Sound is waves of moving air. The waves have high coherence, meaning a single frequency and a single source. So the air wave pushes on the water stream in regular places and not in others. The implication here is that distance between “water waves” correlates with the sound frequency. Note that you can’t hear the sound making 24kHz I think.
The up and down motion of the water is caused by playing with the phase of the waves.
Let me give you an analogy. Remember the first time you saw a laser? It was probably red and you were probably struck by the richness of the red. Lasers are monochromatic . This device is similar in that way.
I am not sure how it works (other than obviously through sound waves) but it is very fascinating. I am surprised I have not seen more commercial fountains doing things like that.
"So the air wave pushes on the water stream in regular places and not in others."
Yes, but that doesn't explain why the water stream moves backward towards the set-up rather than straight down after it passes the high point of the wave.
The water stream doesn't move backwards towards the set-up.
The water is constantly pouring down. But the pattern moves upward. And that gives the appearance of the water moving backward.
Plus all this is being recorded in frames that run at speed similar to the sound waves.
When I was five years of age I asked my mother, "why are the wagon wheels going backwards when the wagon is going forward?"
She said, "Because the movie camera is going clicky-clickity-clickety-click and the movie projector is going clicketyclicketyclicketyclick and the television camera is doing it's own thing and our tv is showing at its own speed so when all that is put together we finally see the wheels look like they're going backwards. But we already know they are really going forward much faster. It's just one of those amusing shortcomings of technology that we learned to accept."
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Sound is waves of moving air. The waves have high coherence, meaning a single frequency and a single source. So the air wave pushes on the water stream in regular places and not in others. The implication here is that distance between “water waves” correlates with the sound frequency.
Note that you can’t hear the sound making 24kHz I think.
I’ll go watch the rest.
The up and down motion of the water is caused by playing with the phase of the waves.
Let me give you an analogy. Remember the first time you saw a laser? It was probably red and you were probably struck by the richness of the red. Lasers are monochromatic . This device is similar in that way.
And light can be polarized left or right just like populations.
This would make for an interesting fountain if you could get a multitude of streams going at once.
24 Hz is suspiciously like the frame rate. So it's a wagon wheel spokes effect.
The speaker changes the launch angle of the water. It's not a wave, just water falling in the direction it was launched, strobed by the camera.
I am not sure how it works (other than obviously through sound waves) but it is very fascinating. I am surprised I have not seen more commercial fountains doing things like that.
"So the air wave pushes on the water stream in regular places and not in others."
Yes, but that doesn't explain why the water stream moves backward towards the set-up rather than straight down after it passes the high point of the wave.
The water stream doesn't move backwards towards the set-up.
The water is constantly pouring down. But the pattern moves upward. And that gives the appearance of the water moving backward.
Plus all this is being recorded in frames that run at speed similar to the sound waves.
When I was five years of age I asked my mother, "why are the wagon wheels going backwards when the wagon is going forward?"
She said, "Because the movie camera is going clicky-clickity-clickety-click and the movie projector is going clicketyclicketyclicketyclick and the television camera is doing it's own thing and our tv is showing at its own speed so when all that is put together we finally see the wheels look like they're going backwards. But we already know they are really going forward much faster. It's just one of those amusing shortcomings of technology that we learned to accept."
And I go, "oh."
Amazed how my mother knows everything!
"The water is constantly pouring down. But the pattern moves upward. And that gives the appearance of the water moving backward."
Maybe, but the pattern in the first set-up (I watched the apex of the wave) maintains its vertical position relative to the speaker.
In the second set-up, the "25hz forward effect," the entire pattern does move as you say.
Anybody wanna ballpark range guess the distance between peaks in the sinusoidal waterfall (in inches or centimeters)?
I’ve hatched a theory.
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