Gravitational Lenses and Observations

[Jarvamundo]

http://www.extinctionshift.com/SignificantFindings.htm

http://adsabs.harvard.edu/abs/2007AN....328..186D

Time resolved images from the center of the Galaxy appear to counter General Relativity


interesting read...

also some great reads on the double slit paradox from that site

The Ad-hom conservatives should probably have a squiz here: http://www.extinctionshift.com/author.htm

[renormalised]

Very interesting.

[bojan]

Einstein's rings ?
Microlensing and discovery of extrasolar planets?
Just a two that comes to my mind.... I am sure others will come up with much longer list.

Once I knew a guy who was very clever... published a lot in area of theoretical physics.. then he went crackpot. Ended up in mental hospital, despite all his academic references.... paranoia and schizophrenia

[Jarvamundo]

It's well worth reading the material, as what you have mentioned so far is thoroughly discussed...

another nice irrelevant adhom... sigh

[bojan]

Yes.. nobody understand your points..
That is the beginning ;)

[Jarvamundo]

Just letting you know that the difficulties you have raised are exactly what is covered in this material.

re the adhom, i'm sure the 'guy' you knew is a nice bloke, i'm just saying he is probably not this guy, who is currently building laser equipment and satellites at Goddard space flight center.... ie someone whos job it is to ensure scientific accuracy of empirical measurements of light itself...

The point here is irrelevant adhom attacks can be a tool used by conservatives to distract from the science...

anyways.. the content is there.. i found the content interesting and relevant to this forum... just want to highlight where adhoms can have an insulating effect on science, especially when constructed in the irrelevant way you have done.

http://www.extinctionshift.com/lensing_animate.gif
(in a nutshell for ya...)

[Coen]

Ad-hominem: http://www.sjsu.edu/depts/itl/graphics/adhom/adhom.html

The jump to the relationship "I knew a guy who was brilliant but..." can be construed as ad-hominem as how is it relevant to the topic of discussion except as an implied potential link to the mental state of the author (by association) so the work can then be dismissed rather than discussed.

The abstract is interesting, the journal is peer reviewed and prestigious: http://www3.interscience.wiley.com/journal/60500255/home/ProductInformation.html (no guarantee that everything is perfect but certainly helps limit nonsense).

I can not readily get to the underlying article so can not comment further.

Observations are observations, theory is theory, we try and match the two but of the two observations are what is kept if one is not lining up with the other. For example, just as Newtonian view of gravity is pretty good most of the time, so might be the case for relativity. Prior to Kepler there was a way of describing the orbits by many circles - still possible but not as simple or elegant as ellipses and then gravity to explain why ellipses. What helped all this were observations, e.g. Tycho & others.

[renormalised]

Yes, and I can think of a few others, but is that what we are seeing and do we really understand what we are seeing?? Just because we see something and it can be explained by what we feel is the correct theory for why it happens, doesn't mean that we are actually correct in what we are saying is happening. What if there is an equally possible, but different, explanation. It has to be tested, yes, but what if that new explanation turns out to be as rigorous in its testing and can be proven. Which idea do you then use??? Do you throw one out in favour of another or do you create a synthesis of both ideas and then test that??.

We may think we know and understand a lot, but we actually know less than what we believe we do.

Let's test these new ideas, instead of trying to dismiss them because we think we know what's going on.

[rally]

Thanks Alex.

A most interesting concept and explanation.
Is there a publicly accessible version anywhere ?

Cheers

Rally

[Jarvamundo]

I've been unable to locate the paper, i'd imagine since it's been published in that professional journal, it'll be a few more years before it's released publicly, and i can't track down a pre-published version... let me know if you do.

This page (from the authors site) gives a great run down, along with animations, including the observations measured around Sag A.

http://www.extinctionshift.com/topic_07.htm

[sjastro]

What I found interesting about the article http://www.extinctionshift.com/SignificantFindings.htm (http://www.extinctionshift.com/SignificantFindings.htm) is the misinterpretation of GR by attempting to explain it from a "plasma physics" perspective.

