Nobel Prize-winning physicist Charles Townes was single-minded about a lot of things, colleagues say. And also a very nice guy. Julian Wasser/The LIFE Images Collection/Getty hide caption

itoggle caption Julian Wasser/The LIFE Images Collection/Getty

Physics is full of big, interesting questions about phenomenon such as black holes. This illustration shows the supermassive black hole at the heart of the active galaxy NGC 3783 in the southern constellation of Centaurus. M. Kornmesser/ESO hide caption

itoggle caption M. Kornmesser/ESO

This artist's impression shows the surroundings of the supermassive black hole at the heart of the active galaxy NGC 3783 in the southern constellation of Centaurus. M. Kornmesser/ESO hide caption

itoggle caption M. Kornmesser/ESO

This artist's illustration shows what NuSTAR should look like in orbit after its 30-foot-long mast deployed. JPL-Caltech/NASA hide caption

itoggle caption JPL-Caltech/NASA