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Tractor Beam Created Using Water Waves

samzenpus posted about 2 months ago | from the get-over-here dept.

Australia 71

KentuckyFC writes The idea that light waves can push a physical object is far from new. But a much more recent idea is that a laser beam can also pull objects like a tractor beam. Now a team of Australian physicists has used a similar idea to create a tractor beam with water waves that pulls floating objects rather than pushes them. Their technique is to use an elongated block vibrating on the surface of water to create a train of regular plane waves. When the amplitude of these waves is small, they gradually push the surface of the water along, creating a flow that pushes floating objects with it. However, when the amplitude increases, the waves become non-linear and begin to interact with each other in a complex way. This sets up a flow of water on the surface in the opposite direction to the movement of the waves. The result is that floating objects--ping pong balls in the experiment--are pulled towards the vibrating block, like a tractor beam.

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Won't work (-1)

Anonymous Coward | about 2 months ago | (#47401953)

space does not have a medium to create waves in, and the amount of light you would need to throw at it would fry it.

Re:Won't work (1)

TWX (665546) | about 2 months ago | (#47401981)

In space, no one can hear you steam...

Re:Won't work (1, Funny)

lorenlal (164133) | about 2 months ago | (#47402109)

That's no pool...

Re:Won't work (1, Funny)

TWX (665546) | about 2 months ago | (#47402269)

...that's a space heater!

Re:Won't work (3, Insightful)

mangamuscle (706696) | about 2 months ago | (#47402017)

If you can compress space to achieve warp speed, you can then also compress space to create waves in the vacuum.

Re:Won't work (0)

gstoddart (321705) | about 2 months ago | (#47402147)

If you can compress space to achieve warp speed, you can then also compress space to create waves in the vacuum.

You don't compress space, you bend it.

And, no, I don't actually know what that means either. :-P

Re:Won't work (1)

mister_playboy (1474163) | about 2 months ago | (#47402389)

Gravity bends space, although always in the same basic way. (I think)

So lets imagine there may be some other way of bending space...

Re:Won't work (5, Funny)

JustOK (667959) | about 2 months ago | (#47402477)

If only we had some sort of robot that could bend things for us

Re:Won't work (1)

Anonymous Coward | about 2 months ago | (#47402485)

Bite my shiny metal ass.

Re:Won't work (3, Funny)

shadowrat (1069614) | about 2 months ago | (#47402607)

Gravity bends space, although always in the same basic way. (I think)

So lets imagine there may be some other way of bending space...

What?!?! Next you are going to tell me that gravity can somehow draw one object towards another. Preposterous!

Re:Won't work (1)

RabidReindeer (2625839) | about 2 months ago | (#47403589)

Gravity bends space, although always in the same basic way. (I think)

So lets imagine there may be some other way of bending space...

You don't bend it, you fold it.

Of course, you need a supply of the spice melange, first.

Re: Won't work (1)

zevans (101778) | about 2 months ago | (#47413537)

There is. Acceleration. Accelerate hard enough and all sorts of strange things happen in your wake, the trivial example being Unruh radiation.

Since when (0)

Anonymous Coward | about 2 months ago | (#47402867)

Since when does "not yet detected" = "there is no medium in space"?

Re:Since when (0)

Anonymous Coward | about 2 months ago | (#47404915)

Since the term for pink unicorn density was dropped from Maxwell's equations.

Why not (-1)

Anonymous Coward | about 2 months ago | (#47401959)

Spam your unreadable medium.com crap some more, why not. Certainly don't even try to find a readable site, or something with original content.

Re:Why not (-1)

Anonymous Coward | about 2 months ago | (#47402069)

woohoo medium.com the next social media hype job! lets all create a bunch of content for them for free so they can sell out to a bigger social media company! the internet is sooo innovative!

This is new? (0)

Anonymous Coward | about 2 months ago | (#47401979)

I'm fairly certain I duplicated this experiment in the bathtub as a child (and maybe even as a teenager).

Re:This is new? (2)

TWX (665546) | about 2 months ago | (#47402001)

I doubt those were the same experiment, even to each other...

Lame (0)

drinkypoo (153816) | about 2 months ago | (#47401983)

No beam. Less space than a Nomad. Lame.

How did they discover this? (1)

kruach aum (1934852) | about 2 months ago | (#47402011)

If the backwards flow of water is a result of a complex system of causal interactions, they couldn't have come to the conclusion that this would work based on what they already knew. So how did they discover it? Was it an accident? If not, can one of them look into the future? This is a pretty awesome result if it didn't depend on coincidence.

Re:How did they discover this? (0)

Anonymous Coward | about 2 months ago | (#47402241)

I'm betting one of the researchers saw a rip along the beach and it came from there. A rip will have a section where the water is pulled offshore and smaller sections on both sides where the water is pulled onshore.

