I agree with this impression. I often reflect on our times and wonder why there seems to be such a stark difference. Why do we lack such figures, pushing the boundaries in the same impressive way? Is it that not enough time has passed to fully realize the impact of the discoveries and works of our time, like there has been for the work of the early 1900's? Have the problems gotten harder that we are bumping up against a kind of soft boundary that's preventing the seemingly frequent revolutionary breakthroughs? Or is it a matter separate from the practice of science or art; a phenomenon of culture that is impacting the our capacity to discover? I think it's an interesting question to mull over.