Reviews
John L. Hubisz, Ph.D., Hubisz@unity.ncsu.edu

Clouds in a Glass of Beer: Simple Experiments in Atmospheric Physics by Craig F. Bohren, Foreword by Jearl Walker and published by John Wiley & Sons (1987) paperback.
What Light through Yonder Window Breaks?: More Experiments in Atmospheric Physics by Craig F. Bohren and published by John Wiley & Sons (1991) paperback.

I have heard many weird explanations of the various phenomena discussed in these books – most of them false. When presented with a problem having to do with atmospheric phenomena or any other question, the author designs an experiment and carries it out. You can carry out the same experiments with easily obtainable and inexpensive equipment. Regardless of whether you carry out the experiments, you can be confident in the answers that the author provides.

The Trachtenberg Speed System of Basic Mathematics, originally published by Doubleday in 1960, followed by a Bantam paperback in 1973.

The author developed this system of rapidly calculating completely in his head while a prisoner in concentration camps for eight years. There is no long division, and no multiplication tables, just a number of tricks and the ability to count to 11. You can check sums by the methods of nines and elevens for accuracy. You may have come across some of these tricks yourself, e.g. I remember being told that products like (a+b)x(a-b) were, in fact, useful for multiplying, say, 53x48, which is (50+3)x(50-2). Squaring a number such as 55 is simply done by noting that the answer will always end in 25. Changing the first 5 to 6 and multiplying 5x6 to get 30 and your final product is 3025. The book goes way beyond this to train elementary school children in a way that they will enjoy. The book encourages mental calculation for addition, subtraction, multiplication, division, squares, and square roots. The last chapter is an algebraic description of the method.

Mousetrap Racers: The Complete Builder’s Manual by Alden J. Balmer and published by Fox Chapel Publishing Co. , Inc., 1970 Broad Street, East Petersburg, PA 17520, (projected Fall 2008) 144 pp. $14.95

I have not read the book, but have seen the preliminary material and it looks good and is certainly a fun project for kids of Middle School age.  Chapter 2 has two flaws to watch out for: One can not “feel” accelerations as acceleration is a kinematic variable i.e. dependent only on space and time.  What one “feels” is a force, which is a dynamic variable.  Forces cause accelerations.  Also, acceleration is the rate of change of velocity, i.e. a change in speed and direction or both, with respect to time. To leaveoff with respect to time is a serious mistake.