Gravitational Lensing : Eddington Experiment

The God said:
And now you have got stuck with this...the curvature of spacetime in absence of mass and energy....So, Mr. GR Expert will you please tell 'us' after t = 0 (BB onwards) which portion of space or spacetime which you can find and which you can term ' in absence of mass and Energy' ? This will help you understand the practical aspect of GR in much better perspective than your so called formal education in GR, which does not reflect from your posts so far.
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One can, and indeed, many people have, produce models of spacetime where there is no mass or energy. Please take a look at any textbook on the history of GR or of cosmology.

You are the person here confusing the Newtonian prediction of deflection with the non-deflection where there is no mass or energy.

But, please, let's see you prove that there are no straight lines in GR, like you have been saying.
 
PhysBang said:
One can, and indeed, many people have, produce models of spacetime where there is no mass or energy. Please take a look at any textbook on the history of GR or of cosmology.


But, please, let's see you prove that there are no straight lines in GR, like you have been saying.
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Don't get shaky, answer the question, where will you find something called 'in absence of mass and energy' as asked in previous post.

PhysBang said:
You are the person here confusing the Newtonian prediction of deflection with the non-deflection where there is no mass or energy.
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You are again mis-attributing, I had very clearly taken you through that Newtonain Calculations (based on Equivalence principle) as done in 1911 when GR/curved spacetime concept had not come by, was x, and when the same was done in 1915 taking curved spacetime into consideration was 2x. It is you, who is mixing 1911 flat spacetime with 1915 and beyond flat spacetime.

Anyway answer the question....
 
Dear TG
You made a mistaken assumption about my "formal education".
The truth is I was setting you up to surprise you but there is no point.
 
hansda said:
So, there is no spacetime curvature in the weak gravitational field as there is no "observable evidence" for it.



Is the "mass/object falling under gravity" observable or not?




This case of Muons is an effect of relativistic speed. A "mass/object falling under gravity" does not fall with a relativistic speed. So, this Muon example has NO relevance here.
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Xelasnave.1947 said:
"BINGO"
He raised education then avoids the issue.
Really I dont care but if you raise an issue one invites cross examination but he seems to avoid it.
I suspect he does not care that such avoidance reduces ones credibiliy.
Still I am here to learn science not be reminded how humans can disappoint ones expectations of reasonable bahaviour.
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Talk about raising nonsense. How about denigrating Donald Trump by saying he has New York values. Smart move exlax. Ted check his shorts Cruz. Sure you remember that phrase. 1947 and all. The intellectual dishonesty runs unchecked thru these pages. He could possess a Doctorate from MIT but all the knowledge in the world is of no use to fools. As per The Eagles. Kinda sounds like Ben Carson. Doctorate/Fool.
 
Greetings brucep
I am following this thread to witness the complete demolition of GR and you suggest he is a fool.

Damn it I thought I was witnessing history unfold.
 
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Dear TG
Here something for you.
Sorry I have not added notes but I dont want to spoil the ending for you.
I sincerely hope you enjoy the links and maybe come accross something you dont know as remote as that may be.
Tests of General Relativity

Universality of Gravitational Red Shift : http://www.exphy.uni-duesseldorf.de/...2-PRL10401.pdf
Gravitational Potential at Short Distances : http://www.exphy.uni-duesseldorf.de/...2-PRL10401.pdf
Tests of Lorentz Invariance : http://relativity.livingreviews.org/...005-5Color.pdf
Gravitational Red Shift / Pound-Rebka : http://luth2.obspm.fr/IHP06/lectures...avRedshift.pdf
Light Deflection within the Solar System/Shapiro Delay : [astro-ph/0302294] The Measurement of the Light Deflection from Jupiter: Experimental Results
Lunar Laser Ranging to test Nordvedt Effect : Phys. Rev. 169, 1017 (1968): Equivalence Principle for Massive Bodies. II. Theory
Hafele-Keating Experiment for Time Dilation : Around-the-World Atomic Clocks: Predicted Relativistic Time Gains
Thirring-Lense Effect : http://www.nature.com/nature/journal...ture03007.html
Geodetic Effect : Phys. Rev. Lett. 106, 221101 (2011): Gravity Probe B: Final Results of a Space Experiment to Test General Relativity
Orbital Decay through Gravitational Waves in Binary Pulsar System PSR J-0737-3039 : Tests of General Relativity from Timing the Double Pulsar
 
Xelasnave.1947 said:
Dear TG
Here something for you.
Sorry I have not added notes but I dont want to spoil the ending for you.
I sincerely hope you enjoy the links and maybe come accross something you dont know as remote as that may be.
Tests of General Relativity

