Well done book about the constraints of physics on the evolution of life and the implications for the possibilities of life among the stars. ( )

This was fascinating until the final two chapters. ( )

Is biology universal?

Sitting under my rock as I do, I had no idea there were astrobiologists. For a couple of decades now, apparently. One of them, Charles Cockell has written a book called The Equations of Life. Not only does it examine extraterrestrial life, but it firmly places physics underlying all of biology. Biology is totally dependent on physics.

Every lifeform seems to work along basic principles of physics or quantum physics. It’s all about processing electrons for their energy. The basic building blocks of life, amino acids, sugars and fatty acids are apparently raining down on planets all over the universe. Asteroids transport them. And water, which we like to think is our extraordinary trump card, is found commonly all over. The ingredients for life are everywhere. So there must be life out there, and there must be work for astrobiologists.

Cockell finds that life is pretty much going to be carbon-based, regardless of the planet or galaxy. Silicon-based life is possible, for example, but is just unlikely because of silicon’s inherent weaknesses. Silicon-based life is probably doomed to be primitive. Carbon however, is not only everywhere, it binds with everything appropriate to life. It’s the odds-on favorite for creating life. And will win the Darwinian battle.

The book takes a very long time to get to the good stuff. There is a lengthy examination of the ladybug, and how its wings and legs express physics equations. There is an in-depth examination of anthills and the sociology of their builders. These are interspersed with physics equations, partially explained, barely applied, and skippable. There is a great deal of basic biology and chemistry, including a long discourse on the periodic table. It is, despite Cockell’s efforts, rather flat.

Back in outer space, we do not know if the DNA/RNA system is universal, or how a DNA/RNA mutation system might perform in other environments, gravities, atmospheres, climates and seasons. But at the physics level, it is easier to predict. It’s the relationship of atmosphere to gravity to body mass that dictates it. This does not limit lifeforms; it enhances variations. Anything is possible, as long as it obeys the laws of physics. So, Cockell says, if there were a small planet with lesser gravity, and a thicker atmosphere, the top animals might be flying beings of human size. Maybe they wouldn’t have invented the automobile and burnt up all the carbon. Maybe they’d have really advanced flying machines. That’s the fun part of astrobiology. There is far too little of it in The Equations of Life.

Meanwhile, back on Earth, while we can’t say biology is universal right now, we can say that physics is. Everything that acts can be reduced to an equation. Is that good news. or what?

David Wineberg ( )