Yesterday, I had an enjoyable morning helping my neighbor set up his booth at the USA Science and Engineering Festival at the Washington Convention Center (Mount Vernon Square). The existence of said Festival was unbeknownst to me prior to yesterday's volunteering. The first Festival occurred 2 years ago on the Mall and they upgraded to an indoor venue this time around. Aerospace, environment, robots, bugs, chemistry. It's all there! While unloading cargo in the bowels of the convention center, I saw no less than 5 dewers of liquid nitrogen being filled and hauled up!