Comments on: Video: water appears frozen in sine wave

By: SamSam

SamSam — Wed, 13 Mar 2013 17:50:00 +0000

…no, the effect you’re seeing is precisely because of the video frames. See my post above about the wheel wagon effect, or the video below with the helicopter.

In real life this would just look like a hose waving back and forth, and wouldn’t look odd at all..

By: Brad Bell

Brad Bell — Wed, 13 Mar 2013 10:17:00 +0000

The video does show us what it’s like in person. The frame of the video doesn’t add to the effect. And there is no strobe. Just the house bouncing in response to sound waves from the speaker.

By: Jesseham

Jesseham — Wed, 13 Mar 2013 07:39:00 +0000

That’s awesome.

By: Marcellus King

Marcellus King — Wed, 13 Mar 2013 05:20:00 +0000

This comment deserves more likes

By: Brad Ackerman

Brad Ackerman — Wed, 13 Mar 2013 03:53:00 +0000

For SCIENCE!

By: cabalist

cabalist — Wed, 13 Mar 2013 03:02:00 +0000

OMG, MAGIC!

…and the Arthur C. Clarke quote, of course…

By: Noctilucent Studios

Noctilucent Studios — Wed, 13 Mar 2013 01:39:00 +0000

I was hoping to see what would happen if he moved his hand or a stick through the water, to try and get a sense of how it would look IRL.

By: Joel Moore

Joel Moore — Wed, 13 Mar 2013 01:21:00 +0000

Boston’s Museum of Science had (still has?) a similar interactive demonstration where you can “freeze” an arc of water droplets in midair by adjusting the frequency of a strobe light. Or you could tweak the rate to make them slowly march to the left or right. I remember playing with this 30+ years ago.

By: jheiss

jheiss — Wed, 13 Mar 2013 01:07:00 +0000

I thought it was interesting that when the actual speaker sound leaked through briefly it sounded rather like a film projector, cause, well 24 frames per second…

By: Felix Turner

Felix Turner — Tue, 12 Mar 2013 22:31:00 +0000

yes: https://vimeo.com/52888178

By: autark

autark — Tue, 12 Mar 2013 21:51:00 +0000

“Any sufficiently advanced technology is indistinguishable from magic.” – Arthur C. Clarke

By: SvenOrtmann

SvenOrtmann — Tue, 12 Mar 2013 21:47:00 +0000

It’s quite the same effect as with the helicopter whose main rotor doesn’t seem to move (same frequency as camera, again).

http://www.youtube.com/watch?v=O020Bh9O4qo

By: PhasmaFelis

PhasmaFelis — Tue, 12 Mar 2013 21:22:00 +0000

This loses a lot by not showing us (something approximating) what it would look like in person. Just an ordinary hose spray?

By: SamSam

SamSam — Tue, 12 Mar 2013 21:17:00 +0000

Yes, it’s called the Wagon wheel effect, where the spokes of a wagon wheel — or the propellors of a helicopter or jet engine — appear to slow down, become stationary, and/or reverse.

We see this so often with propellors in movies that I know many people who think that real propellors actually look like this to the naked eye — they don’t, it’s just an effect of the movie frame-rate.

In this case the water is waving back-and-forth, but each frame of the camera happens to sync up to when the wave was exactly where it was last time, so the wave appears to be stationary.

By: GlyphGryph

GlyphGryph — Tue, 12 Mar 2013 20:22:00 +0000

Yes. Each “piece” of water is following a set curve, but since we only see that piece every so many fractions of a second…

By: SomeGuyNamedMark

SomeGuyNamedMark — Tue, 12 Mar 2013 20:21:00 +0000

Now just install this in a men’s room.

By: TacoChuck

TacoChuck — Tue, 12 Mar 2013 19:39:00 +0000

If I am understanding this correctly, it is the hose bouncing that is making the water appear like, the water itself is not being held in that pattern by the sound waves. What is happening is that the end of the hose is being bounced which is making the water fall in that pattern.

By: Marius van Voorden

Marius van Voorden — Tue, 12 Mar 2013 19:29:00 +0000

Yes, it would :)

By: xzzy

xzzy — Tue, 12 Mar 2013 19:29:00 +0000

Too bad James Cameron didn’t know about this trick back in the 80′s or he’d have abused the shit out of it for his T-1000 melting scene.

By: Brainspore

Brainspore — Tue, 12 Mar 2013 19:12:00 +0000

Remember when that thing made friends with Ed Harris?

By: Jesseham

Jesseham — Tue, 12 Mar 2013 19:06:00 +0000

That’s too cool. I wonder if the effect would work IRL if your lit a room with a matching frequency strobe…

By: eldritch

eldritch — Tue, 12 Mar 2013 19:05:00 +0000

I would have appreciated a comparison of how it looks at a much higher framerate, to roughly simulate what our eyes would actually see. It’d help to reinforce the physics of what is happening.