| Topic: |
Science > Physics |
| User: |
"chuckles" |
| Date: |
27 Dec 2005 11:08:00 AM |
| Object: |
You cannot observe anything without affecting it. |
Here's something that doesn't seem to make any sense. Taken from an
article I found very useful on wikipedia about the <a
href="http://en.wikipedia.org/wiki/Double_slit_experiment"> double slit
experiment<a>.
<quote>A refinement of this experiment consists in putting a detector
at each of the two slits, to determine which slit the photon passes
through on its way to the screen. But when the experiment is arranged
in this way, <b>the fringes disappear</b> -- for reasons related to the
collapse of the wavefunction.</quote>
Can anyone explain this, simply? Probably not but if you can try. It
just seems so bloody typical.
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| User: "Dastardly Fiend" |
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| Title: Re: You cannot observe anything without affecting it. |
27 Dec 2005 01:12:35 PM |
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"chuckles" <chuckleberryfinn@gmail.com> wrote in message
news:1135703280.133324.250040@z14g2000cwz.googlegroups.com...
Here's something that doesn't seem to make any sense. Taken from an
article I found very useful on wikipedia about the <a
href="http://en.wikipedia.org/wiki/Double_slit_experiment"> double slit
experiment<a>.
<quote>A refinement of this experiment consists in putting a detector
at each of the two slits, to determine which slit the photon passes
through on its way to the screen. But when the experiment is arranged
in this way, <b>the fringes disappear</b> -- for reasons related to the
collapse of the wavefunction.</quote>
Can anyone explain this, simply? Probably not but if you can try. It
just seems so bloody typical.
A photon is two waves, not one; a magnetic and an electric.
Hence the term "electromagnetic radiation"
A "wave" in time is not the same as a water wave.
To see why, ask yourself what the wavelength of this
oscillator is:
http://www.kettering.edu/~drussell/Demos/SHO/damp.html
That oscillator can be thought of as a car bouncing on
its springs, but cars also move. If it is moving at 30 mph
and there are bumps in the road every 44 feet, it will bounce
once every second, because 30 mph is 44 fps.
If the bumps are 88 feet apart, it will still bounce once a second
if the speed is 60 mph.
The photon is a field, as you know it from a magnet, gravity
and eelectrostatics such as a TV tube and passes through BOTH slits.
http://id.mind.net/~zona/mstm/physics/waves/interference/twoSource/TwoSourceInterference1.html With no second slit, there is no intereference.Beware of Wacky-pedia, any idiot can write it.DF.
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| User: "chuckles" |
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| Title: Re: You cannot observe anything without affecting it. |
27 Dec 2005 03:19:24 PM |
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If you haven't already please disregard my question.
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| User: "" |
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| Title: Re: You cannot observe anything without affecting it. |
27 Dec 2005 03:21:59 PM |
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You cannot observe anything without affecting it.
**********************************
Really? If you observe the Andromeda Galaxy, you affect it?
Perhaps you meant to say "at the microscopic, not the macroscopic
level".
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| User: "PD" |
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| Title: Re: You cannot observe anything without affecting it. |
27 Dec 2005 03:36:08 PM |
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chuckles wrote:
Here's something that doesn't seem to make any sense. Taken from an
article I found very useful on wikipedia about the <a
href="http://en.wikipedia.org/wiki/Double_slit_experiment"> double slit
experiment<a>.
<quote>A refinement of this experiment consists in putting a detector
at each of the two slits, to determine which slit the photon passes
through on its way to the screen. But when the experiment is arranged
in this way, <b>the fringes disappear</b> -- for reasons related to the
collapse of the wavefunction.</quote>
Can anyone explain this, simply? Probably not but if you can try. It
just seems so bloody typical.
That depends on what you call "simply". If you mean in terms of
ordinary behaviors that you're accustomed to at an intuitive level, no
I can't explain it simply. The quantum behavior of things is entirely
non-ordinary and non-intuitive.
There are two small (read: inexpensive) books that you can probably
find used on Amazon that are worthwhile things to digest, both of them
by R. Feynman:
1. The Character of Physical Law. (There is a set of chapters in the
middle that address this experiment)
2. QED: The Strange Theory of Light and Matter
PD
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| User: "chuckles" |
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| Title: Re: You cannot observe anything without affecting it. |
27 Dec 2005 04:03:55 PM |
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Cheers PD, but I read a series of posts recently with subject "Quantum
physics study - Where to begin?"
A post by David MacManus gave me some perspective; I'm probably never
going to fully understand any of this and I should stop asking
questions now.
But thanks.
ps google groups seems to be propogating slowly (at least where I am)
sorry to all for the duplicate posting.
Ignorance in stereo.
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| User: "Gregory L. Hansen" |
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| Title: Re: You cannot observe anything without affecting it. |
27 Dec 2005 08:42:46 PM |
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In article <1135721035.917288.23960@g49g2000cwa.googlegroups.com>,
chuckles <chuckleberryfinn@gmail.com> wrote:
Cheers PD, but I read a series of posts recently with subject "Quantum
physics study - Where to begin?"
A post by David MacManus gave me some perspective; I'm probably never
going to fully understand any of this and I should stop asking
questions now.
"The most merciful thing in the world, I think, is the inability of
the human mind to correlate all its contents. We live on a placid island
of ignorance in the midst of black seas of infinity, and it was not
meant that we should voyage far. The sciences, each straining in its own
direction, have hitherto harmed us little; but some day the piecing
together of dissociated knowledge will open up such terrifying vistas of
reality, and of our frighful position therein, that we shall either go
mad from the revelation or flee from the deadly light into the peace and
safety of a new dark age."
-- HP Lovecraft, "The Call of Cthulhu"
--
"When the fool walks through the street, in his lack of understanding he
calls everything foolish." -- Ecclesiastes 10:3, New American Bible
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| User: "chuckles" |
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| Title: Re: You cannot observe anything without affecting it. |
30 Dec 2005 09:33:12 AM |
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Hmm....subtle. ;-)
"Thus were they defiled with their own works, and went a whoring with
their own inventions." -- Psalms 106:39, King James Bible.
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| User: "Y.Porat" |
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| Title: Re: You cannot observe anything without affecting it. |
30 Dec 2005 09:45:21 AM |
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well said Hansen
there was someone who said:
'let a thousand flowers flourish'
(oddly enough he was a communist leader!! ..... (:-)
ATB
Y.Porat
-------------------------
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| User: "" |
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| Title: Re: You cannot observe anything without affecting it. |
30 Dec 2005 10:05:11 AM |
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chuckles wrote:
Here's something that doesn't seem to make any sense. Taken from an
article I found very useful on wikipedia about the <a
href="http://en.wikipedia.org/wiki/Double_slit_experiment"> double slit
experiment<a>.
Nothing makes sense in Newtonian physics, which
physcists have been told since it was invented,
So the only thing that doesn't make sense is that
after 300 years of genuflecting to the god
of particles, they still whine continuously
that the universe doesn't make sense.
Even after Gauss, Hilbert, Van Newmann, and Godel proved
that they are laser salesmen
looking for a job in New Mexico rather than scientists.
<quote>A refinement of this experiment consists in putting a detector
at each of the two slits, to determine which slit the photon passes
through on its way to the screen. But when the experiment is arranged
in this way, <b>the fringes disappear</b> -- for reasons related to the
collapse of the wavefunction.</quote>
Can anyone explain this, simply? Probably not but if you can try. It
just seems so bloody typical.
.
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