What if the Moon was a different size or distance?

[geordief]

What if eclipses of the Sun by the Moon  were not complete as we now have them.

 

Because,say  it's orbit had increased over time  and so appeared small compared to the size of the Sun as seen from Earth.

 

Suppose this was the case  and Einstein had just proposed General Relativity (1915  I think it was)....would GR have been taken seriously or did everything depend on the experimental confirmation of his predictions carried out by Eddington.

Might GR have just attracted a dwindling cult following or were there other   dramatic  confirmations available that would have  ensured this did not happen?

 

I have read one of Einstein's  contemporaneous publications where he calls  for the measurements to be undertaken at the forthcoming eclipse (quite a dramatic  and vivid read )

[beecee]

51 minutes ago, geordief said:

What if eclipses of the Sun by the Moon  were not complete as we now have them.

 

Because,say  it's orbit had increased over time  and so appeared small compared to the size of the Sun as seen from Earth.

 

Suppose this was the case  and Einstein had just proposed General Relativity (1915  I think it was)....would GR have been taken seriously or did everything depend on the experimental confirmation of his predictions carried out by Eddington.

Might GR have just attracted a dwindling cult following or were there other   dramatic  confirmations available that would have  ensured this did not happen?

 

I have read one of Einstein's  contemporaneous publications where he calls  for the measurements to be undertaken at the forthcoming eclipse (quite a dramatic  and vivid read )

Interesting contemplation, to say the least. 

The facts are that when the Moon was first formed, it was half its present distance, and a day on Earth was shorter. Due to tidal gravitational interactions, the Earth is ever so slowly being lifted in its orbital path, and at the same time, days are getting longer. This will I think continue until the Moon is double its distance, and a day on Earth, is equal to a Lunar month, and one side of the Earth will be eternally facing the Moon, just as we have one side of the Moon eternally facing Earth. Obviously if we, and the Earth are still around then, there will be no more total eclipses [just annular] just as in the past, all eclipses were total with no annular.

 

All I would say is that other aspects have been borne out by GR since the Eddington eclipse. 

Edited February 19, 2020 by beecee

[pzkpfw]

Did Eddington's experiment actually need the exact kind of eclipse we now get?

The point is starlight "bent" around the Sun, and the Moon eclipsing the Sun making it possible to record that.

If the Moon were only partially blocking the Sun, I don't see why a similar experiment couldn't have been performed; maybe just with slightly more difficulty.

[swansont]

9 hours ago, pzkpfw said:

Did Eddington's experiment actually need the exact kind of eclipse we now get?

The point is starlight "bent" around the Sun, and the Moon eclipsing the Sun making it possible to record that.

If the Moon were only partially blocking the Sun, I don't see why a similar experiment couldn't have been performed; maybe just with slightly more difficulty.

More than slight, if the moon was smaller or further away. The moon’s position would have to nearly coincide with the star’s in order to see the star. Also need a smaller field of view so you don’t capture extra light. 
 

You get, at most, 1 star, instead of the 13 here

Determination of the Deflection of Light by the Sun's Gravitational Field, from Observations Made at the Total Eclipse of May 29, 1919

F. W. Dyson, A. S. Eddington and C. Davidson

Philosophical Transactions of the Royal Society of London. Series A, Containing Papers of a Mathematical or Physical Character

Vol. 220 (1920), pp. 291-333

[geordief]

https://en.wikipedia.org/wiki/History_of_general_relativity#Sir_Arthur_Eddington

"In the early years after Einstein's theory was published, Sir Arthur Eddington lent his considerable prestige in the British scientific establishment in an effort to champion the work of this German scientist. Because the theory was so complex and abstruse (even today it is popularly considered the pinnacle of scientific thinking; in the early years it was even more so), it was rumored that only three people in the world understood it.

There was an illuminating, though probably apocryphal, anecdote about this. As related by Ludwik Silberstein,[20] during one of Eddington's lectures he asked "Professor Eddington, you must be one of three persons in the world who understands general relativity." Eddington paused, unable to answer. Silberstein continued "Don't be modest, Eddington!" Finally, Eddington replied "On the contrary, I'm trying to think who the third person is."

 

I was wondering whether,at that perhaps  stage any failure to  experimentally confirm the  theory might have been a serious setback or whether there were other paths to acceptance in the scientific establishment and outside it via alternative  dramatic experiments.

 

 

 

 

[swansont]

It would be 20 years before the first muon decay measurement to confirm SR. Einstein might not have had as much influence, nor have attracted as much relativity research interest, without a relativity confirmation. But recall that his Nobel was not for relativity, so probably not a huge difference.

[Airbrush]

If the moon was so close that its' tidal effects were (hundreds or thousands of times greater?), washing miles up on land every few hours, much more extreme and frequent then.  Also imagine the giant waves generated by the backwash, giant and frequent tsunamis crossing oceans and colliding from multiple angles.  What a chaotic period in the early Earth's history. 😲

Edited February 22, 2020 by Airbrush