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A question on solar eclipse & Eddington

June 29 2017 at 12:57 AM
nakayama 

 
The moon is passing in front of stars. To observe the effect of gravity (on the position of stars), this situation seems to be more suitable than solar eclipse (in qualitative). But no book refers to the moon.

 
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nakayama

Re: A question on solar eclipse &amp; Eddington

June 30 2017, 1:35 AM 

Ratio of mass sun:moon is approximately 27,000,000:1. However,distance of star’s position and the center of the moon is shorter. So, gravity will be stronger (than the ratio above).

 
 
Anonymous

Re: A question on solar eclipse &amp; Eddington

June 30 2017, 12:18 PM 


>>>...this situation seems to be more suitable than solar eclipse

very very very very... small - they can't measure it -https://www.forbes.com/sites/jillianscudder/2017/04/26/astroquizzical-can-planets-bend-light/#5bfff5455bee

 
 
Amigo

Re: A question on solar eclipse &amp; Eddington

June 30 2017, 9:31 PM 

>>>very very very very... small

How much?

 
 
Anonymous

Re: A question on solar eclipse &amp; Eddington

June 30 2017, 10:30 PM 

>>>How much?

0.01037 arcseconds

 
 
nakayama

Re: A question on solar eclipse & Eddington

July 2 2017, 2:31 AM 

Suppose we observe the earth (and stars) from the moon. At the position of the star, the ratio of gravity (Earth : Sun) is about 1 : 100. If there is no mistake in calculation.

The density (decreasing) of atmospheric air on earth is well known. But, why any reexamination (after Eddington) is not be done ? Because it is doubtful ?

 
 
Amigo

Re: A question on solar eclipse &amp; Eddington

July 2 2017, 6:44 PM 


Maybe - if rich nations build on the moon research stations like the research stations in Antarctica.

 
 
Anonymous

Re: A question on solar eclipse &amp; Eddington

July 2 2017, 10:02 PM 


Are you kidding? The MOON will make Antarctica look like Miami Beach -https://www.youtube.com/watch?v=fxY4epFFqwI

 
 
nakayama

Re: A question on solar eclipse & Eddington

July 6 2017, 2:52 AM 

Then, how about as gravitational lensing by the moon ? Is it observable or not ? No book seems to refer to it also.

 
 
Anonymous

Re: A question on solar eclipse &amp; Eddington

July 6 2017, 1:25 PM 

>>>Then, how about as gravitational lensing by the moon ?

not possible to measure moon's lensing (= 0.01037 arc-sec) because the moon has airy's diffraction disc -https://www.revolvy.com/topic/Airy%20Disk&item_type=topic

 
 
Amigo

Re: A question on solar eclipse &amp; Eddington

July 6 2017, 2:29 PM 

>>>the moon has airy's diffraction disc

1/2 true. The dark portion of the moon's disk has no Airy's diffraction pattern or disc.

 
 
nakayama

Re: A question on solar eclipse & Eddington

July 7 2017, 1:38 AM 

To anonymouse,
In some web sites, value of surface gravity of the moon and the sun is shown. The ratio of the two is 0.165 : 28.02. So, 0.01037 arc sec (you showed) seems to me to be questionable (Edington supposed to be 1.6 arc sec on the sun).

 
 
nakayama

Re: A question on solar eclipse & Eddington

July 7 2017, 1:48 AM 

To anonymouse,
Sorry, I made a mistake. The value you showed seems to be true.

 
 
Anonymous

Re: A question on solar eclipse &amp; Eddington

July 7 2017, 1:00 PM 

umm - calcs way too long -https://web2.0calc.com/

 
 
Einstein, top of mind.

Re: A question on solar eclipse & Eddington

July 7 2017, 5:55 PM 

[linked image]

 
 
Amigo

Re: A question on solar eclipse & Eddington

July 7 2017, 6:00 PM 


>>>calcs way too long

What are you talking about? It's only 1 equation:
[linked image]
http://www.lacosmo.com/DeflectionOfLight/index.html


 
 
nakayama

Re: A question on solar eclipse & Eddington

July 7 2017, 9:14 PM 

The value of bending of light that Eddington observed is said to be 1.75 arc sec. The ratio of surface gravity of the sun and the moon is 28.02:0.165. So bending of light that that must be observed on the moon (at the same position) is 0.0103 arc sec. But it is said that the annual parallax of fixed stars is measured with an accuracy of 1 / 1,000 arc sec. Bending of light that is claimed by relativity seems not to be observed on the moon. It will be a well known fact. However, no book touches on it.

 
 
Anonymous

Re: A question on solar eclipse &amp; Eddington

July 7 2017, 9:23 PM 

>>>>What are you talking about?

you're a riot ..https://www.youtube.com/watch?v=wzRaQvvaKhA .. radius ratio is non-squared in the shortcut --->>> arctan([m_m/m_s] x [r_s/r_m] x tan(1.75/3600)) x 3600 = 2.589 x 10^-5 arc second.

 
 
Anonymous

Re: A question on solar eclipse &amp; Eddington

July 7 2017, 10:43 PM 

FINAL NOTE = so the moon bends light from stars by 2.589 x 10^-5 arc sec - i.e, about 0.03 milliarc-sec. & since Hipparcos - the most accurate scientific satellite in history - had an astrometric accuracy of about 1 milliarc-sec-https://en.wikipedia.org/wiki/Hipparcos - no astronomer in the world right now can measure the 0.03 milliarc-sec of the moon.

 
 
 
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