Gravitational Lensing : Eddington Experiment

Thes papers also can be seen for Gravity and Index of Refraction relation.

http://www2.ups.edu/faculty/jcevans/Matter waves gravity.pdf

http://arxiv.org/pdf/gr-qc/0604009v1.pdf

 

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Thats a commendable approach.

[/QUOTE]

The purpose of my starting this thread was to take a position that Eddington Experiment did not prove curved spacetime. As I stated earlier

Total Deflection = Newtonian + Due to Refraction.

This can explain the observation of Eddington experiment, that is 0.89 Arcseconds + x, this x is a variable component and thats why no two elipses observations yielded matching data, and no observation was less than 0.89 Aseconds but they were less than 1.75 Aseconds. If the curvature of spacetime is a reality then the minimum value of deflection should be 1.75 arcseconds, the refractive index should have added on this. But thats not the case.

 

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We all understand the purpose of your post. It was to take a childish look at the very first attempt to measure such lensing. Rather than look at the rest of the science that has happened in a century, you want to us to ignore all of that so that you can feel smarter than Einstein without doing any work.

So, yeah, we all understand how pathetic you are.

 

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What do you mean by Newtonian deflection? Particle photon is massless.

See the conclusion of the paper I linked in post #337. "The results indicate that, the concept of inhomogeneous vacuum is mathematically equivalent to the curved spacetime in the general relativity."

 

Actually it appears to be a misnomer. Einstein in 1911 based on SR (equivalnce principle..flat minkowski spacetime) derived a deflection forumula which was 2GM/rc^2 (0.89). This deflection value was termed as Newtonian Deflection angle by Eddington. In 1915 Einstein came up with 4GM/rc^2 (1.75) based on curved space time. Eddingtone was aware of these values before this experiment and he was expecting a value closer to 1.75, which would have estbalished GR.

 

Firstly redshift/blue shift come in three different varieties: Doppler, cosmological and gravitational and is caused by three effects as follows....a massive body moving towards or away from an observer[doppler].....Intervening space expanding,[cosmological] and light climbing out of or falling into a gravitational well/source [gravitational]
It has nothing to do with lensing.
Refraction concerns itself with the effects we see from the apparent speed of light within certain materials. Refraction is chromatic and different wavelengths are refracted at different rates according to the refractive index.
Gravitational lensing is caused by the property of light/photons following geodesics in curved spacetime and is achromatic.
That's the accepted data in a nutshell.
So again, what are you claiming? Are you claiming that gravitational lensing does not happen and the effects are all due to refraction?
So what do you think astronomers/cosmologists have been doing since 1919 and Edddington's experimental results?
Do you really believe that they are ignorant of all the effects that we have discussed and how they differentiate between such effects?

http://arxiv.org/abs/astro-ph/9504001
REMOVING DEGENERACY OF MICROLENSING LIGHT CURVES THROUGH NARROW-BAND PHOTOMETRY OF GIANTS
Abstract:
The standard light curve of a microlensing event provides only two constraints on the six unknown parameters of the lens. We show that narrow-band photometry during a microlensing event of a giant star can in addition determine the angular radius of the Einstein ring and the proper motion of the lens. This possibility results from the fact that the extended atmospheres of giants emit the cores of resonant lines primarily from a narrow ring (limb brightening). The radius of the emission ring can be determined to a precision of 20% by detailed spectroscopic observations of the source after the lensing event has ended. A considerable fraction of the clump giant stars in the bulge have a ring radius >10^{12} cm, within the range of Einstein radii for sub-solar mass lenses. The extended thin ring also provides a sensitive probe of possible planetary companions as it sweeps across the lens plane. The ring signature can be detected photometrically, using a narrow-band filter centered on the CaII K line at 3933 A.

and this.......
http://spiff.rit.edu/classes/phys240/lectures/microlens/microlens.html

Yes, I know and that's why I detailed as best as I could, remembering it was you who dragged red/blue shift into this debate.

I don't believe anyone has denied that. So again, I must ask what is your point?