Universality of Gravitational Red Shift : http://www.exphy.uni-duesseldorf.de/...2-PRL10401.pdf
Gravitational Potential at Short Distances : http://www.exphy.uni-duesseldorf.de/...2-PRL10401.pdf
Tests of Lorentz Invariance : http://relativity.livingreviews.org/...005-5Color.pdf
Gravitational Red Shift / Pound-Rebka : http://luth2.obspm.fr/IHP06/lectures...avRedshift.pdf
Light Deflection within the Solar System/Shapiro Delay : [astro-ph/0302294] The Measurement of the Light Deflection from Jupiter: Experimental Results
Lunar Laser Ranging to test Nordvedt Effect : Phys. Rev. 169, 1017 (1968): Equivalence Principle for Massive Bodies. II. Theory
Hafele-Keating Experiment for Time Dilation : Around-the-World Atomic Clocks: Predicted Relativistic Time Gains
Thirring-Lense Effect : http://www.nature.com/nature/journal...ture03007.html
Geodetic Effect : Phys. Rev. Lett. 106, 221101 (2011): Gravity Probe B: Final Results of a Space Experiment to Test General Relativity
Orbital Decay through Gravitational Waves in Binary Pulsar System PSR J-0737-3039 : Tests of General Relativity from Timing the Double Pulsar
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"Dear" Xelasnave.1947
"Here something for you."

What you Posted, in your Post #786, seems oddly similar to what was Posted on August 11th, 2012, by Markus Hanke at this Link :
http://www.thescienceforum.com/physics/29823-modern-tests-relativity.html

Since you evidently understand the "copy/paste" method of Posting - I will now "copy/paste" the following for you to read :
James R said:
Plagiarism and copying
14. Plagiarism – the copying of another person’s writings and passing them off as your own – is a breach of copyright, as well as being intellectually dishonest. If you post something that somebody else wrote, you must name the author and appropriately reference the source (e.g. with a link). Posts that include material from elsewhere that is not properly acknowledged will be deleted.
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The ^^above quoted^^ from : http://www.sciforums.com/threads/sciforums-site-rules.142880/
 
Thank you dmoe for drawing that to my attention.

You are most certainly correct.

I thought I had included a link clearly I have not but unfortunately I can not edit my post now.

I appologise to the forum it was not my intention to claim all that as my own.​
 
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Observation tells us that gravity is doing so.

Or, more accurate, the GR equations tell us that gravity is doing so. And the observational results do not seem to disagree with these predictions. In the pictures of the various objects which are considered to be evidence for gravitational light bending we do not see rainbows instead of stars. All the light, independent of the frequency, comes from the same place, even if the resulting picture looks quite distorted.

Refraction by the corona would give some rainbow-like picture, which would allow to distinguish it from what gravity causes.
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Hmmm....yet gravity is achromatic.

Hence achromatic does not give the full spectrum of anything , at all (from my post #617)
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My point still stands

river
 
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The God said:
Don't get shaky, answer the question, where will you find something called 'in absence of mass and energy' as asked in previous post.
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If you don't understand the answer given, then I'm not sure that you are asking a proper question in English. Could you try to be clearer?
You are again mis-attributing, I had very clearly taken you through that Newtonain Calculations (based on Equivalence principle) as done in 1911 when GR/curved spacetime concept had not come by, was x, and when the same was done in 1915 taking curved spacetime into consideration was 2x. It is you, who is mixing 1911 flat spacetime with 1915 and beyond flat spacetime.
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The 1911 calculation are Newtonian. The >1915 calculations are GR. In either case, we can extrapolate a path of light that happens without the effect of gravity. In GR, the effect of gravity results from the presence of mass and energy.

Thus, we can consider what the path of light might be if there were not a large presence of mass and energy in a particular place. E.g., if the Sun were not present.

In such a case, we extrapolate to a straight line in a flat spacetime.

But you have said that there can't be straight lines. Then you said there can be straight lines. Then you said that there can't be straight lines. So let's see your proof.
 
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Observation tells us that gravity is doing so.

Or, more accurate, the GR equations tell us that gravity is doing so. And the observational results do not seem to disagree with these predictions. In the pictures of the various objects which are considered to be evidence for gravitational light bending we do not see rainbows instead of stars. All the light, independent of the frequency, comes from the same place, even if the resulting picture looks quite distorted.

Refraction by the corona would give some rainbow-like picture, which would allow to distinguish it from what gravity causes.
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Click to expand...

I reiterate; from post # 790

Hmmm....yet gravity is achromatic.

Hence achromatic does not give the full spectrum of anything , at all (from my post #617)​
My point still stands

river
 
hansda said:
So, there is no spacetime curvature in the weak gravitational field as there is no "observable evidence" for it.
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paddoboy said:
There certainly is spacetime curvature in the weak gravitational field, except of course like the pissing into the Ocean, we are just unable to measure it at those scales.
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Is the spacetime curvature in the Planck's scale that they cannot be measured or tested in the weak gravitational field?
 
river said:
Okay.

Now how does this relate to the OP?

Again just asking

river
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This is to find the reality of spacetime in the weak gravity field. Gravitational Lensing proves spacetime. Eddington's experiment was carried out in a strong gravity field.
 
hansda said:
This is to find the reality of spacetime in the weak gravity field. Gravitational Lensing proves spacetime. Eddington's experiment was carried out in a strong gravity field.
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Would not a weak gravity field be found as well with the moon effects on light coming from the same star ?
 
hansda said:
These effects are so small that, they can not be distinguished from a straight line ?
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If the gravitational field is too weak, yes.

But, as I said, for massive particles it is much easier to distinguish their trajectories from straight lines, because they can have much lower velocities. And then the difference can be easily seen even in a weak field.
 
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