Disagreeing On Everything
As theoretical physicists, we deplore the publication of A. Garrett Lisi and James Owen Weatherall’s “A Geometric Theory of Everything,” as well as of Zeeya Merali’s “Rummaging for a Final Theory” [News Scan] in the September issue, which was PR-level praise of Lisi’s research that presented him as struggling against an entrenched establishment.

As you surely knew Lisi’s views to be, to say the least, controversial, basic editorial precaution would have required first consulting a reputable particle physicist. You would have learned that duly refereed and published work of Jacques Distler of the University of Texas at Austin and Skip Garibaldi of Emory University has shown that Lisi’s model cannot even reproduce parity violation.

This effect, experimentally verified more than 50 years ago, is a basic element of the overwhelmingly successful Standard Model of particle physics. Instead Lisi predicts a host of particles that have not been detected and fails to account for the existence of other particles that do exist. His model simply fails to provide any correct physics.
Stanley Deser, Albion Lawrence and Howard J. Schnitzer
Brandeis University

THE EDITORS REPLY: Merali’s article covered a scientific meeting on new algebraic approaches to unifying physics, one of which is Lisi’s. She acknowledged his theory to be controversial, mentioning the work by Distler and Garibaldi, even quoting Garibaldi himself. She also quoted Lisi’s response, in which he said his ideas are still works in progress and sketched a possible solution to the criticism.

Separately, we had invited Lisi and Weatherall to describe Lisi’s work for the benefit of readers who may have been ­­curious about it after seeing its geometric beauty hinted at elsewhere. We did so in the spirit of presenting fresh ideas that are illuminating if admittedly tentative—one notable example being Scientific American’s articles on string theory in its early days. That decision was made after consultation with experts, most of whom were indeed skeptical about Lisi’s theory, but some of whom still thought it promising.

I was saddened to see the inclusion of water fluoridation in Michael Shermer’s “The Conspiracy Theory Detector.” Perhaps Sher­mer should go back and look at Scientific American’s own coverage of fluo­ride [see “Second Thoughts about Fluoride,” by Dan Fagin; January 2008] or, better still, read the science in the 2006 National Research Council report “Fluoride in Drinking Water: A Scientific Review of EPA’s Standards.”

I have seen and read the science, and I no longer drink and cook with my city’s fluoridated water supply. I wish I could afford to not be forced to wash in it. Incidentally, carbon filters such as Brita’s do not remove fluoride from the water, and boiling it makes the fluoride more concentrated. Infants exposed to fluoride could have reduced IQ. Can our society really afford to take that chance?
Greg Warchol
Oakville, Ontario

In “Hallucinogens as Medicine,” Roland R. Griffiths and Charles S. Grob describe the therapeutic benefits of hallucinogens such as psilocybin and LSD, as well as some of their risks. I was surprised, however, to see no discussion of perhaps the largest risk: causing patients to form false beliefs. Patients in the studies they cite emerge from their hallucinogenic experience believing that “all is One,” that “God asks nothing of us except to receive love,” and having a “peculiar disregard for ... their impending death.”

Indeed, having used both psilocybin and LSD myself, I have experienced these states. Not only did I have a disregard for my own death, I spent half an hour during one trip considering whether I ought to chew off and eat my own fingers. Happily, I chose not to, and overall I recall the trips of my youth fondly. But the visions they gave me were not real or true; they were the result of overstimulation of specific brain centers by a chemical. Allowing credulous patients to alter their entire life outlook and philosophy based on such experiences is, I think, fundamentally unethical, whatever the positive side effects might be.

Imagine if a study proposed to hypnotize patients, to tell them to believe all sorts of nonsense, and then to wake them up and leave them with those beliefs for the rest of their lives because it was expected that the nonsense beliefs would produce positive clinical outcomes. Would such a proposal pass an ethical review panel? I would certainly hope not. That situation is precisely parallel to the hallucinogen studies, except that instead of the doctor whispering falsehoods into the patient’s ear, it is the drug given by the doctor.
Ben Haller
Department of Biology
McGill University

GRIFFITHS AND GROB REPLY: We were glad to read that Haller did not eat his fingers. This is not surprising, however, as hallucinogen-involved trauma is very rare under the haphazard conditions of illicit use—which we nonetheless caution against—and it is virtually unheard of within supervised research settings. Haller dismisses the philosophical statements by psilocybin study volunteers as “false.” We regard them as unfalsifiable, and so, as scientists, we take no position for or against them. We do note, without judgment, that they tend to align with the mystical teachings of the world’s religions. The analogy with hypnosis is spurious, because in our psilocybin sessions we do not introduce explicit content to the patient.

During informed consent, candidate volunteers learn up front of psilocybin’s potential effects, including lasting changes in philosophy and outlook. Our ethics committees have approved our studies, which we stand behind. The risk-to-benefit assessment for this research is favorable. Preliminary studies in patients and healthy volunteers suggest substantial and sustained positive effects.

In “Know-It-All Toll Roads” [“World Changing Ideas”], Tom Vanderbilt claims pricing the roads is a better alternative to sitting in traffic. We thoroughly disagree. Free-market principles work fine for commodities that can be produced by several competitors, such as TVs. For public goods such as roads, however, there is usually only one best route and all others are much less desirable. “Ration by queue” gives all people equal access to the best option. The fact that so many people are willing to sit in traffic is proof those routes are more desirable for everyone. With “ration by price,” only the rich could afford the desirable routes. It sounds like an absolutely terrible idea and would set a dangerous precedent.
Steven and Luci Jones
Rocklin, Calif.