How long would an "immortal" person live?

Ok…the question isn’t as dumb as it sounds. Lets presume that tomorrow science develops an anti-aging syrum that stops or at the very least greatly slows the aging process so that we would live for centuries and never physically grow older than…say…45 (but you wouldn’t look a day over 4,500).

But…you are not indestructible. You can still die of a car crash, violent crime, accidents, war, famine, whatever. As Tyler Derdan says, "given a long enough timeline, the survival rate for everyone is zero.

So, for all you actuaries out there. How long can a person be statistically expected to live if the only thing they had to worry about was getting killed by something other than old age?

Tricky, since even if the aging process was stopped, simple wear-and-tear on brain and nerve cells would cause them to eventually fail, and since they don’t regenerate, as muscle cells do, you might simply spend your last 50,000 years in paralyzed senility.

But putting that aside, there are demographic issues involved. If lifespans increased dramatically, it can be assumed that birthrates would fall dramatically, at least in the industrialized nations (or at least this has been the tendency over the last century). Since many violent criminals and incompetent drivers tend to be in their teens and twenties, a reduction in the number of people in this age group should mean fewer murders and fatal auto accidents.

You’re asking a serious question, but there simply aren’t enough facts available to form a serious answer.

Sure there are. We have reams of data on accidental death. I’m late for work, or I’d look it up.

Basically, you can say that if a person has a 10% chance of dying accidentally through a normal lifespan, then through ten normal lifespans he’d have about a 65% chance of dying in some form of accident. I don’t know if 10% is a reasonably close answer, but it should be easy enough to find out.

The real wrinkle here is that immortal people would probably change their tolerance to risk. Whether they would accept more or less is anyone’s guess - I think it depends on how much fun immortality would be.

Within 10[sup]2000[/sup] years, the universe will experience heat death, if it hasn’t already undergone a big crunch (but that’s not likely). So there’s an upper limit, even if it isn’t terribly helpful.

Nevertheless, I think we can compute a rough estimate of how long a person could expect to live if old age were no longer inevitably fatal. Let’s give the OP a little satisfaction, at least. I will make all sorts of simplifying assumptions here which I’ll try to summarize later. (One of those assumptions is that we can even know what all the assumptions are.)

If there’s a probability P of dying in any given year, then the probability of surviving the year is 1 - P. Moreover, the probability of you surviving Y years is (1-P)^Y – that is, (1-P) to the power of Y. This quantity can also be viewed as the proportion of a large population that would still be alive after Y years.

This is an exponential “decay” function, much like the one that describes radioactive decay. You can even compute the “half-life” of an immortal human population by solving the equation (1-P)^Y = 1/2 for Y. If you do, you get the expression:

Y<half-life> = ln(1/2) / ln(1-P)

where “ln” is the natural, e-based logarithm. If we make the additional simplifying assumption that P is much much smaller than 1, then the above can be well approximated as Y<half-life> ~= ln(1/2)/(-P) = ln(2)/P = 0.693/P. Let’s call this half-life your expected lifespan – the number of years you can reasonably hope to live, knock on wood.

Now you just need a value for P, the annual death rate. I just happen to have a URL for that:

You – as in you, the OP – didn’t specify whether murder and disease were still concerns, or whether accidents are the only threat. If it’s only accidents (35.6 deaths per 100,000 people per year), then you’ll have an expected lifespan of about 1,950 years. If you add in the risk of murder, then you’re cut down to 1,660 years. If you’re also at risk for hypertensive renal disease, well then, you poor schmo, I’m sorry to say you’re down to a mere 1,430 years.

But let’s be more optimistic. Say you move to Manitoba, keep in good shape, visit a doctor every year, get reliable cures for whatever ails ya, drive very little, and are extra cautious around household appliances. In other words, let’s say accidents are your only threat, and that through meticulous caution you are able to lower the accident risk by a factor of oh, maybe five? In this scenario, your expected lifespan grows to 9,730 years – about ten millenia.

Putting it big-picture terms: you might reasonably expect to live for a few thousand years. You’ve got a shot at ten thousand. Hardly a chance in hell though that you’ll make it to a hundred thousand or more, even in the best of circumstances.

All of this analysis works under the following assumptions:
[li]Your death rate is not changing remarkably from year to year.[/li][li]The probability of dying from two or more causes at the same time is negligible. (I.e. the causes are independent of each other.)[/li][li]The reference URL cites statistics only for the U.S., but there’s a lot of variation in the world at large of course, and even within the U.S. (Maybe we Americans are recklessly clumsy.)[/li][li]As Bryan mentions, there are effects from such extended life for which medical science presently has no cure. I’m assuming away this minor problem.[/li][/ul]

But best of luck on your journey through eternity! Don’t count on Social Security after the first couple centuries though.

Well, there is the possibility of escaping to other universes in the multiverse at the end of this universes life, but that is all just theory right now.

