Vacuum Bazookas, Electric Rainbow Jelly and 27 Other Saturday Science Projects

Abstract

11R65. Vacuum Bazookas, Electric Rainbow Jelly and 27 Other Saturday Science Projects. - NA Downie (Air Prod and Chem, Blasingstoke, UK). Princeton UP, Princeton. 2001. 253 pp. Softcover. ISBN 0-691-00986-4. $18.95.Reviewed by A Nachman (4808 45th Street NW, Washington DC 20016).The book in question is intended (by the author) to motivate (or further motivate) youngsters to pursue science/technology. He does this by describing 29 projects (each description between 5 and 10 pages with quite nice figures) of various levels of difficulty (which he himself rates) that can be done at home. The author commendably provides reasonably clear instructions for making and then employing the devices in each case and further provides some little historical context for the device or the principle the device illustrates. He also provides some “Science and Math” narrative (in a few cases involving calculus which would not be communicable to youngsters) and a narrative called “The Surprising Parts” which confronts the subtleties of the phenomena within each project. It is these sections that elevate this book above the “Mr. Wizard” or “Mr. Nye the Science Guy” level.This reviewer believes that some of these projects (about 1/2) are indeed of interest to the ASME community either as a teaching aid (even for undergraduates) or for self-amusement. Interestingly neither of the two projects mentioned in the title rate highly with this reviewer. The Jell-O project involves mobility of certain colored gels under an electric field (the relative differences serves to spread them into a rainbow within a petri dish) while the Bazooka project, though indeed mechanical, is not very interesting (a T-shaped tube driven by a vacuum cleaner which can shoot ping-pong balls). More interesting are projects which demonstrate some (possibly) counterintuitive phenomena. These include a pole which is vibrated by a small electric motor (many projects require a small electric motor) and which has one or more washers which can thereby be made to slide “up” the pole as well as almost stand still. The title of Hovering Rings for this project is quite apt. The explanation in terms of nodes and traveling waves on the pole (and of course friction between the washers and the pole) is well written. A related project shows that a pendulum can be kept in the vertical (plumb bob end closest to the ceiling) position by the expedient of suitably vibrating the other end with a small electric motor. Those who have been exposed to serious nonlinear oscillations material would not be surprised, but undergraduates might be, and this is a demonstration that could be undertaken in a classroom. Once again the explanation is sound. There is a project (Fishy Boat) which, while not so easy to make (it requires having a model boat and being willing to “modify” it as instructed), is really interesting. It argues that the single oar Venetian gondola method for boat propulsion has some merit in that the back-and-forth motion is well matched by the workings of a steam engine and a real case could be made for using it to navigate weed infested swamps, since it has no propeller to get tangled and is quiet. The next project argues that one could replace the rudder in a ship with a rotating cylinder (Rotarudder) and exploit the Magnus effect. Not a new idea, but still the accompanying narrative is very good and sending undergraduates from an introductory fluids course to read these few pages will be rewarding to them. There is a project for guiding a mobile toy car using a light beam (a warm-up exercise for laser-guided bombs!), and this is actually an excellent project for an introductory class in control theory—this reviewer regards this as the best project in this book—and another for cracking nuts using a snapped string (cracks the shell without crushing the meat). The discussion on the forces generated by such a suitably deployed string is just the sort of thing an undergraduate engineering student needs to read. The nonmechanical projects are also fun to read. This reviewer especially liked the toothless gearwheels made from magnets and the homemade amplifier. While this reviewer thinks every person who teaches general science (and especially physics) in any grade up to 12 should obtain Vacuum Bazookas, Electric Rainbow Jelly and 27 Other Saturday Science Projects, he cannot make the same recommendation to the AMR reader. He can only say that this book is entertaining and edifying and is not expensive, so if the AMR reader has the slightest inclination toward books such as this one, then the impulse to buy should not be stifled.