Question about photons

@deepthought said
It depends on what the theory of light in play is. What the Wikipedia page is referring to is a game one can play where one takes the Newtonian formula for the gravitational potential:

V = -GMm/r

and claims that a photon in a gravitational well loses that much energy escaping. Since it's energy is given by Einstein's formula E = mc^2 one can get a formula for the ...[text shortened]... should be deflected by massive objects is not sensitive to the theory of light in Einstein's theory.

How did Einstein conclude light would be bent by gravity? Was it his conclusion or someone else? Since classical physics explains at least some of it I am guessing the idea was already there before Einstein, but was Einstein the first to claim gravity would be bent even more with relativity?

Some people say Einstein predicted the bent light, but was that merely his assertion or do his equations indicate it? I thought the equations were about mass attracting mass, not mass attracting mass-less photons. Have I overlooked something?

Can you explain this?

https://science-andinfo.blogspot.com/2019/12/nasa-saw-something-come-out-of-black.html?fbclid=IwAR1zpVHJNozRTCgI790LAIojcnguIYDUm3XRMfrg2u9IIo9B3-MOMezfYF4

@metal-brain said
How did Einstein conclude light would be bent by gravity? Was it his conclusion or someone else? Since classical physics explains at least some of it I am guessing the idea was already there before Einstein, but was Einstein the first to claim gravity would be bent even more with relativity?

Some people say Einstein predicted the bent light, but was that merely his ass ...[text shortened]... omething-come-out-of-black.html?fbclid=IwAR1zpVHJNozRTCgI790LAIojcnguIYDUm3XRMfrg2u9IIo9B3-MOMezfYF4

It wasn't a new idea at the time, Johann Georg von Soldner published this paper [1] on the subject in 1804 and Newton had discussed the idea. There's a review of tests of General Relativity of a fairly technical nature here [2], although it predates tests based around LIGO.

[1] Ueber die Ablenkung eines Lichtstrals von seiner geradlinigen Bewegung, Berliner Astronomisches Jahrbuch, 1804, pp. 161-172
English translation at: https://en.wikisource.org/wiki/Translation: On_the_Deflection_of_a_Light_Ray_from_its_Rectilinear_Motion
[2] The Confrontation between General Relativity and Experiment, Clifford M. Will, 2006.
https://arxiv.org/pdf/gr-qc/0510072.pdf

Edit: the system replaced : O with 😲 in reference [1]. To fix this I introduced a space between the colon and the 'O' as in the previous sentence. This means you may have to remove the space from the URL bar in your browser if you follow the link.

@metal-brain said
How did Einstein conclude light would be bent by gravity? Was it his conclusion or someone else? Since classical physics explains at least some of it I am guessing the idea was already there before Einstein, but was Einstein the first to claim gravity would be bent even more with relativity?

Some people say Einstein predicted the bent light, but was that merely his ass ...[text shortened]... omething-come-out-of-black.html?fbclid=IwAR1zpVHJNozRTCgI790LAIojcnguIYDUm3XRMfrg2u9IIo9B3-MOMezfYF4

How did Einstein conclude light would be bent by gravity?

General relativity.

Was it his conclusion or someone else?

Whether somebody else before him theorized gravity might bend light, the fact remains he independently concluded it from his GR theory and not from somebody else.

Since classical physics explains at least some of it

Despite that mysterious wiki comment that seems to imply the contrary, it doesn't. At least not the BENDING of light but rather the shift in wavelength. To see that, see;
http://curious.astro.cornell.edu/about-us/140-physics/the-theory-of-relativity/general-relativity/1059-if-gravity-isn-t-a-force-how-does-it-accelerate-objects-advanced

So I speculate the wiki editor may have simply confused the two things with each other.

Some people say Einstein predicted the bent light, but was that merely his assertion or do his equations indicate it?

Both. Although he initially predicted it via GR concepts without his equations.

I thought the equations were about mass attracting mass,

This shows how much you think you know about it contrasts with how little you know about it.

Have I overlooked something?

"overlooked" is a massive understatement.

Can you explain this?

https://science-andinfo.blogspot.com/2019/12/nasa-saw-something-come-out-of-black.html?fbclid=IwAR1zpVHJNozRTCgI790LAIojcnguIYDUm3XRMfrg2u9IIo9B3-MOMezfYF4

"explain" what part of it? You have repeatedly shown that to us and we have repeatedly explained/clearly-implied that that link is NOT saying something escaped a black hole from BELOW its event horizon thus nothing in that link contradicts GR.
So what is it about what this link says that still confuses you?

@deepthought said
It wasn't a new idea at the time, Johann Georg von Soldner published this paper [1] on the subject in 1804 and Newton had discussed the idea. There's a review of tests of General Relativity of a fairly technical nature here [2], although it predates tests based around LIGO.

[1] Ueber die Ablenkung eines Lichtstrals von seiner geradlinigen Bewegung, [i]Berliner Astrono ...[text shortened]... This means you may have to remove the space from the URL bar in your browser if you follow the link.

