Interesting Optical Illusion

[youtubehd]mODqQvlrgIQ[/youtubehd]

  Quote

This is really simple but has such an awesome effect. Fill a bucket full of water and place it about 5 feet off the ground. Place a subwoofer about 1 foot lower than the bucket. Run a plastic tube from the top bucket down in front of the subwoofer. Tape the tube to the front of the speaker. Then aim the end of the tube to an empty bucket on the floor. Get the water flowing from the top bucket. Now just generate a 24 hz sine wave and set your camera to 24 fps and watch the magic happen. Basically your cameras frame rate is synced up with the rate of the vibrations of the water so it appears to be frozen or still. Now if you play a 23 hz sine wave your frame rate will be off just a little compared to the sine wave causing the water to "move backward" or so as it appears. You can play a 25 hz sine wave and cause the water to move slowly foward.

Posted this in fav youtube videos last week.

Static water, I thought it was well cool.

Ah yes, that bloated time sink of a thread.

Jazz it is!

can I make this for a school project?

  On 4/20/2012 at 5:52 AM, logakght said:

can I make this for a school project?

i dunno, can you?

I guess I have a great idea that combines art, some math, electronics and physics (sound), like the video but synced up with a beat (using some nice subwoofers with killer kicks yo) or something like that to make colored water like dance, yea yea

I saw something very similar to this in physics but instead of a sub, the teacher used a strobe light. Looks a lot cooler here because it isn't as choppy.

There's an emusic.com commercial running in the states that features similar effects:

25 fps cell phone camera + 25 Hz sine wave