[Bored chemist]

Holes covered by mirrors..

The sides of lasers are not covered by mirrors.
Stop making up nonsense.

[Bored chemist]

So, if it's not you, who states all those  things, then who is it? Should I understand, that you don't associate with your own claims?

You would need to show how you came to the mistaken view that I said any of them.

[CrazyScientist (OP)]

What defines the energy of EM radiation?

The product of the number of photons and the energy which each photon has.
And, in your opening gambit, you kept increasing the number of photons.
Once you have added C^2 worth of energy you will have increased the mass by 1Kg.
It doesn't matter if that's microwave photons or visible photons which is why this

It's because the difference of the wavelenght/frequency of EM radiation.

is nonsense.


Go away and don't come back until either you have learned some science, or until you are prepared to learn some.

So you say, that a constant emission of light inside a perfect spherical cavity will lead to the constant increase of the energy in the system, until a critical level is reached and cavity explodes or a BH is formed

Everything what differs emission of visible light and emission of thermal energy, is the wavelenght of emitted EM waves - do you agree with that?

So now let's replace the constant source of light with a constant source of heat - what will happen in this case?

[Bored chemist]

Ok, I should be more specific:
What is the difference between emission of light and emission of thermal radiation? Are there any substantial differences between both mechanics?

There are differences in detail but the processes are substantially identical.

Are you beginning to understand the importance of not saying stupid things?

[Bored chemist]

So you say, that a constant emission of light inside a perfect spherical cavity will lead to the constant increase of the energy in the system, until a critical level is reached and cavity explodes or a BH is formed

No.
Stop doing that.
I never said that.

[CrazyScientist (OP)]

Holes covered by mirrors..

The sides of lasers are not covered by mirrors.
Stop making up nonsense.

Ahh, you were talking about the inner surface of the cylinder... Sure, big portion of photons is absorbed by it - and yet the energy level inside cavity is growing until equiblirium is reached. Why should any other case of photons trapped in a reflective cavity, give us a completely different result?

So you say, that a constant emission of light inside a perfect spherical cavity will lead to the constant increase of the energy in the system, until a critical level is reached and cavity explodes or a BH is formed

No.
Stop doing that.
I never said that.

I am treating it as an increasing number of photons (and, accordingly, and increasing mass of photons).

since mass is a form of energy

Increasing number of photons = increasing mass = increasing energy

[Bored chemist]

you were talking about the inner surface of the cylinder

No

Stop doing that.
I never said that.

Just stop making up nonsense then pretending it's what I think.
It is clear that you are not interested in any real discussion here.
You only want to argue with rubbish that you claim is my viewpoint.
That sort of straw manning is dishonest.

[Bored chemist]

Quote
Quote from: Bored chemist on Today at 21:17:10
Quote from: CrazyScientist on Today at 21:16:00
So you say, that a constant emission of light inside a perfect spherical cavity will lead to the constant increase of the energy in the system, until a critical level is reached and cavity explodes or a BH is formed
No.
Stop doing that.
I never said that.


Quote from: CrazyScientist on Today at 20:34:49
I am treating it as an increasing number of photons (and, accordingly, and increasing mass of photons).

Quoting me out of context is also dishonest.
You just tried to pretend that I was talking about a source inside the sphere when the actual discussion point was a source outside the sphere with the light (and mass) going in through a hypothetical valve..

You really need to stop making false statements.

[CrazyScientist (OP)]

Quoting me out of context is also dishonest.
You just tried to pretend that I was talking about a source inside the sphere when the actual discussion point was a source outside the sphere with the light (and mass) going in through a hypothetical valve..

You really need to stop making false statements.

Huh? I was talking about a source of radiation placed inside the cavity since the beginning of this thread... This is what is written in the 1st post..

"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)..."

I didn't mention even once in this thread about a scenario where a source of radiation is placed outside of the cavity - and if I did, please tell me where exactly...

BTW Can you please explain me, why the location of source is here so important, that it completely changes the supposed outcome of photons trapping in a cavity?

I would say, that the build-up of energy in the cavity would just take longer for EM radiation directed from an outside source, than for a source, that is placed inside (energy of radiation is being lost, when it is directed from a source to a specific location) - or greater energy input would be required, to achieve the same effect, as for a point-source inside the cavity. But in the end the final outcome will be almost exactly the same in both cases - system reaches energetic equilibrium after some time of constant emission of EM radiation...

[Bored chemist]

Do you know what a diode does?
It's a one way valve.

OK, the inside of the sphere is perfectly-reflecting, and there's an ideal optical diode to let light in but keep it inside

[Bored chemist]

Do you know what a diode does?
It's a one way valve.

