Ray Kurzweil is a technological rock star, responsible for great music synthesisers and much of the developments around optical character recognition and speech recognition. This is what makes him a good futurist. The fact that he has had his hands dirty.
The Age of Spiritual Machines: When Computers Exceed Human Intelligence is a book of two parts. In the first part, Kurzweil outlines how technology has progressed since the dawn of computing with Charles Babbage’ difference engine. Kurzweil uses this trip down computer memory lane to demonstrated that computing power has been increasing exponentially since the dawn of time rather than just the dawn of Intel with Moore’s Law on the doubling of transistors. Even though silicon transistors may top out computing power will keep on trucking (though Kurzweil doesn’t necessarily have the answer of what is the next technology).
The second part of the book is likely future scenarios; and this is where things get interesting. Kurzweil is setting himself up for a FAIL. Bill Gates and Nathan Myhrvold missed the internet in the first edition of The Road Ahead when it was first published in 1995 and Kurzweil sets himself up for a potentially bigger fall in the scope of his book. Even if Kurzweil has his timing a bit wrong or doesn’t get everything right his book is still a great thought experiment in how intelligent computers would impact humanity.