[Kryptid]

There is also a cosmic gamma ray background radiation. The sun produces gamma rays and so most if not all other stars and galaxies.

The Sun only releases gamma rays into space during solar flares, and they are much weaker (4 GeV) than the gamma ray photon mentioned in the article (31 GeV). The energy of a gamma ray is inversely proportional to how common it is. That is, weak gamma rays are more common than strong ones: https://ned.ipac.caltech.edu/level5/ESSAYS/Fitchel/figure1.gif

How many gamma rays are detected by Fermi satellite each second ?

I don't know, but gamma rays with billions of electronvolts of energy are very rare (see the chart I posted above).

[Yaniv (OP)]

You heard wrong. An attempt to detect differences in speed between high energy electromagnetic radiation and low energy electromagnetic radiation generated by a distant gamma ray burst failed to find any such difference: https://arstechnica.com/science/2009/10/quantum-gravity-theories-meet-a-gamma-ray-burst/

I don't have your relativistic faith to accept this paper as conclusive proof all photons travel at the same speed. My theory predicts gamma photons should travel faster than visible photons. I wonder if in gamma ray bursts gamma photons arrive before visible photons ?

[Kryptid]

I don't have your relativistic faith to accept this paper as conclusive proof all photons travel at the same speed. My theory predicts gamma photons should travel faster than visible photons. I wonder if in gamma ray bursts gamma photons arrive before visible photons ?

Relativity has nothing to do with it. Speed is distance divided by time. No relativity required.

[Colin2B]

My theory predicts gamma photons should travel faster than visible photons. I wonder if in gamma ray bursts gamma photons arrive before visible photons ?

No, your theory is wrong. Gamma radiation speed can be measured here on earth and is same as light - again as @Kryptid says, dont need to use relativity.

I also note you are confused about the base current in the transistor laser, if i have time I’ll write out the detail of what happens and why current is not lost.

[Bored chemist]

I wonder if in gamma ray bursts gamma photons arrive before visible photons ?

Observedly, no.
You don't need to "wonder" about this- it's been checked.
https://en.wikipedia.org/wiki/GRB_080319B
So, if you were interested in actual science, you would now ditch the idea (the one you keep lying about being a theory) but I predict that you won't because you are trolling.

[Yaniv (OP)]

I wonder if in gamma ray bursts gamma photons arrive before visible photons ?
Observedly, no.
You don't need to "wonder" about this- it's been checked.
https://en.wikipedia.org/wiki/GRB_080319B
So, if you were interested in actual science, you would now ditch the idea (the one you keep lying about being a theory) but I predict that you won't because you are trolling.

And I had read Gamma ray photons usually arrive hours before visible photons.
https://en.wikipedia.org/wiki/Gamma-ray_burst

No, your theory is wrong. Gamma radiation speed can be measured here on earth and is same as light - again as @Kryptid says, dont need to use relativity.

Reference welcome.

I don't have your relativistic faith to accept this paper as conclusive proof all photons travel at the same speed. My theory predicts gamma photons should travel faster than visible photons. I wonder if in gamma ray bursts gamma photons arrive before visible photons ?

Relativity has nothing to do with it. Speed is distance divided by time. No relativity required.

I read the sun produces GeV gamma photons by interactions with cosmic rays. If the sun produces GeV photons most other stars also produce GeV photons. There are plenty of GeV photon sources. What I meant you need a relativistic faith to conclude this single photon must have originated at the burst.

[Kryptid]

And I had read Gamma ray photons usually arrive hours before visible photons.
https://en.wikipedia.org/wiki/Gamma-ray_burst

Please quote the part of that page which states that visible light arrives hours after the gamma rays do, because I can't find it.

I read the sun produces GeV gamma photons by interactions with cosmic rays. If the sun produces GeV photons most other stars also produce GeV photons. There are plenty of GeV photon sources.

You make it sound as if Fermi only detects gamma rays without any ability to tell what direction they came from. The 31 GeV gamma ray was detected using the Large Area Telescope instrument, which has several layers of silicon microstrip detectors. The direction of the photon can be determined by the way that the resulting electron-positron pair passes through these layers. So we know that the photon came from the direction of the gamma ray burst.

What I meant you need a relativistic faith to conclude this single photon must have originated at the burst.

Relativity has nothing to do with determining where a gamma ray photon came from.

[Yaniv (OP)]

Please quote the part of that page which states that visible light arrives hours after the gamma rays do, because I can't find it.

"After an initial flash of gamma rays, a longer-lived "afterglow" is usually emitted at longer wavelengths".
"The William Herschel Telescope identified a fading optical counterpart 20 hours after the burst".
"The following year, GRB 980425 was followed within a day by a bright supernova".

