Activity for Mark‭

Type	On...	Excerpt	Status	Date
Question	—	Re-working physics for a Newtonian universe There's a famous saying in science fiction: "Relativity, causality, FTL: pick two". I choose causality and FTL. In a Newtonian universe, where there's a privileged reference frame, the speed of light isn't an absolute limit, and Einstein was wrong, what parts of physics would I need to re-work? In... (more)	—	over 7 years ago
Answer	—	A: How can you make a stable configuration including a moon that has a moon? In order for an orbit to be stable in the short term, it needs to be within the Hill sphere of its primary. For a circular orbit, the radius of this sphere is approximately: $$r = a\sqrt[3]{\frac{m}{3M}}$$ where a is the semi-major axis of the primary's orbit around its parent object, m is the mas... (more)	—	about 9 years ago