Coriolis effect demonstration at the equator in Uganda | Hacker News Reader

Coriolis effect demonstration at the equator in Uganda

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10 pointshliyan8 comments

This is just a common tourism scam. https://www.snopes.com/fact-check/coriolis-effect/

Obviously fake, but how do they get your money?

Usually scammers like this will do a demonstration or create something without asking for payment, and then after it is done and demonstrated or given to you, they ask for payment. Tourists will give them money because they assume it is some local custom, or they otherwise just don't want to be involved in a dangerous situation.

When you are a tourist and a stranger does absolutely anything for you - even something simple like holding a door or giving directions - assume they will ask for payment. Get in the practice of saying "no" frequently.

Someone has already pointed out the Snopes article about the Coriolis force being too weak to determine draining directions, which is true.

But there's a second consideration - the Coriolis force varies as the sine of your latitude. It's tiny near the equator (this is why hurricane are unable to form at the equator) so you certainly wouldn't get a sharp transition as you walked over 0 degrees.

So, how is the scam achieved? You can pour the water 'off-center' so that it starts with some angular momentum. If you give it a small amount of angular momentum then it's not obvious before the plug is pulled, but the angular speed increases as the water flows towards the plug hole (the 'ballerina effect'). The guy putting the barrier in briefly won't necessarily remove the angular momentum of the water.

When they should the 0 degrees bowl and it drains 'straight' out it looks like maybe that bowl is shallower? That would help remove the initial angular momentum from an off-center pour. I'm less clear about how they're getting that one to work with no-circulation though.

I think this is just fine with magnets. It would be by far the easiest way and he definitely removes enough water momentum that it shouldn't soon anywhere near that fast. Plus I don't think he is just spinning it as he puts it in because you can see it speed up.

If I had to guess I would say it is an electromagnetic coil laminated in the bowl and the battery and controller are in the stick part.

There's one born every minute. In both hemisphere's it would seem!

Genuine demonstration of this effect:

https://www.youtube.com/watch?v=mXaad0rsV38

It's not that strong. You need to have a huge pool of water and something like colored liquid in it to observe anything.

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