# Spin

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So if the photon doesn't fit the required energy to move the electron exactly the next or some multiple of the next energy level, then the photon will be absorbed and re-emitted nearly instantly?

It's got to be exact to an energy gap within the limits of the HUP, not some multiple of it.

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If you look at energy quanta and light waves, they have wavelength and frequency. Wavelength is connected to distance and frequency is connected to time. For energy, the product of the two is connecte

The wikipedia article is kinda crappy, but then there's a lot of conflicting information in popular science; one needs to take a consistent view. Mass is not a conserved quantity. [imath]E^2=m^2c^4

! Moderator Note Hypothetical musings belong in speculations. The are not appropriate as answers to questions outside of speculations.

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It's got to be exact to an energy gap within the limits of the HUP, not some multiple of it.

I'm saying for a photon not matching the exact limit of an electron, when it hits that electron, what happens before the electron "re-emits it"? Because it can't go to some energy level in-between the exact energy levels, but at the same time, the energy has to go somewhere, or that the electron has to do something with that extra energy.

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I'm saying for a photon not matching the exact limit of an electron, when it hits that electron, what happens before the electron "re-emits it"? Because it can't go to some energy level in-between the exact energy levels, but at the same time, the energy has to go somewhere, or that the electron has to do something with that extra energy.

The photon is re-emitted within a time consistent with $\Delta{E}\Delta{t}>\hbar/2$

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I'm saying for a photon not matching the exact limit of an electron, when it hits that electron, what happens before the electron "re-emits it"? Because it can't go to some energy level in-between the exact energy levels, but at the same time, the energy has to go somewhere, or that the electron has to do something with that extra energy.

I wonder if this has to do with why some frequencies of light bounce off (reflect) certain electrons instead of getting absorbed.

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I wonder if this has to do with why some frequencies of light bounce off (reflect) certain electrons instead of getting absorbed.

Is this not to do with the very original basis of Einstein and Plank and the photo electric effect demonstating the quantum effect . The frequency of infra red was not high enough to give the high enough energy for the electron to be emitted. No matter how intense the IR. Yet one photon of Ultra violet had sufficient high frequency to develop enough energy to release an electron. More photons of UV more electron emitted.

Edited by Mike Smith Cosmos
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Is this not to do with the very original basis of Einstein and Plank and the photo electric effect demonstating the quantum effect . The frequency of infra red was not high enough to give the high enough energy for the electron to be emitted. No matter how intense the IR. Yet one photon of Ultra violet had sufficient high frequency to develop enough energy to release an electron. More photons of UV more electron emitted.

Good point, but upon rereading I think we diverted from Steevey's issue about where the energy goes between absorption and re-emission. Actually, your post would answer that though by reference to the electrons emitted, which I'm guessing occurs because the energy level jump in the absorbing electron would bump high level electrons in the same atom or others out as free electrons as the atoms themselves become positively ionized (maybe?)

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Good point, but upon rereading I think we diverted from Steevey's issue about where the energy goes between absorption and re-emission. Actually, your post would answer that though by reference to the electrons emitted, which I'm guessing occurs because the energy level jump in the absorbing electron would bump high level electrons in the same atom or others out as free electrons as the atoms themselves become positively ionized (maybe?)

I'm still reading hard. You might like to look at a post I have just placed in the virtual particle thread. Its from wikipedia and says a couple of really interesting things about electrons, virtual photons and spin. Have a look and tell me what you think, as I notice your mind 'ticks' a bit like mine.

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I'm still reading hard. You might like to look at a post I have just placed in the virtual particle thread. Its from wikipedia and says a couple of really interesting things about electrons, virtual photons and spin. Have a look and tell me what you think, as I notice your mind 'ticks' a bit like mine.

You might get something from this:

http://wsminfo.org/articles/spin-qed.htm

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The photon is re-emitted within a time consistent with $\Delta{E}\Delta{t}>\hbar/2$

That's pretty quick, so if an electron re-emits a photon without actually doing anything else before the photon is emitted but after the electron has absorbed it, doesn't that mean that "movements" on the atomic and subatomic level are quantized? I'm not saying as in moving from one orbital to the next, I mean as if the trajectory of the electron itself around an atom was quantized and appeared to be moving around it in a pixel-like fashion.

