A glider that flies forever, as long as you walk behind it

Sometime today, John Collins, the so-called Paper Airplane Guy, is going to try to set the world record for paper airplane flight.

Cool. But to me, even cooler, is this video Collins made about follow-foils. Around since the 1950s, follow-foils roll in mid-air, riding on an updraft you create simply by walking along with a piece of cardboard. If you’ve never seen one, watch the video. Fun.