OK, the inside of the sphere is perfectly-reflecting, and there's an ideal optical diode to let light in but keep it inside

However the point is still moot. Is power supplied form the outside or not.
If not, then the energy is obviously limited and the experiment just generates a flat battery.

But, if the power is fed in from outside the sphere to drive the lamp then you have a different problem; anything which can emit light must also absorb it
https://en.wikipedia.org/wiki/Kirchhoff%27s_law_of_thermal_radiation

So, the light will bounce around until it is absorbed by the lamp.

That will burn the lamp out.

Again, that's not an interesting experiment.

The case where it can produce a black hole, can not include any light source inside the sphere.

BTW Can you please explain me, why the location of source is here so important, that it completely changes the supposed outcome of photons trapping in a cavity?

The conservation laws.
If you are using a battery inside the sphere to provide power then it loses mass as it is used and that exactly compensates for the mass of the photons produced.

If the power source is outside the sphere then it can add relativistic mass to the contents of the sphere, causing it to collapse into a BH

Once again, this is all pretty much high-school physics.

[CrazyScientist (OP)]

It's also interesting, how perfectly you managed to completely ignore this:

Ok, so let's now assume, that the battery is actually placed somewhere outside of the spherical cavity and is powering up a source of heat (thermal radiation), allowing it to maintain a constant temprature of 1000°C. Can you explain the mechanism, which in this case could possibly lead to creation of a BH out of the thermal radiation, which is constantly emitted by the source of heat inside the cavity?

Tell me, how you will solve that. I would love to hear some cool fairytale for good night

[Bored chemist]

Honestly, I don't know,why he included it in his answer, since the question was about a source placed INSIDE a spherical mirror.

Because, if the original energy source (a battery, a chemical reactor or whatever- even a nuke) is inside the mirror you won't get a black hole, but if the source is outside the spherical mirror, and the light is allowed in through some magic valve, you will get a BH.

I presume he wanted to avoid talking about the version that is boring.

Which leads to the interesting question; why are you talking about a version of the experiment which can't produce the interesting outcome?

[Bored chemist]

, the source won't absorb any energy from the cavity

If the source is able to emit at some wavelength then it will absorb at that wavelength.
The size, shape, cost or colour of the cavity don't affect that.

[Zer0]

Thanks and no problem I rarely take things personally.
Such Mental Stability & Maturity is a Rare Commodity nowadays.
👍
Glad you have this positive outlook towards Life.


But honestly, after witnessing the general response, I'm thinking about making a thread: "what if God can be proven by science?".
i heard a Scientist once say that, " There was No Space & No Time before the BB. Hence GOD had no space & time to create the Universe. "

IMHO, that was a Foolish Statement!
Believers can Easily think or say that GOD is on the Outside.
Just like a pizza baker need Not get inside of the bread to bake it.

Still, IMHO, it was a Foolish Statement!
Bcoz it Linked...
' Religion ' vs ' Science '
Both Subjects are Completely Different in their Essence.
Religion works on Faiths & Beliefs.
Science implies on Facts & Evidences.

But here's the Point...
Just bcoz a Scientist made One Foolish Statement does Not mean he/she is a Fool.
Just bcoz a group of Scientists repeatedly make Foolish Statements Does Not Mean Sciences are the leisure pastimes of Fools!
🙏
Bottomline - Science Does Not Prove or Disprove the Existence of GOD...Honestly, Science Does Not Care!
🙏



I can bet, that it will be the most active thread for a looooong time...
i did Suggest this to the Forum Mods...wished to have
' Philosophy ' & ' Religion ' subsections.

But my suggestions were Not entertained & let to pass.

Rightfully So!
👍
Bcoz NOW i Understand how Futile my suggestion was.

A " Religion " section will attract people of faith & belief to come in here & pass sermons & preach.
But Obvious, Rationale Thinkers would be Uncomfortable & Oppose.
Then, as mostly it is, & has been proven in History...Religion will spark off a Holy War in here.
✌️
A " Philosophy " section would seem attractive & tingle young minds into indulging in it.
Whole days & years they might keep Philosophising in here.
Instead of becoming a Good Doctor, Chemist, Physicist & having a successful career & help in supporting their families...they might end up becoming a Great unpaid Philosopher.
✌️
Even a Dead Logical Thread in here is Alot More Meaningful, than an Active Illogical Meaningless One.
👍


I know the difference between my private beliefs and science, but it could be interesting, to have a place, where we could speak about the meta- side
of physics...What do you think?
i Think You are on the path of Learning, Understanding & acquiring Real Knowledge!
👍
I most certainly would Not wish to deflect you from the Trail of Sciences, & pull you into the Deep Dark Woods of Philosophies.
🙏
IMHO, GOD is Dead & so is Philosophy!

