Hosted by The Math ForumProblem of the Week 1250The Loopy Lunatic
It comes as a surprise to many that the orbit of the moon around the sun has no loops in it. Indeed, it is a convex curve not very different from the orbit of Earth around the sun. Imagine a moon orbiting a planet orbiting a star where:
What is the smallest value of L so that the orbit of the moon around the start has a loop? Is nonconvex? Assume all orbits are circular and all lie in the same plane (so that "loop" and "convex" have clear planar meanings). Sources: Helmer Aslaksen's The Orbit of the Moon around the Sun is Convex! Noah Samuel Brannen, "The sun, the moon, and convexity," College Mathematics Journal 32 (2001) 268-272. Laurent Hodges, "Why the moon's orbit is convex," College Mathematics Journal 33 (2002) 169-170. |
[Privacy Policy] [Terms of Use]
Home || The Math Library || Quick Reference || Search || Help