Re:How did they discover this? (3, Insightful)

MightyYar (622222) | about 2 months ago | (#47402247)

This is a pretty awesome result if it didn't depend on coincidence.

That's why I don't use penicillin.

Re:How did they discover this? (1)

Anonymous Coward | about 2 months ago | (#47402315)

Have you ever taken a bath and noticed that there's a dead spider or something in the tub? You definitely don't want to touch the dead spider, but you do want to transport it down to the far end of the bath. So you try creating some waves. Somehow, the effect of the waves is to bring the spider closer to you, instead of moving it further away. Then, if you're a physicist, you say, "That's odd...."

Re:How did they discover this? (1)

Anonymous Coward | about 2 months ago | (#47405185)

they couldn't have come to the conclusion that this would work based on what they already knew.

They had some good expectation for something like this to work because similar systems were built using light, it was just a matter of getting similar setups with messier water waves. The paper covers a piece of the thought process and once could see that the principles it is built on could be thought out before hand, although sometimes just building something is easier when dealing with something that might be borderline (e.g. exactly what size vorticies are produced and in what quantity, etc., although doesn't seem too relevant here where it works over a decent range of parameters).

I see immediate practical applications. (4, Insightful)

SuricouRaven (1897204) | about 2 months ago | (#47402013)

Large scale: cleaning up oil spills.
Small scale: Device for more effectively scooping up dirt and dropped leaves from a swimming pool.

Re:I see immediate practical applications. (0)

Anonymous Coward | about 2 months ago | (#47402103)

oil spills typically don't take place in bodies of water where it's possible to carefully control the complex interactions between the eddies and currents in order to generate the appropriate non-linear waves to do this. it would be impossible to perform this in anything other than a near still body of water

Re:I see immediate practical applications. (5, Funny)

Minwee (522556) | about 2 months ago | (#47402105)

Immediate use: Cleaning up spilled ping pong balls on still water.

Re:I see immediate practical applications. (1)

mossy the mole (1325127) | about 2 months ago | (#47403849)

Immediate use: Cleaning up spilled ping pong balls on still water.

Finally an experiment that cleans up after itself :)

Re:I see immediate practical applications. (1)

oursland (1898514) | about 2 months ago | (#47405463)

Near future use: Cleaning up spilled ping pong balls on "water" in frat houses.

Re:I see immediate practical applications. (1)

fisted (2295862) | about 2 months ago | (#47406111)

Patent pending: Cleaning up spilled ping pong balls on "water" on a computer

Re:I see immediate practical applications. (0)

Anonymous Coward | about 2 months ago | (#47402131)

Large scale: pulling in floating debris (plastic in the various ocean gyres perhaps?) into a floating collection/recycling vessel

My only concern would be that to use this on a massive scale may induce some kind of unforeseen wave effects on the local area that may be damaging in some way to the local flora or fauna.

Re:I see immediate practical applications. (1)

Anonymous Coward | about 2 months ago | (#47402135)

Until someone discovers that the high freq waves kill plankton, make dolphins deaf and do one or more of the other thousand horrible things that could go wrong.

Re:I see immediate practical applications. (1)

kruach aum (1934852) | about 2 months ago | (#47402167)

As pushing is trivial, and both of your applications can be achieved by pushing, they were already covered before this discovery.

Suction Better (1)

Roger W Moore (538166) | about 2 months ago | (#47402917)

Pushing is nowhere near as effective in cleanup operations which is why vacuum cleaners suck instead of blow (and very early victorian models did). Suction concentrates the particles in a fixed location whereas blowing scatters them.

Re:Suction Better (4, Insightful)

amxcoder (1466081) | about 2 months ago | (#47402983)

Tell this to all the gardeners and landscaping crews in the country, as instead of raking up leaves now, their favorite toy seems to be the leaf blower to scatter all the debris to neighboring yards so they can get paid to do it there next.

Re:I see immediate practical applications. (2)

pr0t0 (216378) | about 2 months ago | (#47402191)

Maybe auto-docking boats in a busy marina-of-the-future.

Re:I see immediate practical applications. (1)

sumdumass (711423) | about 2 months ago | (#47403501)

They already have autopilots for boats..

Perhaps an automatic rescue system that pulls people who fall in back to safety at the marinas? Or maybe in a pool where children may find their way where they aren't supposed to be.

Re:I see immediate practical applications. (0)

Anonymous Coward | about 2 months ago | (#47402311)

This is cool, because it was unexpected. However, there's much easier ways to make things in water flow towards you. Just suck in the water. Swimming pools have skimmers, which work insanely better than this trick every could.

