Gravitational Lensing : Eddington Experiment

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One can only smile at such false fabricated indignation.....

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Takes all kinds.

 

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Yes, yes, one can only smile at your dishonesty. You cannot fool anyone by making such comments after your utter ignorance is exposed. Anyway the idea was not to expose already established dishonest liar like you, but nonetheless it further proves yours and origin's ignorant stand.

 

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For all interested...

Did a small research, and could thrash out something from various literature available

1. The 1919 expedition was carried out at two places, At Sobral headed by Dyson and at Principe Island headed by Eddington.

2. Eddington was a fan of GR, and both Eddington and Dyson knew beforehand that Newtonian Prediction (considering Flat Minkowski Spacetime) is around 0.85 arcseconds deflection and GR prediction is 1.75 arcseconds

3. Eddington faced problems due to bad weather, still he could manage some observations, and his initial analysis was that deflection lies somewhere between 0.85 arcseconds to 1.75 arcseconds, kind of keeping the issue open.

4. The other set of observations as taken by Dyson at Sobral were closer to higher value.

5. When both the data were clubbed together, it gave a value which was much higher than 0.75 arcseconds (flat spacetime based) but still it did not conclusively match with the GR predictions.

6. Since the observed data were way away from 0.85 arcseconds, promptly the Newtonian version was disproved and only alternative left was GR, which was pushed.

7. But the rider is that this experiment although disproved Newtonian, but noway could conclusively establish the cause of deflection, that is curved spacetime cannot be proved by this experiment, what the experiment proved was that light bends due to Gravity, how and why was not the part of expedition etc.

8. This observation and subsequent tremendous publicity blitz established GR, obvioulsy due to doubtful nature of data, opposition came from various scientists.

9. The data was re analysed with better computational power on preserved samples (in 1978) and still the outcome remained more or less the same, the deflection was closer to higher value.

10. After 1919 solar eclipse, the experiment was conducted on various other solar eclipses, but not much could be established decisively.

11. The observation of Radio Quasar behind the massive Galaxy and lensing thereof, further data could be gathered, but due to lack of precise knowhow of the lensing Galaxies' mass distribution and orientation, nothing conclusively can be established except that light bends and lensing takes place.

12. There are hundreds of models available for lensing analysis, one such model which is a part of popular science showing the source as point, clarifies the concepts behind the lensing. In reality stars are not point sources. Its a spread and diffracted image, not the point image.

My take which is based on mainstream papers only is that Gravitational Lensing proves bending of light (light is weighty as claimed by Eddington), it does not conclusively establish curved spacetime.....That was the point of this thread.

I am saddened by the abusive participation from Origin, Paddoboy and Physbang. These guys from the seat of ignorance (as confirmed by their insistence on 0.85 arcseconds deflection as part of curved spacetime) tried their level best to push the thread to pseudoscience...

 

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I think in this discussion, this paper http://arxiv.org/pdf/physics/0508030v4.pdf is interesting. Here it is assumed that the particle photon has mass. Is it true?

 

So you think the people who were explaining gravitational lensing as resulting from the theory of General Relativity are discussing pseudoscience? Just out of curiosity have you lost your mind or are you just a troll?

 

Some points:

1.) Whatever the accuracy reached by Eddington, the result was that light is curved by gravity, and the number was not in conflict with GR. Which is what mattered at that time.
2.) Today the accuracy has only historical interest, because we certainly have today much more accurate results, and these are also in agreement with GR.
3.) Newton's theory of light was a particle theory. Given that in Newtonian gravity the mass of a test particle does not matter (it has also an equivalence principle) he did not even have to speculate about the mass of the light particles - knowing the speed of light in the vacuum far away from the Sun, one could simply follow the Newtonian trajectory of a particle.
4.) But Newtons particle theory of light was already dead, because of its inability to describe wave effects of light. Maxwell theory, with light as a wave, was the winner. As a consequence, nobody cared about what Newton's dead theory of light tells.
5.) Maxwell theory itself did not provide any formulas for the gravitational influence on the EM field. AFAIK, there was also no wave theory of how light behaves in a gravitational field. Without gravity, it predicted light following straight lines.
6.) There was SR. Maxwell theory was already SR-compatible (Lorentz-invariant) from the start. SR was incompatible with gravity, and suggested a way how it has to be modified - by making it Lorentz-invariant too. There have been proposals for Lorentz-invariant theories of gravity, the first in Poincare's 1905 paper which is considered by some as having the priority for SR. In this theory, it was gravity which was modified, not EM theory (which was already Lorentz-invariant). Once EM theory remained unchanged, one can say that the prediction was that light follows a straight line, as defined by the Minkowski metric.
7.) Thus, the theories viable at that time were GR and variants of SR-based theories of gravity, which predict light going straight. Newtonian particle theory of light was dead anyway, thus, irrelevant.

