Famous Double-Slit Experiment Holds Up When Stripped To Its Quantum Essentials (mit.edu) 22
Longtime Slashdot reader ndsurvivor shares a report from MIT: MIT physicists have performed an idealized version of one of the most famous experiments in quantum physics. Their findings demonstrate, with atomic-level precision, the dual yet evasive nature of light. They also happen to confirm that Albert Einstein was wrong about this particular quantum scenario. The experiment in question is the double-slit experiment, which was first performed in 1801 by the British scholar Thomas Young to show how light behaves as a wave. Today, with the formulation of quantum mechanics, the double-slit experiment is now known for its surprisingly simple demonstration of a head-scratching reality: that light exists as both a particle and a wave. Stranger still, this duality cannot be simultaneously observed. Seeing light in the form of particles instantly obscures its wave-like nature, and vice versa.
[...] Now, MIT physicists have performed the most "idealized" version of the double-slit experiment to date. Their version strips down the experiment to its quantum essentials. They used individual atoms as slits, and used weak beams of light so that each atom scattered at most one photon. By preparing the atoms in different quantum states, they were able to modify what information the atoms obtained about the path of the photons. The researchers thus confirmed the predictions of quantum theory: The more information was obtained about the path (i.e. the particle nature) of light, the lower the visibility of the interference pattern was. They demonstrated what Einstein got wrong. Whenever an atom is "rustled" by a passing photon, the wave interference is diminished. "Einstein and Bohr would have never thought that this is possible, to perform such an experiment with single atoms and single photons," says Wolfgang Ketterle, the John D. MacArthur Professor of Physics and leader of the MIT team. "What we have done is an idealized Gedanken experiment." Their results appear in the journal Physical Review Letters.
[...] Now, MIT physicists have performed the most "idealized" version of the double-slit experiment to date. Their version strips down the experiment to its quantum essentials. They used individual atoms as slits, and used weak beams of light so that each atom scattered at most one photon. By preparing the atoms in different quantum states, they were able to modify what information the atoms obtained about the path of the photons. The researchers thus confirmed the predictions of quantum theory: The more information was obtained about the path (i.e. the particle nature) of light, the lower the visibility of the interference pattern was. They demonstrated what Einstein got wrong. Whenever an atom is "rustled" by a passing photon, the wave interference is diminished. "Einstein and Bohr would have never thought that this is possible, to perform such an experiment with single atoms and single photons," says Wolfgang Ketterle, the John D. MacArthur Professor of Physics and leader of the MIT team. "What we have done is an idealized Gedanken experiment." Their results appear in the journal Physical Review Letters.
Not a single detected tracking script! (Score:5, Informative)
Damn, MIT is hygienically clean! I feel like I've step on holy turf.
Not sure I've ever visited a website entirely devoid of tracking scripts. Certainly not in recent years at least.
Re: Not a single detected tracking script! (Score:5, Funny)
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It's only because you observed it. Those of us who didn't observe got script-snooped. But on the up side, our cats will live, but your Fluffy has a fifty-fifty.
Stripped slits, eh? (Score:2)
Someone's feeling frisky in the nerd department today.
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I confess, bell curves arouse me.
Not so fast! (Score:3)
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Young never Actually Performed the Experiment (Score:5, Informative)
His name got attached to it because the double slit is one of the simplest apertures to both calculate the diffraction pattern from and to experimentally show diffraction but Young himself likely never performed the experiment (or at least never wrote about it if he did) and it is almost certain that he never performed in it 1801 since the paper he wrote in 1804 [royalsocie...ishing.org] describing the experiments he did do in laborious detail shows that he used a narrow strip of card and studied the interference caused by the overlapping diffraction from each edge of the card. This shows the same physics as the double slit experiment but in a way that is a lot harder to calculate the pattern for. He did use a single slit created by the edges of two knives (these were the heady days of physics when you could make major discoveries using items lying around the house!). So while it is known as Young's double slit experiment and he definitely discovered the physics that lies behind it, it is wrong to say that he performed the experiment in 1801 as the article and summary both do, and it is likely that he never actually performed a double slit experiment at all.
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> Has it been verified by the flat earth society yet?
They merged with the MAGA Science & Space Laser Institute
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They merged with the MAGA Science & Space Laser Institute
I assume the lizard people are pissed.
and also, Einstein was right (Score:4, Insightful)
...but Einstein (with Boris Podolsky and Nathan Rosen) were also right, or at least they were very very insightful. The paradoxical effects they pointed out in the famous 1935 paper turns out to be absolutely central to current understanding of quantum mechanics.
Bohm/diBroglie ignored (Score:2)
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Looks to me like they merely performed an experiment. Let us know when someone detects a pilot wave.
https://www.popularmechanics.c... [popularmechanics.com]
Alternative interpretation (Score:2)
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Why would we "let go" of quantum mechanics. As you say, the maths and experiments work.
All the insane things people imagine that could be the case, like entanglement, quantum computation, the double slit experiment working with one particle at a time, lasers, vacuum birefringence, tunneling, eave function collapse. All of those deeply improbable things that quantum mechanics predicted turned outs to be real.
We can't drop it because it works. Sure it can be refined, but it still has to predict all the stuff
Dumb question (Score:2)
Is it possible that some photons move as waves and others as particles? Are there just... different types of photons?
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false old saw about particle and wave (Score:1)
photons are point particles, the only "waves" are probabilities, the 1930s notion of "matter waves" is long cast aside. A "wavelength" is just region of probabilities of interaction.
Get with the QED times! Particles are points (e.g. electron, neutrino, quark, photon) or they are composite entities.