A University of Pennsylvania demographer, Samuel Preston, said "American life expectancy has been steadily rising, usually by about two to three months from year to year. This year's jump of fourth months is an unusually rapid improvement.

But is it? Is he falling victim to perceiving the growth in life expectancy as a linear function of time rather than a exponential which has been in a slow period of growth.

There's a compelling argument that most information technologies are subject to an exponential, moore's law effect, and health would definitely fit into that. Due to the technologies that are increasing life expectancy are advances in information rich medical sciences.

I think that four month pace will definitely quicken once we incorporate biotechnology into the average person's medical treatment arsenal. The really important question in my mind is will this growth continue to the point where we are gaining more than a year's worth of life expectancy per year, because if so that implies some kind of psuedo-immortality, with parts being able to be continually replaced, like a worn down house.

Or will will life expectancy reach an asymptote as it approaches 1 year increases per year. Either way if we reach even 8 or 9 months per year we'll have 150 year old before long and a dramatically different societal landscape with possibly 7 or 8 generations of a family alive at a time. Though I suspect family will be a rather blurred and useless term by then.