It's easy to come onto a science forum/s [this is not primarily addressed to you] that are open to any Tom, Dick, and Harry and criticise GR or standard 21st century cosmology and offer different alternatives, but let's be fair dinkum about all of this, do you really believe that astronomers/cosmologists have been doing nothing since GR and Eddington's first experiment?
We have a myriad of religious nuts that have attempted to deride/invalidate SR/GR and standard 21st century cosmology, simply because cosmology has pushed back the need for a magical pixie in the sky somewhere, to have waved his magic hand and created all we see. That incenses these brainwashed individuals and they will by any means possible, by hook or by crook, promote any aspect they they imagine can invalidate what they see as inherently evil in science.
These turkeys are also inherently ego inflated "would be's if they could be's" with delusions of grandeur.
And let's be fair dinkum about all this nonsense that they are currently carrying on with....If any of them had anything of substance in anything they have claimed, they would not be here.
Even other science forums have them permanently banned due to their abusive anti science nonsense, as sprayed by the likes of the one who sees himself as the god

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So after all that, the answer to your question would be yes, partly and in some cases, but just as certainly, gravitational lensing is the larger part of the effects we see.

 

As you have been incessantly told time and time again, the curvature/warping of spacetime has been shown to be valid in many ways.
Still, you as the forum's chief god bothering crank, will never accept that, just as you refuse to accept the other validated accepted theories of cosmology. So sad...so ignorantly stupid.

 

Stop abuses and for once think without any prejudice..

Just read about Sundogs (parhelia), you will get a fairly good idea about what refraction can do to light rays.

Now ponder why the defelction should be taken as only based on curvature of spacetime, completely negating the refraction?

 

The usual hypocritical nonsense from the forum's chief hypocrite.

Let me again state in no uncertain terms, that the curvature/warping of spacetime has been shown to be valid in many ways.
To ignore that is ignorant and in your case a contrivance to support your general anti accepted cosmology stance.
As explained to handsa, Refraction concerns itself with the effects we see from the apparent speed of light within certain materials. Refraction is chromatic and different wavelengths are refracted at different rates according to the refractive index.
Gravitational lensing is caused by the property of light/photons following geodesics in curved spacetime and is achromatic.
That's the accepted data in a nutshell that intelligent learned scientists accept, based on evidence.
Accept that and you may start to make some sense, not withstanding what I have said in post 346, which certainly applies to you..

 

http://arxiv.org/pdf/1010.3829v1.pdf
Abstract.
Gravitational lensing has developed into one of the most powerful tools for the analysis of the dark universe. This review summarises the theory of gravitational lensing, its main current applications and representative results achieved so far. It has two parts. In the first, starting from the equation of geodesic deviation, the equations of thin and extended gravitational lensing are derived. In the second, gravitational lensing by stars and planets, galaxies, galaxy clusters and large-scale structures is discussed and summarised.

Summary:
7. Summary Many are the applications of gravitational lensing to cosmology, and the results are numerous, as the preceding discussion has shown. A review like this must be based on a subjective selection which is necessarily biased to some degree. Within these limitations, I summarise the results as follows:

• Microlensing experiments in the Galaxy have shown that, although massive compact objects exist in its halo, they are insufficient to make up all the dark matter in the Galactic halo. These studies have extended towards the Andromeda galaxy M 31. It is not clear yet what fraction of the observed microlensing must be attributed to self-lensing by the visible stars. Low-mass planets have been detected by means of microlensing.

• Central density profiles of lensing galaxies are well described as isothermal within the radial range where they produce multiple images. Their cores are thus more concentrated than CDM predicts. This indicates that galaxy density profiles have been steepened by baryonic physics. At larger radii, weak galaxy-galaxy lensing shows that the isothermal density profiles steepen and approach the NFW density profile shape. • Galaxy-galaxy lensing finds large halo sizes with radii of & 200 h −1 kpc. Halos of cluster galaxies seem to be smaller, as expected. The biasing of galaxies relative to the darkmatter distribution is found by galaxy-galaxy lensing to be almost scale-independent, or gently increasing with scale.

