An essay published on the web in 2001 by an inventor with a real record behind him — optical character recognition, print-to-speech for blind readers, music synthesis. It is mostly charts.

We won’t experience 100 years of progress in the 21st century — it will be more like 20,000 years of progress (at today’s rate).

Ray Kurzweil, “The Law of Accelerating Returns”, 2001

The procedure is fixed and is stated openly. Take a capability. Find the best machine of each era that had it. Plot cost-performance against year, with the vertical axis logarithmic. Draw a line through the points.

On a logarithmic axis a straight line means a doubling at a constant interval, and a great many things that grow at all can be made to sit near one. The points are record-holders, so the failures and the ordinary machines of every era are not on the chart. The capability is not quite the same capability across a century of it. None of this is hidden — the axis is labelled, the sources are given, the selection is described.

The line is then extended to the right.

The chart is a record of what happened. The part past the present is a different kind of object, drawn in the same ink.