. >> host: we have been talked about the author and educational, trent ray.out her book "the road out: a teacher's odyssey in poor america." >> henry petroski talks about the role of engineers in society. he discusses why some design eventually fail in his book to forget to sign he looked headline to keep failures like 1940 tacoma narrows bridge collapse. the space shuttle challenger explosion in the deepwater rights and oils though. it's about 25 minutes. >> host: you are watching the tv on c-span2. from time to time, we go to universities throughout the country to talk with professors who are authors about their books. today we have on the duke university campus in durham, north carolina. joining us is professor henry petroski. professor petroski, what do you do for a living besides teach it to? what is your background? >> guest: my background is mostly academic. about 20 or 30 years ago i began writing about engineering, increasingly books. since then, that is a principal occupation, lecturing and generally doing a lot of thinking about engineering. >> hos