While I’m on the subject of foundational concepts in the relationship between science and engineering, here’s the outline of a methodology for applying current science to assess lower bounds on the capabilities of a select subset of future technologies. (As many of you know, some of those lower bounds are startlingly high.)
A subset of the potential capabilities of future levels of technology can be understood by means of a design process that can be described as exploratory engineering. This process resembles the first phase of standard design engineering (termed conceptual engineering, or conceptual design), but it serves a different purpose:
- In standard engineering, design leads to the manufacturing of a product.
- In exploratory engineering, design leads to understanding of what a future manufacturing process could produce.
Because of this difference in objective (products vs. knowledge) conceptual engineering and exploratory engineering have both similarities and differences:
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Conceptual engineering |
Exploratory engineering |
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Objective |
Create and evaluate system-level designs (typically parameterized) |
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Enabling technology |
Current fabrication technologies |
Prospective fabrication technologies |
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Process of analysis |
Specify a system-level design, describe the necessary subsystems and components, calculate their required performance parameters |
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Basis of design calculations |
Known performance of specific classes of existing materials and components |
Physics-based, lower-bound estimates of the performance of specific classes of potential materials and components |
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Results |
Estimates of the performance of fully refined, system-level designs |
Lower-bound estimates of the performance of fully refined, system-level designs |
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Production and performance |
Product is intended to be manufacturable in the near future and competitive with well-designed products based on the same technologies |
Product is not intended to be manufacturable in the near future, and need not be competitive with well-designed products based on the same technologies |
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Implications for design criteria |
Seek to maximize performance and minimize cost of production, while ensuring that the product will be reliable |
Seek to minimize the cost of design and analysis, while ensuring that lower-bound estimates of performance will be reliable |
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Implications for design choices |
Seek efficient designs with adequate but not excessive design margins, aiming to produce a good estimate of the expected performance of a detailed, fully optimized version of that design. |
Seek simple designs with generous design margins, aiming to produce a reliable estimate of the minimal performance of a detailed, fully optimized version of design of the same general kind. |
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Results of the design process |
A system-level design concept, intended to guide decisions regarding engineering and production |
Estimates of the capabilities of the potential products of future fabrication technologies, intended to guide evaluation of research and policy options |
In the early 20th century, a missing fabrication technology was the combination of engineering expertise and metalworking techniques (among others) that were required to build large aerospace vehicles. The physics of rocket propulsion, however, were well understood, and the strength and weight of large, well-made aluminum structures could be estimated with reasonable accuracy.
On the basis of exploratory engineering applied to this kind of knowledge, engineers who studied the matter were confident that orbital flight could be achieved by means of multistage chemically fueled rockets. By the 1940s, a study by the British Interplanetary Society had filled in considerable detail and given a good estimate of the size of a vehicle that could reach the Moon.
Those who hadn’t studied the matter were sometimes confident of the opposite.
Astronomers who knew the daunting speed of orbiting objects (but didn’t trouble to examine the exploratory engineering analysis) sometimes called spaceflight absurd. In a characteristic move, a Professor of Physics and Chemistry, one A. W. Bickerton, demonstrated the impossibility of something irrelevant, then generalized it: He did a silly calculation that implicitly assumed that a rocket must put its fuel into orbit (and a bad fuel, at that), then announced that spaceflight was simply impossible.
Reasoning from the unworkability of a bad idea to the impossibility of a well-researched engineering concept is a repeated theme of interactions at the interface between science and engineering. (Engineers ignoring a crucial scientific fact is, of course, another.)
Here’s an entertaining list of quotations from the history and prehistory of flight, and spaceflight.
See also:
- The Physical Basis of High-Throughput Atomically Precise Manufacturing
- How to Learn About Everything
- How to Understand Everything (and Why)
- A Map of Science
- The Antiparallel Structures of Science and Engineering
- Science and Engineering: A Layer-Cake of Inquiry and Design
- A Telescope Aimed at the Future
{ 2 comments… read them below or add one }
Would you consider “Heteroaromatic Rings of the Future” (William R. Pitt*, David M. Parry†, Benjamin G. Perry‡ and Colin R. Groom, J. Med. Chem., 2009, 52 (9), pp 2952–2963
DOI: 10.1021/jm801513z) to be exploratory engineering? They aren’t specifying the fabrication technology in detail, but do select a large subset of the skeletons as synthetically tractable. In the application to medicinal chemistry, simply increasing the number of viable alternatives is a help, so in
that sense they are improving a lower bound on performance.
Yes, of a sort — but a rather unusual sort.
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