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Physicists Smash Record For Wave-Particle Duality

Soulskill posted about 5 months ago | from the call-me-when-it-works-on-a-baseball dept.

Science 95

KentuckyFC writes "One of the central concepts in quantum theory is wave-particle duality — that every object can be thought of as a particle and a wave. Indeed every object has a quantum wavelength associated with it and so can form a quantum superposition with itself. That's easy to demonstrate with fundamental particles such as photons and electrons by passing a beam of them through a double slit and watching the interference pattern that forms on the other side. In this way, physicists have observed the interference patterns associated with atoms and even molecules such as buckyballs. Now, a group at the University of Vienna has observed the interference pattern formed by the quantum superposition of molecules containing over 800 atoms, or around 5,000 protons, 5,000 neutrons and 5,000 electrons. That's the most macroscopic occurrence of wave-particle duality ever observed, they say."

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95 comments

Whatever (5, Funny)

For a Free Internet (1594621) | about 5 months ago | (#45371305)

Wake me up when they can find the wavelength of a Turtle, because quantum theory holds that the universe is made of picoturtles. Why should anyone believe quantum "science"?

Re:Whatever (3, Funny)

Anonymous Coward | about 5 months ago | (#45371357)

Picoturtles? What about the femtoturtles? It's turtles all the way down!

Re:Whatever (1)

Anonymous Coward | about 5 months ago | (#45371481)

don't forget ninjaturtles.

Somebody resurrect Michael Crichton! (0)

Anonymous Coward | about 5 months ago | (#45373501)

Or extract his blood out of some fossilized amber so that he can build us a time machine to send us back to the Middle Ages.
 
capcha: viable

MOD PARENT UP!!! (0)

Anonymous Coward | about 5 months ago | (#45374427)

To the heavens, I declare!

Re:Whatever (5, Funny)

Charliemopps (1157495) | about 5 months ago | (#45371737)

Don't forget the four elephants on the back of the turtle holding the world up. It's like you people had never taken a science class before.

Re:Whatever (1)

Anonymous Coward | about 5 months ago | (#45373183)

Maybe because the science works. So you should start learning to eat turtle, beginning with your own words..

Re:Whatever (-1, Flamebait)

rubycodez (864176) | about 5 months ago | (#45374415)

you were making a joke, but the wavelength of a turtle can be calculated quite simply. take planck's constant and divide by the product of the turle's mass times its velocity. For massive objects the wavelength is very small.

Re: Whatever (0)

Anonymous Coward | about 5 months ago | (#45376185)

Actually the other way around it is very large the frequency is small and wavelength is large

Re: Whatever (1)

Another, completely (812244) | about 5 months ago | (#45376385)

The equation is irrelevant. The Chelonian Uncertainty Principle demonstrates that the more accurately you know the momentum of a turtle, the less accurately you know its position. Since any usefully accurate value for its quantum wavelength would need very high accuracy for its momentum, you would never be able to find the turtle for which you had made your calculations, especially since they can look just like little rocks under the water and are naturally given to hiding.

The Turtle Moves!

Re: Whatever (1)

rubycodez (864176) | about 5 months ago | (#45394577)

but it is turtles all the way down, so like electrons, we really only observe a turtle-shaped hole in the sea of turtles

Re: Whatever (1)

rubycodez (864176) | about 5 months ago | (#45394481)

no, you are confused. this is not the size of an object, but uncertainty in position. for a turtle at normal velocities, and for your body, that "de Broglie" wavelength is quite small

Re:Whatever (0)

Anonymous Coward | about 5 months ago | (#45374753)

Are you telling me that the universe is a LOGO program?

Re:Whatever (1)

maxwell demon (590494) | about 5 months ago | (#45376585)

Almost. It's a Quantum Logo program. Where you have commands like

simultaneously:
  20% forward 10
  30% backward 20
  50% turn 30

Why should anyone believe quantum "science"? (0)

Anonymous Coward | about 5 months ago | (#45376101)

Because it has an uncanny way of explaining what happens next.

