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Author Topic: What is the difference between scattering and reflection of photons ?  (Read 2713 times)

Offline McQueen

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Yes; that is a useful simplification of reality. Treating electrons as probability clouds results in simpler maths than models that dare to consider the paths of electrons around individual circuits of their orbits, even below the Planck time scale.

Analogous models, i.e., models that are analogous to familiar mechanical systems, may offer a deeper and more psychologically satisfying reality. Some of us, who have not yet fully outgrown the "Why?" phase of our childhood development, are not fully satisfied with that electron cloud analogy. We need to know why the clouds is shaped as it is. Such quests for a deeper understanding, when not proven to have economic benefits, are considered frivolous, if not heretical, by all "serious" scientists. That has always been the case, hasn't it? Copernicus, Galileo, ....

The problem as I see it is not in having mathematical models of electrons  that are the result of a probability wave but that those same  mathematical models of the electron result in the need for multiple dimensions: 

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On the subject of the multiple Dimensions arising from Schrodinger’s equation Max Born had this to say:

“ We have two possibilities. Either we use waves in space of more than three dimensions…………..or we remain in three dimensional space, but give up the simple picture of the wave amplitude as an ordinary physical magnitude , and replace it with a purely mathematical concept into which we cannot enter.”

I am getting a bit tired of quoting the same passage over and over again, however, from the gist of the quote it is quite clear that Max Born, the founder of the probability wave, was able to accept that the Schrodinger wave equation involved multiple dimensions, and that this was a mathematical artifice into which it was not possible to enter (ergo., what are those multiple dimensions, where do they exist ? : not possible to explain or imagine), but that he was able to live with that possibility if he could get the correct answer at the end. This reasoning might make sense to a statistician ( it probably does make sense to a statistician) but it doesn't make much sense to me, nor is it a very satisfying solution. This is especially so when the Lamb shift has proven through solid, reproducible experimental evidence, the existence of virtual photons and especially when the emission and absorption of virtual particles automatically means that the need for an electron following the physical pattern of wave/particle duality no longer exists.
 

Offline agyejy

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This is especially so when the Lamb shift has proven through solid, reproducible experimental evidence, the existence of virtual photons and especially when the emission and absorption of virtual particles automatically means that the need for an electron following the physical pattern of wave/particle duality no longer exists.

Virtual particles cannot and do not exist outside of quantum field theories like Quantum Electrodynamics. In general they are described as excitations of the underlying quantum fields that aren't stable enough to be real particles. You can think of real particles as solitons while virtual particles are closer to evanescent waves. In quantum field theories everything is both wave and particle. Not sometimes a wave and sometimes a particle but for lack of a better way to describe it a wave and a particle. Some experiments emphasize one aspect over the other but there is always a wavelength and everything is always discrete packets. If anything virtual particles being highly unstable excitations of the field tend to be more obviously wavelike than most things we call particles. The reality is that the existence of virtual particles actively necessitates the blurred line between the classical notions of particle and wave in the quantum realm that is the currently accepted paradigm. This is of course the exact antithesis of the quoted statement.
 

Offline McQueen

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Virtual particles cannot and do not exist outside of quantum field theories like Quantum Electrodynamics. In general they are described as excitations of the underlying quantum fields that aren't stable enough to be real particles.

It is obvious that you do not read anything properly before replying. I have stated that there is solid, verifiable and reproducible experimental evidence that 'virtual' particles do exist, in the form of the Lamb shift. (You will be surprised to learn  that until a very short time ago Quantum Mechanics supporters were claiming with equal fervour, that there were no such things as 'virtual' particles. ) That being so, how can you claim that virtual particles exist only in quantum mechanics ? Or that they do not exist outside of the quantum field? This is like saying the moon can only be seen from your window! You may claim that they are excitations of the underlying quantum fields. That doesn't mean that you are right. It is perfectly reasonable to accept that there are really small interactions  in the sub-atomic world that we cannot see  or measure, and that being impossible to measure on our scale that they do not violate the conservation of energy laws. This does not mean that they are evanescent waves or that they have to be evanescent waves.  This will bring you full circle through the Schrodinger wave equation, to the question of how a wave, cloud or whatever, can absorb or emit a particle. Or does it emit a wave that turns into a particle. OR does this wave/particle entity have super powers that means it has to be neither and can interact with either ? Or that it is a particle when being measure and a wave  when it is propagating. I repeat my Question WHY? WHY? WHY? when it is no longer necessary ?
Even more important and something that tells us a lot about what Quantum Mechanics is is the fact that if you except 'virtual' photons as being excitations of the field that the electron interacts with, then why is it still necessary to have the cloud theory. A dog in the manger is a veritable angel when compared to Quantum mechanics which just seems to want to hoard and hoard, everything it has ever thought of, even when thos ideas are obsolete.
« Last Edit: 25/03/2016 12:38:31 by McQueen »
 

Offline agyejy

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It is obvious that you do not read anything properly before replying.

Talk about irony.

