[CrazyScientist (OP)]

And this:
https://www.eenewseurope.com/news/light-trap-turns-photons-massive-quasiparticles

If you put enough mass in a small enough space, it collapses.
That's still true if it's in the form of massive quasiparticles.

You seem to be arguing against yourself.

Where exactly it is mentioned in that article?

Besides "to collapse" mean different things in QM and in GR - collapse of a wavefunction have nothing to do with a gravitational collapse into a BH...

[Bored chemist]

Where exactly it is mentioned in that article?

The title...

[Bored chemist]

But you can't simultaneously receive multiple AM/FM stations at similar wavelenghts using one antenna - can you?

Yes, you can.
That's why you can buy antenna splitters.
It's why people in blocks of flats can choose different radio stations, and it's why a spectrum analyser can record the signals from two different radio stations at the same time.

Why do you think that it is helpful to keep repeating something which is false?

Besides "to collapse" mean different things in QM and in GR - collapse of a wavefunction have nothing to do with a gravitational collapse into a BH...

I know. And when someone says that something with enough mass in a small space will collapse, the grown ups can work out which meaning is in use.

There are two sorts of people, those who can extrapolate from incomplete data...

This means, that it should be possible to simultaneously detect multiple photons at similar frequencies, that are overlaping each other in a single volume of space..

The sky is blue.

[Bored chemist]

Quote from: CrazyScientist on Today at 20:25:35
Quote from: Bored chemist on 20/06/2021 15:06:01
Instead of answering, you cam up with this tosh

Quote from: CrazyScientist on 14/06/2021 17:11:04
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?

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 15:06:01
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.

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...
So, are you still saying that the point of a cricket bat is to slow the ball down?

It's a simple yes or no.
You are the one who was going on about sleeping through  school science; not me.

Why did you get that school science wrong?

[CrazyScientist (OP)]

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.

It's also common practice for blocks of flats to have a single aerial  feeding to all the flats.
You are trying to say that these don't exist.
https://www.screwfix.com/c/electrical-lighting/splitters/cat4740084

And that's silly.

Only here we need to include the rate at which the EM field is being measured and the structure of the antenna (EM wavess received in multiple points of that antenna).

Let's focus on an satellite dish or somekind of antenna that receives one kind of frequency band in a small localized area. In this case intensity of radiation at each wavlenght in a specific frequency band, can be described as the probability of detecting a photon at a specific wavelenght. EM field with a maximum intensity at a particular wavelenght in a given frequency band means, that each time, when a measurement is made, we are detecting a photon at this particular frequency and not at any other similar frequencies.

When there's a lightning strike near an antenna, it causes a pulse of radiation (EMP), which has much higher intensity than the EM waves received by this antenna. It means, that in the time when the EMP wave is passing through the volume of space occupied by the antenna, in the given bandwidth, photons will be detected, mostly (only) at the frequency of EMP wave and not at the frequency of a radio station, which we're listening to.

Now let's say that in a single volume of space, intensity of the potential EM field is shared 50-50 by 2 similar frequencies - let's say by EM waves at 100 and 117 KHz. Thanks to the uncertainty principle, we can now get two possible ways to describe this situation: Amplitude of the EM waves at each of those 2 frequencies becomes 50% smaller in comparisment to an EM field with maximum intensity at only a single wavelenght, so for each of those frequencies, photon is being detected half of the times, when we try to detect it at one of those frequencies..

In shortcut, for an potential EM field, which has maximum level of intensity at 100KHz, for each measurement, which is being made at the same frequency as the EM radiation (100KHz), we will detect a photon in each measurement. If for example 10% of the total intensity will then go to EM waves at 117KHz, then in a measurement at 100KHz, photon will be detected 90% of the time and in a measurement at 117KHz, photon will be detected 10% of the time

Of course in the real life, one volume of free space is being occupied by EM radiation with multiple different frequencies with different intensities - but only waves at similar lenghts can interfere with each other. This is why it's possible to detect a photon in 100% of all measurements at frequencies from different bands (for example at frequencies ƒKHz and ƒGHz)

Also things are different for radiation, which is trapped in a cavity

TBC

[CrazyScientist (OP)]

But you can't simultaneously receive multiple AM/FM stations at similar wavelenghts using one antenna - can you?