Great news (-1)

Anonymous Coward | about 5 months ago | (#45371381)

So when will they do the same with Obama so that coon can fuck himself in the ass like he's done with the rest of the world?

Re:Great news (-1)

Anonymous Coward | about 5 months ago | (#45371511)

And you Republicans wonder why your popularity is so low.

Re:Great news (-1)

Anonymous Coward | about 5 months ago | (#45371711)

Our popularity is so low because we have the balls to let the spoiled kids know they can't always get what they want.

Re:Great news (-1)

Anonymous Coward | about 5 months ago | (#45371787)

Unless it is loose gun laws, tight birth control laws and loose financial regulation...

Re:Great news (-1)

Anonymous Coward | about 5 months ago | (#45372447)

and as long as the spoiled kids in question aren't rich

Not enough (4, Funny)

HeckRuler (1369601) | about 5 months ago | (#45371409)

I won't be happy until they get a whole cat [wikipedia.org] to exist in superposition.
Then a lab assistant [wikipedia.org].
THEN THE WORLD!

Re:Not enough (0)

Anonymous Coward | about 5 months ago | (#45371485)

I won't be happy until they get a whole cat to exist in superposition.

I'm happily looking forward to pictures of coherent cats on the internet.

Re:Not enough (5, Funny)

maxwell demon (590494) | about 5 months ago | (#45372059)

There are lots of pictures of coherent cats on the internet. Unfortunately as soon as somebody looks at them, they immediately collapse into a picture of a lolcat.

Re:Not enough (2, Funny)

Anonymous Coward | about 5 months ago | (#45371533)

Looks like we're going to need another Timmy!

Re:Not enough (0)

Anonymous Coward | about 5 months ago | (#45371537)

seems it would get quite messy trying to jam a cat through the little slit

Re:Not enough (0)

Anonymous Coward | about 5 months ago | (#45372217)

Trying to suppress dirty joke that comes to mind that I will not even post as AC....

Re:Not enough (2)

mark-t (151149) | about 5 months ago | (#45371565)

If they can really do that, they will have invented a teleporter.

Re:Not enough (0)

Anonymous Coward | about 5 months ago | (#45371643)

And the cat copy will mysteriously have a goatee.

Re:Not enough (1)

mark-t (151149) | about 5 months ago | (#45373059)

why would a teleported cat have to be a copy? This experiment strongly implies that macroscopic objects have a superposition just as much as atomic particles do... the question becomes, however... how do we manipulate it? Basically, increasing the probability of something being at one location high enough that it just is there instead of wherever the heck it was.

Re:Not enough (0)

Anonymous Coward | about 5 months ago | (#45374139)

You manipulate the probabilities of it being some place else by doing things that amount to moving it someplace else. Increasing the probability a cat's wave function goes elsewhere amounts to picking up the cat and putting them some place else. You could try teleportation, but that would involve creating some entangled system, then moving half of that system some place else (and necessarily destroys the state original half at the origin).

Re:Not enough (1)

mark-t (151149) | about 5 months ago | (#45374389)

I'm suggesting that the concept of "destroying the original half" would be meaningless in this case, since the half of the entangled system that you are moving is just as much half of the original as the destroyed half was.

Re:Not enough (0)

Anonymous Coward | about 5 months ago | (#45375407)

In quantum teleportation schemes, you can create an entangled pair of systems separate from the system you want to teleport, then transfer the state of the system you want to teleport to one end of the entangled pair. That necessarily destroys the original system, while not necessarily creating a copy of it, as the state of the entangled pair at that point is some transformation of the original state. This means there will be a period of time where possibly no copies of the teleported state exist, and is where the need for classical communication enters as you need to send info you got from destroying the original copy to undo the transformation at the destination.

useless (1)

Thud457 (234763) | about 5 months ago | (#45372043)

good grief, what use is a teleporter just for cats?!!

