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What Do You Think About Photon To Photon Scattering?


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#1 rhertz

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Posted 28 April 2019 - 09:35 AM

Findings at the CERN LHC about light scattering off light in the last year or so, puzzles science

to explain the phenomena.

 

This is the first time that photon-photon scattering has been "detected", when two opposite beams

of lead ions, accelerated to reach almost the speed of light, collided and the photons that each beam

was generating scattered with other photons.

 

This is the link to the most fresh news from the ATLAS team at CERN about this subject:

 

https://home.cern/ne...cattering-light

 

Is it the first "evidence" that high energy photons behave as if have mass, or is something else?

 

 



#2 Flummoxed

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Posted 28 April 2019 - 10:23 AM

 

 

Is it the first "evidence" that high energy photons behave as if have mass, or is something else?

 

Maybe its the chicken and egg, how high energy do you want to go https://phys.org/new...=daily-nwletter Pulsars creating matter via interacting with virtual photons, creating particles with out violating energy conservation. Could it be that black holes/high mass objects can lose energy by more ways than just Hawking radiation??? :sherlock:


Edited by Flummoxed, 28 April 2019 - 10:23 AM.


#3 OceanBreeze

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Posted 28 April 2019 - 10:28 AM

Who can second-guess the Cern physicists? If they say it was light-light scattering, it must be so. After all, didn’t these guys also see faster-than-light neutrinos? Ooops!

 



#4 Flummoxed

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Posted 28 April 2019 - 10:44 AM

Who can second-guess the Cern physicists? If they say it was light-light scattering, it must be so. After all, didn’t these guys also see faster-than-light neutrinos? Ooops!

 

Was that last week.



#5 rhertz

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Posted 28 April 2019 - 11:26 AM

Was that last week.

 I've been reading about these findings for more than a year and a half.

 

This new article is an obvious probe that they are certain about the scattering, because it

is proved by number-crunching huge amounts of data, separating false or undesired results.

 

Then, if this is true, maybe is a step forward to finally demonstrate that light has mass (even

if it of electromagnetic nature).



#6 exchemist

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Posted 28 April 2019 - 11:28 AM

Findings at the CERN LHC about light scattering off light in the last year or so, puzzles science

to explain the phenomena.

 

This is the first time that photon-photon scattering has been "detected", when two opposite beams

of lead ions, accelerated to reach almost the speed of light, collided and the photons that each beam

was generating scattered with other photons.

 

This is the link to the most fresh news from the ATLAS team at CERN about this subject:

 

https://home.cern/ne...cattering-light

 

Is it the first "evidence" that high energy photons behave as if have mass, or is something else?

This was predicted by QED ages ago and does not indicate that photons have mass.

 

According to QED a photon has a small probability of transiently becoming a pair of virtual particles. As these behave as charged entities, a second photon can be scattered by them.   

 

More here: https://en.wikipedia...-photon_physics

 

It's obviously a very low probability process but with a high enough flux of high energy photons it should occasionally happen. I'm not sure from your link, but it may well be that these photons in the CERN experiment are in the γ-ray region of the spectrum. 


Edited by exchemist, 28 April 2019 - 11:31 AM.


#7 OceanBreeze

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Posted 28 April 2019 - 03:30 PM

Findings at the CERN LHC about light scattering off light in the last year or so, puzzles science

to explain the phenomena.

 

This is the first time that photon-photon scattering has been "detected", when two opposite beams

of lead ions, accelerated to reach almost the speed of light, collided and the photons that each beam

was generating scattered with other photons.

 

This is the link to the most fresh news from the ATLAS team at CERN about this subject:

 

https://home.cern/ne...cattering-light

 

Is it the first "evidence" that high energy photons behave as if have mass, or is something else?

 

 

I found this very recent ( 9 April 2019 ) CERN paper (pdf) that may be of interest to you..

 

It is 28 pages, but the last 20 pages are all references!

