Popular Science, September edition

Way back in 1485, Leonardo da Vinci sketched out plans for a human-powered aircraft. Even now, engineers are having a hard time getting such a device off the ground. The main problem is that sustained flight requires more lift and power than the human body can generate for itself. But that hasn’t stopped people from trying. In this month’s issue of Popular Science, Rebecca Boyle writes about recent efforts to take flight without engines and jet fuel. Engineers have been trying to alleviate the limitations of human-powered craft by tweaking their designs — adding larger wings to give more lift or interconnected rotors to allow for helicopter-style flight. Some of these devices work, but don’t expect to be cruising to work in them anytime soon. Most of these machines can attain only limited altitudes and fly only short distances. In 2010 a pedal-powered ornithopter — an aircraft that flies by flapping its wings — made it only 11 feet into the air.

Don’t be cruel
“The Science of Evil,” Basic Books

When people do terrible things to other people, we label them as evil. But doing so does not explain their actions. In “The Science of Evil,” psychologist Simon Baron-Cohen attempts to find a more concrete explanation for horrible deeds. He defines evil as the absence of empathy — when people treat others like objects rather than like thinking, feeling individuals. How does empathy get whittled down? Baron-Cohen offers a host of explanations, from environmental factors to neurological and psychiatric problems such as Asperger’s syndrome, which impairs social interactions. Examples of severe human cruelty abound in this book, which is not for the faint of heart. At least Baron-Cohen is upfront about it: “You can’t write about human cruelty in a cheerful way,” he writes in the introduction to the book, which was first published last year and is now available in paperback. “So if you’re looking for a fun read, proceed no further.”

Book cover, “The Science of Evil” by psychologist Simon Baron-Cohen. (Basic Books/Basic Books)

Aaron Leitko