Physics for the 21st Century This course covers a broad scale, from sub-atomic particle physics, through atomic and molecular physics, to cosmology. The video programs feature 22 case studies of researchers from leading research labs and universities who are breaking new ground in their fields.
Which Famous Cathedral Collapsed?
Four of the grandest medieval cathedrals are shown -
one of which was not structurally sound and collapsed.
After looking at the photos try to select which cathedral
fell and see if you can determine, from the picture, why
it might have happened.