 

It is a very interesting read. One takeaway is the extreme complexity and signal processing that goes into making these measurements. I would argue that the complexity is at least comparable with the complexity behind the measurement of the Cosmic Backgroud Radiation, even including mapping the anisotropy.

 

I have to wonder then, why you seem willing to accept these measurements done by CERN yet have such deep reservations about the measurement of the CMB BB curve?

 

I tend to think that measuring and plotting the CMB BB curve is much simpler than the observation of the light-by-light scattering process, γγ → γγ, in Pb+Pb collisions at 5.02 TeV.



#8 rhertz

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Posted 28 April 2019 - 03:54 PM

I found this very recent ( 9 April 2019 ) CERN paper (pdf) that may be of interest to you..

 

It is 28 pages, but the last 20 pages are all references!

 

It is a very interesting read. One takeaway is the extreme complexity and signal processing that goes into making these measurements. I would argue that the complexity is at least comparable with the complexity behind the measurement of the Cosmic Backgroud Radiation, even including mapping the anisotropy.

 

I have to wonder then, why you seem willing to accept these measurements done by CERN yet have such deep reservations about the measurement of the CMB BB curve?

 

I tend to think that measuring and plotting the CMB BB curve is much simpler than the observation of the light-by-light scattering process, γγ → γγ, in Pb+Pb collisions at 5.02 TeV.

My answer might be poor and unconvincing, but I'll try to make it.

 

First at all, from my point of view, the complexity of calculations, algorithms and second and third order theories behind the data analysis of the whole CBR has

increased exponentially from COBE to WMAP to PLANCK satellites, as the databases increased their size with each generation. It take YEARS to compute and

refine raw information from Planck (it took almost FOUR YEARS for the COBE dataset).

 

There is no comparison in complexities.

 

My answer is: I do believe that photons have an electromagnetic mass. So CERN results are aligned with my thought on this matter.

But I don't believe that the Universe behave as a black body cavity, because it violates the origin of everything: Kirchoff's law for

thermal radiation, which led to solve his challenge to find the spectral distribution of energy WITHIN a black body cavity.

 

The Universe has no depth, so absorptivitty can't be applied. Also, I believe that radiation sources are anisotropic and can't be

correctly evaluated in strength and depth. Not to mention that our Milky Way emits random radiation in the same bands, which is

millions of times much more powerful than background RANDOM noise.

 

And, as an electrical engineer with many, many years working in telecommunications (radiowaves, optical signals) the first thing

that you understand and after can measure is THIS: You can't recover a random signal deeply buried into random noise.

All the theorethical physicists, for decades, have written volumes about this fact, related to the Information Theory and Noise.

 

The only way it can work (used by the military and civilian mobile techniques) is to pseudo-randomize your signal with a known

pseudo-random encoding sequence. Then, you known what to expect and can send a signal below the noise level OR, as in

mobile telephony using CDMA, you can send a thousand digital voice channels in the same bandwidth. Each channel has its

own pseudo-random encoder and decoder so, even when the other channels appear as noise to your receptor and at higher

level than your expected signal, you can recover it and hear perfectly.

 

As you can see, I believe in one thing and don't believe in the other. As simple as that (or complex, if I have to proof the CBR

subject problem).



#9 Flummoxed

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Posted 29 April 2019 - 02:50 AM

 I've been reading about these findings for more than a year and a half.

 

This new article is an obvious probe that they are certain about the scattering, because it

is proved by number-crunching huge amounts of data, separating false or undesired results.

 

Then, if this is true, maybe is a step forward to finally demonstrate that light has mass (even

if it of electromagnetic nature).

 

Sorry the "was it last week" was meant as a little joke. ie time travel at faster than c via neutrinos. It will only take them 10 light neutrino years to get here instead of 20 at light speed. A bit stupid realy, but hey ho, joke crashed and burned.

 

Under QED photons can momentarily become a particles, before recombining to become a photon again. 

 

A photon on its own has no electric field or magnetic field, (unless speculating, Maybe its made up of two virtual particles which cancel each others electrical and magnetic properties etc and some sci fiction)


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