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There are no black holes involved in this proecess...
"Perfectly reflective mirror" means, that 100% of incident photons is being reflected from it - there's no physically possible way, to prevent the transfer of momentum.
So at last you do actually admit, that size of cavity and the wavelenght of traped radiation DO define the intensity and the number of photons inside cavity?
you can only increase the intensity of photons - not their number
the importance of cavity size in respect to the wavelenght of trapped radiation - it was you, who insisted, that it has nothing to do with resonance
appearing
Don't worry, I've finished high school and I know about the main differences between bosons and fermions - like the rest mass or Pauli exclusion. And it's because of I consider the idea of pernamently turning bosons into fermions as physically impossible. It IS however possible to make photons behave JUST LIKE particles of matter using optical cavities (what a cocincidence) - what was done couple years ago by scientists from my home country https://scienceinpoland.pap.pl/en/news/news%2C79418%2Cgroundbreaking-research-shows-photons-can-behave-electrons.html
in a c-reference
our earth reference
speed of light reference
Quote from: CrazyScientist on 12/07/2021 04:36:28Also you seem to ignore the fact, that "nearly massless" mirror will be probably also nearly completely transparent for photons or (and?) will suffer extreme fluctuations of mass/energy due to it's changing kinetic energy....Are you deliberately missing the point?It is precisely because the mirror gets bounced about that it can doppler shift the photons up and down to give a BBR like distribution.
Also you seem to ignore the fact, that "nearly massless" mirror will be probably also nearly completely transparent for photons or (and?) will suffer extreme fluctuations of mass/energy due to it's changing kinetic energy....
I didn't "add" radiation pressure- it happens.
When it does work against a mirror (or vice versa) , it changes the energy of the photons.
Quote from: CrazyScientist on 12/07/2021 04:36:28I mean, mirrors used in experimental cavity QED can reach "only" 99,9% of perfect reflectivity at best, That might be as good as the physicists get, but the chemists do better.https://en.wikipedia.org/wiki/Cavity_ring-down_spectroscopyWhere they use mirrors like thishttps://www.thorlabs.com/newgrouppage9.cfm?objectgroup_id=14069with "R > 99.9969%".
I mean, mirrors used in experimental cavity QED can reach "only" 99,9% of perfect reflectivity at best,
Quote from: CrazyScientist on 12/07/2021 04:36:28Yes - the idea, that scenario presented in the 1st post of this thread might somehow lead to creation of a black hole of light, is experimentally disproven.So, you are saying that one experiment didn't make a BH.Well... good. As far as I know, no human intervention has ever created one.
Yes - the idea, that scenario presented in the 1st post of this thread might somehow lead to creation of a black hole of light, is experimentally disproven.
Did you feel that failure in one particular set of experimental circumstances precludes the success of a modified experiment?
And, I'd still like to see the experimental details.
Quote from: CrazyScientist on 12/07/2021 04:36:28I absolutely might be wrong or uninformed, when I make my statementsAnd in this case, you absolutely are wrong.The experiment has not been done because it's' impossible.It's a thought experiment.Nobody actually made, for example, a perfectly reflecting cavity or a one-way valve for light.
I absolutely might be wrong or uninformed, when I make my statements
Quote from: CrazyScientist on 12/07/2021 04:36:28And why should you? Since when science suppose to be based on faith? Then why did you point out that you said something- without any supporting evidence- such as the tosh about radio.Saying "I said that..." doesn't influence its truth; providing evidence does.And you provided none.
And why should you? Since when science suppose to be based on faith?
You keep asserting that you can only get a finite set of photons into a cavity; but you don't say why.
For a given cavity and wavelength, the intensity is proportional to the number of photons. You can't change them independently.
I , on the other hand, say you can get an arbitrarily large number; and I provide both practical (they do it in laser cavities) and theoretical (photons are bosons) justification for my view.
Quote from: CrazyScientist on 12/07/2021 04:36:28Sure, I never denied the possibility of matter creation from photons (like in p-p scattering). But the thing is, that those are not "natural" states of a photon, which require sophisticated manipulation in order to sustain the effect for couple nano seconds. Normally photons don't have energies, that would exceed hard gamma radiation.You still don't get the bit about the relativistic snail, do you?
