Life at its physical limits

“What cannot be measured properly, is not science”, sentences Matthieu Louis when he introduces William Bialek’s talk at the PRBB. There’s a packed room of close to 100 people, many of them left standing, others sitting on the floor.

There’s always a silence, longer than average, before Bill answers any question directed to him. You are left to wonder whether he has heard you. But he has. It’s just that, unlike many people, he actually thinks before he speaks.

And he obviously knows he’s talking about complex issues, too complex for the average human brain to grasp easily (not that the brains in this room are average, though). So his discourse is slow-paced, as if there’s a conscious thought before every single word he says. He stops and looks at the ceiling while reflecting, takes his glasses out and runs his hand through his face and dense beard before continuing.

With a green pen he writes formulae on a whiteboard with as easy a flow as if he was using words. Mathematics is his language and he thinks, as did Galileo Galilei, that it is also the language in which Nature is written.

He starts his talk with a Calvin and Hobbes Cartoon (one of his favourites) about how mathematics allow us to make predictions about the way things work, and throughout the seminar he gives some sharp and crisp examples of ‘life at its best’, i.e. of how Nature gets very close to its physical limits, such as the workings of the compound eye of a fly.

“The default assumption that evolution is sloppy and imprecise is probably not fair”, concludes the physicist from Princeton University. He leaves us with a question: are all these examples of optimization of information transmission just independent cases or can they all be connected to a general theory? Here’s some food for thought.