Re:useless (3, Funny)

lgw (121541) | about 5 months ago | (#45372497)

Finally they can stop scratching at doors until you let them through. Best invention ever!

maybe teeny-weeny little kittens... (0)

Anonymous Coward | about 5 months ago | (#45372771)

most cats I have encountered are more than 800 atoms.

Re:useless (1)

dissy (172727) | about 5 months ago | (#45373781)

good grief, what use is a teleporter just for cats?!!

Imagine: It's 3am on a Wednesday night. You are up on the Internet arguing with a troll.
Suddenly you press a large jolly and candy like button on your cat teleporter, and without warning a thousand terrified cats materialize directly above the troll and rain down upon him like the clawing and hissing metric ton of fur it is.

<Nathan Explosion> Release The Kitties!

Re:Not enough (1)

Anonymous Coward | about 5 months ago | (#45371763)

What about politicians? Thats and entire person who can take dual positions and only pick a single position based on the audience.

Re:Not enough (1)

maxwell demon (590494) | about 5 months ago | (#45372071)

Have you ever seen a politician that is coherent?

Re:Not enough (0)

Anonymous Coward | about 5 months ago | (#45374799)

All politicians are coherent and logic in the politician way, its like quantum physics as it's only coherent ans logic in a quantum physics way.

Can you do this in reverse? (1)

tp_xyzzy (1575867) | about 5 months ago | (#45371423)

I mean, their current setup is displaying an interference pattern.

But how about doing it in reverse. Start from existing interference pattern, and go through all possible molecules until you find the one which matches the same interference pattern?

Re:Can you do this in reverse? (0)

Anonymous Coward | about 5 months ago | (#45371587)

I wonder if that would be related to the continuing radiation from the big bang.

Disclaimer: I have no idea what I'm talking about.

Re:Can you do this in reverse? (0)

Anonymous Coward | about 5 months ago | (#45371803)

And here I was hoping you meant that scientists should start shooting enormous objects: jets, buses, trucks, through the slits, getting a little smaller each time, until they find one that interferes with itself.

Re:Can you do this in reverse? (1)

tp_xyzzy (1575867) | about 5 months ago | (#45371971)

I was thinking more like getting teleportation working. if we know the interference pattern, can we use that info to construct the molecule?

Re:Can you do this in reverse? (1)

amRadioHed (463061) | about 5 months ago | (#45375875)

I'm pretty sure the interference pattern is determined by the mass and velocity of the particle. Because of this the pattern would not be unique to any one particle.

Vortices in Superfluids beats this (1)

Anonymous Coward | about 5 months ago | (#45371457)

Vortices in superfluids 3He or 4He are an expression of the wave-function.

Experiments have been done up to 70 Mol, that is a lot more that 800 atoms.

Re:Vortices in Superfluids beats this (3, Interesting)

hubie (108345) | about 5 months ago | (#45371695)

There are some really interesting experiments going on these days with QM behavior of macroscopic objects (micrometer-scale). I've seen descriptions of MEMS cantilevers built and they measure its vibrational modes, and these guys [phdcomics.com] describe how they did it using reflected laser light. The trick is to cool the device to get rid of the phonons and detect when it falls into the ground state.

Re:Vortices in Superfluids beats this (0)

Anonymous Coward | about 5 months ago | (#45372465)

Good morning, Freeman. They're expecting you in the test chamber. You better suit up.

Try it with life (0)

Anonymous Coward | about 5 months ago | (#45371463)

Soon, we will be able to try it with a living form like a virus. Quantum being, here I come!

Re:Try it with life (0)

Anonymous Coward | about 5 months ago | (#45371505)

Circuses have been doing this with humans for years, and so far the closest thing to an interference pattern they've come is a nice red splotch.

