Enigma 1711: Illuminated artwork
15 August 2012
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From New Scientist #2878, 18th August 2012 [link]
In our town square is a piece of installation art consisting of 300 rods of equal length arranged in a cubic lattice. The whole structure balances on a single vertex, with the diagonally opposite vertex at the top. Each rod contains an LED strip light, which can be independently switched on and off. A microprocessor controls this, lighting up the rods that form the shortest continuous path between the bottom and top vertices.
Each combination of rods (meeting the shortest continuous path criterion) is lit up for 10 seconds, then another and so on, until all combinations have been displayed, when the cycle starts again.
How long does it take to complete a full cycle?