One of the big mysteries of physics is the interaction between immaterial light and material matter, or in a wider context the interaction between immaterial soul/mind and material body.
Descartes believed that the interaction soul-body took place in the little pineal gland in the center of the brain. Modern neurobiology does not give much support to Descartes' idea but has not really any better theory and so the mystery of how soul and body interact remains to be resolved.
What does then modern physics say about the interaction of light and matter? There are two competing theories depending on the nature of light as
- Deterministic electromagnetic waves described by Maxwell's equations.
- Statistics of massless particles.
2. connects to Newton's old corpuscular theory of light, which was revived by Einstein in 1905 after it had been declared dead and had been replaced by Maxwell's wave theory in the late 19th century.
2. became popular because it offered a resolution to the light-matter interaction problem by simply side-stepping the whole question by claiming that everything is (statistics of) particles: If light is not an immaterial electromagnetic wave phenomenon, but simply some sort of material particles (albeit without mass, but never mind) then there is no wave-matter problem to resolve!
Clever, but maybe too clever since after all light is an electromagnetic wave phenomenon. This brings us back to 1. and the real question of how an immaterial wave can interact with a material body?
In Mathematical Physics of Blackbody Radiation I suggest a resolution with immaterial waves interacting with matter by wave resonance and statistics replaced by finite precision computation. This is a resolution in terms of waves with electromagnetic wave motion interacting with wave motion in matter ultimately also consisting of electromagnetic waves.
The wave-matter interaction problem is thus in this case resolved by understanding that everything is (finite precision) wave and wave resonance, both light and matter. In the wider context: everything is soul and soul resonance.
We have thus two possible solutions of the light-matter interaction problem:
- Everything is (finite precision) deterministic wave and wave resonance.
- Everything is statistics of particles and collision of particles.
Maxwell and Schrödinger said 2. What do you say?
Inlägg
I think that your presentation of two separate phenomena as 1 and 2 are a misrepresentation and a straw man.
SvaraRaderaAnd forcing a definite choice of 1 or 2 is a logical fallacy as pointed out earlier in the comments on some of your posts. My guess is that this becomes very clear for most students taking a course in modern quantum mechanics on a master level (Sakurai like courses).
And it becomes even more clear if one takes the step to second quantization.
There is one thing that makes me really curious. What is your view on experiments where radiation decays into particles or where particles decay into radiation?
Sincerely,
Dol
You are such a boring person, not reading what others comment. Light IS not this or that. It can sometimes be DESCRIBED as waves, sometimes as particles. I think it is time for you to open some basic books of Physics. /Anders
SvaraRaderaSchrödinger said that everything is waves, which mainstream physicists did not like and still do not like. But it was S who invented quantum mechanics and thus maybe one should listen to him with open mind and not just closed body. What physic book did I miss to read?
SvaraRaderaTo say that light is both particle and wave. Is contradictory, and it is nit less contradictory because mainstream physicists pretend that it is no contradiction. To say that light not IS anything is mysticism not science.
SvaraRaderaClaes wrote:
SvaraRaderaBut it was S who invented quantum mechanics and thus maybe one should listen to him with open mind and not just closed body.
The Schrödinger equation is completely useless when dealing with fundamental interactions. If you do not understand why, you should educate yourself in this particular subject.
Exactly what is your educational background in quantum physics? Have you done any research related to the fields?
I get the feeling that you do not really understand (that is has a working knowledge in) what you are criticizing.
Sincerely,
Dol
Claes wrote:
SvaraRaderaTo say that light is both particle and wave.
Where in a modern treatment is this stated?
Sincerely,
Dol
True, my backgrounds is math not physics, but I have derived Planck's law using math without resort to the cheap trick of statistics used by Planck in "an act of despair". What proof of Planck's law without statistics do you find in physics literature?
SvaraRaderaQuantum mechanics was discovered by Heisenberg in 1925 and formulated as Matrix mecanics, which is completely free of "waves"
SvaraRaderahttp://en.wikipedia.org/wiki/Matrix_mechanics
In 1926 Schrödinger found the formulation in terms of the Schrödinger equation, which is NOT a wave equation. It is a heat equation with complex coefficients.
The best description of the modern view is that light is neither a wave nor a particle, but in certain circumstances it has behavior which is close to that of a wave or a particle.
