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Quote from: CrazyScientist on 20/06/2021 13:11:24Of course! Because of the momentum conservation, when the ball is being hit by the bat, their relative velocity can be higher, than before their collision OK, it's becoming increasingly clear that you are just posting nonsense, and you are doing it deliberately.
Of course! Because of the momentum conservation, when the ball is being hit by the bat, their relative velocity can be higher, than before their collision
I already said Quote from: Bored chemist on 20/06/2021 10:32:26from the point of view of the batsman?Stop trolling, and answer the question.
from the point of view of the batsman?
So I guess it means, that sunlight propagates as a buch of different photons, that occupy the same volume of space. This means, that it should be possible to simultaneously detect multiple photons at different frequencies, that are overlaping each other in a single volume of space...However it seems, that such situation is hysically impossible..
Quote from: Bored chemist on 20/06/2021 13:16:55Quote from: CrazyScientist on 20/06/2021 13:11:24Yes.... And each kind of EM radiation has a specific and measurable wavelenght... So...?So... you say "yes", but you mean "no".I mean exactly, what I say...
Quote from: CrazyScientist on 20/06/2021 13:11:24Yes.... And each kind of EM radiation has a specific and measurable wavelenght... So...?So... you say "yes", but you mean "no".
Yes.... And each kind of EM radiation has a specific and measurable wavelenght... So...?
I still have no idea, what any of this has to do with cavity
If you compress a mirror box with light in then you do work against that photon pressure.Where does that energy go?I contend that it raises the frequencies of the photons in the box. What do you think happens to it?Or are you really claiming that energy is not conserved?
Obviously into the atoms, that make the resonance cavity
Nope. it's exactly opposite - momentum transfer during reflection of an EM wave increases it's wavelenght
I guess, you slept during physics classes, when the Newton's laws of motion were discussed... If you wouldn't sleep, you would know, that to slow down an object, that moves at constant velocity, you need to use a force - so photons, which are slowing down the mirror are giving up their own energy... It's basic physics - aren't you ashamed to not know such things?
So I guess
This means, that it should be possible to simultaneously detect multiple photons at different frequencies, that are overlaping each other in a single volume of space...However it seems, that such situation is physically impossible...
Because creation of matter particles from radiation in the laboratory has nothing to do with the stable matter, that surrounds us
Explain, what for you defines the mass/energy of EM radiation
my idea of X-stationary photons
I guess, it's too hard for you to understand, that visible light has a very short wavelenght, so the size of cavity matters mostly at the microscopic level.
Quote from: CrazyScientist on 20/06/2021 13:32:16Quote from: Bored chemist on 20/06/2021 13:16:55Quote from: CrazyScientist on 20/06/2021 13:11:24Yes.... And each kind of EM radiation has a specific and measurable wavelenght... So...?So... you say "yes", but you mean "no".I mean exactly, what I say...So you do understand that there's an uncertainty relation for energy which means that (in any finite time) the wavelength is not perfectly defined so you can't say whether or not it exactly fits into a cavity?Yet you say that things can or can't happen depending on whether it fits or not.
Quote from: CrazyScientist on 20/06/2021 13:42:55I still have no idea, what any of this has to do with cavity Once again, we are back with the problem of your memory...It's relevant to the idea of compressing a cavity with light in it until it becomes a blackhole.You may, if prompted, remember thisQuote from: Bored chemist on 12/06/2021 22:47:40If you compress a mirror box with light in then you do work against that photon pressure.Where does that energy go?I contend that it raises the frequencies of the photons in the box. What do you think happens to it?Or are you really claiming that energy is not conserved?And your absurd replyQuote from: CrazyScientist on 13/06/2021 00:52:12Obviously into the atoms, that make the resonance cavityTo which I pointed out that , since the mirrors are perfectly reflective, you can't put energy into them that way.And then you posted a diagram which you misunderstood and said thisQuote from: CrazyScientist on 13/06/2021 00:52:12Nope. it's exactly opposite - momentum transfer during reflection of an EM wave increases it's wavelenghtThen you got shouty about a mirror's movement being relativistic- as if that was somehow magical- until I pointed out that a snail's movement is relativistic, it's just that the relativistic corrections are rather small.But you still didn't seem to grasp the fact that bouncing a photon off a mirror that's coming towards you will mean that the photon comes back at you with a higher energy, and the mirror gets slowed down a bit.Fundamentally, you still have not answered the question.What happens to the work done against photon pressure if you compress a box that has light in it?Instead of answering, you cam up with this toshQuote from: CrazyScientist on 14/06/2021 17:11:04I guess, you slept during physics classes, when the Newton's laws of motion were discussed... If you wouldn't sleep, you would know, that to slow down an object, that moves at constant velocity, you need to use a force - so photons, which are slowing down the mirror are giving up their own energy... It's basic physics - aren't you ashamed to not know such things?Now, since you framed your bilge in terms of high school physics, then, regardless of any weirdness due to quantum effects, it should work in terms of high school physics.But you say that if a ball exerts a force on a moving bat, the bat will gain energy (yet it slows down) and the ball will lose energy (though its speed increases). Do you really believe that?Please don't waste time on energy losses and coefficients of restitution- this is an ideal, perfect mirror.There are no losses.