The author uses Gauss' law of gravity (which is the gravity variant of Gauss' general laws for electromagnetism) to explain the bending of light.
In essence a particle is deflected in a gravitational field by a force exerted on the particle much like a charged particle is deflected in an external electric field.
There is one little problem however, photons have no mass. Hence a photon cannot be deflected by applying Gauss' law of gravity irrespective of how close the photon is to the source.
In GR the bending of light is through the scalar gravitational potentials of the field (space-time curvature) instead of the vector gravitational field itself as is implied through Gauss' law.

Then there is the argument that the lack of evidence of gravitational lensing around the supermassive black hole Sagattarius A* supports the view that there is an inconsistancy between lensing and GR.
From a GR persepctive there is no such problem.
For a photon to be observed it needs to be beyond the event horizon of the black hole.
The radius of the event horizon is directly proportional to the mass of the black hole. For a supermassive black hole of several million solar masses such as Sagittarius A*, the event horizon is so far away from the centre of the black hole that space-time is quite flat in the vicinity of the horizon. Hence the bending of light even grazing the horizon may not be apparent.

Regards

Steven

[Jarvamundo]

The author makes particular comment on exactly this SJ...Did you read all the material? You are suggesting a fundamental misunderstanding and misapplication of GR's equations for the subject matter, when it's in the title of the peer reviewed journal... Although possible, I doubt this would've gotten through Astronomische Nachrichten.

Particularly interesting is the common misapplication of GR bending of light equations, when interpreting astrophysical events. The author goes on to mention "Ray Geometry Technique for Gravitational Lensing". http://www.extinctionshift.com/SignificantFindings07.htm

As far as his emission 'theory', this would seem to secondary to the observations conflicting 'observations' reported in the journal.

[sjastro]

To suggest that peer review is a confirmation of the "correctness" of a journal......
" There seems to be no study too fragmented, no hypothesis too trivial, no literature too biased or too egotistical, no design too warped, no methodology too bungled, no presentation of results too inaccurate, too obscure, and too contradictory, no analysis too self-serving, no argument too circular, no conclusions too trifling or too unjustified, and no grammar and syntax too offensive for a paper to end up in print." Drummond Rennie, deputy editor of Journal of the American Medical Association.

Plasma and mainstream cosmology involve the publication of peer reviewed journals yet both cannot be right.

Regards

Steven

[Jarvamundo]

easy now, I merely made the point that you suggested a fundamental error on the author's GR math. To me (yep i read the material), he directly commented on the GR math derivations, which you dismissed the author on?

Yes, I also would think that fundamental GR math would be fairly well understood by the peer review process of this particular journal (the oldest in existence).... but that's irrelevant, as the above point still holds. The author is aware of mathematical GR predictions, as it is the subject of the paper, and is directly mentioned in the content of his site.


Couldn't have said it better myself.

However, i'm not arguing theories, just alerting to observations, which i found interesting when trying to assess validity of either.

I just found your previous post a little dismissive and based on misapplication of GR fundamentals, i thought you may not have actually read the content, so i just pointed out the part where the GR maths were applied, i'd be interested on comments on this.

You've now moved away from specifics GR fundamentals of the science, into a vague dismissal based on what gets printed in what journal.

I'm not interested in this.

[sjastro]

Evidently you have failed to comprehend my first post.

Steven

[Jarvamundo]

I fail to comprehend how the content does not already address your post.

I acknowledge the differences in gradients as you have described, but that is exactly what is derived here?

[sjastro]

He hasn't derived the equation from GR at all.

The "xi" term in the denominater of the equation is not the radius R of the star. If it was it would correspond to the GR equation of light grazing the limb of the star. The "xi" term has no meaning in GR.

This is the whole point of my first post. He is not using GR but Newtonian gravity based on Gauss' law. This is not shades of grey but black and white.

