Among the many accolades bestowed upon it, the highest praise given to the Serial podcast was that it made people who had never heard of podcasting fiddle with iTunes or (gasp!) Stitcher for the first time in order to listen to the show. Although becoming a subject of parody on Saturday Night Live is another strong indicator of popularity…
I’m very interested in these “killer app” instances, because just because something can be done doesn’t always mean that it should. This represents something of a philosophical divide between different branches of science. When discussing differences between mathematicians and physicists, Richard Feynman explains that while physicists use math (alot), the equations always have to be “for something.” He mentions the joke that when the physicist asks for the solution to a set of equations in 3 dimensions (what non-scientists would call “the real world”), the mathematician replies “well, first solve them for n dimensions, and then let n = 3.” Mathematicians are usually dismissive of such utilitarian attitudes, which is why they became mathematicians in the first place.
In contrast, most physicists (like me!) usually act like shameless magpies, stealing shiny bits of math whenever we need to build out theoretical nests, while leaving most of the rigor behind.
But it turns out that the universe is elegant and contains deep symmetries that can only be adequately described by math. So, in a real sense, the Universe is the Killer App of Mathematics.