I like the story of the physicist, Lord Kelvin, arguing that the Sun could not have been around long enough for Darwin's evolution to have occurred on the Earth. It turned out Darwin was right.
http://www.csicop.org/sb/show/darwin..._age_of_earth/
"This story should be more widely told in textbooks and other science literature because it is a great example of good science in action. Here we have a revolutionary new idea clashing with older knowledge at several levels and requiring another dramatic discovery in a seemingly unrelated field in order to survive. When the new idea does survive, as happened with evolution, we gain additional confidence that science truly relates to an objective reality that is really out there."