Posted on 02/22/2016 10:57:24 AM PST by Reeses
With its ideas of particles zipping in and out of existence, quantum mechanics is probably the kookiest-sounding theory in science. And our understanding of it is little helped by the mysterious "probability fields" most physicists say dictate the zipping.
But a more intuitive picture may lie beneath. As new research demonstrates, beneath the shroud of probability, particles can in fact be viewed as behaving like billiard balls rolling along a table - although in surreal fashion.
The result helps resurrect an 80-year-old picture of quantum mechanics, and provides one of the most stirring demonstrations yet of an effect Einstein called "spooky action at a distance".
The work, reported in Science Advances, is a new version of the most famous experiment in quantum mechanics, in which particles of light, called photons, are fired at two slits before being detected on a screen.
Hog-tied by Heisenberg's uncertainty principle, for decades physicists thought they could never know which slit a particular photon went through - any attempted measurement stops it in its tracks.
But in 2011, physicist Aephraim Steinberg at the University of Toronto achieved the seemingly impossible by tracking the trajectories of photons using a series of "weak" measurements, gentle enough not to disturb their position.
This method showed trajectories that looked similar to classical ones - like those of balls flying through the air.
Although it was a seemingly outstanding result, some physicists were not convinced, highlighting the experiment's inability to deal with "entanglement" (where two particles, in this case photons, are intimately connected so that measurement on one instantly affects the other, no matter how far away it is).
The critics pointed out that doing the same experiment with two entangled photons would lead to a contradiction - such as the photon's trajectory being measured as going through the top slit, but the photon itself hitting the bottom of the detector (as if it came from the bottom slit). They coined the term "surreal trajectories" to describe this result.
Now Steinberg's team has achieved the experiment for entangled photons, and shown how the surreal behaviour is caused by the "spooky" influence of the other particle.
The team first entangled two photons, then sent one of the pair through the regular two-slit apparatus, and the other through an apparatus that monitored polarisation - the plane the light waves are travelling in.
Weirdly, the choice made by the experimenters in how to measure the polarisation determined which slit the first photon went through - as if interfering with one particle caused the other to change direction instantaneously.
This kind of bizarre phenomenon is exactly what Einstein had in mind when he dubbed it "spooky action". Physicists have seen evidence of it before, but never in such a direct fashion.
The results bolster a non-standard interpretation of quantum mechanics, which throws out the notion of abstract probability fields altogether.
First put forward by Louis de Broglie in 1927, the interpretation treats quantum objects just like classical particles, but imagines them riding like a surfer on top of a so-called pilot wave.
The wave is still probabilistic, but the particle does take a real trajectory from source to target.
The new work does not disprove the standard "probabilistic" view of quantum mechanics, but it does highlight that the pilot-wave interpretation is perfectly valid too. That is "something that's not recognised by a large part of the physics community", says Howard Wiseman, a physicist at Griffith University who proposed the experiment.
It may be easier to visualise real trajectories, rather than abstract wave function collapses.
"I would phrase it in terms of having different pictures," says Steinberg. "Different pictures can be useful. They can help shape better intuitions."
Yes, I’m not sure there is any such thing as “random”.
“First put forward by Louis de Broglie in 1927, the interpretation treats quantum objects just like classical particles, but imagines them riding like a surfer on top of a so-called pilot wave.
The wave is still probabilistic, but the particle does take a real trajectory from source to target.”
I think deBroglie was about 90% right. What he missed is that the particle IS the pilot wave. It just has a standing wave at its center that appears to us as a particle.
You think exactly like Albert Einstein and other great minds.
Taking the "Jinks in the machine" and it's connection to human conciseness into consideration, how much of an effect does the conciseness of the scientist at the time have on the outcome of the experiment? If they "believe" there will be a certain outcome, wouldn't that interfere with the final results? If so, how much?
It's the perplexing mind over matter thing. How much does the conciseness of the scientists play a role? If thought is energy, and that energy resonates at a certain vibration, what affect would that have on particles - which themselves are energy? What about the possibility of entrainment?
(I think about weird stuff. So many questions and so little time.)
Ahhhhhhh.....Quantum Entanglement.
Just writing it makes my head hurt.
There has to be. The possibilities start out as virtually endless. (Eventually, though, all possibilities will run out, and then there's no turning back.)
Randomness indicates actions, not possiblities.
Between existence and non-existence there is no mean. This principle is inviolable. To declare that something oscillates between existence and non-existence is illogical, and untrue.
Particles do not pop in and out of existence. The Universe does not pop in and out of existence.
Any theory of the Universe that contradicts that, is an invalid theory and untrue.
The evidence is collecting that waves are physically real things, but what the wave medium is is anybody's guess. If there's an edge to the wave medium, any waves hitting it should bounce back like hitting a mirror.
“conciseness” = consciousness?
Quantum ping
Sorry. Misunderstood the post. I'm more of a Fred Allen Wolf type fan. I believe conciseness does affect matter, and I have a tendency to see and read everything from that perspective.
I read the post to say: "There's no such thing as coincidences." .
I’m sure I’m not the only one, but quantum mechanics was something of a “brick wall” I hit in my study of physics.
Up until that point, I was comfortable with physics, even if I didn’t understand every nuance. But I could never get my head around QM.
If there is no randomness then the entire past and future of the universe is knowable.
LOL. I even used spell checker.
I've never bragged about my spelling abilities. I have GOT to be the worst speller on the planet. And my comma splices are legendary. My children will be telling stories about my spelling to their children and their children's children someday!
Those are the students that go on to contribute to QM. The students that think they understand it cause all the trouble.
Knowable to God, if he wanted to skip to the end of the book, but we're forever cut off from being able to do that. So for us randomness really exists, even though it really doesn't.
Disclaimer: Opinions posted on Free Republic are those of the individual posters and do not necessarily represent the opinion of Free Republic or its management. All materials posted herein are protected by copyright law and the exemption for fair use of copyrighted works.