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I have stated that there is solid, verifiable and reproducible experimental evidence that 'virtual' particles do exist, in the form of the Lamb shift.

Never disputed that part of the statement.

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(You will be surprised to learn  that until a very short time ago Quantum Mechanics supporters were claiming with equal fervour, that there were no such things as 'virtual' particles. )

No one that actually understands quantum field theory would ever make that claim. Also, theoretical understanding in science evolves over time. You cannot dismiss an entire domain of thought because it has gradually progressed through dedicated study and comparison to observation. To do so would be to deny the very concept of science itself and at that point the entire discussion becomes meaningless.

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That being so, how can you claim that virtual particles exist only in quantum mechanics ?

That isn't even remotely the point I was making. Assuming that you think I was trying to say virtual particles aren't physical things that exist. To be explicit and perhaps pedantic I said virtual particles are thought to exists because of quantum field theories.

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Or that they do not exist outside of the quantum field? This is like saying the moon can only be seen from your window!

When one thing is made of something else that first thing can't exist without the second thing. Virtual particles are made from quantum fields and thus don't exist without quantum fields.

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You may claim that they are excitations of the underlying quantum fields. That doesn't mean that you are right.

There is no way to develop a theory that includes the concept of virtual particles that does not rely on the existence of quantum fields. The whole formalism surrounding virtual particles is derived from quantum field theory.

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It is perfectly reasonable to accept that there are really small interactions  in the sub-atomic world that we cannot see  or measure, and that being impossible to measure on our scale that they do not violate the conservation of energy laws.

But these would not be virtual particles and would not be capable of producing the indirect observational evidence of virtual particles like the Casimir effect which by the way was again a direct consequence of quantum field theory and the physical existence of quantum fields. Further, these small interactions would have to be local in nature and thus impossible of actually reproducing the quantum mechanic effects we actually observe in nature because it is now well proven that quantum mechanics is inherently non-local.

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This does not mean that they are evanescent waves or that they have to be evanescent waves.  This will bring you full circle through the Schrodinger wave equation, to the question of how a wave, cloud or whatever, can absorb or emit a particle. Or does it emit a wave that turns into a particle. OR does this wave/particle entity have super powers that means it has to be neither and can interact with either ? Or that it is a particle when being measure and a wave  when it is propagating. I repeat my Question WHY? WHY? WHY? when it is no longer necessary ?

For starters why is a highly unscientific question and generally does not have an answer within the realm of science. Secondly, reality doesn't care a whit about whether or not you think something makes sense or not. The current formalism that science has developed is extremely accurate and until you can conclusively prove through quantifiable predictions that a discrepancy exists between current theory and experiment that you can resolve by some other theory we have no choice but to accept current theory. Any new theory will have to reproduce the successes of all previous theories and thus are unlikely to change too much. For example, we have fairly good evidence that quantum mechanics is non-local and probabilistic and that there is no way to construct a theory that matches observational evidence that isn't also non-local and probabilistic. Finally, as I have already pointed out the classical notions of particle and wave do not apply to the quantum realm. Things in the quantum realm simultaneously have properties normally associated with classical particles and classical waves. A quantum entity is not a particle at one point and a wave at another nor does it emit a wave at one time and a particle at another. All quantum entities are things that are not entirely wave nor entirely particle and how we happen to measure the entity defines the ratio of particle properties to wave properties that we see.

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Even more important and something that tells us a lot about what Quantum Mechanics is is the fact that if you except 'virtual' photons as being excitations of the field that the electron interacts with, then why is it still necessary to have the cloud theory. A dog in the manger is a veritable angel when compared to Quantum mechanics which just seems to want to hoard and hoard, everything it has ever thought of, even when thos ideas are obsolete.

The electron cloud is a consequence of the fact that quantum entities have properties we normally associate with classical waves. The fact that other non-solitonic wave like things exist does nothing to change that fact.
« Last Edit: 25/03/2016 13:10:22 by agyejy »
 

Offline McQueen

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No one that actually understands quantum field theory would ever make that claim. Also, theoretical understanding in science evolves over time. You cannot dismiss an entire domain of thought because it has gradually progressed through dedicated study and comparison to observation. To do so would be to deny the very concept of science itself and at that point the entire discussion becomes meaningless.
This a new theories forum so you can't relate everything back to quantum mechanics, saying things like , "Oh QM says it's not like that it's like this.". Immediately the whole concept of a New Theories forum becomes obsolete and it becomes instead a forum where Quantum Mechanics is literally forced down everyone's throats, regardless of any points or discrepancies that might be raised. 
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You cannot dismiss an entire domain of thought because it has gradually progressed through dedicated study and comparison to observation.
That is precisely why I am dismissing it, why have a wave/particle duality when there is no reason for it ,then again remember there is no reality in the sub-atomic world so how can you refer to it : Look at this quote from QM once again:
The electron is present as a cloud. Averaged over the cloud, the positive kinetic energy is half as big as the negative potential energy. More importantly, the cloud really is the state of the electron. It's not a picture of where some dot-like particle probably is. It isn't anywhere in particular. It also doesn't have any particular velocity.  In a hydrogen atom, it's certainly not going in a circle. The cloud doesn't go anywhere at all. There's no reason for it to radiate.
Firstly it is obvious that the whole raison d'etre of the 'electron as cloud' theory is because if it was not a cloud it would radiate energy and fall into the nucleus. Look in particular at the last sentence which is the justification: "There's no reason for it to radiate.". Well if the electron interacts with 'virtual' particles, whether they are fluctuations of the field or whatever there is an absolutely verifiable theory as to why it does not spiral into the nucleus, i.e., it mediates its energy through emission and absorption of 'virtual particles'.  How come you now have two theories for why electrons do not fall into the nucleus? One because it interacts with 'virtual particles' and one because it is a wave or cloud?  Notice I do not say , two reasons why electrons do not radiate, because the statement would not be supported by the facts. AND please do not try to brush this aside!
 
