Life Week: Delaying Decay

If there is one fact to rule them all in the Universe, it is that entropy always increases. Hot things cool down, energy disperses, and order turns to disorder. The increase of entropy of the Universe is so unyielding that it is often called "the arrow of time."

Though only scientists typically couch it in these terms, part of why life seems so perplexing is that it seems to defy the law of increasing entropy. While most things crumble and cool toward a state of equilibrium, life grows evermore complex and organized. The great physicist Erwin Schrödinger wrote: “It is by avoiding the rapid decay into the inert state of ‘equilibrium’ that an organism appears so enigmatic. How does the organism avoid decay?"

Either life is some magical, mystical phenomenon that defies the laws of nature, or it isn't. Schrödinger and several other physicists proved the latter.

Living things are like highly inefficient engines. We ingest energy in order to move and grow, only to disperse most of it back to the environment as heat or waste of a severely broken down form. In other words, our metabolism works to keep our own entropy low, but in so doing, it accelerates the increase of entropy of the environment.

With our tables laid at the top of the food chain, humans consume low-entropy beings like animals and plants. We break down their structure and use the freed energy to build structure of our own. This keeps our entropy low, but since so much of the material that we break down is wasted and expelled, entropy increases overall in the Universe.

At the bottom of the food chain, plants feed on sunlight by way of photosynthesis. Several decades ago a couple of physicists ventured into the realm of biology to show that photosynthesis is an entropy-creating process: plants only use about 10% of the energy they absorb. The rest is re-emitted in a diluted, lower-frequency form (which has much higher entropy than the original light). Plants, animals, and all forms of life maintain structure and complexity by removing it from the world around us.

Organisms cannot halt the arrow of time forever, though. Our metabolic processes gradually become less effective at sustaining our low-entropy state. Eventually we cannot delay decay any longer, and that is when we die.