[Bored chemist]

Those wavelenghts are associated with so called eigenstates, where the energy and number of photons can reach only a certain level for each of those states

Another thing you keep misunderstanding.
The number of eigenstates for a particle in a box is finite.
But photons are bosons.
You can have as many of them as you like in one of those states.

 (to a very good approximation- specifically, if you have too many, the box collapses into a BH)

[Bored chemist]

But to increase the temperature beyond some level, you would have to start increasing the frequency of emitted radiation

Yes.

And here is the bit where you realised how to do that.

And if in the laboratory frame, mirror will move fast enough, then due to Doppler shift, reflected radiation will have higher frequency (shorter wavelenght) than before the reflection...

[CrazyScientist (OP)]

And if in the laboratory frame, mirror will move fast enough, then due to Doppler shift, reflected radiation will have higher frequency (shorter wavelenght) than before the reflection...

And, finally, you work out what a bat is for.

That's what I have been saying all along.

thing is, that energy of photons is in this case relative and doesn't get higher in the rest frame of cavity (mirror)

[Bored chemist]

Thing is, that intensity of radiation trapped in a cavity can reach only a certain level and the radiation pressure will then become constant.

You keep saying this, but offering no valid reason.
Is your confusion  caused by not realising that you can have many photons in the same eigenstate/ mode?

[Bored chemist]

And if in the laboratory frame, mirror will move fast enough, then due to Doppler shift, reflected radiation will have higher frequency (shorter wavelenght) than before the reflection...

And, finally, you work out what a bat is for.

That's what I have been saying all along.

thing is, that energy of photons is in this case relative and doesn't get higher in the rest frame of cavity (mirror)

As I have pointed out, I'm not in the cavity.
The energy of the photons if they are "lucky" can be raised arbitrarily high from my perspective.

[CrazyScientist (OP)]

But to increase the temperature beyond some level, you would have to start increasing the frequency of emitted radiation

Yes.

And here is the bit where you realised how to do that.

And if in the laboratory frame, mirror will move fast enough, then due to Doppler shift, reflected radiation will have higher frequency (shorter wavelenght) than before the reflection...

Problem is, that Doppler shift is in 100% relative and symmerical, so an energy level, which is constant in the lab frame will appear to increase in the rest frame of moving cavity/mirror - just as constant energy level in the rest frame of moving cavity will appear to increase in the lab. frame...

Shortly, none of this can't produce any definitive effects. To create a Kugelblitz, frequency of trapped radiation would have to be increasing in both frames...

I have now couple things to do, but I'll be back soon enough...

[Bored chemist]

To create a Kugelblitz, frequency of trapped radiation would have to be increasing in both frames...

I guess  we are making progress, you were saying things like this

Personally, I consider both those options as completely wrong and physically impossible.

In the end it seems that QM handles the behavior of light much better than GR - but if you prefer to believe in black holes made of pure light, then it's up to you

What is then actual science for you? Black holes made of pure light?

and it seems you now realise you were wrong and that they are possible.

If the creation of a Kugelblitz is somehow possible, then it can be achieved ONLY by the increase of frequency of trapped radiation and not it's intensity

[Bored chemist]

Woow! It's the first time, when I agree with  your predictions

And it's only taken you a month or so to notice since I originally posted it.

Great; unfortunately, you then decided to disagree with yourself.
My prediction was that you get BBR.
And that includes some photons with higher than average energies i.e. higher frequencies.
And then you say.

But to increase the temperature beyond some level, you would have to start increasing the frequency of emitted radiation

Well, once you have BBR, you already have those increased frequencies.

Problem solved. Black holes for everyone!

[Bored chemist]

Imagine bouncing a snooker ball off a bowling ball- it bounces back.
But if you try to bounce a snooker ball of another snooker ball the first ball stops and the second one moves off at the same speed as the ball that hit it was travelling.

Doh!
I thought about it again.
The momentum transfer works the other way. To avoid it you need a low mass mirror.
Never mind; you were still wrong.
It does make a difference so this

Momentum transfer will be exactly the same, no matter what's the rest mass of the mirror

is wrong.

Could you just pretend that where I said something like " as long as the mirror is massive enough..." , I said"...light enough...".
Thanks

[CrazyScientist (OP)]

To create a Kugelblitz, frequency of trapped radiation would have to be increasing in both frames...

I guess  we are making progress, you were saying things like this

Personally, I consider both those options as completely wrong and physically impossible.

In the end it seems that QM handles the behavior of light much better than GR - but if you prefer to believe in black holes made of pure light, then it's up to you

What is then actual science for you? Black holes made of pure light?

and it seems you now realise you were wrong and that they are possible.

