(faceslap)...this isn't news, is it?!

Article offers this:
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"We have figured out a way of creating waves that can force a floating object to move against the direction of the wave," said Dr Horst Punzmann, from the Research School of Physics and Engineering, who led the project.

"No one could have guessed this result," he said.
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Well *I* thought of it years ago. Actually, I *read* about it years ago. It had me ponder "reversing" waves as gravity itself.

Maybe I will have better luck later finding the specific article, but the article I read a few (?) years ago described why boats experience drag in shallow water. I own a canoe so I have felt this first hand. The article illustrated that the wake of a boat could reflect off the shallow bottom and the trough of the reflected wave could then drag on the stern.

But you knew that already, right? So why is this article news?

Replace the water with dark matter and then it's a party.

@Jag_Pop, I think the article is news because they are controlling the object's position, rather elegantly and precisely, rather than just saying some phenomenon is theoretically possible.

http://www.ship-squat.com/ documents the 'wake of boat' thing, but that is barely related to this wave-shaping effect. A nearer step might be the non-linear way convergent wave groups may interact to throw up a ship-smashing 'rogue'.

( This process is different to the more predictable 'wind against current' monsters of eg the Agulhas Current. )

Hmm. Hmm.

So, I wonder if we put a wave-producing plunger on an America's Cup yacht, we could generate useful wave patterns to move the boat faster.

Two plungers! Four!

I'd say five, but I don't think there's a toilet on those yachts. Four should do it. :P

Well, this experiment just ads another piece into similarity of the vacuum and water surface behavior. The tractor beams with sound and light were prepared and used many times already.

As yet no mathematical theory can explain these experiments

It would be interesting to do this experiment in a smoke chamber. Maybe it's an interplay between turbulent waves and turbulent air?

(alternatively one could check whether the effect also happens with a flat object)

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Interesting

I've been able to generate square waves on a water surface

Never leave spacedock without it.

So can the necessary waves be generated in open water or is the phenomena to delicate to be replicated with other waves around? If so then this does get really useful. Sounds like we have enough of a mathematical description that the engineers can use it while the physicists figure out the theory behind it.

chemicals and radioactive isotopes can be directed toward ports of intended depopulation. Now we can attrit the enemy much more easily. Within a couple generations they will be gone.