Tim Urban writes,

The movie Back to the Future came out in 1985, and “the past” took place in 1955. In the movie, when Michael J. Fox went back to 1955, he was caught off-guard by the newness of TVs, the prices of soda, the lack of love for shrill electric guitar, and the variation in slang. It was a different world, yes — but if the movie were made today and the past took place in 1985, the movie could have had much more fun with much bigger differences. The character would be in a time before personal computers, internet, or cell phones — today’s Marty McFly, a teenager born in the late 90s, would be much more out of place in 1985 than the movie’s Marty McFly was in 1955.

This is for the same reason we just discussed — the Law of Accelerating Returns. The average rate of advancement between 1985 and 2015 was higher than the rate between 1955 and 1985 — because the former was a more advanced world — so much more change happened in the most recent 30 years than in the prior 30.

See, Accelerating Returns is a law. A LAW. That’s how we know progress happens faster and faster, because LAWS do that.

Still … the facts are pretty thin on the ground here, aren’t they? And then there’s Urban’s assumption that 1985 was “a time before personal computers,” which suggests that he hasn’t really thought about this. As it happens, around this time in 1985 I was typing on my Macintosh while listening to a recent U2 record and pausing from time to time to find out what Chris Berman has to say about the Super Bowl. So from some points of view nothing has changed in the past three decades.

But let’s not be quite so anecdotal. We could try a thought experiment, in the form of a few questions.

  • Did automobiles change more from 1955 to 1985, or from 1985 to 2015?
  • Did television change more from 1955 to 1985, or from 1985 to 2015?
  • Did household appliances change more from 1955 to 1985, or from 1985 to 2015? (Think for instance about the prevalence of air conditioning.)
  • Did space exploration change more from 1955 to 1985, or from 1985 to 2015?
  • Did military weaponry change more from 1955 to 1985, or from 1985 to 2015?
  • Did cancer treatment change more from 1955 to 1985, or from 1985 to 2015?

If you’re not already a True Believer in Ray Kurzweil’s LAW — or even if you are a true believer but are thoughtful enough to realize that 30 years is a really short period and unlikely to demonstrate evenly-paced and universally-distributed development — questions like these will complicate the Whiggishness of your narrative.