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Quantum mechanics flummoxes physicists again
Nature ^ | 7/22/10 | Jon Cartwright

Posted on 07/24/2010 5:35:11 PM PDT by LibWhacker

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To: James C. Bennett
The observer in the latter case has practically no effect on the outcome of the game. However, in the former case, “observation” implies interference because there is no way of observing a sub-atomic particle without affecting the particle

Except that in the double-slit experiment we are observing the outcome of both cases in the exact same way.

In other words, our manner of interfering in order to observe the outcome of the experiment is no different in the case that results in the wave manifestation than in the case that results in the particle manifestation. In both cases, we are observing by measuring the impact of the electrons or photons on a screen after having passed through the slit or slits, in the same way.

So the different results cannot be explained by a difference in the way we are interfering in order to observe.

51 posted on 07/24/2010 9:17:40 PM PDT by SirJohnBarleycorn
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To: SirJohnBarleycorn

I didn’t follow that. Could you elaborate on how that applies for each case? Specifically, how do you apply the notion of observation deciding the outcome, and how do you keep the act of observation completely benign, in the double-slit experiment?

I’m also interested in knowing about the “neutrality” of the slits themselves, and how they ensure that only one particle is ejected at a time, with certainty.

What I’m basically trying to clarify, is the following. The particle-wave duality of electrons is confirmed by the double-slit experiment in the following manner:

Case 1: Pass electron beam through double slit, unobserved. Result: Interference patterns on screen.

Case 2: Pass electron beam through double slit, observed.
Result: No interference pattern on screen.

What I said earlier was that the act of observation was not benign.


52 posted on 07/24/2010 9:43:50 PM PDT by James C. Bennett
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To: James C. Bennett

more like:

Case 1: Pass electron beam through double slit, after which beam strikes passive detection screen. Results on screen shows a wave-like pattern of troughs and valleys of intensity as if the electrons are interfering with each other like two sets of ocean waves.

Case 2 (close one slit): Pass electron beam through single slit, after which beam strikes passive detection screen. Pattern on screen does not show a wave-like pattern (instead, particle-like).

And interestingly, in the double-slit case, even if you slow down the electron beam so that each electron goes one at a time, the pattern that emerges on the detection screen still shows the wave-like pattern, as if the electrons as a group are interfering with each other like the two sets of ocean waves.


53 posted on 07/24/2010 10:36:38 PM PDT by SirJohnBarleycorn
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To: SirJohnBarleycorn

And may also be worth noting that God SPOKE light into existence.

Speech, to us, in human terms, is creating a wave (a sound wave). Perhaps God was giving us a small clue.


54 posted on 07/24/2010 10:44:56 PM PDT by SirJohnBarleycorn
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To: SirJohnBarleycorn

Basically what you mentioned does not have anything to do with the act of “observation” affecting the choice of what the electron wants to do, right? No hocus-pocus “electron intelligence”...

Just that the electrons produce interference patterns through a double slit, whether they are fired en-masse or one by one, and they produce a single pattern, when fired through a single slit.

Did I infer the above correctly?


55 posted on 07/24/2010 10:55:35 PM PDT by James C. Bennett
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To: James C. Bennett
Except in the following variation:

In the double-slit case, we see a wave-like pattern on the screen, as if the electron beams are like two ocean waves flowing through both slits and interfering with each other.

What if we try to observe the electrons as they pass through the slits? Will we see waves passing through, or particles?

If we do that, the wave pattern collapses, and the electrons act like particles.

So in this case, when we try to observe the electron acting like a wave directly, it doesn't display the wave-like property. So arguably, this variation brings in the consideration you raised as to the act of observation interfering with the sub-atomic particle.

Very mysterious.

56 posted on 07/24/2010 11:11:34 PM PDT by SirJohnBarleycorn
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To: SunkenCiv

Physics ping


57 posted on 07/24/2010 11:14:09 PM PDT by Captain Beyond (The Hammer of the gods! (Just a cool line from a Led Zep song))
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To: SirJohnBarleycorn
Yes, and that is different from saying that the electron somehow displays an "awareness" to a non-interfering act of observation, to change status due to that "awareness" itself.

What it implies, essentially, is that the interfering act of observation is causing the wave function of the particles to be dissipated, and has nothing to do with any supernatural "intelligence" being displayed by the electron itself. Mostly pointing to our lack of understanding of how the wave function gets depleted by the act of interference, and that has not been explained, yet.

58 posted on 07/24/2010 11:21:03 PM PDT by James C. Bennett
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To: James C. Bennett

Arguably, but go back to the post 53 situation, and consider the case where the electron beam is slowed down so as to only emit a single electron at a time.

