tl;dr We haven't had any deep conceptual revolutions nor massive new sources of cheap energy for a while Estimating how much innovation to expect depends on ho

tl;dr We haven't had any deep conceptual revolutions nor massive new sources of cheap energy for a while Estimating how much innovation to expect depends on how you set the baseline. There are a couple of reasons for considering the first half of the twentieth century to have been the most revolutionary period in history both theoretically and technologically (not unrelated areas) at the same time as harnessing vast reserves of hydrocarbons to give us millions of years of stored sunlight to burn as fast as we can build machines to consume it. Theoretical revolutions involved working out consequences of Electromagnetism, Einstein and Quantum mechanics, and of course computation powering the calculations. Electrification, real-time long-distance communication, cars, trucks and planes... We were riding out the consequences of the easiest applications of these novelties and now it's getting incrementally harder to squeeze out the benefits.