Can you explain this?

https://science-andinfo.blogspot.com/2019/12/nasa-saw-something-come-out-of-black.html?fbclid=IwAR1zpVHJNozRTCgI790LAIojcnguIYDUm3XRMfrg2u9IIo9B3-MOMezfYF4

@metal-brain said
Can you explain this?

https://science-andinfo.blogspot.com/2019/12/nasa-saw-something-come-out-of-black.html?fbclid=IwAR1zpVHJNozRTCgI790LAIojcnguIYDUm3XRMfrg2u9IIo9B3-MOMezfYF4

I think the article is somewhat sensationalized, the 'enigma' is why there was a flare rather than that material was ejected at all. We know black holes generate jets along their axes of rotation. What the researchers presumably don't know, the blog didn't seem to have given a reference, is why a short burst happens. The questions are to do with the dynamics of the accretion disk rather than the impassibility of the event horizon. I don't think this represents a challenge to Einstein's theory.

@deepthought said
I think the article is somewhat sensationalized, the 'enigma' is why there was a flare rather than that material was ejected at all. We know black holes generate jets along their axes of rotation. What the researchers presumably don't know, the blog didn't seem to have given a reference, is why a short burst happens. The questions are to do with the dynamics of the acc ...[text shortened]... impassibility of the event horizon. I don't think this represents a challenge to Einstein's theory.

Yeah, I found a better article explaining it.

https://www.zmescience.com/science/black-hole-corona-ejection-09112015/

@metal-brain said
If there is no mass, how can it be a particle? Can you hold nothing in your hand and call it a particle?

If you define a particle as "something with mass which you can
hold in your hand" then you are definitely on to something!

@wolfgang59 said
If you define a particle as "something with mass which you can
hold in your hand" then you are definitely on to something!

Science on the other hand doesn't define a particle in such silly unscientific layperson terms. Only he does.

@metal-brain said
https://www.youtube.com/watch?v=Q2OlsMblugo

I listened to just the few seconds (47 seconds) into that video before seeing it was just one of those moronic BS anti-science ones not worth watching so I didn't waste my time watching any more of it.
In those few first seconds, the idiot speaker first said wave-particle duality is just a myth, which is just BS for starters, then he said a particle is 'vaguely' defined as "A small portion of matter" which he then said is "ALWAYS true", which is just complete and utter BS because the science of quantum physics and particle physics etc doesn't define a particle that way at all, not even "vaguely" so.
Here is proof;
https://en.wikipedia.org/wiki/Massless_particle
"...In particle physics, a massless particle is an elementary particle whose invariant mass is zero. ..."


How about watching some REAL science videos that therefore doesn't lie and doesn't deny science and doesn't say science is all myth etc?
If all science was myth then NONE of our modern technology would work including your computer etc. etc.

@humy
That would never fit his search as a contrarian, anti EVERYTHING in science.
He is just one of millions of people who look for holes in science thinking they will make a name for themselves. He needs recognition above all else.

@humy said
I listened to just the few seconds (47 seconds) into that video before seeing it was just one of those moronic BS anti-science ones not worth watching so I didn't waste my time watching any more of it.
In those few first seconds, the idiot speaker first said wave-particle duality is just a myth, which is just BS for starters, then he said a particle is 'vaguely' defined as "A s ...[text shortened]... all science was myth then NONE of our modern technology would work including your computer etc. etc.

In other words you cannot prove it is wrong. What lie? You never said what he lied about. If you cannot specifically point to a lie it is likely there is not a lie for you to point to.

@Metal-Brain
The title says it all. I don't have speakers on my work comp so can't listen but when it says MYTH, you don't need to even go further.
Just like your dude Cao, they put out these so-called science video's in the hopes of attracting idiots with no education to add to their list so they can gain ad money and maybe even write a book which will completely show off just how stupid they are.

@sonhouse said
@Metal-Brain
The title says it all. I don't have speakers on my work comp so can't listen but when it says MYTH, you don't need to even go further.
Just like your dude Cao, they put out these so-called science video's in the hopes of attracting idiots with no education to add to their list so they can gain ad money and maybe even write a book which will completely show off just how stupid they are.

Why are they stupid? Be specific.

@Metal-Brain
Cao says galaxies have been seen receding faster than c. Totally false. If he is talking about the expansion of the universe, it is probably true galaxies are receding faster than c since the further away they are the faster they seem to be receding and therefore at a certain distance they will be receding faster than c BUT in that case we will NEVER see them, not in a telescope a thousand light years in diameter because there is no light coming from those galaxies they will be forever more invisible.
That is situation A.
Situation B is seeing galaxies going faster than c IN OUR VISIBLE UNIVERSE.
That is also bogus since every event of such has been proven to be a false velocity, people making mistakes in measurements. In neither case will we see with telescopes ANYTHING going faster than c. But he uses that to say that kills relativity.