Hmm, how about the acceleration of technological advances?
Let's take an example . . . in the 18th century, firearms were muzzle-loaded, and had been for a few centuries. Cartridge loaded firearms did not come about until the end of the Civil War. The pace of most technological innovation in the past was similar to that, very slow to come about.
Now, think about the early 1900s . . . and compare them today. The changes in the same period of time are astounding, and they show no sign of slowing down. Think of all the innovations that have come about in the last 80 years - automobiles, airplanes, the jet aircraft, radios, computers, nuclear power.