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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

A fresh take on a classic experiment makes no progress in unifying quantum mechanics and relativity.

If you ever want to get your head around the riddle that is quantum mechanics, look no further than the double-slit experiment. This shows, with perfect simplicity, how just watching a wave or a particle can change its behaviour. The idea is so unpalatable to physicists that they have spent decades trying to find new ways to test it. The latest such attempt, by physicists in Europe and Canada, used a three-slit version — but quantum mechanics won out again.

In the standard double-slit experiment, a wide screen is shielded from an electron gun by a wall containing two separated slits. If the electron gun is fired with one slit closed, a mound of electrons forms on the screen beyond the open slit, trailing off to the left and right — the sort of behaviour expected for particles. If the gun is fired when both slits are open, however, electrons stack along the screen in comb-like divisions. This illustrates the electrons interfering with each other — the hallmark of wave behaviour.

(Excerpt) Read more at nature.com ...


TOPICS: Science
KEYWORDS: double; doubleslit; electrons; experiment; mechanics; photon; physics; quantum; quantummechanics; slit; stringtheory; triple; tripleslit
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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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