TEC154 2010S, Class 09: Engineering (3)

Overview:
* Review of stuff covered so far.
* Some factual questions.
* Chapter summaries, continued.
* The Petroski lens.
* Discussion questions (if time permits).

Admin:
* Those who did not attend missed a good convocation yesterday.
* We're going to work "in the large", as it were, today.
* EC for any event in next week's Rosenfield symposium on the media.  Tuesday's talk on the impact of the Internet is particularly applicable to this course.
* There are no readings for Monday.
* Have a great weekend!
* Thanks to BD for taking these notes

Where we've been
* What an Engineer does
  * Build things
  * Attempt to improve upon previous designs
  * EVentually fail
* Secondary thesis/points
  * Engineering is a natural human/cultural activity
  * Everything fails eventually
  * Repeated stress leads to failure (in physical things)
  * Cannot predict all uses (trends change)
  * Each new structure solves a new problem
  * We learn more form failure than success
* What an Engineer does, continued
  * Takes risks but check their own work and the work of others
  * Consider not only expected cases but also extremes
  * Each structure is its own hypthesis
  * Engineers learn form experience and scientific method
* Factual questions
  * What is a slide rule
    * A mechanical device that simplifies computation (particularly
      multiplication and division)
  * Why did the Tacoma Narrows bridge designer not stay closer to the
    original design?
    * Hypothesis: Thought he could scucessfully innovate for less cost or etc.
    * Hypothesis: Probably dida not predict wins
    * Hypothesis: Miscalculated the amount of use
    * One clear reason: The amount of use was significantly less, so it
      did not make sense to build a bridge as wide as existing bridges
    * Note: Although it broke, it's clear that it survived a significant
      amount of stress
* Ch. 12 summary
  * Can succeed despite odds
    * Innovative and new terriotry yet it worked
    * You do not necessarily have to learn form failure to build success
    * People need to be innovative and new
      * It can lead to failure but the attempt needs to be  htere
    * Easier to learn form failure
      * When you fail, you get a list of not-to-dos
      * When you succeed, you can't always say why
    * Relates back to first chapter by saying that nothing is absolutely dependable.
    * To make the book a little less depressing
* Petroski lens
  * Look at how it might fail
  * Look at how it might be misued
  * Look at the life expectancy
  * What are the design requirements?
  * What did you sacrifice?
  * What are you willing to risk when it fails?
  * What did designers fail to imagine?