Sing Soft kitty! (0)

Anonymous Coward | about 5 months ago | (#45371489)

Soft kitty,
Warm kitty,
Little ball of fur.
Happy kitty,
Sleepy kitty,
Purr, purr, purr.

Re:Sing Soft kitty! (0)

Anonymous Coward | about 5 months ago | (#45371857)

just don't look in the box or you might be disapointed

Nothing new (-1)

Anonymous Coward | about 5 months ago | (#45371797)

They just observed what we already know. I think reality is nothing but waves of energy. Particles are just moments in time of wave interaction, which depending how you look at it, is continuously happening all the time, or barely using a fraction of the actual time available in reality.

Re:Nothing new (5, Informative)

maxwell demon (590494) | about 5 months ago | (#45372149)

They just observed what we already know.

No. They observed what we already expected. Our currently best theories predicted it. But then, our then-best theories didn't predict the null result of the Michelson-Moreley experiment, or the photoelectric effect. We don't really know it until we tried.

Note that there are theories which postulate a modification of quantum mechanics for sufficiently large objects as solution to the measurement problem. Therefore measurements like this can indeed differentiate between competing theories. Although I think you'd need to test even larger objects to test those theories.

Re:Nothing new (1)

Kjella (173770) | about 5 months ago | (#45373819)

I feel this is a rather underestimated aspect of deductive logic that all science is based on, nobody knows that the "laws" of nature that we know them are universally valid. Even if you're doing a high school experiment it is "new" science, maybe things are different today than they were yesterday. You don't expect them to be, but in theory they might be. Every step of the way from confirming gravity for atoms to gravity for galaxies is valuable, expanding the experimental proof of an apparently correct formula or discovery is the dull legwork of science. It's of course particularly interesting when you can extrapolate beyond what's tested before, but even interpolation has a value. You tend to assume that anything between two extremes that follow the same formula to also follow the same formula, but it is only assumption not proof.

Re:Nothing new (0)

Anonymous Coward | about 5 months ago | (#45376819)

I feel this is a rather underestimated aspect of deductive logic that all science is based on,...

While it is great when you get a chance to use deductive logic in science, most of the time you are stuck with inductive logic.

but even interpolation has a value

But not necessarily the same value, and in some cases possibly vanishingly small value. Some laws are so heavily tested, especially say ones involved in the engineering of every day products used around the world, such that testing those laws in normal situations has a really small chance of exposing something new or touching on new conditions. Worse is when experiments are done in a way such that even if it did touch something new, it would not be capable of noticing or describing what it did differently, if any deviation from theory is indistinguishable from measurement or experimental error.

While talking about the value of any test can be great at introducing some of the basic principles in science, in the difficult, real world with finite resources and time, trying to determine where there is more value instead of any value becomes very important.

So (1)

Ultra64 (318705) | about 5 months ago | (#45371973)

What does this mean?

Re:So (1)

hAckz0r (989977) | about 5 months ago | (#45372355)

It means they accomplished a completely new demonstration of what that they can not even begin to explain, except mathematically of course.

.
The mathematics is merely a statistical description of the observations, not details on the mechanism for the underlying process. Please wake me when they describe the actual underlying process.

Re:So (1)

sjames (1099) | about 5 months ago | (#45373045)

It's the political holy grail! They will be able to vote yes and no at the same time.

Re:So (2)

bill_mcgonigle (4333) | about 5 months ago | (#45373373)

It's the political holy grail! They will be able to vote yes and no at the same time.

Politicians are already in a superposition of their principles - the measurement of what those principles are depends entirely on the who the observer is doing the measuring.

Re:So (0)

Anonymous Coward | about 5 months ago | (#45373479)

.The mathematics is merely a statistical description of the observations, not details on the mechanism for the underlying process. Please wake me when they describe the actual underlying process.

