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Physicists Smash Record For Wave-Particle Duality
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."
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"?
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I won't be happy until they get a whole cat to exist in superposition.
Then a lab assistant.
THEN THE WORLD!
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?
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.
Soon, we will be able to try it with a living form like a virus. Quantum being, here I come!
Soft kitty,
Warm kitty,
Little ball of fur.
Happy kitty,
Sleepy kitty,
Purr, purr, purr.
I give it an 8, Dick. It has a nice superposition, but I can't dance to it.
Some settling may occur during posting.
Wait. I'm the evil one. Never mind.
Have gnu, will travel.
What does this mean?
good grief, what use is a teleporter just for cats?!!
the preceding comment is my own and in no way reflects the opinion of the Joint Chiefs of Staff
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.
The Tao of math: The numbers you can count are not the real numbers.
If this scales up, you can have superimposed politicians.
In fact, that might explain some things in DC.
Pics or it did or didn't happen.
systemd is Roko's Basilisk.
Reminds of this, of course: http://www.smbc-comics.com/index.php?db=comics&id=1605#comic
most cats I have encountered are more than 800 atoms.
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
http://en.wikipedia.org/wiki/George_Paget_Thomson
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
I understand that 15 US states now permit mixed particle/wave marriages. The times they are a-changing!
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.
Live today, because you never know what tomorrow brings
To the heavens, I declare!
Physicists have evidence of the Wave-Particle Duality of Macroscopic Chickens in Minecraft.
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. 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.
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
Because it has an uncanny way of explaining what happens next.
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).
The Tao of math: The numbers you can count are not the real numbers.
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.
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.