Physicists make 'tractor beam' in water

[theHandpuppet]

I could see this as having a really useful application in containing oil spills.

11 August 2014
Physicists make 'tractor beam' in water
By Jonathan Webb
Science reporter, BBC News

(excerpt)
Simply dropping a cylindrical wave-maker - a bit like a long rolling pin - in and out of the water, gently, produces a predictable set of waves undulating away from the disturbance. The current on the water surface also travels away from the middle of the cylinder.

wave model The wave patterns were filmed and then re-created using computer models
But if the size of the up-and-down movement is increased, that wave pattern breaks up into choppier pulses. At the same time, the central current switches direction, so that something floating near the middle of the tank can be pulled back towards the wave-maker.

As well as this relatively simple "tractor beam" effect, the team created and modelled various other flow changes that meant they could effectively move a ping-pong ball around their tank at will.

"We can engineer surface flows of practically any shape," said Prof Michael Shats, the paper's senior author. "These could be vortices, these could be outward and inward jets - it's a variety of different flow configurations."....

MORE at http://www.bbc.com/news/science-environment-28739368

[brush]

1. This sounds like it could be used to produce energy

There has been research on the steady, continual, to and fro undulation of waves as a green energy source.

Since they seem to have found a way to create and control movement in water I wish they'd apply their tech breakthrough towards energy generation.

[Scootaloo]

2. Doing it mechanically would consume more energy than it would produce

wave energy is basically just third-hand solar power (sun makes wind, wind makes waves) and so we're not spending our own reserves to "harvest" it.

Really, for true, the sun gives us vastly more energy than we will ever be able to imagine using.

[brush]

3. Good thought

Just using the natural undulation of the waves without the manipulation of this technology would be cheaper — it doesn't make economic sense to spend more energy than what can be produced.

I agree with you on solar (I live in Nevada now and am constantly amazed that this state with all of it's daily, blazing sun, and little-known but regular high winds, plus geothermal in some areas, is not the green energy capital of the US.

All the doers and shakers here want to do is concentrate on casinos and keep the education system dumbed down enough to produce people that can run table games or valet park at the casinos.

Energy is just going to waste out here.

[Scootaloo]

4. part of me doesn't mind

it's a cynical part of me that says, if we could tap the limitless energy of our star... we'd probably just use it to get every scrap of coal and petroleum out of the planet's crust.

it's sort of like in the Civil War. Both sides had automatic guns, weapons that could mow down entire platoons... but the tactics of both relied on charges across the battlefield. This was still a problem all the way into WW2, when the Polish cavalry met the German Wehrmacht on the field and was simply annihilated. or like today's battles, where weaponry and tactics designed for battling another superpower is poorly fitted to fight guerrilla movements.

Basically, we generate technology faster than we can adapt our cultures and practices to that technology. We're just now getting more than our toes wet with the internet's potential. if we had essentially unlimited energy, i imagine we'd probably do some pretty horrible and destructive things with it before we got the hang of it - "Now we can strip the tropics even faster!"

But like I said, it's a cynical side of me. This same side of me also says it's pretty muuch too late to actually transition to solar on any meaningful level, and we'll end up back in village-oriented agricultural societies in roughly two hundred years, never to touch high technology again.

[theHandpuppet]

5. I don't think it will take two hundred years, to be frank

Additionally, there's no way village-oriented agricultural societies can sustain billions of humans. There's going to be a massive die-off of humankind but I suspect that will happen within a century.

[brush]

6. I don't get your first sentence

If we had limitless alternative energy why would we need to get oil and coal out of the earth?

[NYC_SKP]

7. History has already and continues to prove the point. There's no profit in limitless free energy.

This dynamic is why Tesla died a poor man and Edison went on to be the (ewww) role model for young scientists.

[brush]

8. Wouldn't the profit come from green energy though?

We know developing alternative energy sources is not free and there's always going to be a profit motive. Hell, if the oil and coal companies had any sense they'd jump on alternate energy research and development to make money. At lease they won't be screwing up the environment if they're no longer pushing fossil fuel burning.

[NYC_SKP]

9. Yes, it could and would and will. The book "Climate Capitalism" makes a case for it.

Hunter and Amory Lovins have made great cases for energy efficiency and the end of fossil fuels.

But the powers that be, including those in Edison's day, would rather work with commodities that they can control.

Remember when water was virtually free? Well, not water utilities are being bought up by multinationals, and we've been brainwashed into drinking bottled water.

And you hardly ever see drinking fountains, but you will find vending machines.

[Vincardog]

10. I can see it being used to capture an oil spill sooner than energy.