Letters to the Editor

19316

The surprising statistic that teenage calorie consumption has remained stable while obesity has burgeoned and that physical activity among this group has fallen sharply may well suggest a cause and effect, but such a conclusion is premature and untested, at best. I wonder whether closer analysis of food intake would demonstrate an overall shift away […]

19315

The iron-sulfide hypothesis of life’s origin that Michael J. Russell and William Martin propose in this article is attractive because it provides an inorganic cell wall and a matrix with some catalytic capabilities. But even if the Russell-Martin hypothesis is true, it isn’t a comprehensive theory of bioorigins. The cardinal difficulty in the origin of […]

19314

This article addresses how much energy is given up in the viscous processes of a thin sheet of turbulent fluid.