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You might get something from this:

http://wsminfo.org/a...es/spin-qed.htm

Ta, Looks interesting. Some good reading for tonight !

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Ta, Looks interesting. Some good reading for tonight !

I may have posted this too hastily as on further inspection the author seems to have injected his own personal hypothesis into the article...I thought this was a straightforward standard mathematical description of the properties of the electron pertaining to spin with some physical description thrown in where possible; sorry if that's not the case.

Edited by StringJunky
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That's pretty quick, so if an electron re-emits a photon without actually doing anything else before the photon is emitted but after the electron has absorbed it, doesn't that mean that "movements" on the atomic and subatomic level are quantized? I'm not saying as in moving from one orbital to the next, I mean as if the trajectory of the electron itself around an atom was quantized and appeared to be moving around it in a pixel-like fashion.

There is no trajectory around an atom.

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There is no trajectory around an atom.

As far as we know, we can't tell one, but I'm saying more of when the atom itself moves distance. If I throw a rock, isn't the rock's movement through space actually quantized on some level, and moving in a pixel-like fashion?

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As far as we know, we can't tell one, but I'm saying more of when the atom itself moves distance. If I throw a rock, isn't the rock's movement through space actually quantized on some level, and moving in a pixel-like fashion?

How would one tell if that were the case?

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How would one tell if that were the case?

Because as the photon scenario shows, events are themselves quantized. Classically, since things aren't quantized (in classical mechanics), an electron could move into any orbital or have any energy or move to any specific place or be in any specific place, but it can't; when an electron absorbs the wrong amount of energy energy, it doesn't do anything in response to that prior to re-emitting the energy, or in other words, the electron classically would move differently or occupy like a 2.5th orbital after it absorbed the wrong photon but before it emitted it, but that's not the case it just skips that part and absorbs the wrong photon as if nothing happened then emits it, so the movement of the electron itself is quantized, and that's probably true for all other elementary particles. It would be like if I threw a rock and you would see it frozen in the air, then appear to the next place momentum and gravity and air resistance predicts it would go, stop there, then re-appear at the next part, and etc until if you recorded all of the pixel movements it would make an ark. Similarly, an electron's movements, based on what you told me, also acts like this. When it absorbs the wrong photon, its like the electron doesn't have enough time to process that information, so it just skips what it would do and emits it back out.

Edited by steevey
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$\Delta{x}\Delta{p} > \hbar/2$

How will you see if x is quantized, if you can't determine it to an arbitrarily small value?

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$\Delta{x}\Delta{p} > \hbar/2$

How will you see if x is quantized, if you can't determine it to an arbitrarily small value?

Well you know that angular momentum itself is quantized yet electrons still follow that principal. You know that spin is quantized even though electrons and other particles follow that principal, etc. This isn't exactly an x value, its just the recognition of another property which is that electron seems to be moving along in tiny increments of what may be Planck time rather than continuously moving and existing.

Edited by steevey
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Well you know that angular momentum itself is quantized yet electrons still follow that principal. You know that spin is quantized even though electrons and other particles follow that principal, etc. This isn't exactly an x value, its just the recognition of another property which is that electron seems to be moving along in tiny increments of what may be Planck time rather than continuously moving and existing.

And the value of the Planck time is … ?

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And the value of the Planck time is … ?

The time it takes light to travel one Planck length, its very very small, maybe something like 10^-43 seconds.

