by William Gurstelle
Random House, 2006
Hardcover, 224 pages
The technology underground is a thriving, humming, and often literally scintillating subculture of amateur inventors and scientific envelope-pushers who dream up, design, and build machines that whoosh, rumble, fly—and occasionally hurl pumpkins across enormous distances. In the process they astonish us with what is possible when human imagination and ingenuity meet nature’s forces and materials. William Gurstelle spent two years exploring the most fascinating outposts of this world of wonders: meeting and talking to the men and women who care far more for the laws of physics than they do for mundane matters like government regulations and their own personal safety.My Thoughts:
The full title of Gurstelle's book is: Adventures from the Technology Underground: Catapults, Pulsejets, Rail Guns, Flamethrowers, Tesla Coils, Air Cannons, and the Garage Warriors Who Love Them. That pretty much explains what it's about. We're talking about regular people who like to make or invent some interesting devices. After living with a design engineer for many, many years, I have an understanding about the fascination certain people may have in building some of these things in their garage (and he may or may not have built a few of these devices over the years, but I'm not telling.)
Chapters included are: High Powered Rockets, The Technology of Burning Man, Tesla Coils, High-Voltage Discharge Machines, Hurling Machines, Air Guns, Flamethrowers, Electrostatic Machines, Rail and Coil Guns, and Robots. The book includes separate sections with more technological detail on particular devices. Gurstelle suggests that you can read the sections if you are interested in more technical detail, but a casual reader can skip them. The sections are interesting, easy to understand (at least they were for this amateur), and include illustrations.
You need to know that this book is an introduction to the various catapults, aircannons, flamethrowers, etc., not a detailed set of schematics on how to build your own and what materials you'll need. There are notes and a further reading section if you really need to explore making your own "Punkin Chunk" air cannon or a personal Tesla coil. (Really, if you are expecting detailed instructions in a 224 page book that covers a wide range of projects, then you need to rethink that position.)
With shows like Junkyard Wars, BattleBots, and Monster Garage, the whole idea of building something fantastic out of, well, junk or parts, is a concept many people can understand. Be forewarned, however, that this is not a book for the young scientist in your family - well, it might be with the exception of a certain section on, shall we say, "male enhancement," that might not be considered appropriate.
Rocketeers both need and love wide-open spaces—the wider the better. Amateur rocket builders, especially those who specialize in building the largest and most powerful rockets, want only a couple of things: a lot of flat, open, unpopulated land in which to recover their rockets after flight, and clear, sunny skies. This makes places such as Texas, Kansas, and the Canadian prairie provinces ideal spots for LDRS gatherings. pg. 23-24
What rocket makers care about most is the physics quantity called "total impulse." Total impulse is the product of the force acting on a rocket (the thrust) multiplied by the amount of time the thrust is applied. Expressed mathematically, it is: Total Impulse = Average Thrust ´ Burn Time An engine that applies a lot of thrust, for a long period of time, is a high-performance engine. To a rocket engine maker, the goal is lots and lots of impulse. pg 28