• Galaxies have to be structured in order to explain multiple-image geometries and the high fraction of quadruple compared to double images. Anomalous flux ratios of quadruple images seem to be best explained by lensing, but simulations show that the expected level of substructure is insufficient to explain the observed anomalies.

• Measured time delays between multiple images lead to an interesting conflict between the lensing mass distribution and the Hubble constant: Isothermal profiles yield Hubble constants which are substantially too low, and lens models giving compatible Hubble constants have too steep mass profiles. It seems that this conflict can be resolved allowing perturbations of the density profiles.

• The statistics of distant sources multiply imaged by galaxies is sensitive to the cosmological parameters. Recent applications of this method showed agreement with a low-density universe with cosmological constant.

• Galaxy clusters have to be asymmetric, and they must be dominated by dark matter which is more broadly distributed than the cluster light. Cores in the dark-matter distribution must be small or absent. Frequent and substantial discrepancies between lensing and Xray mass determinations are most likely signalling violent dynamical activity in clusters.

• It seems that galaxy clusters in the “concordance”, low-density spatially-flat cosmological models cannot explain the observed abundance of gravitational arcs. Clusters need to be highly substructured and asymmetric, and their dynamics temporarily boosts their strong-lensing efficiency. Yet, theoretical expectations fall substantially below extrapolations of the observed number of arcs. Surprisingly massive and compact clusters which are significant weak and powerful strong lenses exist at redshifts z ' 0.8 and above.

• Although cluster density profiles inferred from strong and weak lensing do typically not contradict expectations from CDM, isothermal density profiles are not ruled out by strong gravitational lensing. Claims of flat central profiles are not supported by reasonably asymmetric models.

• Typical mass-to-light ratios derived from weak cluster lensing range around ' 200 in solar units, but very high values have occasionally been found. While this may indicate a separation of gas from dark matter in cluster mergers, the possible existence of dark clusters is intriguing.

• Cosmic shear, i.e. the distortion of background-galaxy images due to weak gravitational lensing by large-scale structures, has been detected and found to be in remarkable agreement with theoretical expectations. It has enabled constraints on the matter-density parameter and the normalisation parameter σ8 of the dark-matter fluctuations.

• Systematic effects such as image distortions in the telescope, calibration errors on shape measurements, insufficient knowledge of the non-linear matter power spectrum and the redshift distribution of background galaxies and possible intrinsic alignments of source galaxies are important and substantial and need to be carefully corrected.

• Joint analyses of weak lensing and CMB data allow parameter degeneracies in both types of experiment to be lifted. When combined with photometric redshifts of source galaxies, three-dimensional reconstructions of the large-scale matter distribution become possible. This will also allow constraints on the dark energy.

• Cosmic magnification, which is more complicated to measure than cosmic shear, can be quantified by the magnification bias. It has been detected, and most recent measurements are also in excellent agreement with theoretical expectations.

• Gravitational lensing of the Cosmic Microwave Background is inevitable and affects cosmological parameter estimates obtained from the CMB at the per cent level, if uncorrected. It broadens the peaks in the CMB power spectra, creates small-scale temperature fluctuations in the Silk damping tail and converts part of the E-mode polarisation of the CMB into B modes. CMB lensing has been marginally detected at the expected level by cross-correlating the CMB with distant foreground sources.
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In general, I dont disagree with what you say. But after seeing the papers (published by reputed journals) relating "Refractive Index" with Gravity, I am having an open mind that "Refractive Index" also can play some role in Gravitational bending of light.

See one more paper on this subject http://link.springer.com/article/10.1007/s10509-014-1864-4#/page-1

Another Hypothesis http://arxiv.org/vc/arxiv/papers/0704/0704.1942v3.pdf

 

Thanks for these links.

The first link shows how Origin, Physbang and paddoboy acted ignorantly and attempted to troll. This troll Origin wanted thread to be shifted to Pseudo...All these 3 guys pasted one silly image and kept on insisting on only and only curved spacetime effect...

