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Physicists demonstrate new way to violate local causality

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Re: Physicists demonstrate new way to violate local causality

#31

Post by ColanR »

coldtea wrote: post #14
sirclueless wrote: post #4

To someone who doesn't actually know many of the terms here, it sounds like they didn't accomplish much. They defined a stronger form of locality called "bi-locality" and found a way to violate it. The structure of the argument is, "We stood up a strawman and knocked it down," which sounds pretty weak. Is bi-locality an inherently interesting property? Does all classical computation follow it? I don't know enough to…

> The structure of the argument is, "We stood up a strawman and knocked it down," which sounds pretty weak. Weaker than "I don't understand what the paper says, only read a high level layman summary, not sure even what what the experiment was for, but I'm gonna piss on it anyway"? Even assuming what you already describe, the ability to show bi-locality as a new lower bound above which locality constraints apply, is v…

> Weaker than "I don't understand what the paper says, only read a high level layman summary, not sure even what what the experiment was for, but I'm gonna piss on it anyway"?

Come on. Parent was saying what it looked like to a layman, and then asking for someone to address that and ask what was actually going on. No need to "piss on [him]".

Re: Physicists demonstrate new way to violate local causality

#32

Post by agumonkey »

21 wrote: post #23
Roritharr wrote: post #19

Earlier quoted context omitted.

Can you recommend an entry level Physics/QM book?

You can also look at some Susskind talks. He is a very good explainer. They don't skim on the math, but it's followable for somebody with a high-school level of math, at least for the basic concepts like spin or bell inequality. https://www.youtube.com/watch?v=pyX8kQ-JzHI&list=PLQrxduI9Pd...

he also did a small book on QM called "the theoretical minimum" IIRC

Re: Physicists demonstrate new way to violate local causality

#33

Post by coldtea »

ColanR wrote: post #31
coldtea wrote: post #14

Earlier quoted context omitted.

> The structure of the argument is, "We stood up a strawman and knocked it down," which sounds pretty weak. Weaker than "I don't understand what the paper says, only read a high level layman summary, not sure even what what the experiment was for, but I'm gonna piss on it anyway"? Even assuming what you already describe, the ability to show bi-locality as a new lower bound above which locality constraints apply, is v…

> Weaker than "I don't understand what the paper says, only read a high level layman summary, not sure even what what the experiment was for, but I'm gonna piss on it anyway"? Come on. Parent was saying what it looked like to a layman, and then asking for someone to address that and ask what was actually going on. No need to "piss on [him]".

Well, the parent also wrote "it sounds like they didn't accomplish much" and that the structure of their argument is a strawman -- without qualifications.

Re: Physicists demonstrate new way to violate local causality

#34

Post by mgarfias »

RushAndAPush wrote: post #26
coldtea wrote: post #14

Earlier quoted context omitted.

> The structure of the argument is, "We stood up a strawman and knocked it down," which sounds pretty weak. Weaker than "I don't understand what the paper says, only read a high level layman summary, not sure even what what the experiment was for, but I'm gonna piss on it anyway"? Even assuming what you already describe, the ability to show bi-locality as a new lower bound above which locality constraints apply, is v…

It's amazing how so many people on the internet feel so confident in their own intellectual abilities that they can read something that they don't understand and dismiss it as if it's non-important.

That's funny, I read his comment as I don't understand this, it sounds lame, can someone please explain the import for me as I trust this source wouldn't be pushing lame crap.

That is, he was giving credit as respect to the researchers.

Re: Physicists demonstrate new way to violate local causality

#35

Post by [deleted] »

RushAndAPush wrote: post #26
coldtea wrote: post #14

Earlier quoted context omitted.

> The structure of the argument is, "We stood up a strawman and knocked it down," which sounds pretty weak. Weaker than "I don't understand what the paper says, only read a high level layman summary, not sure even what what the experiment was for, but I'm gonna piss on it anyway"? Even assuming what you already describe, the ability to show bi-locality as a new lower bound above which locality constraints apply, is v…

It's amazing how so many people on the internet feel so confident in their own intellectual abilities that they can read something that they don't understand and dismiss it as if it's non-important.

