Amazing Effect When You Put a Whirlpool in a Vacuum Chamber

As some have pointed out there is definitely more going on here than just air pressure. In fact you cannot talk about any fluid flow with only talking about pressure. You have to always talk about fluid velocity and pressure together. We do know there is the centrifugal effect of water being thrown out the sides and also down the middle. But the reason there is ever any flow at all is due to pressure differences. The ball is being dragged down by the water but it is also moving fast and so the atmosphere pushes it down as well. There is also rarified air and eater vapor that forms under the ball pushing it up (maybe). This is definitely a phenomenon that I have never seen before in any literature so if anyone has any resources are open to hear more about this.

The type of 'spinner' you used has a serious effect on this experiment. The agitator at the bottom, is in effect, a sort of centrifugal pump. Water is constantly being flung outward at the bottom, then forced up the walls of the container and flowing back in toward the center (all with considerable tangential flow as well). (this is why this type of 'mixer' is so often used, it circulates the fluid both tangentially around the container, but also radially outward, upward, and back down in the center) This downflow in the exact center, IMHO, is what drags the ball below the surface. After all, when the ball is completely submerged, the air isn't acting on the ball at all. As others have pointed out, as the water spins around it also has centrifugal forces acting on it, so the surface of the water is always perpendicular to the combined centrifugal/ gravitational forces acting on it. It would be very enlightening to use a different mechanism to 'spin' the water. For example, remove the agitator and spin the entire beaker. With all the water spinning at the same RPM, you would not set up the same internal flow pattern. The water at the bottom would not be 'pushed' outward to the walls of the beaker any more than any other water, so there should not be any 'vertical' circulation. Edit: Without this, I predict the water will form a parabola, but the ball will not be 'sucked/pushed' under the surface (much like you saw it under the high vacuum condition).

I swear one of those droplets of water hit my face when he was blowing the straw, so weird...

Alternative explanation: the "air pocket" at bottom (under vac) is actually boiling water.

You would need to also do the test with starting the whirlpool after the vacuum reaches least pressure for this to cover all the bases.

ACTION LAB!! ACTION LAB!! ACTION LAB!! Let the legend continue

Atmospheric pressure, Vortex, Effect of air movement all covered in just 1 short video... Awesome!

As has already been pointed out - Water boils under vacuum. The cooler the water is, the lower the atmospheric pressure needs to be to reach the boiling point. With a low enough pressure, tap water will boil at room temperature. Yes, that's a Fact!. If you place the ball on still water and then pull a vacuum, the water will boil all around the ball like a pan of water on the stove, only the water will NOT be hot to the touch. As the air is evacuated from the chamber water will reach a point at which it boils. Right after this, the vacuum gauge will stabilize and stop dropping until all the water is gone, then it will drop to whatever level your pump is capable of pulling on your vacuum chamber. In your experiment, the "air pocket" that formed under the ball while rotating the water is the water's gaseous state trying to reach the surface. This action creates a lifting force. The bubble formes in the middle of the vortex since this is the water's lowest pressure point. Going a little off subject. Something else interesting about water is it has a "triple point". That is the temperature and pressure at which the three phases (gas, liquid, and solid) can coexist in thermodynamic equilibrium. Under the correct circumstances, water can turn directly from ice (a solid) to gas without first becoming a liquid.

You're always able to explain what you're doing really easily and the subjects are fascinating. Thanks

Waauw Action Lab. You invented a simpel physics-setup that causes discussion among physicists! I envy you! I have my doubts about your explanation, but I cannot come up with a better one (yet).

Man you constantly come up with original and interesting experiments. Happy to say this is not some pop science channel. Your really teaching lots of people obscure and interesting science.

Each of these videos is worthy of a 10th grade science assignment. I sourced and got inspiration for one of my assignments in the action lab video about heating up water by blending/stirring it. I conducted my own experiments and ended up getting full marks. Thanks for the effort and information put into these videos.

It would be so much fun to have this kind of dad. Never gets boring

Drink everytime he says: "lower pressure."

As a college graduate in physics from 101-499, I didn't even expect this... I anticipated that no matter how low you drop the atmospheric pressure outside, the pressure will always be lower once the water starts spinning, there for keeping the ball at the bottom... Where did my calculations go wrong? I'm confused... Lol But anyways, no matter what I have learned in my lifetime, I always seem to learn something new on this channel! Keep up the good work!

Thank you sir, you’re make it easy to understanding. Wish you all the best 🙏🏻

Got my subscription box yesterday !! Bit late but hey, I am sure there were good reasons. It had more than I thought it would. Quality hoses, brass fittings, thread tape for fittings, 2 wrenches, a vac gauge, patch,sticker, pin, instruction book and experiment book ,box with marshmallows -balloons - shaving cream. I like it all. Hope the next one is a bit more timely but I am sure you all were making a great effort. Maybe you got more orders than expected or ?? Thanks..

In the normal pressure part, is it really the pressure from the air that sinks the ball, or the fact that the moving water is moving faster below the ball than above ? Perhaps the high-pressure experiment will tell. In the low pressure experiment, the air vortex below is likely to be vacuum, and the ball seems to be just floating on the walls of the vortex. These are my hypotheses.

Great experiment! Overall air pressure has no direct effect on the ball - it pushes it down (via water) as much as it pushes it up. But the lower pressure allows building of steam- bubbles. They gather in the middle where the pressure is low and they build eventually a vapor column that wants to go up and pushes up the ball. It would be interesting to see the experiment with slightly warmer or colder water...

I am really into space stuff and I really like this video because it shows things we already know about gravity but on an extremely small scale that I never would have guessed to be shown on such a small scale. Tyvm for the upload.