Saying that everything must be either a wave or a particle is nonsense. A concrete example of a different class of object would be a closed string, which is a 1-dimensional compact object.
So a string IS a string or not a string?
SvaraRaderaClaes wrote:
SvaraRaderabut I have derived Planck's law using math without resort to the cheap trick of statistics used by Planck in "an act of despair".
Ok, please answer this for me. Both approaches agrees to the correct physical law (that is an empirical law found from experiments). How do you gauge which one is the right postulation of more fundamental nature?
Sincerely,
Dol
ps. Would you consider post-moderate the comments? As for now I am missing posts that I have written and I guess that it's because of the pre-moderation they astray. ds
Are you aware that there are three different formulations of quantum mechanics all giving the same results? Schrödingers approach is only one of those three. The other two are the mentioned Heisenberg matrix mechanics and the third Feynmans path formulation.
SvaraRaderaThe difference in Schrödingers and Heiwsenbergs views (Feynmans approach is a little bit hard to describe in a comment like this one) are how a state is considered to behave. Schrödinger looks at a state as something that changes (that are time dependent) when acted upon with an operator (fixed in time). Heisenberg looks at it in the other direction, a state is constant (fixed in time), it is the operators that are changing (are time dependent). And come to think of it, there is an evolution of these two views into something that is called the interaction picture where both states and operators are time dependent.
This is something very basic taught early in any serious course in quantum mechanics and must be seen as one of many bare minimum knowledge one should have before thinking about if quantum physics is reasonable or not.
Even further, you ask questions about fundamental interactions between light and matter. There is no possibility to do that with basic non-relativistic quantum mechanics. The guy who took the first approach toward a quantum mechanical understanding of light was Paul Dirac and this resulted in the theory of quantum fields and more specifically the theory of quantum electrodynamics, that is QED for short. This is why, for several reasons, you should focus on this type of quantum mechanics (relativistic) if you want to understand what modern physical models has to say about the questions you ask that is ontology of light and matter and the interaction between the two.
QED is the most advanced (that is not to say that it must be complete in any sense) physical model of light and matter interaction. Can you see any arguments to why this isn't the place to look when you ask questions about light and matter interactions? Of course, one possibility is that you not yet understood what QED is and it is then understandable that you keep acting as stubborn about this as you seem to do.
Sincerely,
Dol
What does QED say about blackbody radiation?
SvaraRaderaClaes wrote:
SvaraRaderaWhat does QED say about blackbody radiation?
Are you in to some kind of mischief, sophistry or ignorance?
In your post you ask about the fundamental nature of light and matter, QED gives you the current physical model.
And concerning blackbodies, the question you seek is not that positioning particles against waves, it is the question positioning continuous classical waves against quantized waves.
Do you understand the difference?
Sincerely,
Dol
The point was that a string is neither a particle nor a wave, it is a string. You have tried to imply that light must be either a particle or a wave. But, those are not the only two options to choose from.
SvaraRaderaMy point is that light in the modern description is neither a particle nor a wave.
The interaction is simply the effect produced on the electrically charged particles of the matter by the time varying Lorentz forces exerted because of the time varying EM fields of the waves. We don’t need to know/say anything else.
SvaraRaderaMichele
So now light is strings?
SvaraRaderaMichele wrote:
SvaraRaderaThe interaction is simply the effect produced on the electrically charged particles of the matter by the time varying Lorentz forces exerted because of the time varying EM fields of the waves.
Is the self interaction problem solved by now? I have a faint memory that classical electrodynamics breaks down when you do detailed descriptions like that since you loose causality when a charge self interact with itself.
So you have to choose when doing classical electrodynamics, prescribe the fields or prescribe the charges.
The classical theory isn't a good model to understand the interactions.
Sincerely,
Dol
"Claes Johnson sa...
SvaraRaderaSo now light is strings?
"
There is no part of my statements where I said that. What I said is that quantum mechanics gives its own description of light, and that description is neither a particle nor a wave. It is a much more complex object.
Particles and waves are not the only two categories of possible objects, as your points 1 and 2 tries to imply.
So light is now a "much more complex object", not particle, not wave not string?
