Chapter 8 is titled Accidents waiting to Happen and I guess that's one way to think about things and I understand the importance Petroski places on failure in advancing technology. I also can understand the attention these failures get in the media. It's like having a car crash occur on your front lawn. You're horrified by the injuries and deaths, but also exceedingly curious about how it happened. What failed? What went wrong? We see this not only when we examine mechanical failures, but also failure in our own human nature. We can't help but wonder what went wrong when a young man goes into a movie theater and opens fire on the audience. What went wrong? Where was the weak link? Can we learn something about ourselves or our society from this?
Sally Rides recent death made me think of the Space Shuttle Challenger disaster in 1986. I was watching it at school on TV with a group of elementary children. In those days, it was still an amazing and unique event when a space shuttle took off. What's amazing to me is that there weren't more problems. After a while, space flight became routine. But think of the level of engineering involved in that project! They must have built with massive redundancy to compensate for so many potential failures. We've been talking a lot about communication and it's importance in engineering. There must have been large numbers of teams working on all different aspects of the space shuttle. Does it make sense that the larger the project, the more people working on it, the more chance there is for error or oversight?
What impresses me is all the engineering in our daily lives that doesn't fail. I guess that would be one thing that I would like to pass on to my students...all those things we take for granted that make our lives easier or more enjoyable...and all the unnamed people responsible for them.
If you want to get an idea of the level of detail involved in designing something for space, watch the Nova show online about the repair of the Hubble space telescope. The amount of tightening force (torque) applied to each and every screw in the telescope was specified and measured during its assembly! Having that information available during the repair made the repair possible!
ReplyDeleteIn Second Grade, over the last few years, using the Smartboard, I have included in several math/science lessons, short you tube videos of photos taken from the Hubble telescope, magnificent classical music plays in the background, and the distance of each shot is noted in numbers of light years away. The children have been (including me) awestruck,quite impressed. At this time I also relate, initially it was difficult to see dark objects clearly from the Hubble Telescope,ideas as to why are shared, and I am able to demonstrate the importance of accuracy,(acknowledging we can never be completely accurate)The error causing the blurring was within the lens, off by a measurement of 1/100th of a mm or 1/50 of a human hair. There are several videos on You Tube applicable to the elementary level,search Hubble Telescope.
ReplyDeleteAs I have been reading this book, I have been thinking about when I took genetics. I was awed and amazed, given all of the opportunities for failure at the cellular level, that the normal human body actually usually works, and rather well at that. Reading about the amazing complexity of engineering reminds me of this. All of the pieces that must be in place for a design not to fail seems overwhelming.
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