“Staring into the Singularity”, version 1.2.1 (updated 31 August 2000), says that the most that can be said about 2035 is that it seems a reasonable upper bound for the Singularity at the current rate of progress, and gives the lower bound as thirty seconds.

One recorded claim. The claim panel gives its qualification, the source passages with their place in each source, and how it was checked.