SvaraRaderaDol, I think a charge doesn’t interact with itself but it interacts with the external field acting on it and these are very near actions which totally vanish already at a distance of a little more than a wavelength from it. The strongly reactive boundary layer (i.e. very chaotic and with many collateral effects further the active one that interests us) is very tiny and out of it there is only feeling its macroscopic effect.
SvaraRaderaMichele
Claes wrote:
SvaraRaderaSo light is now a "much more complex object", not particle, not wave not string?
To be honest, nobody knows what light really is. And there is a possibility that no one ever will.
As for now light is only something in relation to a specific model. Until there is a complete physical model, a theory of everything as it is called, nobody really knows.
To summarize,
for Newton, light was a particle.
For Maxwell and his predecessors light was an electromagnetic wave.
For the ones developing non-relativistic quantum mechanics light still was a classical electromagnetic wave since you applied the field in a semiclassical fashion.
For the developers of quantum field theory light was no longer neither a classical electromagnetic wave nor a classical particle. In this context light is a quantum field modeled by quantum harmonic oscillators.
Do you Claes understand this point, that the nature of light can not be know as it is today?
That is correct Claes. It shouldn't be hard to accept the fact that physical objects do not always fall into the simplified categories of schoolbooks and 19th century physics.
SvaraRaderaScience has progressed by observation of nature, and those observations have again and again shown us that nature is more complex than people thought in the Victorian era.
Saying that light must be either a particle or a wave would like saying that animals must be either mammals or birds depending on whether they fly or run.
But then nature also has bats, which are flying mammals, and ostridges, which are running birds.
To not know is not science.
SvaraRaderaClaes wrote:
SvaraRaderaTo not know is not science.
Then I guess that there is no science at all from your point of view.
I have a strong feeling that you have not understand anything of the points I have been making. And you have no understanding of what physics and philosophy of science are.
You must understand that there is a huge discrepancy between mathematics and physics. In the light of physics it is nonsensical to talk about a mathematical proof of Planck's law as you done on several occasions. Try to think of why.
Sincerely,
Dol
Michelle wrote:
SvaraRaderaDol, I think a charge doesn’t interact with itself
Well, it does. I think that electrical engineering students never encounter this since it isn't a problem in engineering applications (you can pretend the problem doesn't exist) but it is important and standard when you do fundamental physics and look at fundamental interactions. If this wasn't the case one would not need the quite messy method of quantum field theory for interaction between spin 1/2 and spin 1 quantum fields.
Sincerely,
Dol
Claes,
SvaraRaderahow do you solve the problem of induction?
Sincerely,
Dol
Dol, I agree with you but you cannot ignore that your thinking bring us very within the reactive zone closest to the source, where the chaos still prevails. The effect on the matter is a macroscopic action exerted by the source once it has organized itself and it has created a coherent acting field, the far field. I think we have to maintain distinguished the microscopic and macroscopic behavior of the matter.
SvaraRaderaPS. Sorry, simply for accuracy: my name is Michele, not Michelle. There is a fundamental difference!
Michele
Claes
SvaraRaderaOne question for you.
You have earlier claimed that there could be no such thing as an IR photon.
If one dopplershifts an IR-wave into a higher frequency wave (to be extreme, why not x-rays) by moving the observer towards the wave, by what mechanism does the light change its fundamental nature?
Sincerely,
Dol
Michele wrote:
SvaraRaderaSorry, simply for accuracy: my name is Michele, not Michelle.
I apologize for that, never intended to misspell your name. (That name or spelling is unusual here in Sweden).
Sincerely,
Dol
Who said that Doppler shifted waves are not waves?
SvaraRaderaClaes wrote:
SvaraRaderaWho said that Doppler shifted waves are not waves?
If I remember it right, you have earlier stated that you do acknowledge that higher frequencies exhibit quantized behavior.
Sincerely,
Dol
I did not say that.
SvaraRaderaClaes wrote
SvaraRaderaI did not say that.
Ok, but for the record then.
Do you state that there is no light that shows quantized behaviour?
If not so, what frequencies has this possibility?
Sincerely,
Dol
What is quantized behavior?
SvaraRaderaClaes wrote:
SvaraRaderaWhat is quantized behavior?
Does, the ability to be described by a quantum field of oscillators, suffice for you?
Sincerely,
Dol
Seems circular to me as a definition of "quantized behavior".