Steven

[KenGee]

Alex where do you find this tosh? If you want to post weird science stuff there is plenty of web sites for this. As I said in your first set of post, some things only deserved to be laughed at. Alex before you post stuff like this, try poking holes in it yourself. try asking yourself some basic questions like what observations does the current theory not explain? does the author make reasonable representation of the predictions of the current theory? and so on. I'll give you a hint on this one try door number two for a start.
Then listen to Steven he's telling you about door number one. hes got more time to waste.

[Jarvamundo]

Is he not describing the distance r from the gravitational center? The gaussian sphere.



The actual radius of the sun's plasma surface is irrelevant here? The Gaussian sphere is referring to Gauss Law gravitational sphere?
http://www.extinctionshift.com/GaussLaw.gif

Is this not exactly what is used in gravitational lense theory?
http://en.wikipedia.org/wiki/Gravitational_lens#Explanation_in_t erms_of_space-time_curvature

To produce these simulations: http://upload.wikimedia.org/wikipedia/commons/thumb/0/03/Black_hole_lensing_web.gif/220px-Black_hole_lensing_web.gif

You are suggesting the gradient is incredibly steep, due to photons only interacting incredibly close the event horizon of a BH. If the geometry you are suggesting here is the correct interpretation, how does an irregularly shaped cluster of galaxies produce a round-ish 'gravitational lense'.
http://upload.wikimedia.org/wikipedia/commons/thumb/0/0b/Gravitationell-lins-4.jpg/577px-Gravitationell-lins-4.jpg

(we are told to believe this is a gravitational lense)

I see a contradiction of both explanations here SJ...

Either
(1) You are correct, photons only change course very close to the event horizon.
In this case, a cluster of galaxies would not produce a round lense, it would be a far sharper - irregular lense. The above galaxy cluster lense is not a 'your-interpretation' lense... Your geometrical interpretation should produce multiple lenses, not 1 large spherical lense.

or (2) The gauss-law sphere approach is correct, and photons change course according to Gauss sphere, in this case the cluster of galaxies could round out to a sphere... ok.. but then we should see evidence of gauss-like lenses everywhere... and we don't.

Which one is it?

I'm sorry but the lense-photos, i'm told to believe and the two geometric models suggested, 1 by you, the other by this material, do not agree each other.

Regards,

[sjastro]

Gaussian spheres don't exist in GR.

Using your own terminology they are hypotheticals used in Newtonian theory. Think of lines radiating outwards from a point source. The lines represent the gravitational field. If you draw a circle with the point source at the centre, the intersection of the lines with the circle of radius R, represents the force on a particle with mass at a distance R from the point source. The larger the circle the more the lines are spread out and the less the force on the particle.

Gaussian spheres are a pictorial representation for the mathematics behind Gauss' law.



No it's completely different. Light travels along a what is known as a null geodesic path in space time which is the shortest distance between two points in any space time geometry. Any particle that travels along a geodesic path is not subjected to external forces.

As I have stated numerous times the model presented relies on photons being deflected in the field by a force. This is a Newtonian model not a GR model and deflection can only occur if photons have mass.



You seem to have forgotten one important point Alex.
Gaussian spheres are modelled for a single foreground object that causes the lensing of a background objects.
So you can eliminate point (2).

The cluster itself is causing the lensing of background objects and is due to space time curvature. The "effectiveness" of the lens is very much dependant on the geometrical arrangement of the galaxies in the cluster.

Regards

Steven

[Karls48]

It should be relatively easy to prove/disprove effect of plasma on the photons by the experiment. If my memory serves me right there was some very energetic plasma created for experiments to create fusion. It could be possible to fire laser beam to graze this plasma and measure if any deviation from the straight path took place I do realise that power density of man made plasma is a small fraction of the power of plasma around the sun. But under laboratory conditions it could be possible to measure if any deflection took place.

