In the previous post, pendulums of the same length (and hence the same natural frequency) oscillated each other. Here, the point is that the pendulums are of slightly different lengths. And yet:
Comprehensive notes can be found in what appears to be the original source of this demo, Bryan Daniels’ senior project at Ohio Wesleyan University.
To my mind this demo isn’t an example of resonance… and that’s a thought we’ll pick up in the next post in this series. Meanwhile, please do share your favourite pendulum demos in the comments. Or, you know, any pendulum-related anecdotes – there’ll never be a better time for those.
I love this! I also found this fantastic introduction to it including the maths laid out in a really understandable way: http://www.learner.org/courses/mathilluminated/pdf/MathIlluminated_12_txt.pdf
Actually you’ve just raised a really interesting question in my research – in particle accelerators we talk about a “tune” or oscillation frequency of the particles. When we include the electric forces between particles (the coulomb force) the individual particle tunes get ‘depressed’ or change because it provides a kind of de-focusing force in the oscillator equations. I’ve never considered whether over time there might be an effect of spontaneous synchronisation… I’m about to go an ask my colleagues!
Ooh, that’s cool. And do keep us posted – I’d love to be able to demonstrate research impact of public engagement. 🙂