Late last year, the Northwestern social scientist Robert Gordon penned a provocative op-ed in the Wall Street Journal that touched on the very issues we cover here at Change Reaction, especially now, during National Geographic’s 125th anniversary year of exploration. His thesis was simple: In a world that has already invented ways to regulate indoor temperature, grow food on large scale and transport ourselves across large distances, what’s left to innovate? We’ve already gotten all the low-hanging fruit, so the innovations of the next few decades will be incremental, rather than game changing.

Gordon makes some sense. No one can invent the light bulb again. We can’t re-figure out how to produce electricity. But it’s not hard to see comparisons