Robert Ehrlich (1)Critiques

One of the goals of a course I teach in our Honors College is to provide non-science majors with the tools they need to differentiate authentic science from material that has merely been provided a "scientific" dressing. Physicist Robert Ehrlich has provided nine case studies that are ideal for this purpose. Do more guns in the hands of citizens decrease crime? Is AIDS really caused by HIV? Is sun exposure harmful or beneficial? Are low doses of (nuclear) radiation beneficial? Does our solar system have two suns? Do "fossil" fuels really come from abiogenic origins? Is time travel possible? Is the Big Bang a myth? Are there faster-than-light particles? Ehrlich takes a serious and analytical look at each of these questions, and (unfortunately, I think) states his answer at the end of each chapter. The important thing is, of course, not the conclusion but the quest for it.

This is a sequel to Ehrlich's "Nine Crazy Ideas in Science", which was my pick for December, 2001. I don't think it is as good as the first one, although it does have some great strengths; his discussion of the climate change issue is about as good as any, and he also has an especially good discussion of the efficacy of placebos. The other topics not mentioned in the subtitle are: "Is Complex Life in the Universe Very Rare?", "Are People Getting Smarter or Dumber?", (paraphrasing) Intelligent Design, Health Effects of High Cholesterol, and Psychokinesis. One of the strengths of "Eight Preposterous Propositions" is that Ehrlich provides good references, so you (or your students) can follow up on the argument in more detail if you wish.

brief overview of nine ideas (either controversial or 'out there') with a discussion of their importance and their likelihood; entertaining and informative

This collection of over 100 examples of simple physics demonstrations and experiments seeks to dispel the myths that physics is highly abstract, dauntingly complex, user-unfriendly, and remote from everyday life. Intentionally using "low-tech" and inexpensive materials from everyday life, this book humanizes key principles of physics, and shows how the best demonstrations are the simplest ones. The fact that they also save money is an added bonus.
As Ehrlich puts it, "You can actually fit many of these demonstrations in your pocket, bring them to class without any setup required and, best of all, you need not fear that your "demo" will more likely illustrate Murphy's Laws rather than Newton's."
Some of the more intriguing examples include:
Estimating the net forces on a moving book.
Deep knee bends on a bathroom scale.
Recoil force on a bent straw.
Avalanches in a sand pile.
Spinning a penny.
Swinging your arms while walking.
The "Tachyon Telephone" and, of course
Why Toasts land jelly-side down.
An essential resource for Physics teachers, students and anyone with even the slightest interest in physics.

Whether by chance, by design, or by publisher's mandate, Ehrlich moves a little closer to the mainstream in this sequel to Nine Crazy Ideas in Science. The coverage is still deep, dense, and intellectually sophisticated--though highly readable--but the topics are a little less dense and off-putting. This time around Ehrlich takes on the genetic basis of homosexuality, the potential benefits of global warming, the prevalence of intelligent life in the universe, and the reality of telekinesis (among others). It's still highly effective as a crash course in critical thinking, and still not the light, bedtime reading that some readers might wish for.

Ehrlich, a physicist, rounds up nine ideas from the fringes of science and evaluates them. They range from sociology (more guns = less crime) to medicine (HIV is not the cause of AIDS) to geology (oil and gas are not formed by decomposed organic matter) to physics (time travel is possible; faster-than-light particles exist). His goal is not (just) to be entertaining, but to explain how science works and how to critically evaluate scientific ideas.

Ehrlich's explanations are remarkably clear, but they're not easy reading. He takes his role as a thoughtful critic seriously, and before you're very far into any of the nine chapters you're fairly deep in elementary statistics, philosophy of science, and other weighty matters. This is most definitely *not* Carl Sagan or Martin Gardner wittily shooting fish in a pseudoscientific barrel, and partly for that reason it's likely to be a disappointment for readers looking solely for a "good read." The effect is a little like a college-level course in critical thinking taught by an erudite but demanding professor . . . it's not always easy, but if you stay with it you can learn a lot from the experience.½