Yes, you can.
That's why you can buy antenna splitters.
It's why people in blocks of flats can choose different radio stations, and it's why a spectrum analyser can record the signals from two different radio stations at the same time.

Phew! I went through a tone of info about TV antennas and receivers.
First of all, there are 2 types of splitters: diplexers and duplexers. Diplexer works for EM waves at different frequency bands, while duplexer in shortcut works as a switch between transmitter/receiver modes of a single antennas...

Generally, it's possible to watch different TV channels on couple receivers using a single antenna, as all the avaliable channels can be superimposed within one stream of data and then particular frequencies can be amplified from the noise of superposition and provided to different TV receivers by an external amplifier...


https://www.tablotv.com/blog/how-to-antenna-ota-signals-multiple-directions
https://www.quora.com/How-come-we-can-watch-multiple-TV-channels-with-a-only-a-single-satellite-dish
https://www.quora.com/How-do-I-connect-multiple-TVs-to-one-antenna
https://www.quora.com/Can-you-connect-multiple-TVs-to-one-digital-antenna
https://www.quora.com/How-can-multiple-TVs-connected-to-one-aerial-watch-different-channels

Still, if you place 2 similar antennas close to each other and make them to receive EM waves at similar frequency bands, there will be some kind of interference - constructive, if both antennas will receive exactly the same bandwidth and destructive or non-linear, when received frequencies will slightly differ

As for spectrum analyser - it seems, that to see the intensity off the local EM field at all particular wavelenghts, receiver has to sweep through each one of them individually and you can get the impression of real-time display due to the high frequency rate of masurements.

https://en.wikipedia.org/wiki/Spectrum_analyzer#Theory_of_operation

Apparently to know the exact intensity of EM field for each single wavelenght in a given band, you need to measure it individually and extract this information from the local superposition...

TBC

[CrazyScientist (OP)]

So, are you still saying that the point of a cricket bat is to slow the ball down?

It's a simple yes or no.
You are the one who was going on about sleeping through  school science; not me.

No. The point of a cricket, is (probably) to get a better score, than the opposing team,

But if you ask about the frequency of EM waves reflected by a moving mirror, then
a) it will decrease in the rest frame of the mirror
b) it might iincrease in the rest frame of some other observer  if he and the mirror are incoming towards each other fast enough or decrease in any other case of their relative motion
c) it won't change in the rest frames of reflected photons (?) - although according to mainstream science, there's even no rest fame for a photon...

[CrazyScientist (OP)]

Please don't waste time on energy losses and coefficients of restitution- this is an ideal, perfect mirror.
There are no losses.

"Perfect reflection of EM radiation" can be also understood as a total lack of energy absorbtion during the interactions betwen photons and particles of matter. There's no physical way for photons to interact with matter and always maintain a constant frequency - just as there's no physical way for matter to directly interact with photons and always maintain a constant energy level. Absorbtion leads to excitation of atoms (increases the energy level of electron orbitals,by moving it to a higher frequency band or by ejecting electrons), while reflection induces a kinetic pressure/push on interacting matter. And of course,kinetic pressure of EM waves during their reflection decreases together with the increasing frequency of that radiation - what kinda makes sense in maintaining a balance between those 2 alternative outcomes, but doesn't make sense for the gravitational collapse of photons into a "Kugelblitz"...

[CrazyScientist (OP)]

"An informal, heuristic meaning of the principle is the following: A state that only exists for a short time cannot have a definite energy. To have a definite energy, the frequency of the state must be defined accurately, and this requires the state to hang around for many cycles, the reciprocal of the required accuracy. For example, in spectroscopy, excited states have a finite lifetime. By the time–energy uncertainty principle, they do not have a definite energy, and, each time they decay, the energy they release is slightly different. The average energy of the outgoing photon has a peak at the theoretical energy of the state, but the distribution has a finite width called the natural linewidth. Fast-decaying states have a broad linewidth, while slow-decaying states have a narrow linewidth"

And that tells you that an observation made in a finite time will only give you an uncertain assessment of the energy.
So the energy is (like momentum or position) always uncertain.
And that means the wavelength is always uncertain.

