Patrick Collison and Michael Nielsen in The Atlantic:
It’s surprisingly difficult to measure scientific progress in meaningful ways. Part of the trouble is that it’s hard to accurately evaluate how important any given scientific discovery is.
Consider the early experiments on what we now call electricity. Many of these experiments seemed strange at the time. In one such experiment, scientists noticed that after rubbing amber on a cat’s fur, the amber would mysteriously attract objects such as feathers, for no apparent reason. In another experiment, a scientist noticed that a frog’s leg would unexpectedly twitch when touched by a metal scalpel.
Even to the scientists doing these experiments, it wasn’t obvious whether they were unimportant curiosities or a path to something deeper. Today, with the benefit of more than a century of hindsight, they look like epochal experiments, early hints of a new fundamental force of nature.