Description: It can be so frustrating to put great effort into something, and then to have your work and achievements called into question. I can't begin to imagine how frustrated Samuel Pierpont Langley was in 1903. By that time, he had spent over forty years studying astrophysics and aerodynamics. His work on astronomically-derived time measurement in the late 1860's is the heart of the
Showing results 5473 - 5484 of 6064 for National Zoo: Think Tank (Video recording : 1995)