One way to extend human lifespan is… to wait. Average life expectancies in industrialized countries are slowly increasing over time — though this increase is slower than the march of time itself. If the increase in average lifespan were as fast (or faster) as the increase in calendar time, we could be said to have achieved “actuarial escape velocity,” a concept I learned from this entry at the Institute for Ethics and Emerging Technologies weblog:

US life expectancy at 65 up 1 year from 1999 to 2004…

Meaning the U.S. is at 20% of escape velocity. However longevity gains were not shared equally by gender or ethnicity (or social class, but that’s not a term Americans know). During 1999-2004, life expectancy at age 65 years increased by 1.0 year for the overall U.S. population, 1.1 years for white men, 0.8 years for white women, 0.9 years for black men, and 1.3 years for black women.

Leaving aside for the moment the snotty (but, I’m sure, good-natured) implication that Americans don’t understand social class, I think this is a valuable idea. If the rate of increase in average life expectancy was 1 year per annum (five times larger than the current rate of 0.2 years per annum), we’d find ourselves no closer to death (on average) as time went by — a situation with massive demographic implications, obviously, but also a significant inflection point in the story of our relationship with aging and a useful benchmark for practical considerations of anti-aging research.

(Hat tip to Longevity Meme for this link)