Jörg Sprave's day job is as a manager in the world of consumer electronics. But he has been for many years making manifest the sort of things that once filled my school notebook margins with doodles: slingshots and other devices for launching bolts, steel balls, and other stuff at high speed at targets or just into the air. (Some of his "slingshots" are hard to recognize as such; he eschews the classic American
wrist-rocket braced design as well as the old Tom Sawyer forked branch in favor of
things a bit more elaborate.) Thanks to the Internet, hobbies that were once obscure are now easy to follow, and Sprave's homemade slingshots are no exception; you can follow his exploits through an
ongoing series of YouTube videos and a
forum site that builds on these videos. He's doing it in Germany, too, where firearms may be harder to come by than in the U.S., but
giant honkin' firecrackers are available (at least for part of the year), and acts accordingly. Amazingly, he has yet to lose an eye; his goggles are a wise precaution. Sprave has agreed to answer your questions about his own take on physics as a hobby. As usual for Slashdot interviews, you're invited to
ask as many questions as you'd like, but please divide them, one question per post.