Where Does the 5000 Year Life Span Figure Come From?

Aubrey de Grey (and others, like Chris Lawson) have suggested that radical life extension using technologies that could be attained in a matter of decades would lead to life spans of 5,000 years or so. Where does this figure come from?

Once our medical technology has passed the stage of what Aubrey de Grey calls acturial escape velocity - the point at which the effects of aging are being defeated faster than we age - our life spans will be limited only by accident and violence. The odds of death under these circumstances are very well researched for our current Western societies:

The odds of dying from an injury in 2001 were 1 in 1,781.

If you take the statistics for a healthy person in the prime of life and keep calculating the odds of death based on present day statistics, you wind up with a projected life span of thousands of years. As Chris Lawson says, it is perhaps more appropriate to consider ageless individuals to have half-lives in the same fashion as radioactive elements:

[An ageless man] who has lived 500 years has a 50% chance of living another 500 years. And should [he] survive that to reach 1000 years of age, he still has a 50% chance of living another 500 years. This is always true: no matter what [his age], he has a 50% chance of surviving another half-life.


Does anyone else find it ironic that I used the example of driving for easing people into the subject of actuarial escape velocity, and Dr. Aubrey de Grey, who coined the term, doesn't drive?

Posted by: Jay Fox at December 10th, 2004 8:39 AM

> Once our medical technology has passed the stage of what
> Aubrey de Grey calls actuarial escape velocity - the point at which
> the effects of aging are being defeated faster than we age - our
> life spans will be limited only by accident and violence.

Actually, we should be careful how we state this. Actuarial escape velocity can mean many things, depending on what we are "escaping" from. It's an issue I'm trying to flush out, in my typical wordy manner, at my website.

At the most basic level--the first level de Grey talks about--we are escaping the increasing age-specific mortality rates. Even this has two levels.

The first level, the practical level, is to make sure that, for all or most age cohorts, a person's chance of dying doesn't increase with time. This doesn't necessarily mean that aging has been stopped. In fact, it *most likely* doesn't mean it has been stopped, though it would certainly help if it's been slowed quite a bit.

What it means is that the combined effect of slowed physiological aging and rapidly increasing medical technology is making it possible that, statistically speaking, you're as likely to die next year as this year. In other words, you might still be aging (at a reduced rate), but advancing medicine is allowing physiologically older people to survive longer, so you're just as likely to live longer as if you had stopped aging. To put it plainly, you have stopped aging in practical terms.

For example, if medical technology were to increase so rapidly in the next five years that, five years from now, a 65-year-old is as likely to die as that person was when aged 60 today, then we have reached the "cusp" of actuarial escape velocity. Of course, just as an airplane can stall or run out of fuel, if the technology can't maintain this high rate of progress, then we'll fall back below the cusp.

The second level is to reach the point where we actually stop aging physiologically: where our age-specific mortality rate remains less than or equal to what it was the year before, even if we ignore advancements medical technology.

This second level is what I suspect a lot of us in the anti-aging community think of when we think of actuarial escape velocity: reaching the point where we stop aging.

But, in order to get to the point where "our life spans will be limited only by accident and violence", we have to move to the next level. We have to not only stop, but actually reverse aging. By the time we can reverse aging, our medicine will probably be sufficiently advanced that disease in general will be mostly eliminated. At that point, what you have left is, for the most part, accidents and violence.

I think Robert Freitas did a nice numerical analysis, for the ueber-geeks out there. There's a copy of the article at the Longevity Meme:


Posted by: Jay Fox at December 10th, 2004 11:21 AM

Thanks to Jay for this. I would like to try to clarify a little.

As Jay says, my "escape velocity" is the "first level" Jay mentions. However, I think Jay may underestimate the gap in technical difficulty between the first and second levels. I don't even talk about the second level, because though I think it may be just about possible with bodies made out of meat, it's fantastically far off -- possibly even harder than uploading itself. Basically it would entail the development of therapies for eliminating every single accumulating change in the body that is eventually bad for us, however slow that accumulation is. Every one of my seven strands is grossly short of that -- the only reason I can talk about curing aging is because once they're all in existence in crude form I'm pretty sure they can all be improved easily fast enough to exceed escape velocity.