If the creation of a Kugelblitz is somehow possible, then it can be achieved ONLY by the increase of frequency of trapped radiation and not it's intensity

That's because it IS impossible to create a black hole in the scenario from my 1st post, as it includes constant radiation and stationary cavity. It's you, who keep to add some additional variables, to achieve something, what is impossible in this scenario. I've simply proposed you something, what MIGHT (in my humble opinion) allow you to achieve your goal, by adding a secondary source of mechanical force to create a vibrational motion of the cavity...

And just as I wrote down my previous sentence, I started to wonder about the difference of a source that is stationary in relation to the shaking cavity and a source, which is shaking together with the rest...... Hmm, something to think about

Imagine a source of light, like a led lamp (almost no emission of heat), which is enclosed inside a hollow sphere with a perfect mirror as it's inner surface. What do you think will happen, if that source will continuouslly emit light with a constant intensity and frequency, which will be then continuously reflected inside the sphere? Keep in mind, that there won't be no absorption of energy by the inner surface (100% of energy reflected from the perfect mirror)...

And it's only now, that I've noticed my mistake - instead: 100% of energy reflected from the perfect mirror, it should be all incident photons are reflected from the perfect mirror. What matters for me is the NUBER of photons trapped in a cavity...

Woow! It's the first time, when I agree with  your predictions

And it's only taken you a month or so to notice since I originally posted it.

Great; unfortunately, you then decided to disagree with yourself.
My prediction was that you get BBR.

Huh? You've only mentioned about it in your previous post FOR THE FIRST TIME in this entire discussion

My prediction was that you get BBR.
And that includes some photons with higher than average energies i.e. higher frequencies.

Oh really?
https://en.wikipedia.org/wiki/Black-body_radiation

Black-body radiation is the thermal electromagnetic radiation within or surrounding a body in thermodynamic equilibrium with its environment, emitted by a black body (an idealized opaque, non-reflective body). It has a specific spectrum of wavelengths, inversely related to intensity that depend only on the body's temperature, which is assumed for the sake of calculations and theory to be uniform and constant.

Hmm, if I remember correctly, from the beginning I was predicting, that in my scenario, the entire system will simply reach a constant equilibrium at a speific energy level, which in big part depends on the size of cavity...

And then you say.

But to increase the temperature beyond some level, you would have to start increasing the frequency of emitted radiation

Well, once you have BBR, you already have those increased frequencies.

Problem solved. Black holes for everyone!

Huh? BBR represents a system in a termodynamic equilibrium - If you increase the fequency of trapped radiation, you will disturb the static state of this sytem, which will after some time reach equilibriun at a higher level of energy....

And if you want to make a BH out of this, you will have to "completely fill" the cavity with energy equal to I guess something like:

Planck mass * (volume of space / Planck lenght)

What makes a LOT of energy density...

[CrazyScientist (OP)]

Imagine bouncing a snooker ball off a bowling ball- it bounces back.
But if you try to bounce a snooker ball of another snooker ball the first ball stops and the second one moves off at the same speed as the ball that hit it was travelling.

Doh!
I thought about it again.
The momentum transfer works the other way. To avoid it you need a low mass mirror.
Never mind; you were still wrong.

Then think about it again, only this time keep in mind, that in the difference to snooker balls, photons NEVER change their velocity

It does make a difference so this

Momentum transfer will be exactly the same, no matter what's the rest mass of the mirror

is wrong.

Mass of reflective matter doesn't affect the momentum of a photon before the reflection - and in every case the total sum of energy (photon+mirror) will remain the same before and after reflection.

Could you just pretend that where I said something like " as long as the mirror is massive enough..." , I said"...light enough...".
Thanks

But in this case only light can be light enough - matter is never as light as light is.

[CrazyScientist (OP)]

Those wavelenghts are associated with so called eigenstates, where the energy and number of photons can reach only a certain level for each of those states

Another thing you keep misunderstanding.
The number of eigenstates for a particle in a box is finite.
But photons are bosons.
You can have as many of them as you like in one of those states.

 (to a very good approximation- specifically, if you have too many, the box collapses into a BH)

Nope - you have a FINITE number of photons for each avaliable eigenstate

For each wavelenght, you can only increase the intensity of photons - not their number inside the cavity

[Bored chemist]

Huh? You've only mentioned about it in your previous post FOR THE FIRST TIME in this entire discussion

Learn to read.

You can imagine a nearly massless mirror.
When a photon hits it, it will move and take some energy from the photon. But that means that, when another photon hits it on the other side, it will add energy to that photon.
Overall, the sum of the energies will be conserved The wavelengths of the photons will be "scrambled" and will settle down to a black-body distribution.