[bojan]

I am still following this discussion with great interest (despite being accused of placing irrelevant remarks..)..
While personally I can not contribute much - the lack of deeper understanding of the subject (mathematics - mine is on the engineering level, more than enough for what I do professionally but totally in-adequate for going deeper into GR) prevents me from making any statements apart from general ones (which I did earlier), I did some research among people who know the stuff and who-is-who (one friend of mine is in this subject up to his neck, if not deeper) and he confirmed for me that plasma effect on light bending WAS taken into account, during original experiment/measurement... That is why this discussion is pretty meaningless. As it is meaningless to take this author into account too seriously in general ("Only I understand and see what is going on here, all the others were stupid and blind..." which is what he is saying in essence, cherry-picking the experimental results while not describing in detail the methods used, which suggests to the average reader that measurement results were misinterpreted in haste to prove relativity.. which is very far from the truth..... and he is doing exactly the same, only to disprove it. In my book, this is not very scientifically credible approach.. )

Also, for the experimental confirmation of effects of gravity to EM, have a look here:
http://hyperphysics.phy-astr.gsu.edu/hbase/relativ/gratim.html

In the meantime, I am trying to find gravitation simulator (Einstein's ring issue) on the web, which is based on relativity.. I stumbled on it quite some time ago, but I lost the link.
If this simulator is producing the same images as seen in reality (and as I remember it did, quite so), then we can forget about this guy, IMHO.


EDIT:
This is not quite the same website but it will do (simulator is very simple, it uses only one, pointlike mass.. the clusters of galaxies are - as we know - distributed, so the images they produce are much more complex than shown here in simulation):
http://www.astrophysicsspectator.com/topics/generalrelativity/GravitationalLensPointSim.html

also:
http://www.astrophysicsspectator.com/topics/generalrelativity/SchwarzschildLensSim.html
http://en.wikipedia.org/wiki/Einstein_ring#A_simulation
http://www.photon.at/~werner/bh/gvsim.html (http://www.photon.at/%7Ewerner/bh/gvsim.html)

[Jarvamundo]

Re SJ: Thanks will comment

Re Karl: Yes the author mentions experiments where GR and plasma predictions will differ. I have also seen some recent plans for experiments using radio waves.

Re: Bojan, you keep telling me about these guys you know? I don't care.
The first link you sent regarding experimental proof of EM and gravity makes no mention of lensing?

The next link, the lensing simulator you sent, is exactly where i am struggling... It uses 1 solar mass at 1 parsec.

With SagA i have 2.6 million solar masses at say 8,000 parsecs.

On one hand we herald the proof of g-lenses as:
http://en.wikipedia.org/wiki/Gravitational_lense#History


But now SJ is saying i cannot use the same physics to predict and measure the lensing of an object with 2.6 Million solar masses.... the black hole at SagA*

I don't get how:
1) We can use eddington's measurements as confirmation of GR, by bending of light around the sun (1 solar mass)

but

2) I cannot use the absence of bending of light around a 2.7 Million solar mass body as disproof?

Which one is it?

I don't think this is cherry picking observations, this was a 10 year observational program using sophisticated equipment, it was simply not possible to take these measurements in the past... This data does not come around everyday.

I seriously doubt how eddington was able to achieve such a highly accurate confirmation of GR. (note this is still heralded as the proof!)

Here is an interesting read on the modern interpretations of the history:
http://www.newtonphysics.on.ca/eclipse/index.html


Any layman should be able to understand a good theory. That simulator is a good example, but when i hold it up to the sky it just don't work.

Which is what i'm trying to explore here with SJ... still struggling with it.

I don't get how a distributed cluster of galaxies can form a spherical lense, but a concentrated super massive BH at 2.7 million solar masses cannot, when the proof we have used to confirm GR is 1 solar mass.

I hope you see the logical contradictions here.

What would be really interesting is a similar paper on the SAME observational data using the interpretation SJ is familiar with. SJ if you have this i'm all ears.

It seems as far as SJ is concerned that 1 solar mass simulator is trash?

Best

[bojan]

Well, you do not have to.


It mentions the gravity and effects on EM.
The result of this experiment must be taken into account when considering lensing as well - meaning, this guy's interpenetration must explain it as well.



I think it is exactly this (based on all I know and what my mates are telling me.. and I tend to believe them, and not you and this Don Quixote de la Goddard space flight center)...

