Fun story: the Hydrogen Fuel Cell. Yesterday's miracle battery of tomorrow that never quite happened, right? Well, the big picture story is a bit different. It

Fun story: the Hydrogen Fuel Cell. Yesterday's miracle battery of tomorrow that never quite happened, right? Well, the big picture story is a bit different. It was invented shortly before the lead acid battery and US civil war. It accumulated a few refinements and fewer practical uses over the years, until the Apollo era when there was a huge breakthrough (polymer electrolyte membranes). Then it went back to slowly accumulating incremental advancements, and that's still the story today. Exploitation is exponential (the scale of each success determines the resources people are willing to bet on the next win), but exploration is a punctuated equilibrium, and it's a recipe for disappointment to assume that all progress should behave like the former rather than the latter.