ADVERTISEMENT
See Inside November 2011

Readers Respond to "The Bad Boy of Physics" and Other Articles

Letters to the editor from the July 2011 issue of Scientific American


TRIAGING TREATMENTS
The problems with the U.S. health care system described by Sharon Begley in “The Best Medicine” are accurate. It is gratifying that the National Institutes of Health is finally willing to fund real comparative effectiveness research. But the NIH, under pressure from Congress, has been reluctant to fund studies directly comparing the costs of competing treatments. I retired from the medical research field in part because of this refusal to look for the most effective and least costly answers and to support research on how to reduce unnecessary care.

Why is serious cost control not a part of either political party’s health care “reform” plans? To get elected, one must accept money from the very groups that require reform and regulation. Consequently, we get cosmetic reforms that never address the real issues that double the cost of health care. Instead reductions in care to the aged and poor are the preferred cost-control mechanisms. Until voters are freed from the election propaganda of special interests, the U.S. will continue to have the world’s most costly and least efficient health care system and the worst health care outcomes of any developed nation.
Thomas M. Vogt
Bountiful, Utah

BLEMISH OR BOON?
In “Evolution of the Eye,” Trevor Lamb draws together multiple lines of evidence to create a persuasive narrative for the early evolution of the vertebrate eye. But is it fair to equate historical constraints with defects in describing how vertebrate photoreceptors are on the back of the “inside-out” retina, shadowed by blood vessels and overlying cells? Has a possible advantage to this arrangement been ruled out?
Donald Robinson
Vancouver, B.C.

Lamb replies: There are indeed clear advantages that presumably led the eye vesicle to fold inward during evolution. This infolding put the photoreceptors in close proximity to the retinal pigment epithelium, enabling the biochemical recycling of retinoids following light absorption, the atten­uation of light that passes through the photoreceptors unabsorbed, and the delivery of oxygen and nutrients from the overlying choroid tissue. Other by-products of this infolding remain as “scars” of evolution, however.

BLACK HOLES REVISITED
In Peter Byrne’s interview with Leonard Susskind, “The Bad Boy of Physics,” Susskind insists that reality may forever be beyond reach of our understanding, partly because of his principle of black hole complementarity, which holds that there is an inherent ambiguity in the fate of objects that fall into a black hole. From the object’s point of view, it passes the hole’s perimeter and is destroyed at the singularity at its center. To an external observer, it is incinerated at the event horizon. It seems clear that this apparent ambiguity stems from the fact that—according to general relativity—the passage of time differs for the object and observer.

What actually happens is that from the vantage point of the observer, the object appears “frozen in time” when it arrives at the event horizon (and permanently disappears from view upon the horizon’s expansion). One should not conclude that the object’s fate is ambiguous. The event is merely observed in a different way depending on the observer’s frame of reference.
Anthony Tarallo
The Hague, the Netherlands

Share this Article:

Comments

You must sign in or register as a ScientificAmerican.com member to submit a comment.
Scientific American Special Universe

Get the latest Special Collector's edition

Secrets of the Universe: Past, Present, Future

Order Now >

X

Email this Article

X