But Christopher Bidmead is perhaps the most rewarding single Twitter feed among my Doctor Who list. Bidmead is a science writer who was the script editor of the show in its 18th season (succeeding Douglas Adams, the toughest act to follow). He only held the post for that single year, but there was no other year like it in the entire history of Doctor Who. The stories produced in his short tenure skillfully combined thoughtfulness with suspense, adventure with science and philosophy, and some impressively weird imagery.
Saturday morning, Bidmead shared this video, which I thought I would share, even at risk of its being a too-long-didn't-watch at a length of an hour.
It's a lecture by physicist Jeremy England about how to define life according to the terms of physics. It was quite fortuitous for me that Bidmead would link this video after I just wrapped up the most sustained philosophical argument on my own blog. I was quite honoured that SK, one of the regular semi-troll commenters on Phil Sandifer's website visited my old post about the Star Trek episode "The Measure of a Man" from this May after Vaka Rangi linked to it in his discussion of that story.
The Star Trek episode is a cheekily over-dramatized trial, where Starfleet must decide whether Data has any rights, or if, as a machine, he is the institution's property. SK kept hammering me on the old point in philosophy of mind, that because Data is a machine, his entire person is a series of mechanical movements and reactions. And because he is determined entirely by physical causes, he does not truly think and express those thoughts, only precisely reproduce exactly what a creature (who is not a machine, so not subject to strict physical determinism) would say.
This juvenile way of thinking about physics and physical determinism is one of the central reasons why philosophy of mind doesn't get that much respect anymore in the scientific community. The conception of physical determinism as strictly linear A-causes-B-causes-C hasn't held much water in the physics community at least since James Clerk Maxwell. The development of the dynamic branches of physics and their cascading effects on the fundamental concepts of every other science is either forgotten or unknown in the general population, who still think of determinism after the fashion of Isaac Newton and David Hume's billiard ball analogy.
Throughout my time as a university-based philosopher, I regularly interacted with people WITH PHDS who said the scientific concept of emergence was nonsense, or who seriously described in professional contexts the neurological activity that constituted personality as "the mind stuff that brains do." My colleague in Texas, Levi Bryant, still regularly vents his frustrations on Facebook about a trend in philosophy to revive old-school vitalist biology, whose key postulate was that there had to be a fundamental force of nature, vitality, that animated organic bodies to be exemptions from the universe's strictly deterministic causality.
All that said, it is very difficult to use the fundamental concepts of physics to understand life. In their mathematical descriptions, all physical processes are fundamentally reversible. Yet living processes never flow in reverse. England's talk discusses how entropy, one of the fundamental concepts of Maxwell's thermodynamics (the revolutionary field that ultimately crushed the Newtonian model of linear causality) can be used to define what life is.
Living bodies, described in the terms of physics, are bodies whose internal processes tend to maximize the efficiency of entropy production.
Of course, the meaning of life as a whole goes far beyond the principle. Reductionism is a stupid way to think as well. But if you're wondering what physical principle might be held in common between me, you, a tree, a lichen, an ant, a trilobite, a paramecium, a plankton, a bivalve, and a herpes virus, entropy efficiency maximization is a pretty reasonable notion.