[deleted]

Re: Physicists demonstrate new way to violate local causality

#36

Post by ENGNR »

toxicFork wrote: post #3

Going meta here, speaking from the perspective of a software engineer with a great interest for physics. There are a lot of terms I do not fully understand in this article. Can you recommend an application that would allow me to select for example the words "distant particles can be correlated in ways that are impossible for classical objects" and find out what lead to that discovery? Or what does "Bell inequality" r…

I'm in the same boat as you, but started looking a while ago when quantum computers started showing promise.

I found:

- PBS Spacetime on YouTube is awesome

- Check out the double split experiment. It seems simple, but when you think about what getting interference patterns when only sending one particle at a time really means..

- Then when ready, the quantum eraser

- Bells inequality is a simple idea that proved the strange interpretation of the double split experiment was true, rather than a more mundane interpretation

Re: Physicists demonstrate new way to violate local causality

#37

Post by semi-extrinsic »

ENGNR wrote: post #36
toxicFork wrote: post #3

Going meta here, speaking from the perspective of a software engineer with a great interest for physics. There are a lot of terms I do not fully understand in this article. Can you recommend an application that would allow me to select for example the words "distant particles can be correlated in ways that are impossible for classical objects" and find out what lead to that discovery? Or what does "Bell inequality" r…

I'm in the same boat as you, but started looking a while ago when quantum computers started showing promise. I found: - PBS Spacetime on YouTube is awesome - Check out the double split experiment. It seems simple, but when you think about what getting interference patterns when only sending one particle at a time really means.. - Then when ready, the quantum eraser - Bells inequality is a simple idea that proved the…

If you like the double slit experiment, you'll probably like Feynmann's "motivation" of the path integral in quantum field theory:

Suppose you take the double slit (plate with two holes in it), and you start adding more holes. Of course the particle will go through all of them, but with less probability the further they are off-axis. We can also add more than one plate, and the particle will go through all possible combinations of holes with some probability. Now suppose we let the number of plates go to infinity, and then let the number of holes in each plate go to infinity. The particle still goes through all of the infinite combinations of holes, with less probability if the path is unlikely. But really, there is nothing left anymore between the particle source and the screen! There is just free space! So this path integral with the particle going sort-of-everyhere weighted by probability actually describes propagation through free space.

Re: Physicists demonstrate new way to violate local causality

#38

Post by kordless »

ENGNR wrote: post #36
toxicFork wrote: post #3

Going meta here, speaking from the perspective of a software engineer with a great interest for physics. There are a lot of terms I do not fully understand in this article. Can you recommend an application that would allow me to select for example the words "distant particles can be correlated in ways that are impossible for classical objects" and find out what lead to that discovery? Or what does "Bell inequality" r…

I'm in the same boat as you, but started looking a while ago when quantum computers started showing promise. I found: - PBS Spacetime on YouTube is awesome - Check out the double split experiment. It seems simple, but when you think about what getting interference patterns when only sending one particle at a time really means.. - Then when ready, the quantum eraser - Bells inequality is a simple idea that proved the…

The two slit experiment has been done with buckyballs, which would indicate all matter is capable of exhibiting quantum nature.

Keep in mind the double slit experiment is designed to illustrate the "effect" we observe, when we observe, is at least partially governed by the observation. Given certain interpretations, it can also have philosophical ramifications[1][2] for the existence of reality, self, and choice.

[1] https://en.wikipedia.org/wiki/Copenhagen_interpretation [2] https://en.wikipedia.org/wiki/Pilot_wave

Re: Physicists demonstrate new way to violate local causality

#40

Post by RandomOpinion »

amoruso wrote: post #10

If anyone wants to learn more about Bell's inequality, the simplest (real, no bullshit) explanation I've ever seen is by David Griffiths. You can follow it if you know the basics of calculus: http://www.physics.umd.edu/courses/Phys270/Jenkins/Griffiths...

For a longer exposition that also covers the historical context more deeply, Jim Baggott's "The Meaning of Quantum Theory: A Guide For Students Of Chemistry and Physics" covers Bell's Theorem in Chapter 4 and also requires only basic knowledge of calculus.
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