Lithium hydride
Before the Castle Bravo nuclear weapons test in 1954, it was thought that only the less common isotope lithium-6 would breed tritium when struck with fast neutrons. The Castle Bravo test showed (accidentally) that the more plentiful lithium-7 also does so under extreme conditions, albeit by an endothermic reaction.
Bravo (software)
Bravo was the first WYSIWYG document preparation program. It provided multi-font capability using the bitmap displays on the Xerox Alto personal computer. It was produced at Xerox PARC by Butler Lampson, Charles Simonyi and colleagues in 1974.