“The laws of life,” a feature article in the March issue of Physics Today is a stimulating exploration of how fundamental and universal principles of physics shape life and its success. In addition, an extraordinary tribute to the life of Mildred "Millie" Dresselhaus the renowned MIT physicist celebrated for her discoveries of the physics and chemistry of carbon, appears on the magazine’s website. Dresselhaus died last week, and the online tribute contains comments by many of her colleagues and former students expressing appreciation for her inspiring impact on their lives. The Physics Today online tribute includes a link to the recent GE commercial that honours (right) Dresselhaus’ achievements and example. Both articles are available for free from Physics Today, devoted to physics and the physical sciences community.
Physics of Biology
In “The laws of life,” astrobiologist Charles Cockell, of the University of Edinburgh in Scotland, takes readers on a contemplative journey along the path physics lays down for biology. Starting off (relatively) big, Cockell discusses the question of why animals don’t have wheels, laying down the parameters that would disfavor these circular extensions of the body. First, wheels can surmount objects no larger than their radius, thereby making a poor showing in comparison to legs. That doesn’t mean that advanced technologists like humans are the only ones who seek the wheel; Cockell points out that on flat, dry plains, dung beetles make part of their living by shaping and rolling balls of dung.
Cockell also finds broad illumination by going into the physics of the miniature and, for example, looks at why carbon stupendously outclasses silicon as a potential life keystone. He grants that contingencies may have a role in the evolution of life, but argues that physics will tightly constrain the outcome of any evolutionary experiment.