 

As usual, eventually cranks start lying about people. I have never said anything about any particular amount of deflection. I merely asked that this lying crank give us some definition of the very terms he was using. As usual, the cranks could not do this and immediately started dodging the question and attacking a direct relevant question as some sort of abuse.

Congratulations, crank.

 

I'll let our peers on this forum, your peers and mine, be the best judge of who is ignorant and who is lying and who has a history of dishonesty.
I'm not going to comment on all your dummy spitting misinterpreted tirade, but there is some conclusive remarks I will make.....

Most here are interested in science, the scientific method, and proper peer review of any claim......You fail all three.

Gravitational lensing certainly proves that light follows geodesics, and it follows that this infers curved/warped spacetime.
And as most here also know, the bending/warping/twisting of spacetime in the presence of mass has also been evidenced many times.
Your tirade is no more than a cop out.
The path of the light from the emitter to the observer, is dictated by curved spacetime or geodesics.
The eye interprets that curved geodesic path as a straight line and gives an apparent position different from the true position.

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Not really...You are actually seething in anger at anyone that dares oppose your usual fabricated crazy views of mainstream science, which you have had threads shifted for in the past. The revelations that you also have a religious agenda, and your apparent past handle that expressed similar crazy notions.
Rest assured though, that your continued pseudoscience rants will be refuted in all circumstances.
And you should also realize that threads don't get pushed to the fringes because some disagreement occurs between participants...they are shifted because the thread initiator is making untrue, unevidenced, pseudoscientific claims about accepted scientific theories.
Your thread/s have been shifted because you yourself are making anti scientific claims, apparently driven by your recent exposed religious agenda.
We have two excellent tutorials on this forum concerning BH's and Cosmology in general. They cover accepted theoretical claims and aspects of BH's and the Universe that you could well improve yourself by reading and taking notice of.

Our friend "the god" sees himself as a resurrection or likeness of his handle.
He very rarely will give any reference or link supporting his nonsense, and suffers from extreme case of delusions of grandeur, in believing that those participating and watching his antics, believes anything he says.
He also continually refuses to reveal his credentials, although evidence points to him being an Electrician or possibly an Electrical engineer.
He has made many many many false claims on this forum, a couple with reference to myself, claiming I am sweetpea and claiming I "fixed"and/or altered an E-Mail from a Professor Hamilton. Both presumably as revenge tactics against his own exposure and a previous handle.

 

To reinterpret for our divine friend: Light follows geodesics in curved spacetime

This point obviously magnifies the misinterpreted/dishonest take that our divine friend will stoop to, to avoid admitting he was wrong.

An observation is handy at this point with regards to an error or otherwise by Schmelzer.
As an independent scientist/researcher and somewhat proponent of the presence of an ether with qualms shall we say about mainstream academia and politics in general, he on all occasions will "quote" the poster and sentence/s or items he disagrees with, except as it now seems, when that disagreement is with a fellow anti mainstream person....or at least so it seems....hence my highlighting of his correct view here and to who it applies.

 

That was not the point of the thread. You clearly put forward these questions in the OP:

Apparently you have finally figured out how silly those questions were so now you are just dodging and weaving so you don't have to admit your mistake. You should know this, that is making you look even sillier.

 

Sorry, no, at this point your divine friend with his point 7 was right. This would be the interpretation in terms of a GR interpretation.

There are other theories with other interpretations, which could obtain similar results, and, in particular, in the Newtonian particle theory of light the light rays would be curved too by gravity, in a Euclidean space without any curvature.