The single electron emitted, in a traditional way of thinking, would only pass through one or the other of the two open slits, not both at the same time.

How does it “know” at the time it passes through one such slit whether the other slit is open so as to (together with its predecessor and successor brother electrons) produce a wave pattern on the screen, compared to the case when the other slit is closed, and no wave-like result is produced?


59 posted on 07/24/2010 11:36:16 PM PDT by SirJohnBarleycorn
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To: LibWhacker

I conclude electrons do not like slits


60 posted on 07/24/2010 11:45:08 PM PDT by woofie
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To: SirJohnBarleycorn

Again, this is not as if the electron is “aware” of the two slits, but rather, two slits guaranteeing a diminishing of the particle’s wave function. The mystery boils down to us not knowing what it is in multiple slits that causes the wave function to diminish, yes?


61 posted on 07/24/2010 11:49:13 PM PDT by James C. Bennett
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To: LibWhacker

WAVE

62 posted on 07/24/2010 11:50:56 PM PDT by woofie
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To: SirJohnBarleycorn

What would truly be baffling, is if the experiment were to be performed with two slits, each divided by a suitable partition from the other, throughout the length of the path the electron takes, and the experiment repeated.

If closing or opening one slit affected the other, in this arrangement, it would be amazing.


63 posted on 07/25/2010 12:00:14 AM PDT by James C. Bennett
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To: James C. Bennett

The EPR Paradox, and confirming experimental data, suggest otherwise.

Personally, I do not subscribe to the Copenhagan Interpretation or the Many Worlds Theory.

I suspect that there is a residual connectedness of all energy (and remember, all matter is merely a manifestation of energy) from the Creation, and that this connectedness stands outside of and apart from our conception of time. And I am not convinced that there is a speed limit “c” of electromagnetic propagation that has always been constant, as claimed by most physicists.


64 posted on 07/25/2010 12:16:15 AM PDT by SirJohnBarleycorn
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To: James C. Bennett

There is no question the same result would obtain in that situation. Yes, be amazed.


65 posted on 07/25/2010 12:17:38 AM PDT by SirJohnBarleycorn
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To: LibWhacker

Actually put the Cat in the box and then decide poison or no poison ... pull the trigger and see if your results are different than expected.

Change your mind after the fact and you have a 50% chance of changing the outcome.

Rocket Surgery at it’s best

TT


66 posted on 07/25/2010 1:21:43 AM PDT by TexasTransplant (I don't mind liberals... I hate liars...there just tends to be a high degree of overlap)
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To: SirJohnBarleycorn
-- How does it "know" at the time it passes through one such slit whether the other slit is open so as to (together with its predecessor and successor brother electrons) produce a wave pattern on the screen, compared to the case when the other slit is closed, and no wave-like result is produced? --

I make no claim on understanding how physical reality works, but in the "single electron" experiment, I don't think there is enough evidence to show an interference pattern, or even the "shades of brightness" inherent in the single slit arrangement.

The brightest at the center, dimming as one deviates from side to side, is a probabilistic artifact. any given particle has a probability of landing somewhere, more likely aligned with the source/slit line, probability of landing elsewhere depends on the angular deviation from that straight line.

So too, the interference pattern depends on more than one wave being present. Although a single wave will have peak/trough.

So, my semi-educated thought is that the observation is an artifact of probabilities, rather than a single electron literally interacting with two slits.

A single electron does not produce multiple impacts on the passive capture screen. Same for single proton, photon, etc.

67 posted on 07/25/2010 3:02:35 AM PDT by Cboldt
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To: James C. Bennett
-- What would truly be baffling, is if the experiment were to be performed with two slits, each divided by a suitable partition from the other, throughout the length of the path the electron takes, and the experiment repeated. --

I don't think you can construct this. What you are describing is two single slit experiments, side by side.

In other words, if the partition runs the full length of the path, one slit or the other will be isolated from a source of electrons (or light, or protons), and will emit nothing.

68 posted on 07/25/2010 4:04:44 AM PDT by Cboldt
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To: Cboldt

You can never have two independent, isolated pathways.

It’s called the tunneling effect.

It can tunnel through time or space or energy barriers. Not every time, but enough times to make you throw out the baby with the bathwater.


69 posted on 07/25/2010 4:13:06 AM PDT by djf (They ain't "immigrants". They're "CRIMMIGRANTS"!!!!)
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To: djf
-- It can tunnel through time or space or energy barriers. Not every time, but enough times to make you throw out the baby with the bathwater. --

While that is true for some barriers, I believe it is possible to erect a barrier, e.g., to block photons. Without a barrier to block photons, how do you make a slit, or differentiate a one-slit "barrier" from a two-slit, etc.?

