It's Newton's Fault

Observations in light of recent reading and listening.

  1. Economics and Reality, Tony Lawson, 1997.
  2. Stuff Matters: Exploring The Marvelous Materials That Shape Our Man-Made World by Mark Miodownik 
  3. An interview with Steven Weinberg on from the Science Weekly Podcast published by The Guardian newspaper about the history of science.


Listening to physicist Steven Weinberg talk about the history of science leads one to be slightly more forgiving of the economics academy. My current thesis in their regard is that economics is stuck in the bottom of a coal pit because the field is consciously an attempt to develop a Newtonian study of markets. The problem is that Newton, and indeed all of physics, are actually kind of an odd bird in the world of science. As Tony Lawson points out, physics is rather unique in presenting a world that can be understood as repeatable instances of cause and effect. Billiard ball A bounces off of ball B in the same way, again and again and again. But no science of living things, and especially no science of human beings, ever gets this nice and clean constant conjunction of cause and effect.

Take evolution: where does one look for cause and effect? The problem is that the time scale is all wrong for observations of this kind. In evolutionary science, both causes and effects are things that take shape over tens of thousands of years. There's no image of Darwin dropping two different species off the Leaning Tower of Pisa (ala my mental image of Galileo, demonstrating that the weight of an object does not change the acceleration of gravity, which is constant) to demonstrate that the same forces that created chickens also created cockroaches.

But note the very first entry on this blog. Evolution is the way smart people understand the world. Why? Because physics is next to useless when it comes to everyday life. Einstein gave us GPS and atomic bombs. You can have em. I'll take Pastuer and Lister over Einstein and Teller every single time. Living is better than dying, duh, and so biology is much more relevant to our daily lives than physics.

But the real point is that human social existence is not like a bunch of billiard balls bouncing in predictable ways. The life of a human navigating through society is much more like ecology or evolution, where you'll never know all the variables necessary to make precise predictions of cause and effect and yet at the same time you need to understand what is happening or you'll die.

So why does the podcast make me more sympathetic to economists? Because Steven Weinberg demonstrates that for physicists, the only science there is is physics. The man managed to get through a 20 minute interview on the history of science mentioning Newton approximately 50 times, but Charles Darwin never comes up. How do you do that? But the fascinating thing Weinberg points out is that Plato did science wrong by believing that you had to reason from the purpose or nature of things to understand the way they behave. It's a lot like the idea of efficient markets, where somehow the purpose of markets causes their behavior.

But here's the most important thing: we still can't make steel any better than the samurai in Japan were making 500 years ago, even though we only began to understand the physics and chemistry of steel in the late 1800s. We went from the Stone Age to the Iron Age without even the tiniest bit of scientific understanding of metallurgy. And that's the thing that should blow every economist's mind to smithereens. Because the entire field is predicated on the notion that you develop a theory and then try to match it to the data, in that order. If you want to understand planetary orbits, maybe that's a good way to go. But if you want to understand people's behavior, it is the most backasswards nonsense that you can imagine. It's just not how we interact with the world.

The above doesn't all hang together exactly, but it's close. I have a feeling Marx was very influenced by Newtonian mechanics in his view of the world. If so, that would explain why liberals and conservatives both get confused in the same way into believing that financial incentives guide a significant amount of human behavior. That would be nice and Newtonian. But it's wrong.