Valve hole can be done that way that it has a little cut on one side of the hole, and that makes water spin in one way. Just cut side of the hole and push one side of the cut up and other side down. But when he press that cut underneath it deforms the cut on the hole to spin water in the opposite way. Tiny deformation can make it work.
Super nice, in the entire first part I was thinking "yeah, that effect exists, but to my knowledge you see this on huge weather systems, not this small and definitely not by walking 10 meters either way". But, the power of someone being very sure in the delivery, can make you wonder. That's how a scam works. :)
Other videos show the demonstrator pooring the water slightly off center, which causes the swirl. It's hard to spot here, but I think that's also his trick. The most impressive to me is the "on the equator" one, where he seems to poor precisely enough that it shows almost no movement (although there is a little)
Good call, the equator part actually requires some practice. :) Maybe it also has to do with the hole? What is he slides his finger one way, would that be enough to cause water to swirl just slightly in a direction?
Scientific American has an article on this entitled "Can somebody finally settle this question: Does water flowing down a drainspin in different directions depending on which hemisphere you're in? And ifso, why?"
To me it looks like he's moving the pitcher to put a swirl in it before pouring. When he walks to the northern side he's subtly swirling it clockwise as he walks. When he sets down the pitcher before pouring, you can clearly see it volatile and swirling around. Then after the Northern "demonstration," he gives it time to settle down as he walks to the south, stopping in the middle. When he reaches the southern point, he spins his body around counter-clockwise, giving a (weaker this time) counter-clockwise momentum in the pitcher water. The water still wants to go in the same circular direction after it's been poured. Of course, this slight of hand and misdirection is assisted by the charming dialogue. I'm loving your videos, Leo. Thank you!
The secret is that he faces the equator/sign each time and tilts the bowl away from himself when pouring, which imparts a rotation in the water, the rotation is different because hes facing the opposite direction each time, he then holds the bowl flat when at the equator. The coriolis effect is real, but far too weak for this demonstration to work in any practical sense. So while it is a scam, it more like a demonstration of a real effect that is amplified by manipulation. Everything he says is technically true, but he's overplaying the effect, as it's easily washed out by any number of other variables.
He seems to have the spots on the ground, where he would do this marked either with a line or some type of impression. My guess is that there was something under that spot, and that the match which he provides may have some type of electrical property such as some type of ferrous powder or maybe the match head itself has some electromagnetic property and between the two effects it results in the spin do you see. If someone asked me to demonstrate or create this effect, that’s how I would approach it.
He fills not in center, but at top. the way water should rotate. Coriolis force doesnt rotate anything, it "adds" or "substracts" velocity not the angular momentum.
It rotates things which span a large range of latitudes, like weather systems and ocean currents. This little bowl of water is too small to feel a noticeable torque.
Seems like the hole has some kind of twist, makes the water drip in a clockwise or an anticlockwise spiral. The switch happens when the hole is plugged and released. The trick would have fallen apart, if the hole was left unplugged, and water added to compensate as it is moved from one position to the next. Hope it makes sense!
Hi Guys - agree Coriolis effect is weaker near the equator. It would have been more obvious with a larger bowl and larger hole. I know Coriolis effect as I used to work on airborne navigation equipment.
In a video that I saw long time ago, it was clear that the artist make a spin in one direction in one side of the equator, and make a spin in the opposite direction on the other side. This is not the case. Let us know if you find out the trick.
He's constantly watching which direction the water is spinning and moving his pour slightly off-center to adjust. He also starts pouring with a little swirling motion.
Hah! I've encountered the same scam and got the same demo and also couldn't tell how they pulled it off. That sucks about your rental car. Did they try to scam you to pay for an extremely expensive repair or a replacement car? Last time I rented a vehicle in Kenya they had sabotaged the oil filter to make it leak (it looked like someone had gone to town on it with hammer) but luckily we checked the oil level manually and caught it before running dry.
How about the laws of probability? This scam is practiced globally, in every country where the equator passes through a busy highway. It's been a popular hustle for conning tourists out of some tip money in exchange for the entertaining "lesson" for many years. Because tourists stop and get out of their cars or buses to take pictures of themselves standing at the Equator sign, it creates a perfect opportunity for locals with no particular talent or special skills to approach them and make some easy money. There are many other homemade videos of this roadside con available on RU-vid if you're not convinced. Some are easier to spot how they force the water spin direction than others. It depends on the bowl they use, the size of the drain hole, and the skill of the hustler at pouring the water while telling a convincing story. Others have made videos demonstrating exactly how to make the water spiral in a chosen direction regardless of which side of the Equator they were standing on. It's easy to show that it's just a trick that has nothing to do with either the Equator or the Coriolis Force. But you'll see if you watch some of the videos that normally only the hustler gets to pour the water! Another wise tourist eliminates all the spin simply by filling the bowl very slowly straight down the edge of the bowl. The biggest reason people still fall for this trick every day is that they're tourists who don't live near enough to the Equator to have likely been warned about this scam in advance. Other locals probably consider it harmless enough not to say anything if they happen to know it's a scam. And almost everyone can recall hearing something about the Coriolis Force from a lesson in grade school science class. But those lessons rarely teach kids that the effect *only* applies to very large areas - weather systems and oceanic currents for example. That's something that's usually only discussed in more advanced science courses that the majority of people will never take. A classic example of "a little knowledge is a dangerous thing", since a vague memory from childhood primes the average person to take the hustler's story at face value. Most tourists probably go home convinced that everything the hustler said was true.
Yes! exactly the deal- it's a "soft" scam, you pay for the entertainment via guilt, because they engage you in a personal way. No harm done really, just not a valid or truthful science experiment.