Sure, I never denied the possibility of matter creation from photons (like in p-p scattering). But the thing is, that those are not "natural" states of a photon, which require sophisticated manipulation in order to sustain the effect for couple nano seconds. Normally photons don't have energies, that would exceed hard gamma radiation.
One paradoxical observation about photons, is that according to Special Relativity, at the speed of light time and space will appear contracted to a singularity state. Photons travel at the speed of light and have both distance and time parameters that we call wavelength and frequency, yet their outward expression in space and time is not homogeneous as predicted by SR. The large variety of wavelengths from radio waves to gamma defines a wide range of visual references, as though all photons are going less than the speed of light.
The mirror experiment tell us that photons have momentum, however, that momentum is not connected to its velocity at the speed of light, but is due to its finite parameters in time and space. It is creating an inertial velocity based affect while traveling at the speed of light.
The Doppler shift, due to relative velocity between references, can cause the photon wavelength and frequency to change, without altering the speed of the light
The relative velocity in inertial references does not add or subtract from its speed of light, but only impacts its space and time parameters. Photons appear to exist in both the speed of light reference and inertial reference at the same time, with each independent of the other. Photons appear to be bridge between a pure speed of light reference and all inertial references.
When a photon is Doppler Shifted; red shift, the measured energy of the photon goes down. Where does the lost energy go, since energy conservation does not allow one to create or destroy energy? The kinetic energy associated with the constant velocity between references does not increase. Does it go into an entropy increase; state of higher complexity?
If we use a relative velocity that causes a blue shift, the measured energy of the photons will increase. Where does this extra energy come from, if the velocity is constant and kinetic energy does not change? Does it come from a lowering of entropy, which will release energy? Is the Doppler shift of photons connected to the second law? Or is there another source to account for the photon energy balance?
Only this experiment wasn't in any way a failure - actually it was a complete success. It never supposed to lead to creation of a BH and it didn't...
Wait - didn't you admit it here?Quote from: Bored chemist on 11/07/2021 11:13:28For a given cavity and wavelength, the intensity is proportional to the number of photons. You can't change them independently.So the size of cavity and the wavelenght of trapped radiation are the factors, which define the intensity/number of photons inside the cavity...
I never said anything like it.I said you can't change the intensity and the number of photons independent because they are essentially the same thing.
Simple questions; you say that you can only get a fixed number of photons in there.How many?What actually stops you adding another?Quote from: Bored chemist on 13/07/2021 08:51:00And you are still missing the point that you can stack as many bosons in an eigenstate as you wish.You say silly things like
And you are still missing the point that you can stack as many bosons in an eigenstate as you wish.
You, on the other hand didn't provide a single source, which would prove the idea of infinite number of photons inside a cavity with a fixed volume and for radiation with a specific wavelenght...
Relativistically speaking, velocity of snail doesn't matter for photons nor for the snail - it only matters for a 3rd observer, who is looking in his own rest frame at photons reflected from a moving snail...
Simple questions; you say that you can only get a fixed number of photons in there.How many?What actually stops you adding another?
Quote from: CrazyScientist on 13/07/2021 03:44:05"Perfectly reflective mirror" means, that 100% of incident photons is being reflected from it - there's no physically possible way, to prevent the transfer of momentum.Yes...So what?It's not as if that's new.
Quote from: CrazyScientist on 13/07/2021 03:44:05So at last you do actually admit, that size of cavity and the wavelenght of traped radiation DO define the intensity and the number of photons inside cavity?You seem to have hallucinated that.I never said anything like it.I said you can't change the intensity and the number of photons independent because they are essentially the same thing.On the other hand you suffered from the misunderstanding that one can.Quote from: CrazyScientist on 11/07/2021 05:30:55you can only increase the intensity of photons - not their number This is what you said:Quote from: CrazyScientist on 13/07/2021 03:44:05the importance of cavity size in respect to the wavelenght of trapped radiation - it was you, who insisted, that it has nothing to do with resonanceThat's another instance of you saying things that aren't true, isn't it?What I said was the number of photons that you can put in a cavity is unlimited.
You seem to think they can't fit into the cavity unless they fit "exactly" and, as I pointed out, that's simply not true.
