Amazing Water & Sound Experiment #2
Why Physics Stack Exchange recommends it
Physics Stack Exchange users link it as the example of the water-hose illusion that many questions ask about, which comes down to vibration frequency versus camera frame rate (stroboscopic aliasing).
Recommended by 3 people across 3 different months, 2013 to 2018.
What it is
A short demo by brusspup in which a stream of water from a hose attached to a speaker playing a tone appears frozen, slowed or reversed on camera. The effect comes from the tone matching the 24 fps camera frame rate and cannot be seen by eye. The description lists the materials needed to recreate it.
What people said
Recommends Fendi · 2013-03 · Physics Stack Exchange · on “Can someone explain how water from a garden hose can propagate in a sine/cosine wave?”
A video [this video] posted on Youtube. How does this phenomenon work? I know he is using frequency to propagate water in a sine/cosine wave, but how does it exactly work this way? Why do we see it as if its paused, or in slow motion, or even in reverse? Can someone please explain this? I am intrigued by the video and want to know it's physics.
Recommends Cort Ammon · 2017-04 · Physics Stack Exchange · on “Motivation for doing classical mechanics”
So I second P.C. Spaniels argument about the gyroscope. I'm pretty sure gyroscopes are actually aliens, and that's after watching the brilliant VSauce video [LINK] on the topic. The reason it seems like all physics does for you is formalize intuitive things is because you're just starting. We intentionally start with intuitive things because it is more comfortable for people. We could start with the surface effects of ferofluids, or flow separation over turbine blades, but why confuse people? Your intuition will get you far, especially if it's good, but at some point you're going to hit limits. At some point you're going to want to have the formalisms to help you convert the things you are l
Recommends Gyromagnetic · 2018-06 · Physics Stack Exchange · on “Why does this rocket stop rolling while going up”
"But what I cannot understand is why the rocket STOPS rolling at some point." It could be an illusion. When the spinning rate starts to match the frame rate of the camera, the image will start aliasing and it will look as it is actually rotating slower. Check out these videos where the play with this "stroboscopic" effect: [this video] edit: The wikipedia article is also quite informative: [LINK]
Cites Amr Abd El Ghany · 2013-03 · Physics Stack Exchange · on “Water excitation with sine waves”
I saw that video when they connected a water hose to a speaker emitting 24 hz sine wave [this video] , and its illusion on the shape of the follow going out of the hose (because the video capture rate is fixed at 24 fps) I wonder if I can obtain similar effects with much lower frequencies i.e. (8-10 hz) and if possible what can I use to simulate the effect or do the experiment.
Cites J.Todd · 2015-08 · Physics Stack Exchange · on “How does sound make water flow in zig-zag patterns?”
I saw this video where water is piped past a large speaker and weird shapes are formed. [this video] Later in the video the pipe actually moves from the sound so that's obviously why the patterns are forming, but for the first 30 seconds the pipe appears to be still while the water flows in a zigzag pattern. [LINK] How do sound waves cause such a bazaar water flow when the pipe isn't moving?
Cites Joo Heon Lee · 2015-12 · Physics Stack Exchange · on “Why does amplitude of a mechanical wave increase and then decrease with increasing driving frequency?”
[this video] Hi Gert, this link should give an idea for how the experiment looks like. In my experiment however, I attached a vibration generator on the end of the water hose and controlled the frequency with a signal generator. This created a wave like motion shown in the video. (At about 1:39 of the video, this is an example of what I was investigating. Note that I had the water path going vertically straight down, so that I could measure the amplitude of the wave created at a certain point, which I did for all other frequencies)
Cites Gagan Saggu · 2017-11 · Physics Stack Exchange · on “What this sound is doing with water?”
I saw a video on youtube with link " [this video] " In the video a stream of water is run from a nozzle attached to a speaker diaphragm. The speaker plays a 24Hz sinusoidal tone, which is the same frequency as the shutter on the camera filming the video. With the speaker playing, the video appears to show the stream of water frozen in a zigzag or wave shape. Is there someone kind enough to explain what is happening in the video I mean by science used.