Ray Kurzweil's projections of the future (as I understand them) are based on the assumption of exponential growth ... compounding information ... which is actually happening in many fields. The results are sharp cost declines and expanding innovation.  This growth is often ignored in the early stages when compounding occurs from a very low basis. 

The rate of exponential growth is actually accelerating in some instances as the progress in various fields such as AI, Nano technology, and biology increasingly feed into each other. The consequence will be a "singularity" of explosive expansion in 25 years and a transformation in what it means to be human.