What we should really be aiming for is a SUBJECTIVE immortality. We need to reverse engineer the human brain (and the rest of the body) and then improve the design so that we can process information at close to the speed of light. We then need to hook ourselves into fully immersive virtual reality. So while I go swimming in “real time” I have a thousand years of VR time in between each stroke. From [url=“”]this very cool FAQ on The Meaning of Life[/url:

So, ultimately we may squirrel our bodies away in hardened bunkers and live millions of subjective years for every second of “real time”. We could have remote controlled bodies to interact with the real world, but as I talked about before, in the time it takes you to walk to the park a few million years of virtual life could have passed you by. We’ll need incredibly complex simulations to keep us stimulated. Heck, we may even do things like live a whole life without access to our memory just for fun. Matter of fact, this could just be a simulation right now. Never mind evil robots ala the Matrix, I WANT a realistic VR and souped up neurons.

DaLovin’ Dj


Fixed link.

Well there are other financial issues to worry about. Like what happens to an economy once a significant % of the population has earned enough to live off the interest of their investments indefinitely (I real possibility if you accumulate enough the first 100 years of work).

I susspect a very large proprotion of imortal humans will chose to die within the first two or three centuries of life. Bordom would set in and lead most to chose death. or else seek out more and more extreme sensations which would itself ultimately lead to a fairly early death. There would be significant differences in lifespan of imortals depending on whether imortality is available to the masses, or is a hyper-expensive option for the very few.

Good point Bippy- I would think that the only people that would want to live thousands of years are those people that are interested in the world and want to learn more and more about the world. Several degrees, Centuries of experience and experimentation, Learning, growing. I.E Brainiacs. Why would Joe Schmoe want to live 10,000 years when after the first several hundred he has seen everything he wants, Played nearly every variation of every video game, watched nearly every possible “reality tv” show out there, watched most of the movies and just doesn’t care anymore. Of course those more dangerous interesting activities will be even more alluring due to the INCREASED perception of risk.

I agree with dalovindj. Subjective timeframe will increase as more and more brain cells die off and are replaced with computer components.

Well, the trouble with using current accident statistics and murder rates is that if an immortality treatment was made widely availabe, society as we know it would undergo some pretty major changes. If many of the murders currently committed are done so by males aged 18-29, for example, and the size of this demographic drops as part of an overall lowering of the birth rate, then surely the murder rate will go down.

Also, if there are fewer children, there will eventually be fewer inexperienced drivers on the road.

A single immortal, or small handful of immortals, won’t affect societal statistics very much, and thus they’ll have to take their chances with the rest of us, but if 1000-year-plus lifespans become as easy to get as vaccinations, there will be considerable shifts in the riskiness of living.

I think suicide would be the largest hazard to the health of immortals.

Couple of questions…

Is it true that aging is caused by Free Radical damage?

I’ve heard theories that the reason women go through the menopause is so that they (should) live long enough to raise the last child to maturity before they die.
If we start living for 1000 years, will women be fertile for 950 years?

No, there’d be no selection pressure for that.

Probably not. However, I think that it would be pretty easy to induce fertility at that particular point in our technological advancement.

How long would an “immortal” person live?

If they were the only one (or one of a rare few) who had access to the anti-aging secret, I’d guess about 5 minutes. Then the angry mobs would storm their compunds and beat them to death

“compounds,” that is. Sorry. Trying to pack too much into this short life…

Bryan, you make a good point. I’d like to find a breakdown of the accident rate by category. A next best approximation (and I’m big on approximations) might be to subtract off the traffic accident rate per 100,000, then maybe on-the-job factory accidents.

Other accident rates probably wouldn’t change much though, even in a society of immortals. Buildings would still catch fire, hurricanes would still wreak havoc, lightning would still strike, and mama grizzly bears would still attack interlopers who appear to menace their cubs. You can avoid hurricans and grizzly bears by living far away from them, but you’d have to be a pretty risk-averse hermit to dodge everything of course.

I’m not completely sure whether the murder rate would go up or down. On the one hand, murder is mostly committed by young men, as you say, and their portion of the population would greatly decrease. On the other hand, living for a few thousand years allows plenty of time to build up grudges. :smiley:
msmith, the economy’s health in a world of near-immortals is an interesting question, and I hope some economist comes by to answer it. It would seem bad, to me anyway, if most people worked for their first 50 years of adulthood and then lived for the next few millenia off of the interest. What happens then if only a fraction of the population is productive, in the economic sense of the word? What happens when all of that money is locked away in savings, doing little else but earn low-risk returns?

For example, imagine in our current society, suddenly multiplying everyone’s salary by a factor of twenty or so, such that most people need only work until about the age of 25, after which they can retire and do nothing if they wish. This would be very bad, economically speaking, wouldn’t it? Or maybe my analogy is a bad one. With so much loose money and so relatively few goods and services for sale, maybe inflation would automatically reduce the value of money to the point where, just like now, most people would need to work most of their lives before they could retire – even if that meant millenia. And tough luck to you if you die after only a few centuries.

A thousand years … in a cubicle. Now that I’ve thought about it, maybe I’ll go live among the grizzly bears.

I read a sci/fi story that had this as a plot point. An actuarian cacluated the odds of dying of accidental death in one year (1 in X). So then he said that a lifetime in which accidents were the only cause of death would be X many years.

I’m not sure how statistically sound that is, though.

I wouldn’t take those numbers to the bank.