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When one thing is made of something else that first thing can't exist without the second thing. Virtual particles are made from quantum fields and thus don't exist without quantum fields.
Look at the prejudice, first you are absolutely sure that the wave/particle duality has to be true because otherwise the electron would radiate away energy and fall into the nucleus , and then when a new discovery is made,namely 'virtual particles' you are equally certain that only the quantum mechanics theory of why they exist is true. How in the Big Bang do you account for the 100 or more fields that quantum mechanics postulate? Maybe each of these particles had its own associated field as a preordained prerequisite of the Big Bang? Your interpretation of  QM sounds more like a h...'s a's the more I hear of it.
 

Offline agyejy

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This a new theories forum so you can't relate everything back to quantum mechanics, saying things like , "Oh QM says it's not like that it's like this.". Immediately the whole concept of a New Theories forum becomes obsolete and it becomes instead a forum where Quantum Mechanics is literally forced down everyone's throats, regardless of any points or discrepancies that might be raised. 

Any theory that directly contradicts established observational evidence is a waste of time and counterproductive.

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That is precisely why I am dismissing it, why have a wave/particle duality when there is no reason for it ,then again remember there is no reality in the sub-atomic world so how can you refer to it :

So what you are saying is that you refuse to participate in actual scientific thought.

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Look at this quote from QM once again:
The electron is present as a cloud. Averaged over the cloud, the positive kinetic energy is half as big as the negative potential energy. More importantly, the cloud really is the state of the electron. It's not a picture of where some dot-like particle probably is. It isn't anywhere in particular. It also doesn't have any particular velocity.  In a hydrogen atom, it's certainly not going in a circle. The cloud doesn't go anywhere at all. There's no reason for it to radiate.
Firstly it is obvious that the whole raison d'etre of the 'electron as cloud' theory is because if it was not a cloud it would radiate energy and fall into the nucleus. Look in particular at the last sentence which is the justification: "There's no reason for it to radiate.". Well if the electron interacts with 'virtual' particles, whether they are fluctuations of the field or whatever there is an absolutely verifiable theory as to why it does not spiral into the nucleus, i.e., it mediates its energy through emission and absorption of 'virtual particles'.  How come you now have two theories for why electrons do not fall into the nucleus? One because it interacts with 'virtual particles' and one because it is a wave or cloud?  Notice I do not say , two reasons why electrons do not radiate, because the statement would not be supported by the facts. AND please do not try to brush this aside!

To start with you have gotten the whole thing backwards. The electron cloud is not a theory it is a consequence of the observed wave nature of electrons and I linked to direct experimental observations of its existence. Another thing to keep in mind is that virtual particle interactions are not the same as radiation. In virtual particle exchanges the number of particles before and after the interaction is the same. In radiation a particle that didn't exists before the event exists after the event and carriers energy away. The radiation talked about in the inward spiral is real photons not virtual photons and you can't substitute one for the other. The exchange of virtual photons does not ameliorate the need for an accelerating charged particle to emit radiation. If the electron was going around the nucleus as a particle it would be accelerating due to moving in a circle and thus would have to radiate real photons. The fact that the electrostatic force keeping it moving in a circle is mediated by virtual photons will not change this fact. The only viable conclusion is that the electron isn't actually going anywhere and exists as an electron cloud.
 
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Look at the prejudice, first you are absolutely sure that the wave/particle duality has to be true because otherwise the electron would radiate away energy and fall into the nucleus , and then when a new discovery is made,namely 'virtual particles' you are equally certain that only the quantum mechanics theory of why they exist is true. How in the Big Bang do you account for the 100 or more fields that quantum mechanics postulate? Maybe each of these particles had its own associated field as a preordained prerequisite of the Big Bang? Your interpretation of  QM sounds more like a h...'s a's the more I hear of it.

Virtual particles were predicted by quantum mechanics before anyone had any experimental reason to postulate they might exist. For a while people did think they were simply a mathematical trick until the theory became more sophisticated and it became clear there were real physically measurable consequences. The very concept of virtual particles would not exist without quantum mechanics. Once again the fact you dislike quantum mechanics is not a valid argument about its validity.
 

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