We are fast approaching a new dark age, says Jonathan Huebner, a physicist working at the Pentagon’s Naval Air Warfare Center.

He says the rate of technological innovation reached a peak a century ago and has been declining ever since.

He plotted major innovations and scientific advances over time compared to world population, using the 7200 key innovations listed in a recently published book, The History of Science and Technology, and found they peaked in 1873 and have been declining ever since. Likewise, the number of US patents granted per decade divided by the country’s population peaked in 1915.

“We are approaching the ‘dark ages point’, when the rate of innovation is the same as it was during the Dark Ages,” Huebner says. “We’ll reach that in 2024.”

But artificial intelligence expert Ray Kurzweil thinks Huebner has got it all wrong. “He uses an arbitrary list of about 7000 events that have no basis as a measure of innovation. If one uses arbitrary measures, the results will not be meaningful.”

Nanotechnologist Eric Drexler agrees. “A more direct and detailed way to quantify technology history is to track various capabilities, such as speed of transport, data-channel bandwidth, cost of computation,” he says. “Some have followed exponential trends, some have not.”