..........AbstractRelativistic light bending and gravitational lensing have traditionally been viewed purely as effects of spacetime curvature. Yet for many years they have also been treated as a quasi-refraction of light in a special optical medium, wherein the refractive index is considered proportional to the gravitational potential. We now propose that this ‘optical-mechanical analogy’ in general relativity can also account for gravity. Using classical optics we show that a photon moving through the refractive medium about a mass transfers momentum first ..................


PS: On this sub forum, unfortunately suporters of GR are failing GR, because many of them (with few exceptions) are ignorants and lack formal education. These three are part of that ignorant group.

 

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The truth is in reality, that the arrogance and nonsensical unsupported claims you make in your posts are all cheapo talk fests and none are verified or validated.
The only ignorance is that shown in your many anti science posts, and your total ineptness in what you claim. GR still stands as the overwhelmingly accepted theory of gravity, the last time I looked, and your anti science posts, like the other agenda laden anti science posts, as usual, are unnoticed in the greater scheme of things:
Some people are born to be no bodies my friend.

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There are many scientific papers published by reputable publishers that discuss and hypothesise purely theoretical aspects of different effects.
Refraction is different from gravitational lensing just as the papers I have given indicate. There are also scientific papers on the ether, white holes, wormholes, parallel universes etc, but the accepted fact by mainstream science is that gravitational lensing is a well evidenced effect caused by curved spacetime, and in reality no amount of discussion with no amount of anti science cranks and doubting Thomases, on any open forum such as this, will ever come up with sufficient evidence to change what is already accepted.
Then of course we have the less than reputable publishers.
In actual fact it's a credit to science that it still emerges with flying colours despite the cacophony of anti science rants by the usual anti science agenda laden "would be's if they could be's.

 

What evidence do you have of your trolling claim?
I see more of what is defined as trolling in your rather absurd statement [even for you] of the following"these 3 guys pasted one silly image and kept on insisting on only and only curved spacetime effect."
The silly image you speak of is a well recognised illustration of what happens with gravitational lensing and the apparent image that is a result.
And of course your usual gilding of the lilly and just plain untruths in claiming no one has recognised refraction. All have but the point that escapes you is that refraction is an entirely different animal with a different recognised result to what is seen with gravitational lensing.

In reality you have shown nothing except a total ineptness in understanding cosmology, and this was illustrated in your thread that was shifted to pseudoscience.
Again, if you believe you have any thing with substance, write up another scientific paper, and get the appropriate peer review.
You havn't, and you won't and you'll also totally ignore this reasonable request.

 

http://www.popsci.com.au/science/100-years-of-general-relativity-why-einstein-still-stands,412131

100 Years of General Relativity: Why Einstein Still Stands

 

Long Live Einstein!

 

What is "mainstream science"? Is it consensus among majority of scientists or a science which is "peer reviewed" and published.

Einstein had a vision. In his vision space or space-time curves. From this vision he developed his maths and equations. His maths are working. They are giving us solutions. They have more predictive power than Newton's math. Thats why GR is preferred over Newtonian model of Gravity.

As far as Gravitational Lensing is concerned and those who are viewing this from Refraction point of view, the math developed by them is giving the same solutions as Einstein's Equations.

As long as there is no conflict in the math, I think we should feel happy about it.

 

No the poor bugger's dead now, but his work along with the work of other greats will certainly live forever.
Which appears to be a grave problem with some on this forum in their failure to want to admit that we have many greats and their works, not only of the past, but also the present, just that we most obviously do not see them here.

 

It is both.

Firstly the Newtonian model is still used even for our most distant space exploration adventures, so it is actually the preferred option albeit it for ease of calculations and approximations. Secondly the predictions of GR including the curvature of spacetime have been verified many times, despite what a bunch of amateurish would be's if they could be's on some isolated science forum would like the world to think.

Like I said, the refraction aspect is caused by an entirely different animal then gravitational lensing. Both are evident in different aspects and both are proven.
Which makes the hidden agenda of the OP along with the initiator of this thread in trying to fabricate some non existent problem so silly and futile.