Not for a standing wave inside a resonant cavity, where photons can remain at one frequency in a prolonged period of time:

[Bored chemist]

Not for a standing wave inside a resonant cavity, where photons can remain at one frequency in a prolonged period of time:

OK so let's try and get back to the original problem.
If you have some photons in a cavity ( exerting some radiation pressure on the walls of the cavity) and you cormpress it, you do work against that pressure.
Where does that energy go?

My contention is that it increases the energy of the photons they bounce off the mirror with slightly reduced wavelengths.
And you say it does something which is impossible by definition.

No. The point of a cricket, is (probably) to get a better score, than the opposing team,

The point of a cricket is to make more crickets.

But the point of a cricket bat is to increase the energy of the ball.

Generally, it's possible to watch different TV channels on couple receivers using a single antenna,

Finally! the light dawns.
I said that all along.
You were the one who wrongly insisted otherwise.

Now, can you see if you can work on your understanding of the conservation of energy.
The moving mirror does work on the photons.
So it must increase their energy.

And them maybe we can get you to recognise that QM means that the size of the cavity is uncertain, and the wavelength of the photons is uncertain. so there's no way to say, precisely, if they are the same (or if one is a integer multiple of the other).

[Bored chemist]

Not for a standing wave inside a resonant cavity, where photons can remain at one frequency in a prolonged period of time:

The size of the cavity is never certain.
The wavelength of the photons is never certain
The energy of the photons is never certain.
The momentum of the photons is never certain
The momentum of the cavity is never certain

Have you simply not understood what the uncertainty principle means?

[Bored chemist]

Phew! I went through a tone of info about TV antennas and receivers.

You should have just believed me.
I have two radios by my bed, They both work.
I listen to the same station on both of them, but I tune them to different frequencies.
They are FM radios so the frequency is about 100MHz.
I just checked. The centres of the radios are 28 cm apart.
That's less than lambda /10 so, for radio wave / antenna purposes they are "in the same place".

And they both work.


(and, in case you wondered, because they are on different frequencies, interference on one typically doesn't affect the other so, on average, I get a better signal to listen to.)

[CrazyScientist (OP)]

Phew! I obviously jumped into a pretty deep water with some of my statements, which I've unnecessarily made without a prior research - and now once again I've had to go through couple hundreds different sites, to adress all of this in a somehow proper way...

Not for a standing wave inside a resonant cavity, where photons can remain at one frequency in a prolonged period of time:

OK so let's try and get back to the original problem.
If you have some photons in a cavity ( exerting some radiation pressure on the walls of the cavity) and you cormpress it, you do work against that pressure.
Where does that energy go?

My contention is that it increases the energy of the photons they bounce off the mirror with slightly reduced wavelengths.
And you say it does something which is impossible by definition.[/qutote]

First of all, to counter the pressure of EM radiation, you'd need to apply a FORCE in the opposite direction - and for a constant radiation pressure, you'd end up with a constant ACCELERATION of a movable mirror. Constant velocity of a mirror in relative motion can't cause a definitive increase of energy in the rest frame of that mirror.

And then you still need to accelerate the mirror at a precise rate, so the trapped EM waves won't cancel each other out. Anyway, in the end trapped EM wave will be cancelled out anyway, if you'll keep reducing the size of cavity and make it smaller than the wavelenght of trapped EM radiation...

Are you saying, that things presented on that slide are impossible? This is exactly, why in this scenario it's sipmly impossible to use an analogy to baseball or cricket and end up with any kind of a valid result...

But on the other hand you CAN use the analogy of a buzzing speaker submerged in a sphere of water and get a pretty nice representation of the most possible outcome

Generally, it's possible to watch different TV channels on couple receivers using a single antenna,

Finally! the light dawns.
I said that all along.
You were the one who wrongly insisted otherwise.

Yes, you can. However it doesn't mean, that two RF antennas in a close vicinity can't interfere with each other - they can and they often do...

Anyway I admit, that this is exactly the part, where I went too far with my claims. It doesn't  mean, that I'm completely wrong here, but the subject is just far more complicated..

https://diy.stackexchange.com/questions/153190/can-two-antennas-in-proximity-interfere-with-each-other-if-theyre-not-amplified
https://en.wikipedia.org/wiki/Antenna_(radio)#Radiation_pattern

Now, can you see if you can work on your understanding of the conservation of energy.
The moving mirror does work on the photons.
So it must increase their energy.

