Giant Molecules Exist in Two Places at Once in Quantum Experiment • Hacker News Board

Re: Giant Molecules Exist in Two Places at Once in Quantum Experiment

#61

Post by williamdclt » Thu, Oct 10, 2019, 10:06 PM UTC

toxicFork wrote: post #33

toxicFork wrote: post #28

Please correct me where I am wrong, I have only studied quantum physics as a hobby. I dislike this description of things existing in two places at once, this is because I believe that objects exist in one place, then they move to the next place. The interference pattern only highlights the probability of where the particle will be when it's next observed, or "where it moved to". The object does not interfere with its…

To go further, I have a colleague who says there are actually no particles, only waves interacting with other waves. I am trying to get him to make a proper thesis out of this but he is busy trying to earn money to support his family. If there are any theories about this, please link them in the thread! It sort of resonates with what Richard Feynman has been demonstrating in some of his lectures but I have not been a…

That's indeed a layman explanation of the mainstream theory.

From what I understand of this theory (not a physicist), particle are not small atomic objects but they're not waves either. Nobody can describe what they are otherwise than by mathematic equations describing their interaction. Some of these equations describe some aspects of reality accurately if you think of particles as objects, some others describe some other aspects of reality well if you think of particles as wave. Doesn't mean that particles are either, they just behave like one or the other depending what you're studying

Re: Giant Molecules Exist in Two Places at Once in Quantum Experiment

#62

Post by coldtea » Thu, Oct 10, 2019, 10:16 PM UTC

toxicFork wrote: post #28

Please correct me where I am wrong, I have only studied quantum physics as a hobby. I dislike this description of things existing in two places at once, this is because I believe that objects exist in one place, then they move to the next place. The interference pattern only highlights the probability of where the particle will be when it's next observed, or "where it moved to". The object does not interfere with its…

>I dislike this description of things existing in two places at once, this is because I believe that objects exist in one place, then they move to the next place. The interference pattern only highlights the probability of where the particle will be when it's next observed, or "where it moved to".

No, that would just be regular motion -- and QM would be no really different from throwing a cannonball (for example) and running the ballistic equations.

Remember the classic quote as a guide: "If you think you understand QM, then you don't understand QM".

Even more so if what you think it all is, is a classic quaint motion description. That wouldn't be any mystery, wouldn't explain the two slits experiment results, and wouldn't perplex scientists and have different interpretations for a century.

>In another way, in my mind, the object exists here, then it exists there, but it did not exist at the time between here and there, unless you happened to have observed it. Then of course "there" would be where you have made the observation because you have given it something to interact with.

That would still not cause interference, of explain the experimental results.

It's just like regular solid body motion but with added intermittent existence of the object.

Re: Giant Molecules Exist in Two Places at Once in Quantum Experiment

#63

Post by toxicFork » Thu, Oct 10, 2019, 11:16 PM UTC

evanb wrote: post #37

toxicFork wrote: post #28

Please correct me where I am wrong, I have only studied quantum physics as a hobby. I dislike this description of things existing in two places at once, this is because I believe that objects exist in one place, then they move to the next place. The interference pattern only highlights the probability of where the particle will be when it's next observed, or "where it moved to". The object does not interfere with its…

> the wave is something separate from the object but is related to it. This is a common idea in Bohmian epistemology, but, speaking as a professional physicist, I don't think most physicists would hold this position. The wave is the object, the object is the wave. "Particle/wave duality" or whatever is just bad language for "a quantum mechanical thing" I think the point of saying it "exists at two places at once" is…

Thank you for your detailed explanation, this helps a lot in my understanding!

Re: Giant Molecules Exist in Two Places at Once in Quantum Experiment

#64

Post by BoiledCabbage » Fri, Oct 11, 2019, 2:01 AM UTC

coldtea wrote: post #62

toxicFork wrote: post #28

Please correct me where I am wrong, I have only studied quantum physics as a hobby. I dislike this description of things existing in two places at once, this is because I believe that objects exist in one place, then they move to the next place. The interference pattern only highlights the probability of where the particle will be when it's next observed, or "where it moved to". The object does not interfere with its…

> I dislike this description of things existing in two places at once, this is because I believe that objects exist in one place, then they move to the next place. The interference pattern only highlights the probability of where the particle will be when it's next observed, or "where it moved to". No, that would just be regular motion -- and QM would be no really different from throwing a cannonball (for example) an…

> No, that would just be regular motion -- and QM would be no really different from throwing a cannonball (for example) and running the ballistic equations.

This is not true. Under the DeBroglie-Bohm interpretation of QM an object exists at a single place at a time, what is fuzzy is our knowledge of where it is. And this interpretation holds up to all of the double slit and interference behaviors we expect from QM.

Re: Giant Molecules Exist in Two Places at Once in Quantum Experiment

#65

Post by hisnameismanuel » Fri, Oct 11, 2019, 2:42 AM UTC

benologist wrote: post #45

gmueckl wrote: post #17

Earlier quoted context omitted.

Thank you! Rant: Not linking to the source article is a crime conmited by many outlets trying to report on science. I do not understand that practice. It is even worse when the researcher's institution does this in a public press release (MIT is consistently guilty of this). Are these people afraid that their watered down "explanations" are so wromg that even a cursory glance over the paper will show this? Some news…

There's a dated document that leaked at the start of the decade called The AOL Way that sheds a lot of light on these tactics - https://www.slideshare.net/cartercole/the-aol-way-leaked-pla... External links are used for SEO and generally reserved for partner-websites or their own properties to recirculate traffic. Here we have an article reposted from space.com to scientificamerican.com that only links to nature.com…

Hey, this is my field. It's not as easy as you've laid it out.

