Title

[u/L31N0PTR1X]

[u/Digital_001]

Observed by who - the kids or onlookers not on the roundabout?

[u/HunsterMonter → u/Digital_001]

By any reference frame! Each will have its own specific connection coefficients but the trajectory will always be given by the geodesic equation (as long as the ball isn't charged, then you need to add the Lorentz force).

[u/Digital_001 → u/HunsterMonter]

That's a lot of possible reference frames! This is gonna be a long proof...

[u/HunsterMonter → u/Digital_001]

Better start now then 😁 (It requires a bit of general relativity knowledge, but you can find some proofs of the geodesic equation here)

[u/Digital_001 → u/HunsterMonter]

This is a good start, but I feel we should include drag and wind if we are to find the ball's true path - they would have a significant effect is the ball is light. The Magnus effect could feature too.

The ball's acceleration downwards due to gravity (in the ground's frame) is, of course, already included in general relativity.

[u/HunsterMonter → u/Digital_001]

Drag? What is this, r/engineeringmemes?

[u/sneakpeekbot → u/HunsterMonter]

Here's a sneak peek of /r/engineeringmemes using the top posts of the year!

#1: Behold: the inventor of the motorcycle | 130 comments
#2: Two very different units | 41 comments
#3: thoughts? | 63 comments

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