alt Hacker News> They orbit the earth in a different shape that is more complex than an ellipse.
But they don't. We know they don't. Not unless you use a weird definition of orbit that is very different from the one lotsofpulp was using. And if you do that you're not countering their argument, you're misconstruing it.
We know they do. An orbit is a mathematical object, and elliptical orbits only exist in universes that have exactly two objects with mass in them. Add another object, even far away, and as far as we know[0] we no longer even have a closed-form description of resulting motion patterns.
And our universe has tons of matter with gravitational mass everywhere, few other types of interaction beyond gravity, and a vacuum that just doesn't want to stay empty.
--
[0] - Not sure if this was mathematically proven, or merely remains not disproven.