This article, written by a bunch of people I know (and one person I don't), just appeared in Nature. Perhaps the best way to describe it is with the abstract:
"Footbridges start to sway when packed with pedestrians falling into step with their vibrations.
Soon after the crowd streamed on to London's Millennium Bridge on the day it opened, the bridge started to sway from side to side: many pedestrians fell spontaneously into step with the bridge's vibrations, inadvertently amplifying them. Here we model this unexpected and now notorious phenomenon — which was not due to the bridge's innovative design as was first thought — by adapting ideas originally developed to describe the collective synchronization of biological oscillators such as neurons and fireflies. Our approach should help engineers to estimate the damping needed to stabilize other exceptionally crowded footbridges against synchronous lateral excitation by pedestrians."
In September 2004, Strogatz (who was on my Ph.D. thesis committee and who is the exceedingly rare applied mathematician with a large number of articles in Nature) visited me at Georgia Tech and gave a public lecture on synchronization. He showed the video of what happened with the Millenium Bridge, and it's really amazing to watch! (In many ways, it's even more amazing then the Tacoma Narrows video.)
As for the other authors, let me go through them one by one: Danny Abrams '00 was a Rudd and APh major. Presumably, several of you also know him. He overlapped with me at Cornell as well (arriving as a Ph.D. student in Theoretical & Applied Mechanics in Fall 2001).
I've met Bruno Eckhardt at a couple conferences (and when he visited Georgia Tech). I originally know his name from his work on quantum chaos. I applied for an NSF postdoc under Ed Ott (but it was rejected). He's part of Maryland's chaos group and is a really nice person. I've never met Allan McRobie.
No comments:
Post a Comment