Personally I think this debate is over and thank most for participating and the very helpful information they provided. I think any intelligent (self-honest) person has to conclude that DDWFTTW is possible and there is a practical working example in the Brennan Torpedo.
The Brennan torpedo is certainly analogous to the DDWFTTW vehicle. So is a cotton reel being pulled along the ground, which was the inspiration for the Brennan torpedo. So is my machine that goes under the ruler. All these machines illustrate the same principle of using the relative movement between two surfaces, or media, to make a vehicle go faster than this movement relative to one of the surfaces, or media. If the Brennan Torpedo clinches the argument for you, fine. But you cannot claim that it actually
is a downwind faster than the wind machine, any more than I can claim this for my ruler-powered cart.
The Brennan torpedo is actually a machine that goes in the opposite direction to the wire (in fact it has two wires, but that is for steering purposes: you could make one with only one wire, but you wouldn't be able to guide it). If you look at the torpedo from the frame of reference moving at the same velocity as the wire, you see that the velocity of the torpedo relative to the wire is in the same direction and greater than that of the water relative to the wire. So somebody who understands frames of reference will recognise that it is a "down water faster than the water" device. But somebody who understands frames of reference will also recognise that Spork's cart on a treadmill is a downwind faster than the wind device. Moreover, it isn't just an analogy of a downwind faster than the wind device, it
really does go downwind faster than the wind, exactly as Bauer's and Goodman's carts did.
Because you hit on something that has convinced
you that DDWFTTW is possible, you announce "I think this debate is over". Other people have been convinced by other means: somebody who understands the analysis of the DDWFTTW principle can be convinced by that alone, another person will have their eyes opened by one of the analogies, another person will be convinced by treadmill tests... Each of these people could say
for themselves "the debate is over" at the moment when they were convinced. For others, the debate goes on. If you're now totally convinced, you can have some fun trying to explain to determined skeptics why you think the Brennan torpedo is such a good example.
As for Spork and JB being only "after the limelight", I think you're mistaken. They have never made a secret of the fact that others had done this before. They are not claiming to have invented something new. They have tried, here and in many other places, to explain how the thing works. They have presented analyses and analogies. I don't know if they'd already seen the Brennan torpedo, but I'm sure of one thing: if they had shown everyone a detailed explanation of how it works, that wouldn't have convinced the hard-core skeptics any more than the other arguments they presented.
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