[Bored chemist]

That's because it IS impossible to create a black hole in the scenario from my 1st post,

Yes, you did say that.
And you said that it had been experimentally disproven.
And we are still waiting for you to either admit you were wrong, or show us the details of the experiment.

You also said a lot of tosh about radio receivers.

Do you understand why I might not take your word for things?

But in this case only light can be light enough - matter is never as light as light is.

What the light actually  "hits" is an electron.
It's perfectly possible to have photons with higher relativistic masses than an electron.

However for a more practical mass, it's like the relativistic snail - the effect is still there, it's just small.

So "light enough" doesn't mean impossibly  light.

[Bored chemist]

Nope - you have a FINITE number of photons for each avaliable eigenstate

No.
And, indeed, you illustrated it earlier.
You showed the light bouncing back and to in a laser cavity, and you lied about what I thought that would mean.

But what it does illustrate is many photons- all in synchrony bouncing back and to.
If you replace teh partially reflecting mirror by a completely reflecting one then, in principle  you valve a cavity in which they bounce "forever".
In reality they won't, because of diffraction.
(Have you ever actually built a laser- from scratch? The insight it gives is quite useful.)

But here's the issue, as far as I can tell
You know that, in an atom, you can only get two electrons into a given orbital.
And you think that, by analogy- since the orbitals are eigenstates of the atom, you can only get a finite number of photons into an eigenstate.

But what you have missed is that photons are not like electrons- (I'm sure I have heard someone say something like that recently).
Photons are not fermions, they are bosons. (Gauge bosons, as it happens).
And so you can stack as many bosons as you like in one quantum state.


presumably you will now say that I should have mentioned this earlier.
Well, I did
https://www.thenakedscientists.com/forum/index.php?topic=82373.msg643464#msg643464

[Bored chemist]

For each wavelenght, you can only increase the intensity of photons - not their number inside the cavity

For a given cavity and wavelength, the intensity is proportional to the number of photons. You can't change them independently.

[CrazyScientist (OP)]

Huh? You've only mentioned about it in your previous post FOR THE FIRST TIME in this entire discussion

Learn to read.

You can imagine a nearly massless mirror.
When a photon hits it, it will move and take some energy from the photon. But that means that, when another photon hits it on the other side, it will add energy to that photon.
Overall, the sum of the energies will be conserved The wavelengths of the photons will be "scrambled" and will settle down to a black-body distribution.

Only in this case you again added yet another variable (opposite radiation pressure). 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....

That's because it IS impossible to create a black hole in the scenario from my 1st post,

Yes, you did say that.
And you said that it had been experimentally disproven.

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.

I mean, mirrors used in experimental cavity QED can reach "only" 99,9% of perfect reflectivity at best, but it still gives a pretty good idea about the most possible result of constant radiation trapped in a resonant cavity

And we are still waiting for you to either admit you were wrong, or show us the details of the experiment.

I absolutely might be wrong or uninformed, when I make my statements... I don't try to pretend to be a professional physicist - physics is for me just some weird kind of a hobby (passion maybe) and nothing more ... I mean, not even 2 months ago, when I began this thread, I've never heard about such things like cavity optomechanics, quantum electrodynamics or harmonic oscillation[/i] .. It just so happens, that recently professional scientists seem to find particular interest in the same things as I did...

Here's for example my scenario tested in practice:
https://www.researchgate.net/publication/340240163_Spontaneous_Decay_of_a_Dressed_Harmonic_Oscillator_Inside_a_Spherical_Cavity

We consider a complete study of the influence of the cavity size on the spontaneous decay of an atom excited state, roughly approximated by a harmonic oscillator. We confine the oscillator-field system in a spherical cavity of finite radius, perfectly reflective, and work in the formalism of dressed coordinates and states, which allows performing nonperturbative calculations for the probability of the oscillator to decay spontaneously from the first excited state to the ground state. In free space, we obtain known exact results and, for sufficiently small radii, we have developed a power expansion calculation on this parameter. Furthermore, for cavities of arbitrary size radius, we developed numerical computations and showed a complete agreement of this method with the exact one for free space and the power expansion results for small cavities, in this way showing the robustness of our numerical computations. We have found that, in general, the spontaneous decay of an excited state of the oscillator increases with the cavity size radius and vice versa. For sufficiently small cavities, the oscillator practically does not suffers spontaneous decay, whereas for large cavities, the spontaneous decay approaches the free-space value. On the other hand, for some particular values of the cavity radius, in which the cavity is in resonance with the natural frequency of the atom, the spontaneous decay transition probability is increased compared to the free-space case. Also, we showed how the probability of spontaneous decay goes from an oscillatory time behavior, for finite cavity radius, to almost exponential decay, for free space.

