On 30 November 2013 12:04, Telmo Menezes <te...@telmomenezes.com> wrote:
> > Thanks for the explanations. Ok, I think I now understand why dark > matter is the best hypothesis. > > It is, to date. Neverthless, you would have been quite correct had it been the anomaly in the orbit of Mercury that you were trying to explain, rather than the anomalous rotation of galaxies observed in 1933 by Fritz Zwicky. Pre-Einstein, various theories were advanced to explain the anomalous perihelion advance of Mercury (relative to what Newtonian gravitation predicted it should have been) including "hidden matter" - an undetected planet (called Vulcan, as Trekkies and Dr Who fans will appreciate) and an odd mass distribution inside the Sun. But in that case, it turned out that the best answer WAS to modify gravity. So far DM has remained the top explanation even as more phenomena involving it have been discovered (garvitational lensing for example). Some of its characteristics are now fairly well measured; its nature remains unexplained... which makes life interesting for particle physicists and cosmologists. -- You received this message because you are subscribed to the Google Groups "Everything List" group. To unsubscribe from this group and stop receiving emails from it, send an email to everything-list+unsubscr...@googlegroups.com. To post to this group, send email to email@example.com. Visit this group at http://groups.google.com/group/everything-list. For more options, visit https://groups.google.com/groups/opt_out.