Is the Ugandan local people's experiment on Coriolis right?

Question

There is a local performance on the equator of Uganda. In the southern hemisphere, which is more than ten meters away from the equator, after pouring a bucket of water, the water in the pool with holes at the bottom will rotate counterclockwise and discharge; In the Northern Hemisphere, which is more than ten meters away from the equator, after pouring a bucket of water, the water will be discharged clockwise; On the equatorial line, after pouring a bucket of water, the water in the pool will be discharged without rotation. Local people explained that this was caused by the rotation of the earth. Is this interpretation and performance correct?

I think they are wrong. It is impossible to carry out this kind of experiment in the washbasin. The direction of pouring water makes the water rotate counterclockwise and clockwise. The water-retaining ruler cannot stop the rotation of water for a short time. Their experiment is shown in this video.

In its current form (v3) the question can’t be understood without watching a video o another site. Please [edit] the question to be self-contained. — rob, Feb 07 '23 at 07:40
Does this answer your question? How to show that the Coriolis effect is irrelevant for the whirl/vortex in the sink/bathtub? — Quillo, Feb 07 '23 at 08:38
Other related/possible duplicates: https://physics.stackexchange.com/q/148974/226902 https://physics.stackexchange.com/q/143032/226902 https://physics.stackexchange.com/q/55190/226902 https://physics.stackexchange.com/q/24498/226902 — Quillo, Feb 07 '23 at 08:40
@GiorgioP-DoomsdayClockIsAt-90 Is the local people's demonstration right? — enbin, Feb 10 '23 at 06:53
@enbin it's obviously not, as you can see from answer here and in the duplicate. — Quillo, Feb 10 '23 at 07:52
A simple order-of-magnitude-calculation is enough to show that that "demonstration" is false. — GiorgioP-DoomsdayClockIsAt-90, Feb 10 '23 at 09:52

score 3 · Accepted Answer · answered Feb 07 '23 at 07:39

3

It’s bogus. The period for a Coriolis-processing pendulum at latitude $\theta$ goes like $1/\sin\theta$, so the effect is weakest at the equator — that is, the period of the precession is very, very long. The suggestion that you could walk a few meters and see a different macroscopic effect is silly.

For a careful experiment, see these paired US/Australia videos which demonstrate the effect in two-meter kiddie pools.

answered Feb 07 '23 at 07:39

rob

89,569

A way for local people to entertain tourists. – enbin Feb 10 '23 at 06:57

Is the Ugandan local people's experiment on Coriolis right?

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