Re: [Phys-l] How did Newton estimate the Gravitational constant?

[Bernard Cleyet <bernardcleyet@redshift.com>]

Another trivium:

They have long been known to be a physically related group of stars rather than any chance alignment. The Reverend John Michell calculated in 1767 that the probability of a chance alignment of so many bright stars was only 1 in 500,000, and so correctly surmised that the Pleiades and many other clusters of stars must be physically related.[5] When studies were first made of the stars' proper motions, it was found that they are all moving in the same direction across the sky, at the same rate, further demonstrating that they were (sic;  I see, no longer)  related.

http://en.wikipedia.org/wiki/Pleiades_%28star_cluster%29


http://en.wikipedia.org/wiki/John_Michell


bc's train:  xkcd => Pleiades => Michell

On 2010, Oct 28, , at 10:39, Bernard Cleyet wrote:

> Yes, and I think credit should be given to Michell who made the beta version of the balance and gave it (indirectly) to C. just before he (Michell) died.