the velocity difference is independent of the vehicle's speed. The acceleration isn't infinite of course, because the energy has to come from somewhere--but so long as the velocity difference between the media persists, energy can be extracted. In this case, that means "as long as the wind is blowing", since the energy to move a lightweight vehicle around isn't going to make much of a difference compared to the total energy in the atmosphere.

Funny; demands to make a bet seem pretty common around this whole matter.

Demands? More like an offer of free money, wouldn't you say? I mean, you'd just have to prove that their clearly impossible machine indeed doesn't work, right?