I’ve always been fascinated by the difference between pattern and randomness -is it purely perceptual or do physical laws apply? I happened to notice these bottles have five lobe-like ‘feet’ blow-moulded into the base so that, when displaced, they rock backwards and forwards in an apparently chaotic way. The film clip can be downloaded here, MP4 format (viewable by e.g. Apple QuickTime), and I recommend turning the sound volume to maximum.

Some day I’d like to: a) scale-up the phenomenon and create a matrix of several thousand -all displaced in a (nominally) identical way and then released. They would each execute different motions -dependent on the detailed starting conditions. b) feed the amplified soundtrack into an analyser and assess the extent to which this is actually a chaotic regime. c) investigate how far this would scale dynamically to work with eg one giant bottle.

This is just one of the emergent phenomena which are, for me, what makes life interesting. Just as you believe the bottle has settled down to some simple backwards and forwards motion, so it jumps off to one side (the highly elastic ‘feet’ seem to amplify the effect). Have I tried this with different levels of water in each bottle, different sized bottles…? No, I’m just keen on the qualitative behaviour. To make the measurements would require a proper scientist).