4 ms·
Somewhere I read that a free fall parabola does not even take into account earth's curvature. Although I cannot remember, what kind of function describes the re
by a3w 6y ago
Somewhere I read that a free fall parabola does not even take into account earth's curvature. Although I cannot remember, what kind of function describes the reference system specific ``path, as a function of time''.
Could this be named more correctly:
Gravity is not a force – free-fall hyperbolas are straight lines in spacetime (timhutton.github.io)
?
- kubanczyk 6y agoThe planet's curvature is not very relevant to the article, but, yes, if an object is in a free fall at a slow speed (I mean non-orbital) its trajectory is: - parabola if you assume flat&infinite ground, - ellipsis if you assume a spherical planet (an ellipsis is crossing the planet's surface). This is Newton, not GR.
- dreamcompiler 6y agoYep. Orbits are always conic sections. Which sometimes inconveniently intersect with the surface of the thing being orbited.
- dreamcompiler 6y agoMore precisely, 2-body orbits are always conic sections. Once you add more bodies, orbits usually become chaotic.
- skykooler 6y agoOf course, a very very eccentric ellipse approximates a parabola quite well. You only start to notice errors when dealing with trajectories dozens of miles long (on Earth).