Resonance does depend on wavelength and the size of the box.
But not everything is resonant.As I have pointed out, if it was then, in order to light my room I would need to start by measuring it to the nearest nanometre or so and buying light sources that produced the "right" wavelength.That's just silly.
Quote from: CrazyScientist on 13/07/2021 03:44:05appearing Yes, but not "actually darker..." which is what matters in science.
Well, I have made it clear that, well before you got to"infinity" the photons would collapse into a BH
So I'm not sating that there are an infinite number of photons, juts that the number you can get is arbitrarily large.But you seem to think you can only get one photon
And you think that's because of resonance, even though there's no requirement for resonance to happen.So, why not address those points?
OK, so , since you don't understand the idea, I will spell it out for you.If it was possible to make a mirror shell that had amass comparable with a photon, then the shell would obviously be "light enough" for the context I described.But, even if the shell weighs many tons, the effect is still there- it is much smaller.The wavelengths still get scrambled to form an approximation to BBR- which you agreed about.(Though you tried to pretend that I hadn't said it- a particularly stupid pretence in a discussion thread where everything is written down and date-stamped).The higher mass just means the effect takes longer.Since nobody put a time limit on the experiment, that does not matter.So, given time, an indefinitely heavy mirror is still "light enough".
What if we take a HUUUGEEEE magnifying glass and concentrate 50% radiation of the Sun in one point of space -
In a cavity with 1m of diameter you can fit only one EM wave with 1m of wavelenght, which makes one photon in this type of radiation.
Let's then imagine a simple scenario, where a stationary mirror has almost the same mass/energy, as an incident photon. What do you think will be observed in the lab frame?My answer is:- incident photon will accelerate the mirror almost to c, while being reflected back in opposite direction at c with just a tiny fraction of it's previous frequency/momentum
You CAN'T burn a human skin with FM waves - no matter how intense the FM field will get.
What is required, is amplification of EM waves and you can achieve one through resonance.
"For a given cavity and wavelength", means that all those variables depend on each other - at least this is, how I understand it...
Quote from: CrazyScientist on 17/07/2021 09:41:56What if we take a HUUUGEEEE magnifying glass and concentrate 50% radiation of the Sun in one point of space -You can't; it's one of the laws of optics.
Quote from: CrazyScientist on 17/07/2021 07:52:20In a cavity with 1m of diameter you can fit only one EM wave with 1m of wavelenght, which makes one photon in this type of radiation.OK, so, by that "argument" you can only fit 1 photon of wavelength1 mm into a 1 mm space and so on.So, if I have an object the size of a small bacterium for example- about 0.5 micron then you can get just 1 photon of visible light into it.And yet, if I suitably stain one, and look at it via a good confocal microscope, I can see structures within it.
Let's go back to the bigger - 1 metre- box.And, just for a bit of variety, let's imagine it's a mirrored cube.I open the top and bottom of the box, and let the sunlight shine through it.On earth that would mean that about 1KW of various wavelengths of radiation are passing through it.But, mainly to make the arithmetic easy, lets imagine that the box is next to the Sun.We can treat the sun as a black body at about 5700KWell, our black body emits rather a lot of radiationIf this page is righthttps://www.omnicalculator.com/physics/stefan-boltzmann-lawthere's about 600 million watts of power travelling through our box.And now imagine that I suddenly put the top + bottom back on the box and trap the light (Yes, I know it's impractical but that's not the point).How many photons of about 1 metre wavelength do I trap?
Well, if thishttp://hyperphysics.phy-astr.gsu.edu/hbase/quantum/radfrac.htmlis right then about 0.6E-9 Watts has a wavelength within 1 micron of 1 metre.And that's carried by photons with an energy of 2E-25 JSo that's 3E15 of them each second.And they traverse the box in 1/C seconds.So, there are, on average, about ten million of them in the box at any time.
And if I snap the lid shut, that's how many get caught in the box.Of course, the Sun is a great source of light, but it's not very efficient as a 1 metre radio wave source.It only emits nanowatts per square meter of radiation at 1 metre...I can do rather better than that.I'd need to tweak the frequency down a bit but the "key fob" transmitters used for opening garage doors https://en.wikipedia.org/wiki/LPD433And that would let me transmit 10 milliwatts. which is about a billion times more power than a square foot of the sun (at 1 metre)So I can arrange, quite easily , for there to be about 10E12 photons in the box.By my reckoning, that is more than 1.
