Science and engineering, despite their close relationship, differ fundamentally
Science and engineering both relate descriptive models to physical systems, sometimes working with similar descriptive models and similar physical systems. Moreover, science and engineering are, in practice, often intermixed, and popular usage often attributes to scientists the accomplishments of engineers (there are many rocket engineers, but no rocket scientists). Nonetheless, science and engineering differ radically in their fundamental nature. Understanding this difference is essential if one is to form a clear understanding of the relationship between present knowledge and future technological possibilities, whether in molecular systems engineering or elsewhere.
How do science and engineering differ? In a sense, they point in opposite directions: Science starts with a physical system and seeks to develop a descriptive model a scientific theory. Engineering starts with a descriptive model an engineering design and seeks to develop a physical system. In this, they are opposites, and from this flow deep differences in thought and goals.
Consider how scientists and engineers choose their objectives. A scientist focuses on what is not yet understood, and studies it. An engineer focuses on what is already understood, and builds with it. Scientists seek simple systems that challenge their understanding; engineers seek to build to build systems of challenging complexity using understandable components. Where a scientist may contemplate solid-state physics and seek to unravel the mysteries of correlated electron phenomena, an engineer will use established principles of solid-state physics to describe the behavior of a set of reliable designs for wires, transistors, and capacitors. A scientist may discover phenomena that enable the creation of a new transistor-like device; an engineer may discover how to organize a million transistors into a new information processing system.
The molecular world has been the province of scientists. Their knowledge provides an essential guide, and engineering efforts in the molecular world will raise questions that spur further scientific study. Whether the people doing the work call themselves “scientists” or “engineers” is of little importance. Regardless of labels, progress in molecular systems engineering, like that in other fields of technology, will require an engineering approach.
Science and engineering contrasted:
Drexler, K. E. (1992) Nanosystems: Molecular Machinery, Manufacturing, and Computation. Wiley/Interscience, pp.493-4.