0 Members and 1 Guest are viewing this topic.
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
But to increase the temperature beyond some level, you would have to start increasing the frequency of emitted radiation
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...
Quote from: CrazyScientist on 04/07/2021 09:14:09And 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 intensity of radiation trapped in a cavity can reach only a certain level and the radiation pressure will then become constant.
Quote from: Bored chemist on 04/07/2021 10:16:28Quote from: CrazyScientist on 04/07/2021 09:14:09And 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)
Quote from: CrazyScientist on 04/07/2021 10:23:12But to increase the temperature beyond some level, you would have to start increasing the frequency of emitted radiationYes.And here is the bit where you realised how to do that.Quote from: CrazyScientist on 04/07/2021 09:14:09And 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...
To create a Kugelblitz, frequency of trapped radiation would have to be increasing in both frames...
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?
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
Woow! It's the first time, when I agree with your predictions
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.
Momentum transfer will be exactly the same, no matter what's the rest mass of the mirror
Quote from: CrazyScientist on 04/07/2021 10:35:24To 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 thisQuote from: CrazyScientist on 29/05/2021 02:31:39Personally, I consider both those options as completely wrong and physically impossible.Quote from: CrazyScientist on 07/06/2021 12:37:40In 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 youQuote from: CrazyScientist on 07/06/2021 18:37:55 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.Quote from: CrazyScientist on 03/07/2021 22:53:44If 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
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)...
Quote from: CrazyScientist on 04/07/2021 10:23:12Woow! It's the first time, when I agree with your predictionsAnd 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.
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.Quote from: CrazyScientist on 04/07/2021 10:23:12But to increase the temperature beyond some level, you would have to start increasing the frequency of emitted radiationWell, once you have BBR, you already have those increased frequencies.Problem solved. Black holes for everyone!
Quote from: Bored chemist on 04/07/2021 10:15:25Imagine 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 Quote from: CrazyScientist on 04/07/2021 09:14:09Momentum 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
Quote from: CrazyScientist on 04/07/2021 09:14:09Those wavelenghts are associated with so called eigenstates, where the energy and number of photons can reach only a certain level for each of those statesAnother 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)
Huh? You've only mentioned about it in your previous post FOR THE FIRST TIME in this entire discussion
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.
That's because it IS impossible to create a black hole in the scenario from my 1st post,
But in this case only light can be light enough - matter is never as light as light is.
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
Quote from: CrazyScientist on 11/07/2021 04:34:10Huh? You've only mentioned about it in your previous post FOR THE FIRST TIME in this entire discussionLearn to read.Quote from: Bored chemist on 07/06/2021 14:11:54You 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.
Quote from: CrazyScientist on 11/07/2021 04:34:10That'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?
Quote from: CrazyScientist on 11/07/2021 05:14:49But 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.
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 mean, mirrors used in experimental cavity QED can reach "only" 99,9% of perfect reflectivity at best,
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 absolutely might be wrong or uninformed, when I make my statements
And why should you? Since when science suppose to be based on faith?
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.
Quote from: CrazyScientist on 11/07/2021 05:30:55Nope - you have a FINITE number of photons for each avaliable eigenstateNo.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 tellYou 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 didhttps://www.thenakedscientists.com/forum/index.php?topic=82373.msg643464#msg643464
Quote from: CrazyScientist on 11/07/2021 05:30:55For each wavelenght, you can only increase the intensity of photons - not their number inside the cavityFor a given cavity and wavelength, the intensity is proportional to the number of photons. You can't change them independently.