Pendulum waves.

[Wayout]

The 'Math Guys' could probably explain this but I just think it looks cool. 

http://wimp.com/pendulumwaves/

[ToeTag]

I didn't look. Magnets would explain alot.



Put little orange dots on the middle of some larger balls and it would make a great target! 

[gyrene81]

it's more of a physics thing than it is a math thing although they go hand in hand... one of those   things...very cool looking though

[curry1]

That is very cool stuff not to mention trippy.

[68ZooM]

it really would of looked cool if he painted each ball with fluorescent paint and filmed it under intense black light

[dedalos]

Explain what?  The balls are hanging at different lengths and therefore swing back an forth at different time intervals.  The rest is just a game your eyes are playing on you.  Your eyes retain an image for 1/8 of second I think so looking from that angle it looks like changing waves.  There is no advanced math or physics involved (unless the guy calculated the lengths of the strings to create that exact set optical illusions).  I have a feeling it would work as long as the lengths are different but it would produce a different sequence of waves.

[allaire]

Ladies and gentlemen, Sir Buzz Killington.  That was cool but I have to agree with the fluorescent point and black lighting.

[fbEagle]

just ask mister Isac Newton he'll explain it lol

[Yossarian]

Cba to think about it too much, but I'll say that the first part of dedalos' post is definitely right, but I'm not sure about the eye-trick bit.  I *think* it's probably the balls approximating simple harmonic motion, but that's as far as I've gotten

[Pigslilspaz]

Cba to think about it too much, but I'll say that the first part of dedalos' post is definitely right, but I'm not sure about the eye-trick bit.  I *think* it's probably the balls approximating simple harmonic motion, but that's as far as I've gotten

Exactly, it's no eye trick. Just quick calculation of the string lengths to set up the effect. The curve caused by the balls while at rest has to be parabolic in order for the effect to work. I've made a couple myself, always fun to watch.

[dedalos]

Exactly, it's no eye trick. Just quick calculation of the string lengths to set up the effect. The curve caused by the balls while at rest has to be parabolic in order for the effect to work. I've made a couple myself, always fun to watch.

Bah, give it a try.  If you pause the movie at the beginning you will she the curve is tinny almost a straight line.  I think you can get the effect as long as the lengths are increasing by the same amount.  The eye trick I was talking about was for the smoothness of the motion and the movement of the wave.

[bozon]

There are two effects that can play here:
One is simple harmonics: if one pendulum has a swing period P and the other has 9/10P (for example), then after 9 swings of the first the other will complete 10 swings and they will be "in phase" again for a brief moment. Setting up the swing periods smartly, there will be several pendulums that can be in sync at any given moment. It is a game of common dividers (that's the english term?) of period fractions.

The other possible mechanism which will be much easier top set up is frequency coupling. If each pendulum can "shake" or swing a little the bar from which they hang, they can bring the other pendulums into sync. This will not be stable since there are many frequencies interacting at ounce and conflicting with the fundamental frequency of each pendulum. They will move in and out of sync naturally. It is similar to the effect above, only that the frequencies do not have to so precise. The bridge in guitars and other string instruments actually make use of such an effect (by passing vibrations between strings).

[ToeTag]

was it just me? Or did it appear to slow down and then speed back up again.

[dedalos]

was it just me? Or did it appear to slow down and then speed back up again.

Just your eyes

[Pigslilspaz]

Bah, give it a try.  If you pause the movie at the beginning you will she the curve is tinny almost a straight line.  I think you can get the effect as long as the lengths are increasing by the same amount.  The eye trick I was talking about was for the smoothness of the motion and the movement of the wave.

The curve is small, yes, but it still follows a parabolic bath, just like the curve on a bullet is small yet it will still fall on a parabola. Also, it won't work if the length differences between two adjacent pendulums are same throughout. i don't know the formula off hand, but I will be willing to go and reread it and post it here about the relationship of pendulum length to it's period.