Monday, June 3, 2013

Engineering is not science

Unfortunately, many people do not make a distinction between science and engineering -- including many scientists and engineers. The terms have become loosely synonymous with some notion of rationality. As a result, people look at giant industrial engineering projects and say "science!", when they should know better.

Science is a particular kind of pursuit of a particular kind of knowledge. Not many people stop to think what this might mean -- I encourage the reader to do so now.

"The pursuit of knowledge" in science's case comes with some burdens. The pursued knowledge is about nature, in a simple, revealing, principled and fundamental sense. This is the goal of "theory". It is in contrast to, or complement with, "the details". Of course, details inspire the pursuit of scientific questions, but "knowing details" is not the kind of knowledge science pursues. Certain details are pursued, surely, as part of the process of asking questions which can lead to both significant experiments and better theories. Scientific knowledge, or a theory (always tentatively held) usually comes in the form of some typically non-intuitive, interesting principle, or model, one that has held up pretty well (or at least better than others) during prediction, observation and experiment, and which offers insight into how the world works: the world outside our senses and intuitions. Examples of scientific insights that have no attached equations (i.e. models): 
  • "the air" is not empty, but is instead full of all kinds of stuff
  • gravity is a property of all 'matter'
  • there is no "matter & energy"... just energy
  • we have no contact-mechanical explanation for gravity
  • etc.
Engineering, by contrast, is "building something" for "some purpose". Now, a lot of engineering is done to help in the pursuit of science. And a lot of engineering is only possible because of scientific results. But they are not the same thing.

A nice example came up, in conversation the other day with a chemical engineer ... when he needs to achieve some result, and one potential chemical reaction doesn't do the trick, he can't stop and ask "what's going on here"? Because that would be science. He has a job to do, so he just tries another process, and another, until the results are achieved. That's engineering.

Some confusion may arise because both are highly technical human activities, and so, from almost any perspective, they have more in common than in distinction. For example, there are two processes that are common to both science (uncovering nature) and engineering (getting stuff done):
  • trial-and-error
  • incremental-improvement
But, again, these are common to all human activity, probably all animal activity, and perhaps all of natural law ... a drop of water finding the optimal path down a slope is doing both of these things. These processes are part of nature, not just part of science and engineering. Humans have some faculties that seem to help us 'perform' these processes ... and some faculties that seem to hinder such performance (tendencies towards dogma, for example). But no matter how smooth our workflow (something we often try to improve, through trial-and-error) we cannot stop ourselves from using trial-and-error and incremental-improvement, whether we are trying to build something, or trying to understand nature.

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