15 uncoupled simple pendulums of increasing lengths dance together
sciencedemonstrations.fas.harvard.edu
15 uncoupled simple pendulums of increasing lengths dance together
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Re: 15 uncoupled simple pendulums of increasing lengths dance together
#2You can see a physical example of this at Technorama (in Switzerland) for those of you with kids that enjoy a good day out.
Re: 15 uncoupled simple pendulums of increasing lengths dance together
#3Hypnotic video.
Only vaguely related, but this reminds me of a story a couple of years back involving a machine learning system that was able to derive the laws of Newtonian physics from observing the motion of a hinged pendulum.
http://worldsciencefestival.com/videos/robot_learning_rebuil...
There's a lot of information buried in the motion of these objects :)
Re: 15 uncoupled simple pendulums of increasing lengths dance together
#4Related: http://wheelof.com/whitney/index.php?var=v6
Warning: Flash + sound
The mathematics behind this are pretty simple. It's just that the human mind is great at picking up patterns.
Re: 15 uncoupled simple pendulums of increasing lengths dance together
#5it seems as if there is another interpretation lurking here... that you can also explain this phenomenon as a single wave of increasing frequency in time observed at 15 points. Because of the discrete nature of the points, there is an aliasing effect as the wavelength of the wave gets shorter. For instance, once the wavelength is equal to the spacing between pendulums, all pendulums will line up. When the wavelength is twice that of the pendulums, they will seem to alternate, etc.
This explains the awesome visual effect of this experiment. Though I'm not exactly sure why adjusting the lengths of the pendulums would mimic a wave of traveling with ever increasing frequency. Maybe it has something to do with dispersion (we see an overlap of waves that travel at speeds proportional to their frequency/length)?
A great experiment would be to have two of these pendulum systems side by side, except one is made of 30 pendulums at half the spacing. Then when the 15 pendulum system is lined up, the 30 system should be alternating,etc.
Re: 15 uncoupled simple pendulums of increasing lengths dance together
#6This made curious what patterns emerge when the objects move along circles instead. So I made this 10 minute hack to simulate it:
Re: 15 uncoupled simple pendulums of increasing lengths dance together
#7This made curious what patterns emerge when the objects move along circles instead. So I made this 10 minute hack to simulate it: http://www.gibney.org/spiral_clock
Very pretty. It's a lot less crowdy if you change line 105 in your script to
var speed =(nr_elements - i)/1000;Re: 15 uncoupled simple pendulums of increasing lengths dance together
#8This made curious what patterns emerge when the objects move along circles instead. So I made this 10 minute hack to simulate it: http://www.gibney.org/spiral_clock
Very pretty. It's a lot less crowdy if you change line 105 in your script to var speed =(nr_elements - i)/1000;
Yeah, then the inner objects move faster and the outer objects move slower. I find it hard to say, which version I prefer.
Re: 15 uncoupled simple pendulums of increasing lengths dance together
#9Related: http://wheelof.com/whitney/index.php?var=v6 Warning: Flash + sound The mathematics behind this are pretty simple. It's just that the human mind is great at picking up patterns.
That is an awesome site. Thanks! I've never seen anything like that before.
Re: 15 uncoupled simple pendulums of increasing lengths dance together
#10The Exploratorium in SF has one of these you can play with. Show up at their monthly "After Dark" and you won't have to compete with the kiddos.