[/quote]


P.S. - Shall Refrain from further Disturbing & Distracting You.
✌️
The Woods are too Dark & too Deep, but We All have our Promises to Keep!
🖖
Tc!
😇

[Bored chemist]

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)...

That's your scenario and it is trivially impossible.
The light source can't act "continuously" because it will stop when the energy source runs out.


here's a less impossible (hypothetically) version
We trap some light in a perfectly mirrored box.

The first question is  does the box weigh less before we fill it with light than afterwards?

I hope you recognise that the answer is yes.

OK now we compress the ball spherically so the density increases. (That's obviously somewhere between impractical and impossible, but never mind.- it's just a thought experiment and I will present a way round it presently)
At some point we will squeeze it inside its own Schwarzschild radius and at that point it will become a black hole.

The radius at which that happens will be a bit bigger than it would be with an empty sphere because of the increased mass due to the photons in it.

Now imagine that we increase the energy inside the sphere and repeat the experiment.
We find that we don't need to compress it so much because the mass is even higher.

Now imagine that we increase the energy in the sphere continuously (with power supplied form outside).
There will be a point where we only need to compress the sphere slightly to get it to collapse.
And shortly after that, there will be a point where it collapses without us needing to compress it at all.
(and, at this point, the impossibility of compression becomes irrelevant).

[CrazyScientist (OP)]

, the source won't absorb any energy from the cavity

If the source is able to emit at some wavelength then it will absorb at that wavelength.
The size, shape, cost or colour of the cavity don't affect that.

Oh really...?

Sorry to inform you, that you couldn't be more wrong. Didn't you learn in high-school, that photons can interact with atoms only at couple specific energy states of the system?

The phase shift induced by a single atom in free space
https://arxiv.org/pdf/1306.2804.pdf

In this article we theoretically study the phase shift a single atom imprints onto a coherent state light beam
in free space. The calculations are performed in a semiclassical framework. The key parameters governing
the interaction and thus the measurable phase shift are the solid angle from which the light is focused onto the
atom and the overlap of the incident radiation with the atomic dipole radiation pattern. The analysis includes
saturation effects and discusses the associated Kerr-type non-linearity of a single atom.

Abnormal behaviour of the electromagnetic modes in an annular spherical cavity
https://ui.adsabs.harvard.edu/abs/1998EJPh...19..319B/abstract

The fluctuating electromagnetic field in a cavity with perfectly conducting walls is generally composed of two kinds of modes: electric (TM) and magnetic (TE). Conventional wisdom says that if the cavity volume is made smaller, the eigenfrequencies rise. Here, a counterexample is demonstrated: if the cavity is spherical and has annular form (inner radius a and outer radius b), then the eigenfrequencies for the lowest electric modes decrease monotonically if the region is made shallower. This abnormality is of quantum mechanical interest. Thus, if an excited two-level atom of free-space emission frequency 0143-0807/19/4/001/img1 satisfying the condition 0143-0807/19/4/001/img2 is situated in the (vacuum) cavity, the atom will be unable to radiate the photon for a = 0. If a now increases, meaning that the cavity takes an annular form, a point will be reached at which emission is permitted. This abnormal behaviour is characteristic of the spherical geometry and is not present in the analogous cylindrical geometry.

Do you actually identify as a Chemist? Because this statement pretty much invalidates your entire self-imposed authority in this field of science...

[Bored chemist]

It's not me with whom you are arguing.
It's one of the laws of physics.
https://en.wikipedia.org/wiki/Kirchhoff%27s_law_of_thermal_radiation
It can be derived from the law of conservation of energy.
If you have a thing which emits then it will absorb.

Sorry to inform you, that you couldn't be more wrong. Didn't you learn in high-school, that photons can interact with atoms only at couple specific energy states of the system?

Yes.
Exactly my point.
At those wavelengths where there is a suitable excited state a ground state molecule or atom or LED can absorb light and, at exactly the same wavelengths that excited state can emit light (and return to the ground state).

This is still true if the excited state has been perturbed by a cavity or, indeed, anything else.

[Bored chemist]

Now, would you like to address the point about the BH?

[CrazyScientist (OP)]

OK now we compress the ball spherically so the density increases. (That's obviously somewhere between impractical and impossible, but never mind.- it's just a thought experiment and I will present a way round it presently)
At some point we will squeeze it inside its own Schwarzschild radius and at that point it will become a black hole

Nope.

If you wouldn't stop following the progress in theoretical and practical science after WWII (or maybe even since WWI), you would know, that your quite radical and completely unverified claims were actually verified experimentally - and the observed results completely disproved the model of EM radiation, which you propose here...

https://en.wikipedia.org/wiki/Squeezed_states_of_light

Squeezed excitation in cavity QED - Caltech Authors
https://authors.library.caltech.edu/4856/1/TURpra98.pdf