You make it sound as if Fermi only detects gamma rays without any ability to tell what direction they came from. The 31 GeV gamma ray was detected using the Large Area Telescope instrument, which has several layers of silicon microstrip detectors. The direction of the photon can be determined by the way that the resulting electron-positron pair passes through these layers. So we know that the photon came from the direction of the gamma ray burst.

How many stars and galaxies are located inside angle of detection ?

Relativity has nothing to do with determining where a gamma ray photon came from.

You so believe light travels at the same speed that you placed the origin of this photon were you wanted it.

[Kryptid]

"After an initial flash of gamma rays, a longer-lived "afterglow" is usually emitted at longer wavelengths".

This says that the afterglow is longer-lived than the initial gamma ray flash, not that the visible light from the initial flash took longer to reach us.

"The William Herschel Telescope identified a fading optical counterpart 20 hours after the burst".

Again, this doesn't say that the light reached us 20 hours after the gamma rays did. It says that the optical counterpart wasn't found until 20 hours after the gamma rays were detected.

"The following year, GRB 980425 was followed within a day by a bright supernova".

GRB 980425 was detected by the BeppoSAX satellite, which didn't use its Narrow Field Instruments to look at the source of the GRB until within 12 hours of its detection. So of course the supernova wasn't found until hours after the burst was detected.

How many stars and galaxies are located inside angle of detection ?

Unknown, but also irrelevant. A stray gamma ray with a 31 GeV energy isn't going to conveniently strike the detector within the same second as photons from the gamma ray burst. The probability can even be estimated based on the statistics of gamma rays that Fermi has detected in the past:

Using the count rate in the LAT during the 200 s directly preceding T0 as a measure of the background rate, the probability that these three photons would arise by accident is 1.2 × 10⁻⁶

So the odds of the 31 GeV gamma ray and two other burst rays (each above 100 MeV) striking the detector within the 0.2 second time span they were detected in by chance alone was 1,200,000 to 1. You're appealing to a miracle in an attempt to debunk the findings. Here is the paper that I got this information from, on page 7: https://arxiv.org/pdf/1005.2141.pdf

You so believe light travels at the same speed that you placed the origin of this photon were you wanted it.

The odds are 1,200,000 to 1 for the origin to not be the burst.

[Yaniv (OP)]

"After an initial flash of gamma rays, a longer-lived "afterglow" is usually emitted at longer wavelengths".
This says that the afterglow is longer-lived than the initial gamma ray flash, not that the visible light from the initial flash took longer to reach us.

The term "after" at the beginning of the sentence suggests to me a flash of gamma rays appear before longer wavelength afterglow.

How many stars and galaxies are located inside angle of detection ?
Unknown, but also irrelevant.

Each star inside angle of detection is a potential source for a strayed GeV photon.

So the odds of the 31 GeV gamma ray and two other burst rays (each above 100 MeV) striking the detector within the 0.2 second time span they were detected in by chance alone was 1,200,000 to 1. You're appealing to a miracle in an attempt to debunk the findings. Here is the paper that I got this information from, on page 7: https://arxiv.org/pdf/1005.2141.pdf

I don't understand this paper.

The odds are 1,200,000 to 1 for the origin to not be the burst.

My theory predicts gamma photons from gamma-ray bursts should arrive before visible photons. The same arrival time of gamma and visible photons will disprove my theory. What's the odds on that ?

[Bored chemist]

The term "after" at the beginning of the sentence suggests to me a flash of gamma rays appear before longer wavelength afterglow.

I don't understand

[Kryptid]

The term "after" at the beginning of the sentence suggests to me a flash of gamma rays appear before longer wavelength afterglow.

That's why it's called an afterglow: the remnants of the burst are still emitting lower-energy light even after the initial explosion has taken place. In no way does that imply that light from the initial burst arrived after the gamma rays did. If such were the case, then it would be common knowledge in the astrophysics community by now that gamma rays are faster than visible light. Such is not the case.

Each star inside angle of detection is a potential source for a strayed GeV photon.

Do you not recall that the odds of that being the case were 1 in 1.2 million?

I don't understand this paper.

I'm not surprised.

My theory predicts gamma photons from gamma-ray bursts should arrive before visible photons. The same arrival time of gamma and visible photons will disprove my theory. What's the odds on that ?

These findings mean that your hypothesis has a 1 in 1.2 million chance of being correct. At best.

[Colin2B]

These findings mean that your hypothesis has a 1 in 1.2 million chance of being correct. At best.

You are being generous today
Earthside measurements indicate gamma photons move at c:
https://link.aps.org/doi/10.1103/PhysRev.84.271
http://adsabs.harvard.edu/abs/1995NIMPA.355..537F
Also for xrays:
2. E.Zolotoyabko and J.P.Quintana. Measurement of the speed of x-rays. J.Synchrotron.Rad. 9 (2002) 60-64. The value obtained converged to the speed of light in vacuum, i.e., c.

