Science and Engineering:
A Layer-Cake of Inquiry and Design

by Eric Drexler on 2009/06/16


Science-intensive engineering

Cassini-Huygens space probe
Engineering-intensive science
(launch to Saturn included)

Inquiry is the essence of science, design is the essence of engineering, and in their pure forms, these activities are utterly different. Scientific inquiry draws observations from the world to reshape the mind; engineering design projects ideas from the mind to reshape the world. One is an eye, the other a hand, afferent and efferent flows of information.

This fundamental anti-parallelism can engender pervasive differences in perception and response, in problem definitions and solutions, and in how institutions are organized. The reasons for the differences are strong. Scientists without direction explore and make unexpected discoveries; engineers without direction flounder and fail to produce expected results. Applying a disciplined, engineering approach to scientific discovery can be stultifying, while applying a scientific approach to the bits and pieces of a system engineering problem can produce fascinating results, year after year, each gift-wrapped in an exciting press release — yet no working product.

Coordination of eyes and hands can be very useful, of course. I find technical progress to be most interesting in areas where scientists are pressing the limits of technology, and where engineers are pressing the limits of knowledge. The results are engineering-intensive science and science-intensive engineering. Some of the most impressive engineering in the world is done by scientists — high-energy particle physicists — who build awesome machines like the Large Hadron Collider. The space scientists who build instruments destined to orbit Saturn, or to fall forever into interstellar space, are of the same breed.

Inquiry and design are seldom separate, so how can it be meaningful to call some activities “science”, and others “engineering”? I think it’s best to look beyond the mixture of inquiry and design in a project, and to consider instead its purpose. If the intended result is knowledge — a better model of what exists in the world and how it works — I think of it as science. If the intended result is a new product, process, or design methodology, I think of it as engineering.

An ambitious project is like a layer cake of science and engineering. What matters most is which layer is on top, because it is the top-level goal that sets the objectives and that determines what kind of organization is necessary to reach them. Is the purpose primarily to explore an area, or is it to build something?

In nanotechnology the cake looks more marbled than layered, and mostly for good reason, but there is something missing. Unlike high-energy particle physics or space science, nanotechnology springs from fields (surface science, materials science, chemistry, biology) that have no tradition of developing conceptual designs for complex systems, debating the knowns, unknowns, costs, benefits, alternative objectives, alternative solutions, and so forth, to eventually converge on objectives that coordinate the work of hundreds or thousands for a decade or more.

Without a tradition of this sort, large opportunities can go unrecognized — and in part because they are large. This will change, but I doubt that the change will be led from within.

In future posts, I’ll say more about under-appreciated aspects of the relationship between science and engineering. Some aspects are abstract, at a more-or-less epistemological level; others are closely related yet very practical, addressing problems of effective communication and planning in corporate R&D labs, where project cost, risk, and delivery time are stake.

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