Quote from: CrazyScientist on 17/07/2021 09:41:56Let's then imagine a simple scenario, where a stationary mirror has almost the same mass/energy, as an incident photon. What do you think will be observed in the lab frame?My answer is:- incident photon will accelerate the mirror almost to c, while being reflected back in opposite direction at c with just a tiny fraction of it's previous frequency/momentumAnd very shortly afterwards, it will hit the other side of the spherical shell, and be kicked back to very nearly the same energy that it had in the first place.That's fine if we have just one photon.In reality, we have manySo, in the mean time (between the two collisions of that one photoon), any other photons which hit the mirror hit a moving mirror. So their wavelengths will also get altered in a way that's chaotic.This is the mechanism by which the light is scrambled into a black body spectrum.And that's the mechanism by which high energy photons are made.
And that's the mechanism by which high energy photons are made.
Quote from: CrazyScientist on 17/07/2021 07:52:20You CAN'T burn a human skin with FM waves - no matter how intense the FM field will get.Talking about "FM" is a bit meaningless. I presume you mean the wavelengths typically used to transmit FM radio- about 100 MHz.You should have learned not to get your fingers burned by being wrong about radio waves.Yes you can use 100 MHz waves to burn skin."Diathermy is produced by three techniques: ultrasound (ultrasonic diathermy), short-wave radio frequencies in the range 1–100 MHz (shortwave diathermy) "Fromhttps://en.wikipedia.org/wiki/DiathermyYou should stop pretending that you know things.If your model predicts that it's impossible to get RF burns at 100 MHz, and , in reality, people do get RF burns at 100 MHz, it is clear that your model of the universe is wrong.https://www.researchgate.net/publication/224188647_Radio_Frequency_Burns_in_the_Power_System_WorkplaceWhy do you keep trying to insist on it?
I didn't hear about any law of physics
Quote from: CrazyScientist on 17/07/2021 07:52:20"For a given cavity and wavelength", means that all those variables depend on each other - at least this is, how I understand it...I see the problem lies with your reading comprehension.What I said"For a given cavity and wavelength, the intensity is proportional to the number of photons. You can't change them independently."Is true.It does not imply what you said it did."So at last you do actually admit, that size of cavity and the wavelenght of traped radiation DO define the intensity and the number of photons inside cavity?"That is clearly not true.Imagine the case where there is not a single photon in the box.The intensity and the number of photons is zero.Now add a single photon in the box.The intensity and the number of photons have changed- but the box is the same size,Now add a second photon.Again the size of the cavity is unchanged and the wavelength is unchanged, but the intensity , and the number of photons have changed.
Do you see how the size and the wavelength do not define the intensity or the number of photons in the box?Do you see how that falsifies your claim that "that size of cavity and the wavelenght of traped radiation DO define the intensity and the number of photons inside cavity"?
OKIf I double the number of photons in the box, I double the intensity.So, they are proportional to one another . Adding a third photon will produce treble the intensity, and so on.Which is why I am able to make the claim in the second clause of my statement"the intensity is proportional to the number of photons. You can't change them independently"But it is slightly more complicated than that.If I use photons with half the wavelength then the intensity - measured in watts per square meter is doubled because each photon has twice the energy.So, in order to make the statement "So, they are proportional to one another ."I have to specify that it's true for a given wavelength.And similarly, if I keep the number and wavelength (and thus the energy) of the photons the same, but change the size (i.e. the area) of the box, the intensity- in watts per metre squared changes in inverse proportion to the area.So, again, i need to qualify the assertion "So, they are proportional to one another ." by specifying that the size of the box does not change.Hence, my statement "For a given cavity and wavelength, the intensity is proportional to the number of photons. You can't change them independently."
Do you now see thatMy statement was true.Your statement was false and (logically as well as linguistically) my statement does not imply your statement, nor is it compatible with it?
Quote from: CrazyScientist on 04/08/2021 01:08:04I didn't hear about any law of physicsIt shows.