<story><title>You are getting sleeeeeeepy ...</title><url>http://blogs.discovermagazine.com/cosmicvariance/2012/10/01/you-are-getting-sleeeeeeepy/</url></story><parent_chain></parent_chain><comment><author>lutusp</author><text>I have a story seemingly remotely associated with this, but actually very much the same.&lt;p&gt;Years ago, at highway construction sites, sawhorses would be erected that were equipped with flashing lights for safety after dark. In those days the flashing lights were gas-discharge lamps connected to a simple charging circuit consisting of a capacitor connected across the lamp and charged by way of a resistor -- a very simple arrangement, but one that would reliably flash the light all night long.&lt;p&gt;It turns out that the specific moment the lamp broke down and flashed  could be affected by nearby lights of the same kind. As a result, if a large number of sawhorses were erected in a dark location, eventually all the lights would get into synchronization. I can remember on a number of occasions on long trips through dark countrysides, cresting a hill and seeing a construction site in the distance, with all the lights flashing as one.&lt;p&gt;As I would approach closer, as my headlights shone more brightly on the construction lights, they would go out of sync.&lt;p&gt;This is a purely historical note, because modern construction sawhorses use LEDs instead of high-voltage gas-discharge lamps -- cheaper and more reliable. The LED&apos;s never become synchronized, of course.</text></comment>
<story><title>You are getting sleeeeeeepy ...</title><url>http://blogs.discovermagazine.com/cosmicvariance/2012/10/01/you-are-getting-sleeeeeeepy/</url></story><parent_chain></parent_chain><comment><author>alan_cx</author><text>There is a place in the UK where this happens with spooky regularity with people walking. There is a covered walk way between Waterloo and Waterloo East railway stations. The mob of people enter it unsynchronised and by the time they leave, they are usually all synchronised. I assume this happens in many other places too, I just haven&apos;t been every where else to see!!!!&lt;p&gt;I always assumed this was because people can hear each other and subliminally fall in to syc, whether this is the same or not, Im already internally debating!!!</text></comment>