Did you do those measurements yourself?

[sjastro]

Hold your horses. The Sun does not have an external event horizon so you cannot equate the Eddington experiment to black holes.

Black holes are very effective at bending light if their event horizons are close to their centres or singulariites. A one solar mass black hole will bend light far more noticeably than our Sun or a one million solar mass black hole.

The radius of the event horizon (Schwarzchild radius R) is

R= 2MG/c^2.

So as you increase mass M the event horizon radius R increases. The radius of a one million solar mass BH is one million times larger than the radius of a one solar mass BH. The larger the radius the less space time curves at the horizon.

Regards

Steven

[Jarvamundo]

Re: Bojan

I do not question your personal affinity with your mates. I certainly make no claim to any personal connection with this papers author.

but again we are straying from the science.

I still don't see how eddington has proved GR with 1 solar mass, when i can't use 2,700,000 solar masses to find a significant result?

But then we can use a cluster of irregularly shaped galaxy cluster to produce a spherically lensed image?

Eddington says a 1 sun did it
SJ says a 2,700,000 sun BH wont do it
Apparantly a group of BHs can combine powers

I do not care (in a sincerely respectful way) about the personal relationships you continue to invoke, the logic does not line up for me.

[Jarvamundo]

Thanks SJ, I'm starting to piece together the illogical geometric picture a Schwardschild Black Hole Lense creates... This is not what the gravitational lense simulators show.

To me it seems to be violating all geometry i am familiar with in all aspects of empirics... generally the inverse square root law, which is apparent is nearly all nature .... hmm...

I think we are starting to get somewhere atleast with trying to describe Schwartschld characteristics.

What we are saying is that a Schwardschild black hole lense IS NOT the same as a gravitational lense?

So the bigger a black hole gets, the sharper the gradient of lensing?

From this:

1) Should we not see these stars disappearing as they pass behind SagA*? As they are 'blocked out' by the sharp event horizon.

This would be the only way to directly confirm a black hole exists?

2) Gaussian curvature of light for a large Schwartzchild black hole is not as applicable, as that of as the gaussian curve of a large gravitational body.

a Schwartzchild Geometrical Curvature picture:
small black hole: ````\__/````
large black hole: ```|_____|```

It seems the r in the Schwartzchild solution is not the same as the r in the GR gravitational lense solutions? Although it's used when considering gravitational effects of orbiting stars...

On one hand we use r to determine curvature of spacetime and the orbits of stars
Then on the other we can't use r to determine the curvature that would effect light

It seems Schwartzchild BH's get their own special set of rules.
puzzling

Why on one hand do we use the gravitation field of the black hole to explain the orbits of those stars.
But on the other... the spacetime curvature is non existent beyond a SMBH horizon, and does not lense.

It's like it's the curvature exists for determining orbits, but does not exist for lensing.... its a contradiction.

[sjastro]

The same principles apply. The only difference is that we can observe the bending of light as close as the limb of a star or galaxy(s). For BHs this is the event horizon. Bending of light occurs inside the horizon, unfortunately we cannot observe it.



The BH's mass is confirmed by the Keplerian orbits of nearby stars. If the orbiting stars are in the same plane as the accretion disk of the BH then probably we would not be able define a sharp horizon. If the orbits are not in the same plane the event horizon would "eclipse" the stars relative to our frame of reference.



The Gaussian curvature is dependant on the density of an object rather than its mass.
Hence the curvature around a one solar mass star is nearly flat where as the curvature around a one solar mass BH is extreme. The curvature of a supermassive BH is also extreme as we get closer to the centre. We can't observe the effects however due to the event horizon.



Nothing unusual at all.
The GR equation for the bending the light has the R value equal to the radius of the star, for BHs R is the event horizon radius.

I'm taking a break from this thread.:hi:

Regards

Steven

[Jarvamundo]

I'm still seeing contradictions, will explore Schwartzchild solutions... How an event horizon can pop into existence and change spacetime in a different way to GR mass puzzles me no end.

cheers mate, thanks for your input...