My list of points was, of course, an answer to God. And I think he understands this. That I have not explicitly quoted him is that my main disagreement was not with a particular sentence, but with the general role of Newtonian theory in his points. And, of course, with laziness on my side, because I doubt very much (10) and (11) but too lazy to prove them wrong. So I have preferred the general point (2), without specifying which particular experiments about this are more accurate.

 

You have conveniently side-stepped the issue........
There is no problem with gravitational lensing nor with the illusion of the image created.
The path of the light from the emitter to the observer, is dictated by curved spacetime or geodesics.
The eye interprets that curved geodesic path as a straight line and gives an apparent position different from the true position.

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I doubt our divine friend does understand. But hey! at least you have cleared that up somewhat.

 

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

At its introduction in 1915, the general theory of relativity did not have a solid empirical foundation. It was known that it correctly accounted for the "anomalous" precession of the perihelion of Mercury and on philosophical grounds it was considered satisfying that it was able to unify Newton's law of universal gravitation with special relativity. That light appeared to bend in gravitational fields in line with the predictions of general relativity was found in 1919 but it was not until a program of precision tests was started in 1959 that the various predictions of general relativity were tested to any further degree of accuracy in the weak gravitational field limit, severely limiting possible deviations from the theory

 

http://astrogeo.oxfordjournals.org/content/50/4/4.12.full

90 years on — the 1919 eclipse expedition at Príncipe



The first experiment to observationally confirm Einstein's General Theory of Relativity was carried out in May 1919, on a Royal Astronomical Society expedition to observe a total solar eclipse. Sir Arthur Eddington travelled to Príncipe, a small island off the west coast of Africa, and sent another team to Sobral, Brazil, from where the eclipse would also be visible. This year, in a new RAS-funded expedition organized for the International Year of Astronomy, we returned to Príncipe to celebrate this key experiment that shook the foundations of 20th-century science.

Since 1687, Sir Isaac Newton's law of gravity had been the workhorse of celestial mechanics. Newtonian gravity could be used to explain the motions of a host of celestial bodies and the heavens were reliable and predictable. There was one small discrepancy: accurate measurements of Mercury's orbit did not quite fit the Newtonian paradigm. Mercury was observed to precess around the Sun slightly too quickly, by an extra degree for every 8400 years. By the end of the 19th century, attempts to explain the anomaly with classical solutions, such as unseen moons or interplanetary dust, had failed.

extract:
While some historians suggest that Eddington's faith in the General Theory of Relativity may have blinded him to contrary evidence, a recent analysis by D Kennefick has dispelled this notion. The basis of the controversy was that remaining partial cloud at Príncipe permitted only two successful astrographic plates to be taken, with five stars on each; the resulting deflection was 1.61±0.30 arcseconds, while Einstein predicted 1.75 arcseconds. By contrast, several plates taken with an astrograph at Sobral, with 12 stars on each, yielded a deflection of only 0.93 arcseconds.

 

http://astrogeo.oxfordjournals.org/content/50/4/4.12.full
extract:
It has been claimed that Eddington dispensed with some of the Sobral data without good reason. However, the Sobral plates were out of focus, leading to great uncertainty in the plate solution. An independent Sobral telescope with a 4 inch lens gave a deflection of 1.90±0.11 arcseconds, consistent with the deflection observed at Príncipe. And it was in fact Dyson who initially rejected the results from the Sobral astrograph, not Eddington. In 1979, a reanalysis of the Sobral plates using modern equipment measured a deflection of 1.55±0.32 arcseconds. The expedition was the first to satisfactorily confirm Einstein's prediction, and Eddington's observations from Príncipe were a key component of that process.

 

" Satisfactorily " confirm Einstein's prediction. But not exactly.

 

The effects have been confirmed and evidenced many times since.

 

No doubt

But has this lensing been throughly investigated?

Meaning that the Suns corona is the cause of this lensing?

 

Exactly what's been observed was predicted by GR. I'd write the derivation out for you but you wouldn't be able to understand it or want to understand it. You don't know anything about the cosmos or want to. No doubt.

 

Exactly.....All this was explained to river a couple of weeks ago.
One of those explanations being that there are other astronomical objects that produce gravitational lensing other than stars.
He hears what he wants to hear and disregards the rest, the modus operandi of most cranks and anti mainstream nuts.