DOES THE EARTH ORBIT THE SUN SERIES

And the Earth orbits the Sun.” This is where, in my opinion, he makes an error. It can appear either way, or some other way, depending on what coordinates we choose and how we visualize them.īut then Muller goes a step too far. Because of this, in Einstein’s theory, we cannot say whether the Earth goes round the Sun or the Sun goes round the Earth. Equal, that is, in the sense that Einstein’s concepts of gravity and motion work equally well in either one. What is Muller saying? He’s certainly right that in Einstein’s approach to gravity and motion, Sun-centered (heliocentric) coordinates and Earth-centered (geocentric) coordinates are equally good. And we have to decide whether to believe him. But now Professor Muller comes along, and tells us Einstein’s conception of gravity implies that the Sun goes round the Earth just as much (or just as little) as the Earth goes round the Sun. This was all in a pre-Einsteinian context.

If the Sun goes round the Earth, then its path does not satisfy the Earth’s T|R law, although the Moon and various human-built satellites do so.If the Earth goes round the Sun, then its path satisfies the Sun’s T|R law, just like the other planets do.We hadn’t (and still haven’t) succeeded in figuring out if the Earth goes round the Sun or the Sun goes round the Earth. For example, this is true of the moons of Jupiter, as well as the rocks that make up Jupiter’s thin ring.Īlong the way, we made a very important observation. T|R laws are indeed found among any objects that (in the Newtonian sense) orbit a common planet. (We all secretly know that this is because the Earth has a smaller mass, though as avid do-it-yourselfers we admit we didn’t actually prove this yet.) The only difference is that the acceleration created by the Earth’s gravity is less at the same distance than is the Sun’s. We also saw that objects that orbit the Earth - the Moon and the vast array of human-built satellites - satisfy their own T|R law, with the same general relationship.

From this law we figured out how much acceleration is created by the Sun’s gravity, and concluded that it varies as 1/R 2. Because we’ll be referring to this law and its variants so often, let me call it the “T|R law”. (A list of the links is here.) Along the way, we rediscovered for ourselves one of the key laws of the planets: Kepler’s third law, which relates the time T it takes for a planet to orbit the Sun to its distance R from the Sun.

DOES THE EARTH ORBIT THE SUN SERIES

And the Earth orbits the Sun,” I was creating a series of do-it-yourself astronomy posts. Back before we encountered Professor Richard Muller’s claim that “ According to general theory of relativity, the Sun does orbit the Earth.

Does the earth orbit the sun