QM includes a mechanism via wave functions. It isn't a statistical description of observations, but says that observations are inherently statistical process, which is a significant difference. You could say that is not good enough and ask for what is underlying wave functions, but any theory or model can suffer someone asking "Why?" only so many times before your at the lowest level of the theory. Anyway, QM may ultimately be wrong, but saying it is merely a statistical description is a gross misrepresentation, and/or suggests a fundamental misunderstanding.

Re: So (1)

tolkienfan (892463) | about 5 months ago | (#45373683)

That's just not true. There isn't a generally accepted interpretation of the math. About the most accepted is probably the Copenhagen interpretation, which basically says the math works, and that's the most we can expect. But it's FAR from generally accepted, and the other theories are all fairly quirky.

Re: So (0)

Anonymous Coward | about 5 months ago | (#45374191)

Umm, all interpretations say the math works. If one didn't it wouldn't be an interpretation of QM since the whole point of interpretation is to take the working math as a premise and try to find an intuitive understanding to it. Nonetheless, that doesn't contradict the previous post at all. The idea that observation is a statistical process (regardless of how you want to think of mechanism how a choice is made) and that underlying states are not statistical views is inherent in the math behind QM. Interpretations won't change that, only coming up with a different theory that is more correct could change that.

Re:So (1)

daknapp (156051) | about 5 months ago | (#45373577)

The mathematics is merely a statistical description of the observations, not details on the mechanism for the underlying process. Please wake me when they describe the actual underlying process.

Um, no. Ever hear of Bell's inequality?

Re: So (1)

hAckz0r (989977) | about 5 months ago | (#45374793)

Yes, it describes a test of the nature of entanglement. It is not a physical description or even a theory of how entanglement happens in the physical world. It provides no physical explinations, but rathet excluding some,and adding to the current mystery.

Re: So (0)

Anonymous Coward | about 5 months ago | (#45375437)

but rathet excluding some

Yes, in particular excluding that QM is a purely statistical description and instead involves some non-local state.

Re:So (1)

Musc (10581) | about 5 months ago | (#45375007)

This is an argument I've had in the past.
If taken a little further, it leads to the question: will science ever end?

At one point, we just knew that matter was made out of small things we called atoms.
We asked what are atoms made of, and we learned they are made of protons, neutrons, and electrons.
We ask what are protons and neutrons made of, and we found quarks.
What are quarks made of? I don't know, because I'm not a physicist. Maybe someone else can answer that for me.

But what are electrons made of? Science has shown that they are not made of anything, they are elementary particles.
They exist, and they have wave properties, and we know a lot about them and their energy states, but they exist like a law of nature, not because of some underlying mechanism or because they are made of smaller things bundled together.
You have to just accept it and move on with your life.

Back to your premise. Wake you when they describe the actual underlying process? What if it is just a law of nature? Even if there is some underlying process, maybe we will never have the resources to discover it because we would need energies we can never achieve.

Not every question has an answer, as much as we would like to think otherwise.

Re:So (1)

maxwell demon (590494) | about 5 months ago | (#45379265)

What are quarks made of? I don't know, because I'm not a physicist. Maybe someone else can answer that for me.

Currently, quarks are assumed to be elementary particles, just like electrons.

But what are electrons made of? Science has shown that they are not made of anything, they are elementary particles.

Actually no. Experiments have not shown any evidence for them not to be elementary. However, it is impossible to conclusively show that they are elementary. After all, they might have a substructure which only can be seen at energies beyond those delivered by our current accelerators,

If this scales up (0)

Anonymous Coward | about 5 months ago | (#45372343)

If this scales up, you can have superimposed politicians.
In fact, that might explain some things in DC.

