(March 30, 2021 at 2:38 am)Peebo-Thuhlu Wrote:(March 29, 2021 at 8:46 pm)John 6IX Breezy Wrote: Out of curiosity, since I'm reaching far beyond my comfort zone, what role does Einstein play in this battle? If Newton put the final nail, but Einstein is often described as somewhat replacing Newton, what does Einstein's theory do to these models? Relativity seems to make use of "frames of reference" and "observers," which at first glance is the main difference between the geocentric and heliocentric model.
Well.... help explain why Mercury does its weird little thing in its orbit.
From a poor memory I think there's a weird little 'bulge'(?) (Or maybe an excentricity in the shape of the orbit?) or some other strangeness that, under Newton, had people looking for another planet tucked in there near Mercury and the Sun.
Einstein's 'Bendy space time' accuratley accounts for the Sun's immense gravity on the tiny mass that is Mercury orbiting so close.
That's all I've got off the top of my head. Hopefully others will add better stuff.
Not at work.
The story of Mercury is actually pretty informative in how accurate things are these days.
Mercury orbits the sun every 88 days. We can think of this as going through 360 degrees of its orbit every 88 Earth days.
The anomaly in Mercury's orbit that was not explained by Newtonian physics amounts to 43 *seconds* of arc in that orbit over the course of a century.
The Ptolemaic system was regularly off by tens of degrees in the position of planets *in our sky* over the course of decades. That 43 seconds of arc in the orbit of Mercury would be even less as an apparent arc in our sky.
The general relativistic correction to the orbit of Mercury took into account that full 43 seconds of arc per century.