The good news, though, is that since all the SENS technologies are **repairs** of damage, the third level Jay mentions is in fact not harder than the second level but the opposite, merely a statement of how we will get to the first level. This is where Jay has misunderstood my work (I think). The technologies wil **not** be ones that get progressively better at keeping frail people alive: keeping frail people alive is actually a lot harder than fixing them up. All my seven SENS strands are repairs.

So I'm sticking by my view that we can get to a situation where no one dies involuntarily of aging within only a decade or two from the arrival of the first effective rejuvenation therapies. I have put this in numerical terms in the past by saying that I expect that the first 1000-year-old is only 5-10 years younger than the first 150-year-old; I stand by that, and of course I extrapolate, i.e. I think the first 10,000-year-old is probably only 10-20 years younger than that.

Posted by: Aubrey de Grey at December 10th, 2004 3:43 PM

there is another reason why life-span will become stretched to 5,000 year or more. Many accidents that currently maim and kill people will be treatable 100-200 years from now. Stem-cell regeneration and nanotech will certainly be advanced 150-200 years later and will be able to regenerate your body if much of it is destroyed in an accident (i.e. car accident). The only kind of accidental death that will not be reversible would be any that destroys the physical stucture of the brain (e.g. fire or explosion). It is, therefor, likely that the major cause of death in 2100 will be aerospace accidents (airplanes and spacecraft). Mike Perry (of Alcor) did a calculation taking such medical advances into acount. He comes up with a human "half-life" of around 100,000 years, give or take a few thousand. Thats definitely time enough for love.

Anyway, space colonization is needed for anything over 200-300 years anyways. 300 years is enough of life on Earth and, if one does not immigrate into space, one would probably become bored staying on Earth for the next 1000 years.

So, Aubrey doesn'r drive. This might not be risk aversion. London is like Tokyo or NYC in that driving is a pain in the arse and that the trains and subways are a more effecient way to get around. Alot cheaper too, given that parking spaces in Tohyo can sell for up to US$100K. If he is, indeed, risk averse; thats his thing. Even with the stong likelyhood of immortality in the near future, I refuse to be risk averse. Living life is about taking chances, especially if you like to go to funky places that most people only see on the telly. If I limit my life-style options because I am afraid of death, I am not really living anyways.

At least that how I look at it.

Posted by: Kurt at December 10th, 2004 3:54 PM

I believe "excape velocity" means when effective cures or medical treatments for the "7 deadly things" are developed and available. If Aubrey is correct (and I see no reason to doubt this), this will be effective curing of aging. So, life-span becomes a matter of statistical "half-life".

It is entirely possible that there may well be other decay mechanisms that are discovered, that only show up once you reach 200 or 300 years old. These will have to be fixed as well. However, it is quite likely that biology will be well enough understood and the tools powerful enough in, say, 2200 that solving these problems would be relatively easy. At least compared to SENS today.

Posted by: Kurt at December 10th, 2004 4:01 PM


I agree that it would be sad to retreat into a risk free existence forever, but consider the precarious nature of our current situation. We don't have life extension or advanced medical nano/bio tech just yet. But there is good reason for thinking that these things will come within our lifetimes. We will be able to make the human body much more resilient to disease, injury and aging than it is now. So why jeopardize our chances of thousands of years of fun by taking silly risks now?

The sensible course of action right now is to live a really risk free life and wait patiently. Once advanced medicine appears and the world is generally safer anyway, then we can start playing around, having all the fun we want and taking the risks. But right now methinks you should stay indoors, don't do anything at all risky and sit tight ;)

Posted by: Marc_Geddes at December 11th, 2004 10:02 PM


I wasn't trying to make a "judgement" of the fact that Aubrey doesn't drive. I just thought it was ironic that I used driving as a metaphor for easing newbies into discussing SENS and escape velocity, and then the next day I find out that the man who coined the terms doesn't drive (I found out in the pop-sci article).

Posted by: Jay Fox at December 13th, 2004 6:56 AM
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