Letters to the Editor

19062

In this article, it struck me that the helicopter lander’s blades might be helped considerably by their undersides’ being dimpled like a golf ball. Those dimples supply significant lift during a ball’s flight. The helicopter wings would seem to benefit in the same way. I suspect that the dimples near the outer radius might be […]

19006

Linguistic cladistics? Based on vocabulary? Linguistic froth, such as loan words from other languages, frequently becomes a source of heated debate. The deep structures of language that can provide a relatively stable field for analysis are more subtle. These include verb-substantive-object order, verbs of giving or receiving, noun declensions, and the like. But even these […]

19005

Your article reports that, after infancy, humans have trouble recognizing facial differences between members of other species.