The history of technology is littered with great ideas, but you've got a make a distinction between the ones that are truly, timelessly great, and the ones that, well, seemed good at the time.
It's usually heartening to see a great mind recognize an error in judgment, or a personal accomplishment gone awry—that's humility, and we love it in our heroes. Sometimes, though, it's just depressing. Anyhoo! Here are eight inventors, technologians and scientists who've come to terms with what they've wrought. Or who've at least tried.