SvaraRaderaClaes wrote:
SvaraRaderaSeems circular to me as a definition of "quantized behavior".
Ok, change the original question to,
Is there light that can be describe with a model of a field of quantum oscillators?
Sincerely,
Dol
Not that I know of.
SvaraRaderaClaes wrote:
SvaraRaderaNot that I know of.
I finally found my book on quantum optics and in there a reference that I've been looking for.
You should take a look at the following paper:
Experimental Evidence for a Photon Anticorrelation Effect on
a Beam Splitter: A New Light on Single-Photon Interferences
Sincerely,
Dol
Have you read the article?
SvaraRaderaIt's an experiment that unquestionable shows that light is quantized in nature.
Sincerely,
Dol
Does it show that infrared radiation is quantized?
SvaraRaderaClaes wrote:
SvaraRaderaDoes it show that infrared radiation is quantized?
Yes it certainly should.
Because you can always Lorentz transform to a frame where the IR-photon has such a frequency that it clearly behaves quantized. Since we have experimental proof that this light is quantized...
If the light at IR-frequencies isn't quantized you have to give a mechanism that explains why the symmetry breaks, and effectively, you must conduct an experiment that shows that the symmetry breaks.
Think about it, if we do not have Lorentz covariance specifically, and more broadly, general covariance in physics, there is kind of pointless to try to do physics at all, so the burden of proof most certainly lies on the one who insists on symmetry breakage.
Sincerely,
Dol
A small extension.
SvaraRaderaThis point of view must be the sane skeptical view.
True skepticism is the ability to acknowledge that certain things are unknown until we have more detailed knowledge, to be able to express the view I have no idea.
Then we have the question what to believe until we have more knowledge. That's where covariance enters. It must be taken as the standard that one uses to express physical laws until one knows better (and in the majority of cases it holds).
Anything else would not be to cope with the scientific method.
Understanding this is integral to understand what theoretical and mathematical physics is about.
Sincerely,
Dol
It should? Does it?
SvaraRaderaClaes wrote:
SvaraRaderaIt should? Does it?
Yes it does. Do you understand why?
Sincerely,
Dol
No.
SvaraRaderaClaes wrote:
SvaraRaderaNo
Do you understand the result of detecting single photon states with coincidence that has been done originally in the experiment I linked to?
Is this an IR photon?
SvaraRaderaClaes wrote:
SvaraRaderaIs this an IR photon?
Are you at all interested in what is going on, or do you consider that you already know what is going on.
As for now I can't see if your intention is honest or not.
Sincerely,
Dol
I asked about experimental detection of IR photons. Is that not a serious question?
SvaraRaderaAre you saying that sometimes light is waves, and sometimes light is "particles"? ;-)
SvaraRaderaSincerely,
Dol
I am saying that light is waves.
SvaraRaderaWhat is the nature, or maybe better, what is the governing equations of the waves you believe in?
SvaraRaderaSincerely,
Dol
Maxwell's equations.
SvaraRaderaClaes wrote:
SvaraRaderaMaxwell's equations.
Did you read and understand the experiment I linked to?
It clearly shows phenomenon that can't be explained with a classical wave model like Maxwell's equation.
Sincerely,
Dol
Phenomena of IR radiation?
SvaraRaderaClaes wrote:
SvaraRaderaPhenomena of IR radiation?
Are you saying that there is two different types of light? One fundamentally classical in nature and one fundamentally non-classical?
Sincerely,
Dol
Claes wrote:
SvaraRaderaPhenomena of IR radiation?
Do you take the position that that there is two regimes where light fundamentally is different then? Otherwise you should give your opinion and motivation why the experiment should be wrong, because it shows that the light in that experiment is non-classical.
Is light classical for long waves, and non-classical for shorter waves? Is light classical waves in one regime and quantized waves in the other? Please give your motivation for how this can be true.
Sincerely,
Dol
I think IR radiation is better described as waves than particles.
SvaraRaderaClaes wrote:
SvaraRaderaI think IR radiation is better described as waves than particles.
Maybe I misinterpret the topic of this blog post but as I see it you ask questions about fundamental interactions between matter and light. And then the question of what light fundamentally is becomes important.
