In 2005, American kids aged 5-14 had a death rate of 16.3 per 100,000. Here’s one way to think about how incredibly low that is:
Suppose a kid could keep that childhood mortality rate forever. What would be his expected lifespan?
Answer: 6,135 years! His median would be a little lower – a mere 4,252 years.
Somehow this makes me more optimistic about the prospects for life extension. To extend our lifespans to thousands of years, scientists don’t have to succeed where billions of years of evolution failed. They just need to figure out how to lock in the safety that the typical human already enjoys for one of his decades.
READER COMMENTS
Sulla
Aug 28 2009 at 1:52pm
How do you calculate that ? o0
Matt
Aug 28 2009 at 1:55pm
This reminds me of the Heinlein novel Time Enough For Love where everyone is immortal but usually dies in an accident after several thousand years or so.
Bryan Caplan
Aug 28 2009 at 2:03pm
Take the reciprocal of the probability of death to get the life expectancy. To get the median, you’ve got to solve for x in the equation (1-p)^x=.5, where p is the mortality rate. Just take logs of both sides.
noahpoah
Aug 28 2009 at 2:16pm
Some argue that death is an evolutionary adaptation (there’s a chapter on it in Nick Lane’s very nice Life Ascending). If so, then the only way to ‘lock in’ the safety of youth would be to ‘succeed where evolution has failed’, so to speak.
blighter
Aug 28 2009 at 4:08pm
“scientists don’t have to succeed where billions of years of evolution failed”
You seem to be assuming that evolution has been tending towards extremely long life for any given individual but I don’t think there’s any reason to suppose that would be evolutionarily advantageous. In point of fact, if it were attained or came close to being attained I would imagine it would act as a significant brake on evolution.
Far more likely is that evolution has been trying for billions of years to evolve beings who don’t die before they reproduce at least once but after that are better off gone, from evolution’s standpoint.
Judging the evidence, I’d say evolution has suceeded admirably and science will have a tough row to hoe in trying to alter reality against a process that best facilitates (and is thus reinforced by) evolution.
Richard A.
Aug 28 2009 at 4:24pm
“To get the median, you’ve got to solve for x in the equation (1-p)^x=.5, where p is the mortality rate. Just take logs of both sides.”
(1-p)^x=0.5
log[(1-p)^x]=log(0.5)
xlog(1-p)=log(0.5)
x=log(0.5)/log(1-p), p=16.3/100,000=0.000163
x=4252 years
Of coarse for a quick calculation you can always use the rule of 70.
p=0.0163%
x=70/0.0163%
x=4,294 years (approximate)
Jim Hobelman
Aug 28 2009 at 4:56pm
Strictly speaking the life expectancy is the
reciprocal of the force of mortality.
Steve
Aug 28 2009 at 5:50pm
All scientists have to do is stop the body from aging?
CAKE
Brandon Berg
Aug 30 2009 at 4:59am
Bryan:
Peter Pan gets into fights with pirates and crocodiles and flies around at dangerously high altitudes using only happy thoughts and fairy dust–a substance of dubious provenance and reliability. I’ll give you two-to-one odds that he doesn’t make it past the six-week mark.
Mark Bahner
Aug 30 2009 at 11:21pm
“Peter Pan…flies around at dangerously high altitudes using only happy thoughts and fairy dust–a substance of dubious provenance and reliability.”
All the rocket men swear by it.
Bill
Sep 1 2009 at 11:28am
All scientists have to do to extend human life span thousands or years is prevent death from old age and prevent the break down of the body due to age and long term abuse (Smoking, lack of exercise, extreme obesity). No problem. 🙂
Patri Friedman
Sep 13 2009 at 11:25pm
The key reason to be optimistic about aging is David Gobel’s “Actuarial Escape Velocity” argument. Basically, if we can rejuvenate people by X years, that extends their lives by more than X years, because they get X years of life, plus X years of rejuvenation research to bring new rejuv treatments.
It turns out that it only takes a modest rate of increase in rejuv technology to get immortality. Right now we gain 0.2years of lifespan per year. As that approaches 1 year/year, lifespans get really long, and at 1yr/yr, old age is a thing of the past:
http://www.singularity2050.com/2008/03/actuarial-escap.html
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