It seems that for some reason there's absolutely not a single mention about a black hole of light - instead, results seem to nicely prove my own predictions...

Here's also a nice paper:
https://authors.library.caltech.edu/106173/15/TR000576_06_chapter-6.pdf

In Chapter 5 we found that an atomic medium with an inverted population (N2 > N1) is capable of amplifying an electromagnetic wave if the latter's frequency falls within the transition lineshape. Consider next the case in which the laser medium is placed inside an optical resonator. As the electromagnetic wave bounces back and forth between the two reflectors, it passes through the laser medium and is amplified. Ifthe amplification exceeds the losses caused by imperfect reflection in the mirrors and scattering in the laser medium, the field energy stored in the resonator will increase with time. This causes the amplification constant to decrease as a result of gain saturation (see (5.6-10) and the discussion surrounding it.) The oscillation level will keep increasing until the saturated gain per pass just equals the losses. At this point the net gain per pass is unity and no further increase in the radiation intensity is possible—that is, steady-state oscillation obtains.

And now your turn - provide me a single source, which might  suggest just in a tiny bit, that scenario in the form, which is presented in the 1st post of this thread,  might somehow result in creation of a black hole - anything, what is supported by actual observation... I'll wait

You also said a lot of tosh about radio receivers.
Do you understand why I might not take your word for things?

And why should you? Since when science suppose to be based on faith? 

I never trust in someone's claims, until I won't verify them by myself - and then I still keep having my doubts about them. Maybe instead having a complete trust in your own judgements, you should also try making someties a simple google research - you might be surprised by the results

But in this case only light can be light enough - matter is never as light as light is.

What the light actually  "hits" is an electron.
It's perfectly possible to have photons with higher relativistic masses than an electron.

However for a more practical mass, it's like the relativistic snail - the effect is still there, it's just small.

So "light enough" doesn't mean impossibly  light.

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.

TBC

[Bored chemist]

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....

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.

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.

I 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_spectroscopy
Where they use mirrors like this
https://www.thorlabs.com/newgrouppage9.cfm?objectgroup_id=14069

with "R > 99.9969%".

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.

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.

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.

I absolutely might be wrong or uninformed, when I make my statements

And 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.

And 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.
You keep asserting that you can only get a finite set of photons into a cavity; but you don't say why.
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.

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.

You still don't get the bit about the relativistic snail, do you?

[puppypower]

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?
 

[CrazyScientist (OP)]

Nope - you have a FINITE number of photons for each avaliable eigenstate

No.
And, indeed, you illustrated it earlier.
You showed the light bouncing back and to in a laser cavity, and you lied about what I thought that would mean.

What it means, that photons will keep coming into the cavity and "bounce" within it, until the density of probability (intensity) won't reach a certain energy level (which depends in big part on the size of cavity) at which the system will reach a thermodynamic equilibrium. This is how cavity QED works in case of lasers just like in case of my scenario... There are no black holes involved in this proecess...

But what it does illustrate is many photons- all in synchrony bouncing back and to.
If you replace teh partially reflecting mirror by a completely reflecting one then, in principle  you valve a cavity in which they bounce "forever".

"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.

In reality they won't, because of diffraction

Yes - and couple other causes
.

(Have you ever actually built a laser- from scratch? The insight it gives is quite useful.)

Actually I didn't - but somehow I just knew the right solution to my scenario (cavity QED) and figured out 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...

But here's the issue, as far as I can tell
You know that, in an atom, you can only get two electrons into a given orbital.
And you think that, by analogy- since the orbitals are eigenstates of the atom, you can only get a finite number of photons into an eigenstate.

But what you have missed is that photons are not like electrons- (I'm sure I have heard someone say something like that recently).
Photons are not fermions, they are bosons. (Gauge bosons, as it happens).
And so you can stack as many bosons as you like in one quantum state.


presumably you will now say that I should have mentioned this earlier.
Well, I did
https://www.thenakedscientists.com/forum/index.php?topic=82373.msg643464#msg643464

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

For each wavelenght, you can only increase the intensity of photons - not their number inside the cavity

For a given cavity and wavelength, the intensity is proportional to the number of photons. You can't change them independently.

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? Thanks! That's what I was telling you from the beginning.

One thing tho - you CAN introduce an external beam of light at the same wavelenght, but with lower intensity in relation to the light trapped inside the cavity, what will result in that beam appearing darker...