The Engineering Method Lecture 3. What is an Engineer? An Engineer is not defined by her product...
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Transcript of The Engineering Method Lecture 3. What is an Engineer? An Engineer is not defined by her product...
What is an Engineer?
• An Engineer is not defined by her product– Nano-robots– Airplanes– Embedded Computers
• An engineer is defined by her method– Finding the best change– Using available resources– In an environment of uncertainty
“To Engineer”
• The clergy in Iran engineered the firing of the president.
• The chessmaster engineered a perfect countermove.
• The general engineered a coup d'état without the loss of life.
Why is Engineering Such a Mystery?
• The Scientific Method– Well-understood, even by the layperson.– “Science is theory corrected by experiment.”– All variables held constant except one.– “Answer in the back of the book.”
• Extensively analyzed by philosophers
Why is Engineering Such a Mystery?
• The Engineering Method– Little significant research into the
philosophical foundations of engineering.– Can you name an engineer who is wise, well-
known, well-read, and scholarly in their role as an engineer?
• Contrast with law, economics, medicine, politics, religion, and science– Can you name a public spokesperson in any
of these fields?
Why is Engineering Such a Mystery?
• Few high school students take engineering courses
• Liberal arts students are not required to study technology– What about vice versa? Especially here?
Four Key Elements of Engineering Problems:
• Change: the situation requires a change.
• Best: the best change is desired...
• Resources: using the available resources.
• Uncertainty: knowledge about the situation is incomplete and sometimes inconsistent
Change
• Four practical difficulties in getting from A to B:– Engineer lacks complete knowledge of the
world at A– The exact final state, B, is unknown and
cannot be anticipated– There is no single path from A to B– Engineering goals can change during the
process (the location of B drifts!)
Change
• Is all change caused by engineers good?
– What about unintended consequences?• Aswan High Dam in Egypt• Can you name any others?
– Can you think of any engineering disasters?• Tacoma Narrows Bridge• Kansas City Hyatt Regency• Chernobyl Nuclear Power Plant in U.S.S.R.
Unforeseen Consequences
• Increased salinity of the Nile by 10%– Led to collapse of sardine industry
• Caused Coastal Erosion
• Displaced 100,000 Nubians– Drastically altering their way of life
• BUT provides ½ of Egypt’s electrical needs
Available Resources
• Tangible Resources– Money available for project– Time to complete project– Raw materials like steel, concrete, silicon– Computer resources– Number and education of engineers
• Intangible Resources– Past experience with similar projects– Engineer’s interests, passions, etc.
Time as a Resource
• Problem: estimate number of ping-pong balls that can fill the room in– 60 seconds
– 2 days
– Unlimited time
• Each time limit defines a new engineering problem because the time resource is different
• Each solution would be correct from an engineering point of view because it was done within the time constraints imposed.
Best
• Best for whom?– Westerners are conditioned to accept Plato’s
notion of the Ideal– A new concept of “best”
• Optimization theory– The Optimum compromise– Apollo Program
• Leapfrog learning• Political vs. Economic tradeoffs
Television Example: Best
Consider a television with only one knob:Increased knob setting results in sharper picture,Increased knob setting also results in worse sound.
Television Example: Best
With Picture is half as important as Sound (for a person with hearing problems)
Uncertainty
• Engineers are asked to find a solution to a problem while lacking complete information
• In Change: both the starting and ending points (A & B) are not fully known
• Resources: intangible resources cannot be quantified, yet they affect the outcome
• Best: the best design is not always clear, best for whom?