Defining the Line
The Doping Dilemma,” by Michael Shermer, suggests that the possible penalties of using artificial enhancements in sports should be made greater than the possible rewards. But it is impossible to determine what is and is not an unacceptable artificial enhancement. With advances in medicine, biology and even prosthetics, the broad gray line will only get wider and murkier. We have reached the stage in our “progress” where meaningful contests between individuals are no longer possible.

Ted Park
Calimesa, Calif.

SHERMER REPLIES: Park has identified the hard problem in sports administration: where to draw the line to create unambiguous decisions about what is allowed in a world of ambiguous grays. The answer is not easy, but we have to draw that line somewhere. I was race director of Race Across America and executive director of the UltraMarathon Cycling Association for a seven-year period, and these gray-area issues came up constantly. I discovered that the most satisfying solution for everyone was open communication between athletes and management to create an agreed-on set of rules that would be clearly defined and strictly enforced.

Environmental Economics?
Robert Nadeau argues in “The Economist Has No Clothes” [Forum] that, by using a discarded theory of physics, a founding school of economics caused all economists to ignore the environmental impact of their subsequent theories. Using physics in economics is reminiscent of trying to apply classical physics in subatomic mechanics. But when I have taught economics with texts from at least 15 years ago, they have imparted such ideas as the scarcity of resources; market failures resulting in spillover costs; taxation as a reallocation technique; the environmental effects of unconstrained pursuit of high GDP; inelastic supply of some resources; and the use of cost-benefit analysis in approaching such problems. I conclude that the writers of these texts escaped some time ago any limited visions of their forebears.

Harry R. Clements
Wichita, Kan.

NADEAU REPLIES: Unscientific axiomatic assumptions became foundational to mainstream economic thought after the 19th-century creators of neoclassical economics substituted economic variables in the equations of a theory in physics. Because there was no basis for assuming that the economic variables were similar to the physical ones, this action is not comparable to failed efforts by classical physicists to explain subatomic mechanics. It was a wholesale abuse of a scientific theory by nonscientists.

I must disagree that mainstream economists have escaped the effects of this abuse. Some theoretical work—such as game theory, nonlinear analyses and convex analysis—has challenged axiomatic assumptions in neoclassical economics. But all these theories are premised on the unscientific assumptions that market systems are closed and self-correcting and move toward optimal states of equilibrium. This problem is not an esoteric one without real-world consequences. Such unscientific assumptions are undermining efforts to implement scientifically viable economic policies and programs that could prevent global warming’s most disastrous impacts. And if we fail to realize this very soon, recent scientific research strongly suggests that our future will be rather bleak.

Sun and Shadow
In “The Color of Plants on Other Worlds,” Nancy Y. Kiang describes how plants on a world orbiting a mature type M star might appear black from adaptation of their photosynthetic pigments to that light spectrum. But such a world’s habitable zone would be so close to the star that it would have a strong chance of being tidally locked, so that one hemisphere would continually face the star. Surface plants would probably develop photosynthetic pigments only on their lighted side. Their shadowed side would tend to be gray or brown and considerably lighter. Discovery of another world’s plant pigments may therefore depend on the angle between the sight line of a space telescope and the line between the world and the star it orbits.

James W. Scott
Wyckoff, N.J.

KIANG REPLIES: Scott raises some excellent, fun points. Even on Earth there is latitudinal adaptation—not so much in pigments to spectral variation in radiation as in a plant’s shape to the sun’s height in the sky. The conical shape of coniferous trees at high latitudes, for instance, is better at intercepting light at low solar elevation angles. So, on a tidally locked planet orbiting a type M star, we might see a longitudinal gradient in plant pigments as well as adaptations to fairly fixed elevation angles of the parent star. The first telescopic missions to obtain planetary spectra will not be able to resolve such gradients, but scientists could make use of variations observed from a planet’s different faces to tease out more information about its surface.

Coming through the Border
Thomas B. Cochran and Matthew G. McKinzie’s description of the exercise where depleted uranium slugs were passed through U.S. ports in “Detecting Nuclear Smuggling” has confirmed what many have long known: radiation portal monitors provide little actual security. The situation is perhaps even worse than portrayed. Not only are the monitors not effective against uranium, but they also do not work against weapons-grade plutonium if one understands the basic physics required to shield it. And those physics are well known around the world.

Jack L. Parker
Retired Fellow
Los Alamos National Laboratory

Note: This story was originally printed with the title, "Letters".