Thursday, 2 January 2020

mécanique celeste

Having so astounded the public at large and his peers within the scientific community with his spot-on prediction of not only the existence but location and general characteristics of the planet Neptune (it was proposed to make the planet’s symbol a monogram of the discoverer’s name rather than the trident ♆, prefiguring some of the controversy over the discovery of Pluto—♇—by Clyde Tombaugh to the consternation of wealthy patron Percival Lowell) using only mathematics and the observations of deviations of the orbit of Uranus counter to the laws of gravitational attraction as set forward by Isaac Newton and Johannes Kepler, no one had any reason to doubt the proposition that famed astronomer Urbain Jean Joseph La Verrier (*1811 – †1877) put forward on this day in 1860, reporting that the perturbations in the procession of Mercury and Venus around the Sun (apsidal precession) required an explanation above and beyond classical Newtonian physics. Like with the Ptolemaic model of keeping up appearances, Le Verrier (with the consensus of the scientific community) logically invoked an intervening though purely hypothetical planet circling the Sun below Mercury—Vulcan (Vulcain, see previously here, here and here). In reality, Mercury’s strange observed behaviour needed not another celestial body to account for it but rather Einstein’s General Theory of Relativity, formulated in 1915, vanquishing Vulcan by staking its reputation on predictions concerning occultation, planetary transit and the effect of gravitational lensing and finally confirmed in September 2015 with the detection of gravitational waves.