Andrew Sullivan deserves a lot of credit for posting dissenting views from readers on his blog. But sometimes he’d be better off not bothering. After posting a silly quote about complexity and the second law of thermodynamics, he posted a dissent from a reader that, remarkably, manages to be even sillier.
Among other things, the dissenter says that “more complex systems are more efficient in their use of energy.” It’s not even clear that that clause even means anything: “more efficient” at achieving what goal? In what sense is a cow “more efficient” than a bacterium?
There is also no sense in which “increasing complexity is built into the fabric of the universe.” Some patches of the Universe (e.g., our neighborhood) are quite complex, but the overwhelming majority is simple and boring.
Finally, the dissenter quotes Einstein as saying “The most important decision we make is whether we believe we live in a friendly or hostile universe.” To an excellent approximation, all quotations attributed to Einstein are apocryphal. If the quote sounds spiritual and woo-woo, while not actually meaning anything, the probability rises to virtually 100%. In this particular case, the earliest printed source seems to be The Complete Idiot’s Guide to Spiritual Healing (2000). Enough said.
I don’t think there’s any problem measuring the efficiency of a thermodynamic process. Depending on the situation, it might be more useful to consider the first law efficiency or the second law efficiency, but those are about the only options. However, evaluating complexity quantitatively is a much trickier problem. It should be related to the information required to specify a system, but that’s not any easy thing to quantify in practice.
Efficiency is defined to be (amount of output) / (energy input). The efficiency of an engine is well-defined, because we know what the output of an engine is supposed to be (work). For other systems, until you specify what’s supposed to be in the numerator of the fraction, the term is meaningless.
If you disagree, tell me this. What’s the efficiency of a cow?
That reminds me of a koan.
A monk asked, “What’s the efficiency of a cow?”
The master said, “Mu!”
“To an excellent approximation, all quotations attributed to Einstein are apocryphal. “
“The trouble with quotes on the internet is that it is hard to verify their sources.” —Abraham Lincoln
I’d add that it’s also a good approximation to say that an argument in the popular press using he Second Law as its basis is wrong. Entropy is a slippery concept, partly because it sounds so simple.