You have just told me that I can't tune a radio to one frequency if someone else has their radio tuned to another frequency.Do you want to think that through again?
I don't understand why you keep saying thing like "for you".It's not me. You can argue the point whether, in this case it's de Broglie's equation or Einstein's.But it's not "me" that's defining anything.You were the one trying to define new words- do you remember?
And the only actual size given for any cavity was a millimetre or so, which is vastly bigger than the wavelength of light.
You keep telling me it's terribly important that the waves fit in the cavity.But you ignore the fact that my lightbulb proves you are wrong.It's a broadband emitter.
Obviously, electrons made in the lab are different- they have a little tag on them which says "made in England".Or, possibly, you're talking nonsense again, and the two scenarios do have a lot of common ground.
Well, sorry to inform you, that time keeps going on and science is constantly progressing... Modern-day nanocavities are capable of trapping a single photon...
That's a completely invalid analogy. Instead try listening simultaneouly to 2 radio stations using one receiver with a single antenna... I might rethink my claims, when you'll manage to do it...
EDIT - you can use 2 receivers with one shared antenna,
So, what then defines the energy/mass of EM radiation - momentum or frequency of EM waves? It's a simple question with only 2 options.- please, try better this time...
But the wavelenght of EM radiation IS very well defined - we know for example the EXACT lenghts of EM waves for each color of visible spectrum - you even said, that you've measured one by yourself. Isn't that quite self-contradictory?
But you still didn't seem to grasp the fact that bouncing a photon off a mirror that's coming towards you will mean that the photon comes back at you with a higher energy, and the mirror gets slowed down a bit.Fundamentally, you still have not answered the question.What happens to the work done against photon pressure if you compress a box that has light in it?Instead of answering, you cam up with this toshQuote from: CrazyScientist on 14/06/2021 17:11:04I guess, you slept during physics classes, when the Newton's laws of motion were discussed... If you wouldn't sleep, you would know, that to slow down an object, that moves at constant velocity, you need to use a force - so photons, which are slowing down the mirror are giving up their own energy... It's basic physics - aren't you ashamed to not know such things?Now, since you framed your bilge in terms of high school physics, then, regardless of any weirdness due to quantum effects, it should work in terms of high school physics.But you say that if a ball exerts a force on a moving bat, the bat will gain energy (yet it slows down) and the ball will lose energy (though its speed increases).Do you really believe that?Please don't waste time on energy losses and coefficients of restitution- this is an ideal, perfect mirror.There are no losses.
Quote from: CrazyScientist on 21/06/2021 00:02:43Well, sorry to inform you, that time keeps going on and science is constantly progressing... Modern-day nanocavities are capable of trapping a single photon...I know.For what it's worth, you can trap a single photon in a big cavity too.But, since we were actually planning to use a bigger chamber your assertion, while true, is irrelevant, isn't it?
Using one antenna is easy enough; my house has a combined TV/ FM antenna both signals come down the same wire.
In principle, I can do a bit better.I can hook a long wire to the input of a modern oscilloscope and what I see is the sum of all the EM fields which the antenna picks up.And then I can ask the 'scope to do an FFT on the signal and it will cheerfully "receive" and display all the radio stations etc in the area.Would you like to buy me a new digital scope?
Quote from: CrazyScientist on 20/06/2021 23:35:13So, what then defines the energy/mass of EM radiation - momentum or frequency of EM waves? It's a simple question with only 2 options.- please, try better this time...It's a simple question, but meaningless.I can calculate the energy of a photon from it's momentum, or from its frequency.So either of them define it.Did you not realise that?
Quote from: CrazyScientist on 20/06/2021 23:24:49But the wavelenght of EM radiation IS very well defined - we know for example the EXACT lenghts of EM waves for each color of visible spectrum - you even said, that you've measured one by yourself. Isn't that quite self-contradictory?Get back to us when you know what the uncertainty principle tells us about energy.Until then, you don't have the knowledge to see why you must be wrong and there's no point carrying on the discussion.Mind you, We won't expect much from the guy who can't face up to having said that the point of a bat is to make the ball go slower.Are you going to address this before, or after, learning what the uncertainty principle says about wavelengths?
But you still didn't seem to grasp the fact that bouncing a photon off a mirror that's coming towards you will mean that the photon comes back at you with a higher energy, and the mirror gets slowed down a bit.
Fundamentally, you still have not answered the question.What happens to the work done against photon pressure if you compress a box that has light in it?
Instead of answering, you cam up with this toshQuote from: CrazyScientist on 14/06/2021 17:11:04I guess, you slept during physics classes, when the Newton's laws of motion were discussed... If you wouldn't sleep, you would know, that to slow down an object, that moves at constant velocity, you need to use a force - so photons, which are slowing down the mirror are giving up their own energy... It's basic physics - aren't you ashamed to not know such things?
