If the earth is fixed, how can the James Webb telescope stay at Lagrange point L2?
A viewer asks how, in a geocentric model, space agencies can park the James Webb Space Telescope at the Lagrange point L2, about 1.5 million kilometers away, since that point of gravitational equilibrium seems to exist only because the earth orbits the sun.
Answer
The Lagrange points do not change between the heliocentric and geocentric models. L2 is about 1.5 million kilometers, roughly a million miles, from the earth either way. The reason is that the celestial bodies, the sun, the earth, and the moon, coordinate with one another gravitationally in only one way, whether you are geocentric or heliocentric, and that geometry produces exactly one L1, one L2, one L3, one L4, and one L5, where Newton's gravitational equation is balanced. It makes no difference which body is bigger or smaller; the balance points sit in the same places, some near, some far. That is why they parked the WMAP satellite, which measured the cosmic microwave background temperatures, at L2, and why the James Webb telescope sits there too. A geocentrist can account for that point just as well as a heliocentrist; it makes no difference.