2045: The Year Man Becomes Immortal

Nice video of Ray Kurzweil talking about all that and Watson(IBM) playing Jeopardy!. http://www.usatoday.com/money/media/2011-02-09-kurzweil09_ST...

All of Kurzweil's predictions are based on extrapolating exponential growth.

That's all very well, but exponential growth in physical systems is usually restricted within limits. In a such a system the negative feedback may also be growing exponentially, which means although initially it may be too small to be noticed, after the growth passes some boundary the negative feedback becomes relevant and the overall growth is no longer exponential.

Unfortunately it's impossible to tell where we are on the growth graph (Although some claim that probability suggests that we are closer to the end. See http://en.wikipedia.org/wiki/Doomsday_argument). Kurzweil makes the assumption we are at the beginning of the growth curve. We could be at the end where the negative feedback is about to overtake and growth will slow.

There will be limits. The speed of light could be a hard limit on computing speed. Or ultimately heat-death could be the hard limit, but there is a limit somewhere. The question is how close are we to the limit and that is something we are only likely to know when we reach it.

See - http://en.wikipedia.org/wiki/Exponential_growth#Limitations_...

You'd better hope it is. If hardware is what limits the rate of improvement of AI, you get slow growth. If knowledge of how to write the software (perhaps by copying algorithms from the brain) limits it, then you get sudden improvements and serious potential for a runaway singularity.

Which would make sense as a complaint if Kurzweil were giving a date without any context, but makes no sense when set against:

1. a rolling series of more mundane predictions providing justification and context

2. some of which were made in the past concerning the present, and were mostly right.