What frame are you talking about here?

And them maybe we can get you to recognise that QM means that the size of the cavity is uncertain, and the wavelength of the photons is uncertain. so there's no way to say, precisely, if they are the same (or if one is a integer multiple of the other).

How can the size of cavity be uncertain, if it was designed to have a precise volume, to get the best possible amplification of trapped radiation?

Position and momentum of a photon remain uncertain, up until we won't measure one of those properties. You can measure a photon and learn it's exact position just as you can learn about the precise wavelenght in the measured EM wave - you just can't learn the exact values for those two properties at the same time...

TBC

[Bored chemist]

it's sipmly impossible to use an analogy to baseball or cricket and end up with any kind of a valid result...

You mean... like Newton's laws?
Well then, why did you post about them then?

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?

[CrazyScientist (OP)]

Phew! I went through a tone of info about TV antennas and receivers.

You should have just believed me.
I have two radios by my bed, They both work.
I listen to the same station on both of them, but I tune them to different frequencies.
They are FM radios so the frequency is about 100MHz.
I just checked. The centres of the radios are 28 cm apart.
That's less than lambda /10 so, for radio wave / antenna purposes they are "in the same place".

And they both work.


(and, in case you wondered, because they are on different frequencies, interference on one typically doesn't affect the other so, on average, I get a better signal to listen to.)

I don't believe in anything, until I can't verify it at my best capabilities. Although  I don't have a proper setup, to get the best possible results, I've used an old-school radio receiver and FM radio apps on 2 cell phones with headphones as their antennas, to see if they will interfere - and they did, but not always. For example in one specific location around the old-school radio receiver, headphones seemed to cut-off the radio waves for that old-school receiver - I guess this happened when the second antenna (headphones) was placed right "on the way" between the transmitter and receiver of RF waves at a given bandwidth.

Also there are different mechanics of interference for AM and FM waves - as I said, it would require a much deeper discussion...

https://www.diffen.com/difference/AM_vs_FM

TBC

[Bored chemist]

What frame are you talking about here?

The laboratory frame.
I have a box on teh bench with photons bouncing round it it.
I compress the box.
In doing so, I do work on the mirrors and they do work on the photons.
Where does that energy go?

Here's a hint; it has to go somewhere, and it can't be absorbed by the mirrors.

Here's another hint.
It is the equivalent of heating a gas by compressing it.

[CrazyScientist (OP)]

it's sipmly impossible to use an analogy to baseball or cricket and end up with any kind of a valid result...

You mean... like Newton's laws?
Well then, why did you post about them then?

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?

Because for some reason you keep going back to cricket and baseball, even if it doesn't make any practical sense

[Bored chemist]

Also there are different mechanics of interference for AM and FM waves

Not really.

Incidentally, it's quite commonplace for a radio to interfere with another radio close by.
But that's usually the local oscillator  causing interference .
It will happen when the difference between the two signals is equal to the intermediate frequency in one or other of the receivers- typically about 10MHz or 440 KHz.

Don't mistake that for evidence that you might be right.

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

[Bored chemist]

it's sipmly impossible to use an analogy to baseball or cricket and end up with any kind of a valid result...

You mean... like Newton's laws?
Well then, why did you post about them then?

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?

Because for some reason you keep going back to cricket and baseball, even if it doesn't make any practical sense

I go back to it because you can't even get the simple stuff right.

You say things like this
"so photons, which are slowing down the mirror are giving up their own energy"
if the mirror is heading towards the photons, and they hit it and bounce off then the mirror loses speed and it looses energy.
So it loses energy
And the photons gain energy.
This is not only "common sense", but demonstrated, even in the case of photons bouncing off a fast moving mirror.


Just keep reading this
"so photons, which are slowing down the mirror are giving up their own energy"
until you realise it is nonsense.

[Bored chemist]

I obviously jumped into a pretty deep water with some of my statements, which I've unnecessarily made without a prior research - and now once again I've had to go through couple hundreds different sites, to adress all of this in a somehow proper way...

Or, you could just believe me.
I have something like a 20 year head start on you when it comes to learning this stuff.