In “The Truth about ‘Self-Driving’ Cars,” Steven E. Shladover strikes a welcome note of sanity in the hype about the predicted advent of automated vehicles on our roads. Yet when he describes “bus- and truck-platoon systems” as among the kind of automated vehicles we are likely to see sooner, it brought instantly to mind systems that have long been in place and that we are all familiar with: namely, freight and passenger trains.

The railway infrastructure has, of course, suffered long-term neglect, but the interstate highway network itself is not without its problems and would require an upgrade of serious proportions to meet the requirements of such systems.

Michael J. Reynolds
Somerset, England

Self-driving cars just have to be better than humans, not perfect. There are plenty of YouTube videos showing the problems that humans have with snow and ice, and San Francisco attests to the fact that humans have a hard time driving in an urban environment. Also, we let seniors drive even when we know they will sometimes experience delayed responses.

Chuck Simmons
Redwood City, Calif.

There are two areas the author did not mention that also affect the likelihood of success. First, vehicles are typically privately owned and maintained, and their complex systems may not be properly cared for or updated. Second, public highways are also not always well maintained, especially in terms of traffic controls that disappear in inclement conditions.

But the potential benefits are immense, and on freeways, automated cars could reliably travel much closer together at highway speeds, providing for two to three times the traffic in existing lanes relatively congestion-free.

Gary Kruger
Portland, Ore.


In “Einstein of the Sea,” Jonathan Balcombe describes behaviors exhibited by fish that involve the use of external objects in accomplishing certain tasks as “tool use.” Even if the fishes' behavior is undeniably remarkable, the word “tool” can be deeply misleading. Human tool use involves mental images of the starting conditions and desired result and a plan leading from the one to the other. The use of “tools” by animals should not be mistaken for these abilities.

William L. Abler
Arcata, Calif.

BALCOMBE REPLIES: Tool use by fishes might not differ from our own tool use as much as Abler believes. Fishes' capacity to communicate with referential signals and to execute sequential tasks in a flexible manner strongly supports their ability to plan, and their ability to remember and to create mental maps invokes a form of mental image making.


“A Plan to Prevent Gun Suicides” [The Science of Health], Nancy Shute's report about a “public safety campaign … consisting mainly of distributing posters and brochures about suicide to gun shops,” is nothing but a feel-good piece.

Among recommendations from the advocacy organization Ceasefire Oregon is a period of delay between purchase of a gun and delivery of the gun to a customer to frustrate those who come to a gun shop with homicide or suicide in mind. What do you think the gun shop owners that Shute portrays as saintly would think of that?

Charlie McKeon
via e-mail

I lost my dear brother-in-law to suicide. He purchased a gun and four months later used it to take his own life.

I'm wondering if part of buying a gun could include two items: a case that has motivational quotes and the suicide prevention hotline on the outside and inside and a newsletter on how to ask for help and stories of people who have overcome the toughest of situations.

Kathryn Williams
via e-mail


I find the capacities of the artificial neural networks described by Yoshua Bengio in “Machines Who Learn” far from brainy. The human brain can manage simple pattern analysis that is far beyond present AI abilities: The June issue of Scientific American lies upside down in front of me. Stacked side by side on the breakfront are 18 books. Half the books and the June issue display the word “the” in their titles. The “the”s vary in font, style and position, and the SA cover is inverted. My coordinated eyes and brain have no difficulty comprehending “the” in all these formats. From the article's description of current AI sophistication, neural networks have a long way to go before they can begin to approximate human capacities for this simple word identification.

David Werdegar
Naperville, Ill.


Michael Shermer investigates the causes of death-row inmates' displays of positivity in “Death Wish” [Skeptic]. Although I am not on death row, I have served five years of a life sentence, so I may have some insight into this. As a felon, you come to grips with the fact that most of society would rather be done with you. Couple that with a dangerous environment that often appears to an inmate to be as humiliating and demoralizing as possible, and, well, death becomes a less terrifying proposition. In short, what do you have to lose? Once you acknowledge that situation, it seems natural to focus on those bright points in your past and reinforce them instead of the monotony of your present life.

Gordon Schumacher
Canon City, Colo.

SHERMER REPLIES: The problem that Schumacher identifies in the prison system is largely the result of the U.S. still mainly engaging in “retributive justice,” or the understandable desire for revenge and to give criminals their “just deserts,” instead of “restorative justice,” or the attempt to repair the damage done to the victim and to rehabilitate the perpetrator. Many countries are experimenting with complementing retribution with restoration, to great effect for victims, perpetrators and society.


“The Fog of Agent Orange,” by Charles Schmidt, referred to the U.S. Department of Veterans Affairs as offering compensation to Vietnam War veterans and their children for particular illnesses that have been linked to exposure to Agent Orange if exposure had been proved. It should have noted that the department considers a veteran's presence in Vietnam or the Korean demilitarized zone during specified periods between 1962 and 1975 to be sufficient evidence of exposure.

In the August 2016 issue the box “Bill Gates on Global Health” in “Health Check for Humanity,” by W. Wayt Gibbs, should have stated that the interview with Gates was conducted in April 2014.


“The Collider That Could Save Physics,” by Howard Baer, Vernon D. Barger and Jenny List [Forum], incorrectly gives the energy released by matter-antimatter annihilations in the proposed International Linear Collider as 250 billion electron volts. It would be 500 billion. Further, the article should have referred to the Large Hadron Collider as producing proton-proton collisions, not proton-antiproton.