Now, since you framed your bilge in terms of high school physics, then, regardless of any weirdness due to quantum effects, it should work in terms of high school physics.But you say that if a ball exerts a force on a moving bat, the bat will gain energy (yet it slows down) and the ball will lose energy (though its speed increases).Do you really believe that?Please don't waste time on energy losses and coefficients of restitution- this is an ideal, perfect mirror.There are no losses.
This is a really good question. Simple as it is stated, it turns out hard to answer, but is worth trying to. It took me and my colleagues a 21 pages paper Phys. Rev. D 91, 016005 (2015) to address a simpler question.The main issue is the radical change of boundary conditions the photon quantum undergoes when (instantly, or better in an insignificant amount of time) gets into the cavity.Before entering into the cavity, the photon is an elementary excitation of the em field in the whole space. It is defined in this way in QFT (I think you are thinking of this case, as a wave packet is only a superposition of elementary excitations), and it is described by a Fock state a(k) |o>. Notice that the a(k) and a(k)^+ operators are defined as those who annihilate or create an elementary excitation of momentum k - IN ALL SPACE R^3 - at an instant of time.That is, these operators remove or add a normal mode of the wave equation in Minkowski space. Those modes are specified by the equation and the boundary conditions. Only by considering both together, the allowed wave numbers emerge.Beyond waves, in quantum physics -i.e. QFT - there are particles; photons in this case. To handle this, we need of a counting tool and the Fock treatment provides us with one, the number operator N(k) = a^+(k) a(k), which counts the number of elementary excitations of momentum k (wave number 1/k) present in the WHOLE SPACE R^3. Coming back to your question; before entering into the cavity there is a photon of wave number 1/k as counted by N(k) (or of wave length λ according to your original wording).The point is that photons inside the cavity are not created or annihilated by the same operators as before, but by operators b(k_n)^+, b(k_n) that add or remove one n-th normal mode of the cavity. Accordingly, photons inside the cavity will be counted by the operator b(k_n)^+b(k_n).Finally, the same quantum state will have different expansions in terms of the R^3 normal modes than in terms of the cavity normal modes. In poor words, what was one free space photon outside may become a bunch of cavity photons inside.Mathematically this is involved as both photon representations are unitarily inequivalent!I hope this explanation will serve to add some light to your question. juan.leon@csic.esI saw your interests in your Research Gate page
Actually I didn't say anything about the size of cavity.
Nobody was trying to make photons smaller than any limit (apart from a rather arbitrary1mm which was chosen as a bit smaller than the radius of an earth mass BH)
Sure - only TV and FM use EM waves at different freuency bands...
It IS important,
Get back to us when you know what the uncertainty principle tells us about energy.
the energy loss due to transfer of momentum
Quote from: Bored chemist on 20/06/2021 15:06:01Instead of answering, you cam up with this toshQuote from: CrazyScientist on 14/06/2021 17:11:04I guess, you slept during physics classes, when the Newton's laws of motion were discussed... If you wouldn't sleep, you would know, that to slow down an object, that moves at constant velocity, you need to use a force - so photons, which are slowing down the mirror are giving up their own energy... It's basic physics - aren't you ashamed to not know such things?It's because you insist to use the baseball analogy, which doesn't have anything to do with cavity QED, which SHOULD be used, to solve the presented scenario...Quote from: Bored chemist on 20/06/2021 15:06:01Now, since you framed your bilge in terms of high school physics, then, regardless of any weirdness due to quantum effects, it should work in terms of high school physics.But you say that if a ball exerts a force on a moving bat, the bat will gain energy (yet it slows down) and the ball will lose energy (though its speed increases).Do you really believe that?Please don't waste time on energy losses and coefficients of restitution- this is an ideal, perfect mirror.There are no losses.Not only you still keep insisting to use this invalid analogy, but you also keep using a 3rd frame of some batsman guy, which can't be applied to interactions between the mirror (baseball bat) and the photon (ball). And what makes your baseball analogy completely wrong, is the fact, that photons suppose to move at a constant velocity of c, while in the rest frame of mirror, those photons are in fact causing acceleration opposite to the constant motion in your 3rd batsman frame...
And this:https://www.eenewseurope.com/news/light-trap-turns-photons-massive-quasiparticles
Quote from: CrazyScientist on 20/06/2021 13:25:32So I guess it means, that sunlight propagates as a buch of different photons, that occupy the same volume of space. This means, that it should be possible to simultaneously detect multiple photons at different frequencies, that are overlaping each other in a single volume of space...However it seems, that such situation is hysically impossible..Really, that seems impossible? If only there were some sort of simple device that could separate the multiple wavelengths into separate wavelengths to see if it is possible, but I guess there just is no such futuristic device.
You had said it was impossible to receive different frequencies, so I chose very different ones to make the point that you were wrong.
But my point about hooking a spectrum analyser to an antenna overrides it anyway.Your "reply" And then, when you try to receive one specific wavelenght in a given frequency band, photons placed around your antenna will collapse to that specific state " makes no sense.The spectrum analysis works.So it's receiving many channels at once.It would be obvious from time to time when the AM radio stations broadcast a minute's silence- all the peaks would drop to zero simultaneously.You can see the intensity of the broadcast at each frequency. So they are resolved; they are no longer in a superposition.It proves that it's possible.