Re:I see immediate practical applications. (1)

SuricouRaven (1897204) | about 2 months ago | (#47403215)

Sucking has rather short range unless you collect a lot of water, which in turn means high energy needs. I don't know what the energy demands of a wave-sucker would be, or some form of hybrid device, but there may potentially be a saving. It could also be done using fewer moving parts, as the oscillatory motion of a wave-maker is achievable with just a magnet and a coil. You'd want to pump it at the natural resonant frequency for maximum efficiency.

I'm imagining this as an improved skimmer, using the waves to increase collection range for a cleaner pool or improved efficiency.

Re:I see immediate practical applications. (1)

Intrepid imaginaut (1970940) | about 2 months ago | (#47402525)

More like, large scale: nuclear submarine wrestling matches.

Re:I see immediate practical applications. (0)

Anonymous Coward | about 2 months ago | (#47404045)

Because sucking all the leaves into the skimmer with a pump isn't working? The last thing I need is some extra gizmo around my pool that requires an electrical connection to operate. That dog don't hunt.

fuck u nigger (-1)

Anonymous Coward | about 2 months ago | (#47402045)

star trek is gay

Re:fuck u nigger (0)

Anonymous Coward | about 2 months ago | (#47407049)

Next time maybe don't try to fit Worf's cock in your mouth all at once?

video (0)

Anonymous Coward | about 2 months ago | (#47402121)

This thread is useless without video.

agree (1)

JcMorin (930466) | about 2 months ago | (#47402253)

I agree, in todays world, such claim need to be backed by something like a video...

Re:agree (4, Funny)

NotInHere (3654617) | about 2 months ago | (#47402297)

Yeah, with a video, you have a reliable proof for every theory [youtube.com] .

Re:agree (1)

NotInHere (3654617) | about 2 months ago | (#47402309)

... but I admit, it would be impressive to have a video actually showing the pull effect.

Re:agree (1)

vux984 (928602) | about 2 months ago | (#47402771)

Just play a video of the push effect in reverse!

MIT (1)

Anonymous Coward | about 2 months ago | (#47402141)

Bet this started out as a thought experiment on how to get chicks to stand close to them.

Re: MIT (0)

Anonymous Coward | about 2 months ago | (#47403279)

Gedankenexperiment, please. It is said this way. It is the only way. And you shall like it. :)

If we could only do this with space-time (1)

hAckz0r (989977) | about 2 months ago | (#47402189)

Anti-gravity! But how does one perturb space-time? We can't even detect gravitational waves much less create them. I don't think we will solve this one overnight

Re:If we could only do this with space-time (2)

93 Escort Wagon (326346) | about 2 months ago | (#47402371)

It's like putting too much air into a balloon!

Re:If we could only do this with space-time (0)

Anonymous Coward | about 2 months ago | (#47403153)

What would help is to look at what 99.9999% of existence is made up of, vacuum and it's geometry, instead of the 0.0001% (matter).

http://quantumworld.tv/videos/nassim-haramein/
http://www.youtube.com/watch?v=mFTMiVs4VhY
https://www.facebook.com/TheResonanceProject

Our biggest obstacles seem to be our ego and the destructive parts of our intelligence.

Re:If we could only do this with space-time (0)

Anonymous Coward | about 2 months ago | (#47403625)

Space-time is bent by mass.
If light is truly massless and it can be concentrated to form matter and later destroyed by antimatter, there's your wave generator.
Good luck realizing that though.

References:
light creates mass [extremetech.com]
matter-antimatter annihilation destroys mass and creates energy [physlink.com]

That's not a moon.... (0)

Anonymous Coward | about 2 months ago | (#47402429)

it's a space station.

Psst... you're forgetting something (0)

Anonymous Coward | about 2 months ago | (#47402441)

Gravity is what makes a floating object move forward/back when a wave passes under it. Waves themselves would just make floating objects bob up and down in the same spot, without gravity. And it only works because the water has a surface for the object to float on top of, because as a wave passes under the floating object, the object will want to slide down that surface, forward or back, away from the wave's peak. (Forward or back, depending on where the wave's peak is and which direction the water is inclined at that side of the wave, obviously; to get any net movement, you need asymmetrical waves.)

In a volume filled with fluid in the absence of gravity, none of this is going to happen.

Freakin sharks.. (1)

dave562 (969951) | about 2 months ago | (#47402445)

..with TRACTOR beams!!

Doesn't transfer to light (0)

Anonymous Coward | about 2 months ago | (#47402549)

However, when the amplitude increases, the waves become non-linear and begin to interact with each other in a complex way.

There's the rub: photons don't become non-linear. Unless you pump out energies where spontaneous matter-antimatter pairs are created from vacuum. But whatever you are going to pull on with a beam of that kind will not arrive in good shape.