What kind of description gives the computational advantage isn't the topic discussed here. So I ask you again, in your opinion, is light as IR radiation fundamentally different in nature then the light described in the mentioned experiment?
Another thought that crossed my mind is that the experiment is from the 80:s. It can very well been repeated with an IR source. If that were the case, would you change your opinion about the nature of light?
Sincerely,
Dol
Oh, I have one more question for you.
SvaraRaderaDo you acknowledge now that there is light that is single state quantized? (What sometimes a little bit sloppy is called a particle or photon or whatever)
Sincerely,
Dol
I see light as wave, not particle. The notion of particle is self-contradictory as something without extension, for matter certainly because matter has extension and even more certainly for light because light as a wave has extension.
SvaraRaderaYou do understand that a particle is only a model, an abstraction? In the same way as a wave is only a model, an abstraction.
SvaraRaderaIf you fix a localized wave packet and "look" at it on a sufficiently long distance it effectively look like a particle.
Because of empirical evidence the more fundamental model is not wave or particle, it is a unification of them both, a quantum field.
You still don't get it?
Sincerely,
Dol
Claes, why don't you answer Dol' s question?
SvaraRaderaAnders
If particle is only an abstraction without physical correspondence and an abstraction which is useless, then forget it. To wave with quantum field theory as the answer to everything is not convincing, to me.
SvaraRaderaI think that the what I read at http://en.wikipedia.org/wiki/Photoelectric_effect
SvaraRadera”Study of the photoelectric effect led to important steps in understanding the quantum nature of light and electrons and influenced the formation of the concept of wave–particle duality.
is not right as the photoelectric effect is formally explained more better with the wave.
The EM wave acting on the wall of the metal body generates two effects. The free valence electrons oscillate: i) on the surface because of the electric force qE and ii) orthogonally to the surface on the basis of the magnetic force qvxH.
If the work done by the magnetic force in the half wavelength acting outwards is greater than the photoelectric work, that’s, the minimum energy that must be given to an electron to liberate it from the surface of the metal body, then the electron is pulled off.
I think that the collision is less effective to explaining because I don’t understand how the metal body accumulates potential energy during the collision and then it pays back it with the liberated electron.
The concept of wave–particle duality seems to me a straining.
Michele
Claes wrote:
SvaraRaderaIf particle is only an abstraction without physical correspondence and an abstraction which is useless, then forget it. To wave with quantum field theory as the answer to everything is not convincing, to me.
This is such a gargantuous straw man that it produces a whole army of straw men. ;-)
Unfortunately you seem to be completely locked in your position without being able to point to why it is a good position. And I do wonder if you really read the paper with the single photon experiment.
This is unfortunate, skepticism is good when it is based on the will to make science progress, not so much when it is used to peddle ones own biased view on grounds of "common sense".
You have earlier expressed the opinion that nature is a finite precision computation. Then one could argue that reality is a simulation. What then would be the best simulation of reality? Reality itself would be the obvious answer, don't you agree?
Since we see quantum phenomena in experiments, this simulation must then be able to calculate quantum phenomena and should then be a quantum computation. This doesn't contradict the fact that we also experience classical phenomena, because through decoherence a quantum computation can still simulate those phenomena to. Unfortunately, this very same decoherence could be the problem that in the end makes a large system of interconnected qubits impossible to build.
Any comments?
Sincerely,
Dol
Michele
SvaraRaderaWhat is your science background?
Sincerely,
Dol
Read my treatise Many-Minds Quantum Mechanics at
SvaraRaderahttp://www.csc.kth.se/~cgjoh/ambsquantum.pdf
Can your many-minds quantum mechanics explain the experiment with the single photon state?
SvaraRaderaSincerely,
Dol
Dol, I am a free thinker which always searches the simplest and most coherent answers. For the photoelectric effect I prefer the impulse-momentum theorem as cause-effect correlation because it is the most rational.
SvaraRaderaMichele
Michele wrote:
SvaraRaderaDol, I am a free thinker which always searches the simplest and most coherent answers.
Does this mean that you are self taught in physics?
Sincerely,
Dol
To Dol: if QM can then there is a good chance that MMQM can.
SvaraRaderaDol, I think that whatever academic qualification doesn’t authorize to considering out of logic.