A lot of SEO marketers try to get links into articles. This is part of what they do.

Many of them are legit.

Enough are not legit.

This causes links to get pointed to shady websites. It also happens that legit websites get taken over and re-built as shady websites.

This has gotten to the point where many newsmedia organizations or publishers have set blanket policies that NO ONE is to be linked to, or at the least no one receive will receive do-follow link.

Re: Giant Molecules Exist in Two Places at Once in Quantum Experiment

#66

Post by mirimir » Fri, Oct 11, 2019, 3:54 AM UTC

ihartley wrote: post #56

mirimir wrote: post #4

Damn, it wasn't so easy to find the article, because TFA doesn't explicitly provide author names, even. But the link in the image title led to Fein et al. (2019).[0] So what I'm curious about is how far apart those "Two Places at Once" are. And if I'm understanding Fig. 2 correctly, it's large . That is ... > Fig. 2 | interference data. a, Counts as a function of the transverse position of the third grating with a si…

Dunno if it was a link when you looked, but "Nature Physics" in the third paragraph links directly to the paper and bypasses the Nature paywall with some sort of referer link. [0]: https://www.nature.com/articles/s41567-019-0663-9

Thanks.

> Now, in a paper published Sept. 23 in the journal Nature Physics, an international team of researchers has caused molecule made up of up to 2,000 atoms to occupy two places at the same time.

That wasn't there when I read it.

Re: Giant Molecules Exist in Two Places at Once in Quantum Experiment

#67

Post by chousuke » Fri, Oct 11, 2019, 6:03 AM UTC

heavenlyblue wrote: post #27

gewa wrote: post #25

Earlier quoted context omitted.

From a quantummechanic standpoint its wrong to say, that its at two places at once. I really dont like the Headline. Superposition means, that it didnt decide for one of the two possible states, and so these both exist in superposition.

Can you say it’s moving between two places with an infinite frequency?

My own understanding of QM at this point is that it's sort of wrong to think of anything being exactly anywhere, ever.

The way I intuit it, QM systems seem to be described by their wavefunctions sort of the same way a bunch of sine waves together makes music. You could have a QM system that is spatially (mostly) at X, represented by a wave function, or at Y, represented by another, but the third option, a superposition, is the combination of those two wave functions.

Re: Giant Molecules Exist in Two Places at Once in Quantum Experiment

#68

Post by mirimir » Fri, Oct 11, 2019, 6:15 AM UTC

mirimir wrote: post #4

Damn, it wasn't so easy to find the article, because TFA doesn't explicitly provide author names, even. But the link in the image title led to Fein et al. (2019).[0] So what I'm curious about is how far apart those "Two Places at Once" are. And if I'm understanding Fig. 2 correctly, it's large . That is ... > Fig. 2 | interference data. a, Counts as a function of the transverse position of the third grating with a si…

I was hoping that someone would review my interpretation of the result. Because I am not a physicist, so most of their discussion is over my head.

What I pointed to tells me that the spacing of interference fringes for a ~4 nm object was ~230 nm.

But does that mean that the object's wave function leads to probabilities spread over hundreds of nanometers?

Or does the fringe spacing merely result from small angular displacements over a long distance?

Re: Giant Molecules Exist in Two Places at Once in Quantum Experiment

#69

Post by rootw0rm » Fri, Oct 11, 2019, 6:55 AM UTC

DoofusOfDeath wrote: post #12

BurnGpuBurn wrote: post #9

Earlier quoted context omitted.

I'm off shooting cats through two slits I made in my living room wall now, to prove or disprove you. For Science!

Always wondered about the backstory for Bill the Cat.

I always wondered about Fritz the Cat...

Re: Giant Molecules Exist in Two Places at Once in Quantum Experiment

#70

Post by coldtea » Fri, Oct 11, 2019, 8:23 AM UTC

BoiledCabbage wrote: post #64

coldtea wrote: post #62

Earlier quoted context omitted.

> I dislike this description of things existing in two places at once, this is because I believe that objects exist in one place, then they move to the next place. The interference pattern only highlights the probability of where the particle will be when it's next observed, or "where it moved to". No, that would just be regular motion -- and QM would be no really different from throwing a cannonball (for example) an…

> No, that would just be regular motion -- and QM would be no really different from throwing a cannonball (for example) and running the ballistic equations. This is not true. Under the DeBroglie-Bohm interpretation of QM an object exists at a single place at a time, what is fuzzy is our knowledge of where it is. And this interpretation holds up to all of the double slit and interference behaviors we expect from QM.

>This is not true. Under the DeBroglie-Bohm interpretation of QM an object exists at a single place at a time, what is fuzzy is our knowledge of where it is. And this interpretation holds up to all of the double slit and interference behaviors we expect from QM.

Under the DeBroglie-Bohm, yes. But the above description (which is also what I criticized in the prior comment):

(a) an object exists at a single place at a time,

(b) what is fuzzy is our knowledge of where it is

Are not enough to get to DeBroglie-Bohm interpretation though -- it misses it's critical element: the pilot wave / guide.