Edited by steevey
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I must say that the more I dig deeper into intrinsic spin of the electron, there seems to be a lot of difference of opinion as to what is physically going on. The post that "spinjunkie " gave me with a web link as he said led to a personal interpretation, which sounded fairly plausible , though I feel many have different opinions. He referred back to the earlier work of Paul Dirac who was one of the first to try to understand spin. Mr Milo Wolff of the linked article described a spherical fields situation surrounding the electron where "in waves go in and outwaves go out " and this is the cause of the spin , which is only in the presence of a magnetic field. Outside of the magnetic field , say outside the atom, No field No spin. That the spin is reflected onto the three dimensional coordinates ( x, y, z ). and Two complete rotations were required to regain symmetry. He claimed he got most of this from Diracs work, but I am still not sure what the latest thinking is , as to what physically is happening.

So capt refremment/ string junkie/ajb/swansont what is going on?

Edited by Mike Smith Cosmos
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The time it takes light to travel one Planck length, its very very small, maybe something like 10^-43 seconds.

And that makes the Planck length ~10^-35m. Now, compare that with Planck's constant in the uncertainty range. You get GigaJoules of energy. (10^28 eV) If you can't get to those energies, you can't observe the Planck time. Similarly for length. You get tens of kg-m/s, which is fine for a macroscopic object, but not for something trying to show quantized location behavior. You need an electron with the momentum of your calculator when you drop it on the floor.

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And that makes the Planck length ~10^-35m. Now, compare that with Planck's constant in the uncertainty range. You get GigaJoules of energy. (10^28 eV) If you can't get to those energies, you can't observe the Planck time. Similarly for length. You get tens of kg-m/s, which is fine for a macroscopic object, but not for something trying to show quantized location behavior. You need an electron with the momentum of your calculator when you drop it on the floor.

I'm not talking about measuring it, I'm just talking about the possibility of it being the case. Unless matter really does move along increments of at least some amount of time, why wouldn't the electron go somewhere or do something with an improper amount of energy? It just absorbs it, a little bit of time passes, nothing happens, then it emits the photon that was wrong for it as if nothing happened.

Unless your trying to say that scientists don't actually know what happens within that time period because we can't measure it and it happens too fast...

Edited by steevey
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I'm not talking about measuring it, I'm just talking about the possibility of it being the case. Unless matter really does move along increments of at least some amount of time, why wouldn't the electron go somewhere or do something with an improper amount of energy? It just absorbs it, a little bit of time passes, nothing happens, then it emits the photon that was wrong for it as if nothing happened.

Unless your trying to say that scientists don't actually know what happens within that time period because we can't measure it and it happens too fast...

Bingo. If you can't test your model, you have no way of knowing if it's correct.

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• 4 weeks later...

I must say that the more I dig deeper into intrinsic spin of the electron, there seems to be a lot of difference of opinion as to what is physically going on. The post that "spinjunkie " gave me with a web link as he said led to a personal interpretation, which sounded fairly plausible , though I feel many have different opinions. He referred back to the earlier work of Paul Dirac who was one of the first to try to understand spin. Mr Milo Wolff of the linked article described a spherical fields situation surrounding the electron where "in waves go in and outwaves go out " and this is the cause of the spin , which is only in the presence of a magnetic field. Outside of the magnetic field , say outside the atom, No field No spin. That the spin is reflected onto the three dimensional coordinates ( x, y, z ). and Two complete rotations were required to regain symmetry. He claimed he got most of this from Diracs work, but I am still not sure what the latest thinking is , as to what physically is happening.

In view of the news out in the New Scientist and Scientific American about the possible discovery of a new Technicolour particle at 145 Gev approx and the possible idea of a fifth fundamental force working within the atomic nucleus . (This all currently due to Fermilab work) . I think this subject of Spin has more to offer. Has anything come out of The Large Hadron Collider project about spin.

.

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• 1 year later...

In view of the news out in the New Scientist and Scientific American about the possible discovery of a new Technicolour particle at 145 Gev approx and the possible idea of a fifth fundamental force working within the atomic nucleus . (This all currently due to Fermilab work) . I think this subject of Spin has more to offer. Has anything come out of The Large Hadron Collider project about spin.

.

This was a year or two ago. But bringing this Spin Thread up to today, to go with the new inquiry about Spin;

Did anything about Spin come out of Cern and the Large Hadron Collider Experiments ?

.

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