SvaraRaderaI know very well that if I want to uncork a bottle of wine, I pull out its stopper and certainly I don’t push in it thinking that, later, something else will send off it.
Michele
michele,
SvaraRaderaaccording to the classical EM-theory the energy density of an EM is proportional to the square of the amplitude of the electric field.
experiments show that electrons escape a metallic plate only if the impinging light has a frequency higher than a certain treshold, disregarding of the intensity. the intensity influences only the number of escaping electrons (if over the treshold frequency).
with all the respect for you as a free thinker, people like maxwell and lorentz agreed that the photoelectric effect cannot be explained by their theories. there are other free thinkers like einstein, planck, d. jackson, bohr, thousands of other people who have dedicated their lives to studying these phenomena, all agree that your explanation is not correct. all these people are also free thinkers, they are not stupid, they've done their homework.
be aware of the fact that this is not an /authority argument/.
i believe that to have a critical and skeptical approach to science is the only sound strategy. but that doesn't mean behaving like a troubled teenager, that knows everything better than anybody else, that with 2 hours googling finds that 10 nobel prizes are puppets in the hands of hidden powers that want to dominate the world. if you want to dismantel 100 years of physics, you can at least write a 3 pages publication where you wrote down the equations and you've done a couple of experiments.
it should maybe cross your mind that the very simple explanation you provide is maybe too simple and if you find out that that's not the case, then you should try to write a paper on PRL and collect your nobel prize next year, instead of (or at least at the same time as) discussing it on a blog.
Good thinking, thanks.
SvaraRaderalorenzo wrote:
SvaraRaderai believe that to have a critical and skeptical approach to science is the only sound strategy. but that doesn't mean behaving like a troubled teenager, that knows everything better than anybody else, that with 2 hours googling finds that 10 nobel prizes are puppets in the hands of hidden powers that want to dominate the world. if you want to dismantel 100 years of physics, you can at least write a 3 pages publication where you wrote down the equations and you've done a couple of experiments.
I think this touches upon a very important point.
I do think that there exists a romantic picture of the lone genius who sits alone in his chamber using tremendous brain power outsmarting everything that has been thought up to that point (thanks for that Einstein...).
Just because it has worked for some in the past, Einstein being the obvious example, doesn't mean that it is 1) generally a good approach and 2) something that is applicable to the modern frontiers of physical science.
One has to remember that the frontiers of physics at the time of Einstein was at a trivial complexity comparing with today's research. A physicist could have a working knowledge in all different fields at that time, that is no longer true. It has become increasingly important to specialize in a field so that you can have a possibility to take part of the great flow of information and look through all noise together with others.
Sincerely,
Dol
Lorenzo,
SvaraRaderaI think you don’t demonstrate at all that someone is in error solely using the discourtesy. That’s a very poor argumentation. I had preferred you spent some words about the extracting action of the magnetic field of the EM wave on one electron at the metal wall. But you cannot have it all in this world.
It’s obvious that the wave acting must be fast enough to avoid that the caught electron escapes its radius of action. The needed work of half wavelength has to be done at a minimal rapidity and so the electron extraction can occur only above a threshold frequency and above threshold intensity.
Where is the heresy in that?
Michele
michele
SvaraRaderai did not intend to be rude, i just wanted to point out that going against the accepted picture does not have a value per se (i apologise if you felt offended) and that a certain degree of caution (or modesty) could help when confronting ones ideas with the ideas of other people.
regarding the main point the heresy lies in that, according to your theory, you could still have extraction with low frequency by increasing the amplitude of the field. experiment show that this is not possible.
if you do an experiment and find out that light with a wavelength of 390 nm (7,7 10^14 Hz) and a certain intensity I_0 extracts electron from a certain metallic plate while light with a wavelenght of 400 nm (7,5 10^14 Hz) does not even if you make its intensity 10*I_0, then you have to conclude that your model is not correct. and since this is what happens...
Lorenzo,
SvaraRaderaI had never claimed that one “could still have extraction with low frequency by increasing the amplitude of the field.” Conversely, I claim that the classical electrodynamics and mechanics are more than enough to explain the electron extraction from a metal plate by means of EM waves.
The wave has an useful window wide L around its impinging point which is passed trough by both the half active wave in a half period T/2 and the electron in a time L/v, where v is its speed within the electron gas of the metal.
