“Your law of gravity is even more flawed,” said Prince Blueblood. “How massive is this world, compared to the Sun?”
“The Sun is about 300,000 times more massive,” answered the Princess.
“By your law, we should be orbiting the Sun, where precisely the opposite is the true situation.”
“That’s because of the powerful magic exerted by Princess Celestia every day,” said Eveningstar, stepping forward to stand beside her monarch. “A magical catastrophe centuries ago caused the Sun to be permanently repelled from the Earth. Only the daily application of magic keeps it in its place. It would require the same amount of magic to put our world around the Sun as it would be to pull the Sun around Equestria. Since the latter is a lot easier to control magically, that is what the first unicorn Sun mages did, and that is what our Princess does now.”
Celestia nodded. “Magically, you can get away with a great deal of subtlety. I am not breaking that gravity law of Mr. Newton, in fact I’m using it. When I cast my spell, it’s as if I become as massive as a million Suns for just an instant, but because it’s magic, only the Sun can feel that mass.”
Voltaire looked distinctly uncomfortable for a few seconds, before finding a suitable comeback. “So I take it that joking about your weight is off-limits, then?”
Only Celestia dared to laugh at that joke.
https://www.fimfiction.net/story/39157/11/the-best-of-all-possible-worlds/chapter-10