Talk:Schiehallion experiment
 | Schiehallion experiment has been listed as one of the Natural sciences good articles under the good article criteria. If you can improve it further, please do so. If it no longer meets these criteria, you can reassess it. | |||||||||
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 | A fact from this article appeared on Wikipedia's Main Page in the "Did you know?" column on January 3, 2009. The text of the entry was: Did you know ... that the 1774 Schiehallion experiment to calculate the density of the Earth also made the first use of contour lines to represent height? | |||||||||
| This  level-5 vital article is rated GA-class on Wikipedia's content assessment scale.It is of interest to the following WikiProjects: | ||||||||||||||||||||||||||||||||||||||||
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Geology rating
editA well-written article; a pleasure to read.
Interesting that this had been rated high in importance by WP:Scotland & WP:Physics, but unrated by WP:Geology until today. I’ll take the liberty of rating it for WP:Geology, as mid, on the basis that:
- Following the Wikipedia:WikiProject_Geology/Assessment#Importance_scale to qualify as high it would have to cover a general area of knowledge. This is not a general area of knowledge; the general area would be something like techniques for measuring gravity.
- However it is an important development which filled in a very significant specific knowledge area – how the gravitational attraction resulting from large masses of earth was initially detected. It served as the basis for the science which subsequently developed to measure the density of the planets & detection of mascons.
- An argument could be made that the importance of this article is “low” – the argument would go that this is an interesting piece of historical trivia that is only useful in instructing beginning students by providing them the insight that gravitation can be measured & giving them an example of the scientific method in practice. However pivotal discoveries & turning points in scientific understanding are arguably noteworthy.
As always on Wikipedia, comments are welcomed if you think I got this wrong.
BAsic Physics.
editThe experiment will find the mean density of the Earth. The basic theory relies on the fact that a sphere of any density distribution can be replaced by a point mass at the centre, of the same total mass. The only requirement is that the density distribution is a function only of the distance from the centre of the sphere; it must be symmetric. (This is true for any inverse-square law.) A nearby mass not lying inside the perfect sphere, or gaussian surface, can be considered as a mass separate to the Earth. The idea of replacement by a point mass was known by the early 1700s ... Leonard Euler I suspect.220.245.41.207 (talk) —Preceding undated comment added 08:25, 4 November 2015 (UTC)
Earth Curvature
editThe experiment assumes a round Earth, and takes into account Earth's curvature. Would it have had a null result if assuming a flat Earth? 115.179.83.12 (talk) 21:34, 5 March 2019 (UTC)
- The gravitational effects would be unchanged but the correction made for the difference in latitude between the north and south observatories would have led to a false result. —BillC talk 13:52, 6 March 2019 (UTC)
Intro
editThe second (final) paragraph of the introduction of this article is written like a teaser. The introduction should instead summarize the findings of the experiment. Jess_Riedel (talk) 15:06, 29 October 2020 (UTC)
Chronology problems
editThe "Repeat experiment" section says that "his result would not be significantly improved upon until 1895 by Charles Boys.[c]"
However, note c says that "his measurements actually led to a value of 5,448 kg·m−3; a discrepancy that was not found until 1821 by Francis Baily."
We need a source to clarify when Baily noticed the error. It was probably 1921, not 1821. Mateussf (talk) 23:07, 12 January 2021 (UTC)