Of course he won’t believe this (or understand) because they challenge his hypothesis. If he has any problems with them i suggest he take it up  with a local physics department

[Yaniv (OP)]

Earthside measurements indicate gamma photons move at c:
https://link.aps.org/doi/10.1103/PhysRev.84.271
http://adsabs.harvard.edu/abs/1995NIMPA.355..537F

I can't get access to these papers. Is there a way to link the papers to this discussion ?
I read in abstract the speed was determined using a scintillation counter. I gather this is an indirect measurement. Can you please explain how speed is determined using a scintillator ?

[Bored chemist]

I gather this is an indirect measurement.

It isn't really, but so what if it were?
Say the measured the speed by setting some gamma rays off down a really long pipe and measured how long it took the bunny rabbits at the end of the pipe to die.
It would still be a measure of the speed.

Also "I can't get access to these papers."

See the earlier comment
"If he has any problems with them i suggest he take it up  with a local physics department"

[Yaniv (OP)]

Please quote the part of that page which states that visible light arrives hours after the gamma rays do, because I can't find it.
"After an initial flash of gamma rays, a longer-lived "afterglow" is usually emitted at longer wavelengths".
"The William Herschel Telescope identified a fading optical counterpart 20 hours after the burst".
"The following year, GRB 980425 was followed within a day by a bright supernova".

I made a mistake here thinking optical signals arrive hours after gamma-ray bursts.

My theory predicts gamma photons from gamma-ray bursts should arrive before visible photons. The same arrival time of gamma and visible photons will disprove my theory. What's the odds on that ?
These findings mean that your hypothesis has a 1 in 1.2 million chance of being correct. At best.

I searched the internet and found a few graphs showing optical signals appear seconds after the start of the burst. Check this link. I also noticed bursts are complex and no two are alike but wonder if several seconds delay between the beginning of the burst and optical signal is a common feature of bursts.
https://science.nasa.gov/science-news/science-at-nasa/1999/ast26mar99_1
 

[Kryptid]

I searched the internet and found a few graphs showing optical signals appear seconds after the start of the burst. Check this link. I also noticed bursts are complex and no two are alike but wonder if several seconds delay between the beginning of the burst and optical signal is a common feature of bursts.
https://science.nasa.gov/science-news/science-at-nasa/1999/ast26mar99_1

The graph looks incomplete. Although background gamma rays are clearly plotted on the graph prior to the burst (almost back to the 35,200 second mark), no such data line exists for background optical photons (even though there most certainly would have been background optical photons). This suggests to me that the optical detector either wasn't designed to detect visible light until it reached a certain minimum threshold of brightness or that the data simply wasn't included on this graph. In either case, that isn't evidence that the visible light arrived after the gamma rays did.

[Yaniv (OP)]

In either case, that isn't evidence that the visible light arrived after the gamma rays did.

This is another diagram from a different burst showing an optical peak appearing several seconds after gamma burst.
http://images.slideplayer.com/26/8876937/slides/slide_3.jpg

[Colin2B]

In either case, that isn't evidence that the visible light arrived after the gamma rays did.

This is another diagram from a different burst showing an optical peak appearing several seconds after gamma burst.

This isn’t evidence that γ-rays travel faster that optical photons because you don't know the profile of the emissions. But you can make a reasonable assumption.
In any explosion the emissions will depend on the temperature over time. For example with a nuclear bomb the initial exceedingly high temperature causes sudden release of a high energy γ-rays E=hν≈1-10 MeV, as it cools x-rays E=hν≈1-100 keV, and as it cools further then progressively lower temperature radiation is released  UV, visible light, IR, microwave, radiowave. These latter frequencies are the ‘afterglow’ with the optical peak following the gamma peak.
GRB in astronomy appears to be far more complex than the simple nuclear explosion.
 

[Yaniv (OP)]

In either case, that isn't evidence that the visible light arrived after the gamma rays did.
This is another diagram from a different burst showing an optical peak appearing several seconds after gamma burst.
This isn’t evidence that γ-rays travel faster that optical photons because you don't know the profile of the emissions. But you can make a reasonable assumption.
In any explosion the emissions will depend on the temperature over time. For example with a nuclear bomb the initial exceedingly high temperature causes sudden release of a high energy γ-rays E=hν≈1-10 MeV, as it cools x-rays E=hν≈1-100 keV, and as it cools further then progressively lower temperature radiation is released  UV, visible light, IR, microwave, radiowave. These latter frequencies are the ‘afterglow’ with the optical peak following the gamma peak.
GRB in astronomy appears to be far more complex than the simple nuclear explosion.

I think you raise an important point here. Different types of radiation could originate at different times. If this is the case in GRBs they are not good systems to test predictions about the speed of light. That GeV photon may have originated at a different time ?