Re:Doesn't transfer to light (1)

socceroos (1374367) | about 2 months ago | (#47404803)

Baby-brain.... how is light always linear? I thought that the slit experiment was evidence of non-linear light? Also, doesn't a photon colliding with an electron potentially release another photon whose trajectory is influenced by the angular momentum of the parent electron?

Re:Doesn't transfer to light (0)

Anonymous Coward | about 2 months ago | (#47404927)

I thought that the slit experiment was evidence of non-linear light? A

That is a completely linear result, as are all simple quantum mechanics superpositions and basic EM wave interactions. The wave is just behaving like a linear sum of two different paths.

Also, doesn't a photon colliding with an electron potentially release another photon whose trajectory is influenced by the angular momentum of the parent electron?

You can work out the interaction between a photon and electron completely in a linear sense, as long as the photon-electron system doesn't have enough energy to pair produce. Multiple electrons or particles can be a different story as media can easily become non-linear, but that is different than talking about in the vacuum of space which will remain linear for the vast majority of the laser light short of intensities we haven't reached yet.

Re:Doesn't transfer to light (0)

Anonymous Coward | about 2 months ago | (#47405337)

There's the rub: photons don't become non-linear. Unless you pump out energies where spontaneous matter-antimatter pairs are created from vacuum. But whatever you are going to pull on with a beam of that kind will not arrive in good shape.

Except that various optical media become non-linear at intensities way below damage thresholds, and there are examples of using this to move objects by making the object or part of it out of such material.

Walls (1)

dkman (863999) | about 2 months ago | (#47402653)

Does it only happen when I have 3 walls that the waves can bounce off of? Because that would not work in an open water setting, only in enclosed settings. It makes me think of pool (billiards) where you could make a ball come toward you by hitting the que off two walls then into the back of the target ball.

If you can repeat it from arbitrary points and arbitrary distances then you start to have something useful.
If you can repeat it with other wave sources then it gets more useful.

Re:Walls (1)

socceroos (1374367) | about 2 months ago | (#47404813)

Well, the solution to this would be to have multiple wave generators, would it not? Or, your singular generator could be housed in a reflector that creates the required interactions?

Re: Walls (1)

dkman (863999) | about 2 months ago | (#47407155)

I'm thinking of ships in the open sea, where having something to reflect off of is impractical.

Oil spills (0)

Anonymous Coward | about 2 months ago | (#47402989)

I wonder if this can be used for oil spills and other water-pollutants...

Rip Currents (0)

Anonymous Coward | about 2 months ago | (#47403371)

Rip currents pull things out to sea opposite the flow of the waves. It seems that Rip currents or riptides are a much simpler and unrelated effect with regard to this phenomenon, but I wonder if it served to pull the researches in the right direction? Pun intended.

The light stuff works totally differently (3, Informative)

slew (2918) | about 2 months ago | (#47403397)

FWIW, this paper [arxiv.org] talks about doing this with light (in the context of micro-manipulation). Doesn't look like we will be using this for any star-ship sized objects in the near future...

The basic idea is that you use a light with a specific profile to stimulate the object you want to attract in a way that causes a scattering field such that there is a net force backward to the emitter (it only works if the amount of net forward momentum of the light is relatively small compared to the scattering).

The water stuff referenced by this article works on a completely different principle, though as described here [arxiv.org] .

They are similar in that they originate with a wave generator, also hitting the target at a glancing angle is a way to achieve the necessary conditions and both provide a net attractive force (aka tractor beam), but the physics is totally different.

Re:The light stuff works totally differently (1)

socceroos (1374367) | about 2 months ago | (#47411509)

When you say that a relatively large scattered field (as compared to the relative momentum of the light beam used) attracts objects - how does a 'scattered field' cause this attraction? I guess I'm trying to determine how a scattered field of light would cause momentum towards the emitter...

Would an electrostatic force be possible in the vacuum of space?

Tractor Beam Created Using Water Waves (1)

rickyslashdot (2870609) | about 2 months ago | (#47403647)

OK - so reversing polarity DIDN'T work - - - NOW go to MAX POWER (Wil Wheaton's last words . . .)

A genetic algorithm could find this solution. (0)

Anonymous Coward | about 2 months ago | (#47403705)

All you need is a computer controlling an actuator and a video camera to track the objects, then you just evolve the solution. In fact you could evolve a full set of motion vectors and then combine them in sequence to drive the object around at will. However this would only apply to the specific environment defined by the test tank and it may not turn out to be a very efficient way of moving anything around, then again if it can scale down to the scale of biological cells it could be very useful for cell sorting, labs on chips etc.

d@3-e.net

Should work in other fluids too, like air. (1)

Mal-2 (675116) | about 2 months ago | (#47404057)

She's gone from suck, to blow!

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