Particle, wave, Nobel prizes...a family affair (4, Interesting)

Trax3001BBS (2368736) | about 5 months ago | (#45372857)

love this one:
"In 1906, J.J. Thompson had received the Nobel Prize for proving that electrons are particles;
in 1937 he saw his son awarded the Nobel Prize for proving that electrons are waves.
Both father and son were correct, and both awards were fully merited."
http://en.wikipedia.org/wiki/J._J._Thomson [wikipedia.org]
http://en.wikipedia.org/wiki/George_Paget_Thomson [wikipedia.org]

It's a generational thing (0)

Anonymous Coward | about 5 months ago | (#45373811)

I understand that 15 US states now permit mixed particle/wave marriages. The times they are a-changing!

Re:It's a generational thing (2)

rubycodez (864176) | about 5 months ago | (#45374479)

yes most marriages until recently were single slit experiments, but now we allow double-slit marriages

Wave-particle duality is not the interesting bit (1)

quax (19371) | about 5 months ago | (#45375411)

But quantum decoherence is, i.e. how the wave nature is actually suppressed in our macroscopic world.

QM offers up the Ehrenfest theorem to explain how we get there, but this theorem is not completely consistent [wavewatching.net]. So gaining an experimental leg up on this process, that the Copenhagen Interpretation just swept under the rug as 'Quantum State Collapse', is what makes experiments with ever larger quantum systems so interesting.

Re:Wave-particle duality is not the interesting bi (0)

Anonymous Coward | about 5 months ago | (#45375917)

HS Green and collaborators showed how the process wave function collapse could be understood but that work seems to be not well known (wrongly). Physicists please take note:

For many years the prescription of von Neumann, usually called the 'collapse of the wave packet', was the accepted view of how this happened. As it assumed that some processes outside quantum mechanics had to be invoked, even going so far as involving the brain of the human observer, people were not comfortable with it, although it seemed the only possible answer. The best known representation of this difficulty appears in the well-known Schrödinger's cat paradox. Bert, together with a number of others such as Wakita and Ludwig, found a much more satisfying explanation, which is basically still the received description, although nowadays in various forms. The idea was to suppose that a measuring apparatus could be of almost any form so long as it was very complicated, that is, contained a very large number (often for mathematical convenience taken to be infinite) of components such as molecules or electrons. The system being measured could be microscopic. When the two systems interact, any 'interference terms' in the state of the microscopic system become vanishingly small purely as a consequence of the size of the measuring instrument. There are, of course, many processes in nature in which a human observer is not involved – especially before homo sapiens evolved – and the von Neumann description is quite unable to say how these could happen. However with Bert's theory all one has to do is to replace the measuring apparatus by the environment to bring about the necessary disappearance of interferences. The only place where this very satisfactory explanation might run into some difficulty is in the early evolution of the universe, where there is no environment!

.

http://www.science.org.au/fellows/memoirs/green.html

Re:Wave-particle duality is not the interesting bi (1)

maxwell demon (590494) | about 5 months ago | (#45376639)

Sounds to me like decoherence. Which certainly explains why the interference disappears, but does not explain why we see a single, definite result. That is, it explains why the stripes in the double-slit experiment vanish, but it doesn't tell us why we get dots.

Anyway, you don't need to have a macroscopic object to destroy interference. Already entanglement with another microscopic object is sufficient to make interference effects disappear. All which macroscopic objects add is that decoherence becomes practically unavoidable, and in addition uncontrollable, so you cannot recover your interference pattern later (as in the quantum eraser setting, where the "erasure" part is possible exactly because the information is in well-controlled degrees of freedom).

Re:Wave-particle duality is not the interesting bi (2)

quax (19371) | about 5 months ago | (#45377109)

Indeed, the understanding of decoherence has fortunately made great strides since Bohr and Heisenberg coined the Copenhagen Interpretation, and we have a much better understanding of how the interference 'dissipates'.

You are exactly putting the focus on the remaining most intriguing puzzle, why do we experience a single reality? I.e. only see one moon, as Einstein put it. To me it seems there's a deep link between decoherence and entropy lurking in there, something, that despite all the QIS progress, we still don't quite capture.

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