<p>As colleague <strong>James K</strong> explains in his reply, amateur astronomer Donald Bruns repeated Eddington's 1919 observation during the August 21, 2017 solar eclipse.</p>
<p>For anyone who wants to check out the details, his methodology, observation execution and results are published in the technical article: <a href="https://arxiv.org/abs/1802.00343" rel="nofollow noreferrer"><strong>Gravitational Starlight Deflection Measurements during the 21 August 2017 Total Solar Eclipse</strong></a></p>
<p>Best regards</p>

CC BY-SA 4.0
2024-01-22T08:57:17.430Z
2024-01-22T08:57:17.430Z
Albert
<p>Yes, observations of this kind are within the technical scope of amateur astronomers.  Several groups succeeded in replicating the experiment during the 2017 eclipse that crossed the USA.</p>
<p>For example <a href="https://www.skyandtelescope.com/astronomy-news/amateur-astronomer-donald-bruns-receives-chambliss-award/" rel="nofollow noreferrer">Donald Bruns</a> measured deflections of multiple stars.</p>
<p>Nasa published a &quot;<a href="https://eclipse2017.nasa.gov/testing-general-relativity" rel="nofollow noreferrer">How To</a>&quot; page for anyone wanting to test GR themselves.</p>

CC BY-SA 4.0
2020-01-27T11:10:44.573Z
Nice. It must be a wonderful feeling to be able to test such an important theory, right in your backyard, with some reasonably affordable equipment.
Eric Duminil
CC BY-SA 4.0
2020-01-27T15:37:30.333Z
Does it mean that gravitation indeed is a curvature of spacetime rather than a force?
user30007
CC BY-SA 4.0
2020-01-27T15:49:54.740Z
@user30007: Where have you been for the last 100 years?
TonyK
CC BY-SA 4.0
2020-01-27T16:37:27.867Z
@user30007 It could be a force that affects light particles the same way it affects everything else.
JiK
CC BY-SA 4.0
2020-01-27T16:43:08.773Z
@TonyK It is a theory that didn't replace Newton's theory but instead both were or still are possible, I dunno. See JiKs comment.
user30007
CC BY-SA 4.0
2020-01-27T16:45:43.807Z
@JiK Light is a massless wave and can only be "attracted" by an object's bending of spacetime. I believe Newton's theory rather than Einstein's because if a probe flies fast enough it isn't attracted as strong as a slower probe by a planet, right? That would be impossible with Einstein's theory, wouldn't it? If space is curved, you'd fall into the bulge, no matter your speed.
user30007
CC BY-SA 4.0
2020-01-27T16:56:11.090Z
@user30007 it's not that one is right and the other is wrong, they both explain some things and don't explain other things. General relativity explains *more* than Newtonian gravitation does, though (by a wide margin)
llama
CC BY-SA 4.0
2020-01-27T17:18:09.250Z
Umm, what? How can both be right? That sounds like doublethink. If you send a probe fast enough to proximity of a celestial body, it won't be affected or not that much, right? That would be impossible with Einstein's theory. I don't oppose it, but just wonder.
user30007
CC BY-SA 4.0
2020-01-27T17:18:42.993Z
@user30007 " I believe Newton's theory rather than Einstein's because if a probe flies fast enough it isn't attracted as strong as a slower probe by a planet, right?"   A faster probe experiences the force due to gravity for a much shorter time, and thus appears to be less attracted by the massive object. In reality the magnitude of attraction for two objects equally far away from the planet is the same, it's the duration that they undergo that force  that is different.
eps
CC BY-SA 4.0
2020-01-27T17:20:54.733Z
@eps You're fully correct, that is what I wanted to tell. As you say "force due to gravity". It would be impossible with Einstein's theory because if there is a spacetime bulge, the probe will change direction and fall onto the body, no matter its speed.
user30007
CC BY-SA 4.0
2020-01-27T17:24:34.027Z
@user30007 In museums they often have a 'coin funnel' (or vortex) where you can put a coin in and it will spin around and around the funnel until it falls in the hole in the middle.  What would happen if you increased the speed of the coin?  At some point it will be moving so fast that it no longer stays in the funnel but shoots out.  This is essentially what happens when the probe shoots past the planet.  It is moving so fast that the curvature of space can't keep it contained.  Now image a funnel with walls so steep that no amount of speed keeps the coin from falling in.  That's a black hole
eps
CC BY-SA 4.0
2020-01-27T17:25:53.277Z
@eps Alright, now I understand it, thank you.
user30007
CC BY-SA 4.0
2020-01-27T17:31:13.133Z
@user30007: Newton's theory has been thoroughly superseded by Einstein's theory. When the two theories disagree, it is always Newton's theory that is wrong. Newton's theory is still used today because (i) it is accurate enough for most practical purposes (but not GPS satellites), and (ii) it is easier to calculate with. But it is only an approximation.
TonyK
CC BY-SA 4.0
2024-01-21T04:28:05.387Z
@James The maximum deflection for a ray grazing the photosphere is 1.75 arcsecs. The 2.8 arcsecs mentioned in the linked article is the size of the star images. "Accounting for his instrumentation and the conditions during the eclipse, Bruns expected his images of stars to be 2.8 arcseconds across during totality. But to measure the Sun’s deflection of the stars’ light, he needed a precision of just 0.02 arcseconds. So with careful planning and attention to detail, he set out to beat down the errors by imaging multiple stars multiple times."
PM 2Ring
CC BY-SA 4.0
2020-01-26T20:22:45.067Z
2024-01-21T07:03:24.357Z
2024-01-21T07:03:24.357Z
James K
<p>In 1919 the gravitational lensing by the Sun has been observed during a total solar eclipse. Did someone observe the lensing in any other total eclipses? Last year there was a total eclipse in Chile and there were many scientists observing it. Did they see the stars in different places too? I mean, today it must be even easier to observe it with current telescopes or something. But there is no mention of any other observations than the one in 1919, is there?</p>

CC BY-SA 4.0
2020-01-27T16:26:41.720Z
More interesting variant of this question: are there any historical images from *before* Einstein made his prediction that show gravitational lensing?
Barmar
<the-sun><amateur-observing><general-relativity><solar-eclipse><gravitational-lensing>
Was the Sun's gravitational lensing observed in other solar eclipses than the one in 1919?
user30007
# Was the Sun's gravitational lensing observed in other solar eclipses than the one in 1919?

