Biophysics seems like a feel-good field … it’s always telling us how well-made we are. A recent piece in the Times Science section served up a crash course on that discipline, alluding to the work of William Bialek, who is a professor of physics, an architect of the Integrated Science curriculum, and apparently the happy owner of an “impish, abstractedly cerebral face and full, free-wheeling beard.”
In the article, Bialek explains why the photoreceptors in our eyes are so ideally constructed: they are designed to respond to even single photons, which are the smallest discrete units of light. “Light is quantized, and you can’t count half a photon,” he says. “This is as far as it goes.” So, at the risk of inane analogy, it’s kind of like a perfect gumball machine that would accept even pennies, accommodating the smallest extreme of currency.
That’s the basic idea behind optimization. Evolution has made some biological systems really, really, unsurpassably good at what they do, as good as the laws of physics will allow. According to the article, biophysicists have spotted such systems throughout the living world — in bacteria, in fruit fly embryos, in sharks, in us. Also,”tenets of optimization may even help explain phenomena on a larger scale, like the rubberiness of our reflexes and the basic architecture of our brain.” (Personally, I would be interested in the basic architecture of Bialek’s beard — build some sophisticated mathematical models for that puppy. You’re welcome, Biophysics Student Still Looking For A Thesis.)