In Young's experiment, observing the wave nature of a photon depends on a single photon having access to more than one slit. When a single photon has access to one slit, a bell-curve pattern results. My remark is that one could run two of those "one photon at a time, one slit" generators and superimpose the bell-curves. What is the result?

70 posted on 07/25/2010 5:02:51 AM PDT by Cboldt
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To: Cboldt

True, which is why I am hesitant to believe that electrons have some kind of “intelligence”, or hocus-pocus, to detect observation and behave accordingly.


71 posted on 07/25/2010 7:24:49 AM PDT by James C. Bennett
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To: James C. Bennett
-- which is why I am hesitant to believe that electrons have some kind of "intelligence", or hocus-pocus, to detect observation and behave accordingly. --

No individual particle (or photon, or unit of other form of electromagnetic radiation) does. The observed patterns are the result of probability, played out over millions of discrete events.

72 posted on 07/25/2010 7:36:07 AM PDT by Cboldt
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To: Cboldt

True, and even the observed anomalies are due to the inherent failings of recordable statistics.


73 posted on 07/25/2010 8:33:18 AM PDT by James C. Bennett
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To: James C. Bennett
Or maybe all times exist simultaneously - and this is “bleed”... who knows?
74 posted on 07/25/2010 9:49:23 AM PDT by GOPJ (..Liberalism is Intolerance..- - Freeper Eric in the Ozarks)
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To: fhayek
Amoebas are closer to humans than we are to God.

Ya think it's hard for the finite to grasp the infinite? Could be...

75 posted on 07/25/2010 10:23:06 AM PDT by GOPJ (..Liberalism is Intolerance..- - Freeper Eric in the Ozarks)
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To: RachelFaith

“If any of them (there are some, and I read their works) knew God then they would be doing totally different sets of studies from totally different points of view.”

.
Your assumption that they do not know God is for the most part incorrect.

Their spokesmen mostly do not know God, but the lion’s share of productive scientists do. The propaganda is all that penetrates to the news, and that is what you’re basing your judgement upon.

.
“Pure and singular length with no mass, no width, no height. What we call light is NOT what these guys are measuring.”

.
Not true!

Light is a band of the electromanetic spectrum that has certain shared properties; some of it visible, and some not.

The devices that I use to do my work use light to make various measurements by sending a coded signal with a beam of light. If the light didn’t occupy all four dimensions (and probably more) those measurements wouldn’t be possible.

Your sense of what the properties of light are is simply not complete.
.


76 posted on 07/25/2010 11:30:40 AM PDT by editor-surveyor (Obamacare is America's kristallnacht !!)
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To: James C. Bennett; SirJohnBarleycorn

“What would truly be baffling, is if the experiment were to be performed with two slits, each divided by a suitable partition from the other, throughout the length of the path the electron takes, and the experiment repeated.”

.
That has been done, and also by splitting the beam with prisms into two temporally simultaneous beams, and in both cases, with the same results.


77 posted on 07/25/2010 11:41:12 AM PDT by editor-surveyor (Obamacare is America's kristallnacht !!)
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To: editor-surveyor

A link to literature describing it would be great. What was it called?


78 posted on 07/25/2010 12:43:01 PM PDT by James C. Bennett
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To: 21stCenturion

...


79 posted on 07/25/2010 3:12:48 PM PDT by 21stCenturion ("It's the Judges, Stupid !")
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To: LibWhacker
If one were to read the comments with a well-placed laugh track, the result would be more and better humor than an episode of Big Bang Theory.
80 posted on 07/25/2010 3:56:43 PM PDT by Rockingham
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To: Captain Beyond; AdmSmith; bvw; callisto; ckilmer; dandelion; ganeshpuri89; gobucks; KevinDavis; ...
Thanks Captain Beyond!

· String Theory Ping List ·
Cat Physicist
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· View or Post in 'blog · post a topic · subscribe ·


81 posted on 07/25/2010 6:17:16 PM PDT by SunkenCiv ("Fools learn from experience. I prefer to learn from the experience of others." -- Otto von Bismarck)
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To: SunkenCiv

A topic that is finally worthy of my sig line.


82 posted on 07/26/2010 12:11:13 PM PDT by ImaGraftedBranch (...By reading this, you've collapsed my wave function. Thanks.)
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To: ImaGraftedBranch

Glad I could help. :’)


83 posted on 07/26/2010 8:05:41 PM PDT by SunkenCiv ("Fools learn from experience. I prefer to learn from the experience of others." -- Otto von Bismarck)
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