(Asked by: username_0 on 2020-01-26)

In 1919 the gravitational lensing by the Sun has been observed during a total solar eclipse. Did someone observe the lensing in any other total eclipses? Last year there was a total eclipse in Chile and there were many scientists observing it. Did they see the stars in different places too? I mean, today it must be even easier to observe it with current telescopes or something. But there is no mention of any other observations than the one in 1919, is there?

**Tags:** the-sun, amateur-observing, general-relativity, solar-eclipse, gravitational-lensing
> **Comments:**
> **username_1**: More interesting variant of this question: are there any historical images from *before* Einstein made his prediction that show gravitational lensing?  

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## 2 answers

### Answer by username_3 on 2020-01-26. Score: 25 | Accepted answer

Yes, observations of this kind are within the technical scope of amateur astronomers. Several groups succeeded in replicating the experiment during the 2017 eclipse that crossed the USA.

For example [Donald Bruns](https://www.skyandtelescope.com/astronomy-news/amateur-astronomer-donald-bruns-receives-chambliss-award/) measured deflections of multiple stars.

Nasa published a "[How To](https://eclipse2017.nasa.gov/testing-general-relativity)" page for anyone wanting to test GR themselves.

> **Comments:**
> **username_4**: Nice. It must be a wonderful feeling to be able to test such an important theory, right in your backyard, with some reasonably affordable equipment.  
> **username_0**: Does it mean that gravitation indeed is a curvature of spacetime rather than a force?  
> **username_5**: @user30007: Where have you been for the last 100 years?  
> **username_6**: @user30007 It could be a force that affects light particles the same way it affects everything else.  
> **username_0**: @TonyK It is a theory that didn't replace Newton's theory but instead both were or still are possible, I dunno. See JiKs comment.  
> **username_0**: @JiK Light is a massless wave and can only be "attracted" by an object's bending of spacetime. I believe Newton's theory rather than Einstein's because if a probe flies fast enough it isn't attracted as strong as a slower probe by a planet, right? That would be impossible with Einstein's theory, wouldn't it? If space is curved, you'd fall into the bulge, no matter your speed.  
> **username_7**: @user30007 it's not that one is right and the other is wrong, they both explain some things and don't explain other things. General relativity explains *more* than Newtonian gravitation does, though (by a wide margin)  
> **username_0**: Umm, what? How can both be right? That sounds like doublethink. If you send a probe fast enough to proximity of a celestial body, it won't be affected or not that much, right? That would be impossible with Einstein's theory. I don't oppose it, but just wonder.  
> **username_8**: @user30007 " I believe Newton's theory rather than Einstein's because if a probe flies fast enough it isn't attracted as strong as a slower probe by a planet, right?"   A faster probe experiences the force due to gravity for a much shorter time, and thus appears to be less attracted by the massive object. In reality the magnitude of attraction for two objects equally far away from the planet is the same, it's the duration that they undergo that force  that is different.  
> **username_0**: @eps You're fully correct, that is what I wanted to tell. As you say "force due to gravity". It would be impossible with Einstein's theory because if there is a spacetime bulge, the probe will change direction and fall onto the body, no matter its speed.  
> **username_8**: @user30007 In museums they often have a 'coin funnel' (or vortex) where you can put a coin in and it will spin around and around the funnel until it falls in the hole in the middle.  What would happen if you increased the speed of the coin?  At some point it will be moving so fast that it no longer stays in the funnel but shoots out.  This is essentially what happens when the probe shoots past the planet.  It is moving so fast that the curvature of space can't keep it contained.  Now image a funnel with walls so steep that no amount of speed keeps the coin from falling in.  That's a black hole  
> **username_0**: @eps Alright, now I understand it, thank you.  
> **username_5**: @user30007: Newton's theory has been thoroughly superseded by Einstein's theory. When the two theories disagree, it is always Newton's theory that is wrong. Newton's theory is still used today because (i) it is accurate enough for most practical purposes (but not GPS satellites), and (ii) it is easier to calculate with. But it is only an approximation.  
> **username_9**: @James The maximum deflection for a ray grazing the photosphere is 1.75 arcsecs. The 2.8 arcsecs mentioned in the linked article is the size of the star images. "Accounting for his instrumentation and the conditions during the eclipse, Bruns expected his images of stars to be 2.8 arcseconds across during totality. But to measure the Sun’s deflection of the stars’ light, he needed a precision of just 0.02 arcseconds. So with careful planning and attention to detail, he set out to beat down the errors by imaging multiple stars multiple times."  

---

### Answer by username_2 on 2024-01-22. Score: 1

As colleague **James K** explains in his reply, amateur astronomer Donald Bruns repeated Eddington's 1919 observation during the August 21, 2017 solar eclipse.

For anyone who wants to check out the details, his methodology, observation execution and results are published in the technical article: [**Gravitational Starlight Deflection Measurements during the 21 August 2017 Total Solar Eclipse**](https://arxiv.org/abs/1802.00343)

Best regards


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