Putting Scale in Perspective

Recently during the 2009 AAPT Summer Meeting in Ann Arbor, we had the chance to talk with CoolStuff Contributor Joe Spaccavento. As always, Joe had another great idea for us. This time on how to introduce the concept of scale and distance to students in a very memorable way. In his unassuming way, Joe shared a great idea he got direct from NASA, all the while pulling an un-inflated beach ball replicating the Earth from his jacket pocket. Between breaths trying to quickly inflate the Earth, Joe started with his questions…

With respect to this globe, how far is 200 miles? Well, look here (pointing to the globe) New York City to Boston is about 200 miles. With respect to this globe, that's about this far. (Holding up his thumb and fore finger barely apart.) Then he asked, "How far out does the Space Shuttle orbit?" Answers are offered all around; 230 miles, 200 miles, 180 miles… Well, it's about 200 miles. The holding up the Earth Ball, he points out that the shuttle would be in orbit around the Earth about here… (Again with his finger barely off the surface). Surprised faces all around.