resisting medium

[Brian W]

Hi all, of late I have been taking an interest in 'historic' astronomy. In the preface to the Sir John W. Herschel book 'A Treatise on Astronomy' Sears C. Walker uses the term - resisting medium - as one possible reason that comets appear to be slowing down.

Would any one happen to know what resisting medium he was referring to?
Brian

[jjjnettie]

Gravity?

[Terry B]

The Ether?

[circumpolar]

Ether.
I came across this term a while back and had to look it up just to make sure. At the time I found a good definition but now can't find it.

This page is interesting. (SAO/NASA, astrophyics data system)
4 pages with diagrams!
http://adsabs.harvard.edu/full/1910AN....184..257B

[lacad01]

The Ether rings a bell as I recall reading about it in the book "The Georgian Star" which is about William and Caroline Herschel.

[Brian W]

Hi all, 'ether' seems to be the emerging consensus. For me it is intriguing to try to understand the thoughts and world view that comes is held within these old books.

Thanks for the help.
Brian

[Robh]

I don't think it refers to the luminiferous aether (ether), which was proposed as the background medium which carried light.
From his observations, Herschel proposed that there were luminous materials in nebulae that were not stars. The resisting medium was probably the diffuse materials he believed occupied space. Laplace later developed the idea which became known as the nebular hypothesis. He proposed that rotating nebulae flattened into rings that formed the planets.

Regards, Rob.