And old idea made new again…

http://tinyurl.com/oh9keff

For nearly a century, “reality” has been a murky concept. The laws of quantum physics seem to suggest that particles spend much of their time in a ghostly state, lacking even basic properties such as a definite location and instead existing everywhere and nowhere at once. Only when a particle is measured does it suddenly materialize, appearing to pick its position as if by a roll of the dice.

This idea that nature is inherently probabilistic — that particles have no hard properties, only likelihoods, until they are observed — is directly implied by the standard equations of quantum mechanics. But now a set of surprising experiments with fluids has revived old skepticism about that worldview. The bizarre results are fueling interest in an almost forgotten version of quantum mechanics, one that never gave up the idea of a single, concrete reality.

The experiments involve an oil droplet that bounces along the surface of a liquid. The droplet gently sloshes the liquid with every bounce. At the same time, ripples from past bounces affect its course. The droplet’s interaction with its own ripples, which form what’s known as a pilot wave, causes it to exhibit behaviors previously thought to be peculiar to elementary particles — including behaviors seen as evidence that these particles are spread through space like waves, without any specific location, until they are measured.

Particles at the quantum scale seem to do things that human-scale objects do not do. They can tunnel through barriers, spontaneously arise or annihilate, and occupy discrete energy levels. This new body of research reveals that oil droplets, when guided by pilot waves, also exhibit these quantum-like features.

To some researchers, the experiments suggest that quantum objects are as definite as droplets, and that they too are guided by pilot waves — in this case, fluid-like undulations in space and time. These arguments have injected new life into a deterministic (as opposed to probabilistic) theory of the microscopic world first proposed, and rejected, at the birth of quantum mechanics.

“This is a classical system that exhibits behavior that people previously thought was exclusive to the quantum realm, and we can say why,” said John Bush, a professor of applied mathematics at the Massachusetts Institute of Technology who has led several recent bouncing-droplet experiments. “The more things we understand and can provide a physical rationale for, the more difficult it will be to defend the ‘quantum mechanics is magic’ perspective.”

http://www.simonsfoundation.org/quanta/20140624-fluid-tests-hint-at-concrete-quantum-reality/

Better URL

As Seth Lloyd, a quantum physicist at MIT, put it, “Quantum mechanics is just counterintuitive and we just have to suck it up.”

OCDC said:

As Seth Lloyd, a quantum physicist at MIT, put it, “Quantum mechanics is just counterintuitive and we just have to suck it up.”

Or is it?

Read the article

Dropbear said:

OCDC said:

As Seth Lloyd, a quantum physicist at MIT, put it, “Quantum mechanics is just counterintuitive and we just have to suck it up.”

Or is it?

Read the article

Yeah, it’s interesting. Especially the oil droplet acting like a double slit experiment, which does vaguely make sense when one thinks about it.

OCDC said:

Dropbear said:

OCDC said:

As Seth Lloyd, a quantum physicist at MIT, put it, “Quantum mechanics is just counterintuitive and we just have to suck it up.”

Or is it?

Read the article

Yeah, it’s interesting. Especially the oil droplet acting like a double slit experiment, which does vaguely make sense when one thinks about it.

Yup… It seemed interesting

>“This is a classical system that exhibits behavior that people previously thought was exclusive to the quantum realm, and we can say why,” said John Bush, a professor of applied mathematics at the Massachusetts Institute of Technology who has led several recent bouncing-droplet experiments. “The more things we understand and can provide a physical rationale for, the more difficult it will be to defend the ‘quantum mechanics is magic’ perspective.”

Jolly good, carry on.

but quantum mechanics is quite intuitive,

SCIENCE said:

but quantum mechanics is quite intuitive,

Then you don’t understand it

As a fluid mechanicist, I ought to be able to look into this.

> Bohr claimed that particles don’t have definite trajectories; de Broglie argued that they do, but that we can’t measure each particle’s initial position well enough to deduce its exact path. … In principle, however, the pilot-wave theory is deterministic

One of the interesting more recent interpretations that I have a soft spot for falls between these two extremes: “quantum mechanics can’t be probabilistic because you can’t get a probability without an exact repetition, and you can never repeat a quantum experiment exactly”.

In Schrodinger’s interpretation the pilot wave is a probability wave. In Cramer’s transactional interpretation the pilot wave is a backward-in-time wave.

> When a droplet bounces along the surface of a liquid toward a pair of openings in a barrier, it passes randomly through one opening or the other while its ripples pass through both. After many repeat runs, a quantum-like interference pattern appears in the distribution of droplet trajectories. … Yves Couder and colleagues at Paris Diderot University discovered that vibrating a silicon oil bath up and down at a particular frequency can induce a droplet to bounce along the surface. The droplet’s path, they found, was guided by the slanted contours of the liquid’s surface generated from the droplet’s own bounces

I’d like to see experimental proof of this “quantum-like interference”. If the waves are significantly faster than the particle then the interaction would be minimal wouldn’t it? Ditto if the waves are significantly slower than the particle. I need to read further to see if the interference relies on the particle vanishing from space-time between bounces.

Two bouncing oil drops can orbit one another. Hmm? What does this imply for quantum mechanics – uncharged particles do not normally orbit one another. The “Faraday wave in the quantum corral” result is particularly interesting. Does this hold for other corral shapes?

They call this quantum interpretation the “exposed variable” interpretation, to show the similarity to the well-known “hidden variable” interpretation.

> “Personally, I think it has little to do with quantum mechanics,” said Gerard ’t Hooft, a Nobel Prize-winning particle physicist at Utrecht University in the Netherlands. He believes quantum theory is incomplete but dislikes pilot-wave theory.

> In its current, immature state, the pilot-wave formulation of quantum mechanics only describes simple interactions between matter and electromagnetic fields, according to David Wallace, and cannot even capture the physics of an ordinary light bulb. “It is not by itself capable of representing very much physics,”

mollwollfumble’s summary. Looks promising. I’ll take it more seriously when I see a fluid drop experiment that reproduces the results of Young’s double slit experiment. It has been said that if you fully understand the Young’s double slit experiment then you understand quantum mechanics. I don’t claim to fully understand it.

> Two bouncing oil drops can orbit one another. Hmm?

I’d like to see an experiment with three drops.

The article shows that you can get double slit interference patterns and explains why

Really interesting paper; I’ve downloaded for a proper read later.

Just glanced at what they have to say about how it ties in with Bell’s work, but it seems (if they are right) that it is consistent with their “pilot wave” approach.

mollwollfumble said:

In Schrodinger’s interpretation the pilot wave is a probability wave. In Cramer’s transactional interpretation the pilot wave is a backward-in-time wave.

The ‘advanced wave’ (backward in time wave) seems to allow for a mechanism of momentum while the retarded (forward in time) wave allows for momenta interference. Would this interpretation be compatible with the material here?-Transactional Interpretation

‘u’r’ right, I don’t understand the claim that it is counterintuitive

Here at Air New Zealand we take safety very seriously…

http://www.abc.net.au/news/2014-07-04/air-new-zealand-strikes-turbulence-over-racy-safety-video/5571126

wrong fred sorry…