Physical scientists have, for generations, pondered whether it is possible to create a perpetual motion machine—something which keeps moving without any net input of energy. The generally accepted consensus is that it is not (unless you consider the universe, to which that description applies fairly aptly). Nevertheless, a strong pursuit of engineers and thinkers alike has been to produce gizmos which keep going under their own power, which feed off of their own energy to keep doing whatever it is that they do.
If this sounds a bit abstract, consider a jet engine. The concept is surprisingly simple—exploding gas and air shoots out the back of the thing, pushing it forward. As it does so, it turns a fan at the back of the engine which is attached to a similar—but larger—fan at the front of the engine. This larger fan sucks air in, and the process repeats. As long as the engine is turning, the engine will keep turning. The egress of gasses out the back can only take place in such a way that more air is pulled in the front, and the pulling-in of more air results in the explosive expelling out the back which causes the process to work in the first place. It’s not a perpetual-motion machine, of course—without fuel, it would stop. But it is about as close as we’ve gotten. That is to say, it is autocatalytic (AW’toe’cat’uh’lit’ik).
Something is autocatalytic if it involves a process or reaction one of the products or results of which is the catalyst for the process or reaction in the first place. In other words, because the expulsion of gasses out the back of a jet engine results in more gas being drawn in—because one product of the operation is the first stage in repeating the operation—it is autocatalytic.
If this still feels a little far-fetched to be considered “awesome”, note that in societies, autocatalysis is ubiquitous. Any self-sustaining cycle which gets worse (or better) as it feeds off its own energy can be said to be autocatalytic. It is this “chain reaction” that leads to depressions, market booms, and population swings. If people are starving, they are too weak to work. If they are too weak to work, they cannot farm. If they cannot farm, there will be no food. If there is no food, people will starve. Conversely, if people are healthy, they will farm abundantly. If food is abundant, people will eat heartily. If people eat heartily, they will have energy and continue farming and making more people who, in turn, will also farm. Either of these operations is autocatalytic.
The problem with autocatalytic processes is that, because they produce the very conditions they need to operate, they can form cycles which are very difficult to break. Consider the economic downturn which began several years ago and how painfully slow recovery from that recession has been. As people’s investments and savings evaporated, they had less money to spend to get the economy rolling again. Job markets and housing stagnated. With stagnant job and housing markets, money was not invested and people didn’t work. Without the growth of investments and without jobs, there has been little movement capable of restarting the job or housing markets. As a result, people continue to be unemployed and vacant properties continue to sit undeveloped. Developers can’t build new homes because prospective homeowners don’t have the wealth to afford them. Prospective homeowners can’t obtain the wealth to afford new homes because of high unemployment, and they can’t find employment because—among other things, and for the sake of example—no one is building homes.
Notice, however, that just because a process is autocatalytic, it is not of the same magnitude from one moment to the next. In the case of the starving population, eventually enough people would die off that the few remaining would have enough food (or the entire civilization would vanish). In the case of the jet engine, the cycle will continue only so long as fuel is present. In the case of the economy, savvy investors will eventually start building and investing, and their projects and investments will require workers, and the workers will require pay, and so the cycle will spiral back upwards.
There are many other examples. In France, nuclear physicists have determined that the only way to build a fusion power plant is to develop an autocatalytic cycle in a gigantic torus. The operation involves smashing heavy hydrogen isotopes together. When they hit, they release energy, but they also release radiation which, in turn, is used to turn other, “normal” hydrogen atoms into the heavy isotopes needed to run the operation in the first place. In this manner, they’ve done something which, for decades, has been seen as impossible, and are presently building the world’s first nuclear fusion power station.
Although you are not likely to use “autocatalytic” in daily conversation, it is a concept of self-sustaining systems which underlies the most efficient machines and does a pretty good job of describing the largest, most complex scales of human interaction.
— Mark Jacobs, Prose Editor
Editor’s Note: This post was written by Mark Jacobs. Mark is the Jet Fuel Review’s prose editor. He is an Aviation major, but the left side of his brain is an avid writer. Mark is a junior and works a few hours a week as a tutor in the Writing Center.