Can an oil bath solve the mysteries of the quantum world?

November 1, 2013, Institute of Physics

For the past eight years, two French researchers have been bouncing droplets around a vibrating oil bath and observing their unique behaviour. What sounds like a high-school experiment has in fact provided the first ever evidence that the strange features of the quantum world can be reproduced on a macroscopic scale.

Now, many researchers are asking if the oil-bath experiments can provide insights into quantum mechanics and more specifically why particles can behave as waves and waves can behave as particles.

In this month's issue of Physics World, Jon Cartwright takes a closer look at some of the key experiments performed by the French pair but finds that not all are convinced that they will lead to a deeper understanding.

The French physicist Louis de Broglie was the first to describe wave–particle duality in 1926 but the phenomenon has since been very difficult to understand because no-one has ever observed something being both a particle and a wave in the everyday world.

That was until 2005, when Yves Couder and Emmanuel Fort found that when droplets of oil were released onto the surface of a vibrating oil bath, they started to bounce up and down instead of becoming immersed in the liquid, creating a series of waves beneath them. By adjusting the amplitude of the vibrations, they could make the droplets land on the crest of the waves and bounce around the bath.

These wave-droplets – or "walkers" as the researchers called them – appeared to be the first evidence of wave–particle duality on a . The waves could not exist without the droplets and the could not move without the waves.

In the years after the initial experiments, Couder and Fort used the oil bath to perform several of the classic experiments in quantum mechanics – including Young's double-slit experiment – and found that the walkers exhibited many similarities to the entities used in the original experiments.

One area where the walkers' analogy with quantum mechanics fails, however, is entanglement – the weirdest quantum phenomenon of all that describes how the physical state of two particles can be intricately linked no matter how far apart in the universe they are.

For this to happen, a wave must occupy a very high number of dimensions so can affect one another over large distances, faster than the speed of light. However, in a walker system the will always occupy just two dimensions, given by the length and width of the oil tank.

"If one thinks of [entanglement] as central to quantum theory, it cannot possibly be reproduced in the [walker] system," Tim Maudlin of New York University told Physics World.

Indeed, the magazine contacted a number of physicists and philosophers with a background in quantum foundations, and found that most were sceptical that the walker systems could shed light on the mysteries of the .

On whether Couder and Fort's work can inspire physicists to find a theory deeper than , Cartwright concludes: "It may be too soon to tell, but one point does seem clear: every time they look, the researchers find more ways in which walkers exhibit supposedly quantum behaviour."

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1 / 5 (13) Nov 01, 2013
"...has in fact provided the first ever evidence that the strange features of the quantum world can be reproduced on a macroscopic scale"?
I thought that distinction went to the Millikan oil drop experiment in 1909, which demonstrated the quantization of electric charge with sufficient precision to measure the charge on a single electron.
1 / 5 (13) Nov 01, 2013
As to the wave-particle duality, the answer is that waves and particles are separate manifestations of a third mathematical quantity, the four-tensor. Measurements of an object which can be represented by a four-tensor will be reduced in dimensionality (depending on the measurement operator applied) to either a 'particle' (a diagonalized tensor) or a 'wave' (an antisymmetric tensor), with properties dependent on the relative motion of the four-tensor and the frame of reference used for defining the operatior applied to the tensor.
1 / 5 (3) Nov 01, 2013
Different entities which can be seen classically, but undergo quantum phenomenas are (topological) solitons, like fluxons/Abrikosov vortices, for which the fact that we can literally see their trajectories, does not prevent interference for them: http://pra.aps.or.../p3541_1

So maybe we can ask about internal structure of particles - search for soliton particle models?
1 / 5 (8) Nov 02, 2013
"For [entanglement] to happen, a wave must occupy a very high number of dimensions so particles can affect one another over large distances, faster than the speed of light. However, in a walker system the waves will always occupy just two dimensions, given by the length and width of the oil tank."

Suppose a layer of another oil, immiscible with the oil bath, is floated on the surface of the bath? That would provide another dimension for the waves to occupy. If the speed of sound in the second layer is sufficiently different from that of the bath, the time-varying thickness (waveheight) of the floating oil can be independent of the waves in the bath.

That means the droplets must be of the same composition as the floating oil, I think. Suppose they're not, suppose instead they are the same oil as that in the bath?

Can the droplets be given spin before being dropped? Would that have any effect on their interactions?
Nov 02, 2013
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Nov 02, 2013
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Captain Stumpy
1.6 / 5 (13) Nov 03, 2013
@ LarryD

good luck getting ANY real data or logical information from Zephyr / Franklins / Teech2 etc. in fact, i have been asking for empirical data since i arrived on this site. still nothing.
in fact, i only get links to spam sites or bullcrap Troll data, or data disproved a century ago... or links to sites that only makes sense when totally pissed on something akin to homemade white lightning. he/they/it LOVES to use that wave/water spider analogy though! you WILL see it a lot! again. and again. and again.
Dont let me get you down, though! if YOU can get it from him/her/it... GO right AHEAD! GOOD LUCK

@Teech2 / Franklins / whomever
Nov 06, 2013
This comment has been removed by a moderator.
1 / 5 (3) Nov 08, 2013
These bouncing drop experiments are an inspiration for my quest for the ``small'' part of a Theory of Everything. The fractal postulate suggests some our-sized, mechanical analog must exist for the behavior of light. The drop experiments seem to be it. The walkers show several quantum world features including self-organizing lattice structure, single particle diffraction, quantized orbits, orbital level splitting, tunneling effects, and wave-like statistics. (See the paper of these comments for references).

Other quantum world observations are also suggested such as quantum entanglement (or quantum weirdness). The speed of the walking droplet is analogous to the speed of light (photon). The speed of the wave in the bath (Einstein's gravitational ether now called ``space'' in general relativity or Descartes' plenum) is much higher than the speed of the drop. Once 2 drops are coupled as one of the videos shows, the matched frequency and phase travels mush faster than the drop (photon).
1 / 5 (3) Nov 08, 2013
For example, a person speaks loudly through the air and into a microphone that transmits a radio signal. Another person has a radio receiver TUNED to the radio signal. The other hears the speech from the radio before hearing it through the air. Only a faster than light ether wave speed and wave frequency effects are required for quantum entanglement.

A slightly disturbing feature of the experiment is the need for a constant energy input provided by the vibrator of the bath. This suggests mass inertial plays a role in the mechanism. Another is the bath must be kept near the vibrating condition. How can these conditions be attained in the quantum realm?
1 / 5 (3) Nov 08, 2013
This paper and comments seem oriented to the Democritus, Newton, de Broglie, Bohm interpretation of QM (Not wave-particle duality). My simulation required each hod (read droplet) generate a wave in the medium. The hods assembled to make photons. This analogy was seen in the ``cloud'' video http://www.youtub...1Qkb97UM where the assembly drops produced interference patterns in the medium. One problem in the simulation was the diffraction of a single photon. Diffraction didn't happen in the simulation without other photons. The video shown on ``Wormhole'' TV showed the wave being reflected by the diffraction grating. Hence, the single drop produced an interference pattern. Because the wave travels faster than the drop, it is reflected and travels back to the drop that helps influence the drops direction. This is the TIQM model in QM. The math of TIQM works.
1 / 5 (2) Nov 08, 2013
TIQM's perceived difficulty was the reverse wave that was thought to be a time aberration that was difficult to accept. The drop experiment suggests the higher speed and reflection of the wave is all that is required. Revive TIQM.

Could the bouncing drop (but not walking) with lower energy be the analogy of the Bose-Einstein condensate?

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