A little off-topic, but I wanted to mention that "The Bathtub Effect" article listed in this week's Optional Resources doesn't seem to be available on the site given. At least I can't seem to access it - I get a 403 error. However I did find a reprint on Resilience.org: https://www.resilience.org/stories/2011-07-30/surfs-are-you-ready-global-storming-ba