The wave is able to produce the electron extraction if i) its half period is lesser or at least equal to the electron time remaining (T/2 ≤ L/v), that’s, its frequency is f ≥ 2v/L and ii) the work done by the Lorentz force, always in a half wave, is at least equal to the work function of the metal. All that clears up the threshold values of frequency and intensity.
It’s important to point out that the electron is able to pass the borderline of the metal plate when the forcing wave is in a node because its acceleration will be nil and therefore also the inertial and radiative reactive forces will be nil. The electron passes the border in a wholly inertial condition. Otherwise the antagonist forces predominate and the electron is rejected back. That cleans up because the photoelectric effect isn’t possible for frequency below the threshold value.
All that without any elf-like particles.
Michele
michele,
SvaraRaderasorry for not being clear. let me try again.
you say that the cut off frequency simply comes from the fact that the wave has to give enough energy into a given time.
my observation is then: since for classical waves frequency and energy are disentangled (energy is prop to amplitude square) then you've got another degree of freedom that you can use, for lower frequency you increase the amplitude and under the same amount of time you deliver the same energy as before (with a higher frequency and lower amplitude). this means that you would not observe a sharp cut-off frequency if the EM-waves would behave classically.
Lorenzo,
SvaraRaderaI say that the cut off frequency comes from the fact that the wave has to give enough energy into a given time and into a given space.
Michele
michele
SvaraRaderain the classical model for em-waves without elf-particles that you propagate for, if the amplitude is big enough you can give whatever energy you want in a given time and a given space. it's easy, since A is disentangled from f and lambda (that are not independent, by the way) you give the time, the space and the necessary energy and then calculate the necessary amplitude.
Lorenzo,
SvaraRaderaYou can easily obtain that the kinetic energy gained by the electron in the traveling direction of wave as direct result of Lorentz force is prop to (E/f)^4 which must be not lesser than the photoelectric work Pw. May be you are talking about different things.
Also, the wave doesn’t take whatever time because it must be quick enough for being able to catch the electron when it is inside the useful window, otherwise the electron darts away. That’s, the frequency doesn’t be lesser than f* which is a characteristic of the metal.
Then, we have two equations: (E/f)^4 ≥ Pw and f ≥ f* and the system is closed.
Michele
michele,
SvaraRaderayou can easily obtain that by using the correspondence principle that says that for large quantum number quantum --> classic.
in the classical model for em-waves there is no correlation between energy density and frequency.
in other words, you're using elf-particles to deny their existence.
sorry michele,
SvaraRaderaforget about my previous comment, i thought you had written down another equation.
i repeat, since E is disentangled from f, for a given Pw, you can have whatever frequency, provided that E^4 ≥ Pwf^4
Lorenzo,
SvaraRaderaNot at all for whatever frequency but on condition that there should be f ≥ f*.
Michele
where does the condition originate from?
SvaraRaderaLorenzo,
SvaraRaderaThe wave has to volley the electron and really we cannot think a tortoise catches the hare.
Anyway, the answer is in my preceding posts: wave window of action, own velocity of electron, imperative necessity for the extraction work to be done meanwhile the engaged electron is contained within the active window because only in this case it can reach the border firewall of the external surface of the metal plate without acceleration and thus without any antagonist EM force for its escaping out.
Michele
michele,
SvaraRaderai feel you're not reading what i write. the time window for delivery of the necessary energy is given by the speed of the electron and a characteristic distance /of extraction/ , fine. i have understood that, my 7 years daughter has understood that. no need to write that again nor to bring in animals in the discussion.
BUT if the wave has an energy that depends only on its amplitude and if the amplitude and the frequency are disentangled than it is possible to deliver whatever energy you want in any given fraction of wavelength.do i have a frequency that is half f*? i just take E to be twice the amplitude needed when the wave had frequency f*.
so, could you explain to me why i cannot simply double E and have photoeffect at f*/2? your equation allows me to do that.
Lorenzo,
SvaraRaderaI do not have to say any more on this point. I think you and your daughter should try to understand the remainder of what I wrote. I’m done.
Michele
michele,
SvaraRaderamy daughter and i understand what you wrote. we also understand that it does not make sense. i hope some day you'll join us and waves and particles will live as one.