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There's no limit to longevity, says study that revives human lifespan debate
- nabla9 8y agoIf I understand this correctly, In the terms of probability aging distribution becomes memoryless for very old people. This would mean that the remaining lifespan for really old people would follow exponential distribution. Just like with radioactive decay, you could determine their half life. The half life could be as short as one year. >At that point, the researchers say, the odds of someone dying from one birthday to the next are roughly 50:50
- fjsolwmv 8y agoThis could also be a subtle variation of the classic fallacy of confusing exponential functions with sigmoids
- yazaddaruvala 8y agoI'm so excited! Every time I read an article about longevity, its like Christmas morning. Everlasting youth is going to be humanity's greatest accomplishment, and its biggest weakness.
- gldalmaso 8y agoIt always comes to mind how many fictional immortal characters and creatures just basically choose to go into an eternal slumber. There seems to be a de facto consensus that it is actually pretty boring stuff.
- meiraleal 8y ago> There seems to be a de facto consensus that it is actually pretty boring stuff. Consensus created not by people with experience de facto. At least not the majority.
- pmoriarty 8y ago"many fictional immortal characters and creatures just basically choose to go into an eternal slumber" This just indicates a failure of imagination on the part of the author.
- tzs 8y agoPerhaps it is a way to deal with limitations of their brains. They usually have finite brains, which presumably have a limit on how much information they can store and organize and process. Suppose you are an immortal working on some long term goal, some plan that will take a few hundred years to complete. It is a complicated plan and you will need to keep it all in your mind, along with its history as it progresses, in order to guide it to success. If you try to lead an active life throughout all this, perhaps your brain will acquire too much irrelevant information, interfering with your ability to carry out your plan. So you sleep for decades at a time, just waking up long enough to check on the plan, learn about changes to the world since your lest check, and make adjustments. Then back to sleep.
- throwaway5752 8y agoNot to rain on your parade, but it would still be very wise to have contingency plans around dying after age 30 (will, insurance) and to assume otherwise you'll die around 75-80. The article is much less optimist than you seem to be interpreting it. It's basically "is there a hard cap on the age you'll die, or is it just random and independent of age past a certain point". It says nothing about the aging process. Being older than 90 still sucks for the most part, and this article says nothing about quality of life. It also is a very minor point, in a practical sense: is it impossible to live past 120, or is it possible with then odds of 1:10^9?
- opportune 8y agoWell, one problem is that longevity may not mean youth at all. Increasing longevity may simply mean getting (and looking/feeling) older and older. Even if we perfect the art of 3d printing new body parts and using gene-targetted cancer treatment, that may not make you spry, less forgetful, or less wrinkly
- red75prime 8y agoBiology isn't the only way to remove wrinkles. Our nervous system isn't very good at interfacing with electronics, but technologists will find a reliable way some day.
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- tathougies 8y agoIt'll certainly be the wealthy's greatest accomplishment. They get to live forever off a permanent underclass of slaves. Congratulations, you have 'fixed' humanity.
- codingdave 8y agoSo biologists say there is a limit. But if you only look at the statistics from extreme examples of people over 105, mortality looks flat for a few years, so statisticians say we can live forever. Is it just me, or is this just bad logic?
- std_throwaway 8y agoIt means that they found data not agreeing with the model of limitless increase of mortality with age. This is just a statistical observation, not physics yet, not by a long shot.
- tomrod 8y ago"Selection" bias takes over at some point. Good genes, good habits, and luck result in a flat mortality rate. Nothing fishy here.
- dibujante 8y agoIt means you have a chance of living forever that asymptotically approaches, but does not reach, zero.
- goatlover 8y agoAssuming you can survive the heat death of the universe, and other events not so friendly to biology prior to that point. It just sounds dumb because it doesn't take into account any physical limitations that would make the curve reach zero.
- frgtpsswrdlame 8y agoIsn't that just Zeno's paradox rephrased for aging? If I shoot this arrow it will asymptotically approach but never actually reach you.
- theoh 8y agoNo, in the case of Zeno, we all agree that the arrow would impact at time t, we just argue that you can take tiny timesteps so you never get there. But after time t, the target has definitely been hit.
- unit91 8y agoGiven that theory, we never see people over about 120 because...?
- meiraleal 8y agoSome speculations: 1. there are few, as the world has 7billion++ people today and 120 years ago it was around 1 billion. You certainly are not going to meet them. 2. Someone that is still sane past 100 years will not care about bragging his age to us younglings. 3. Finally, we don't ask these people their age. And when we do, we don't believe the answer. There are some histories of people with more than a hundred year. Li Ching Yuen[1] was a Chinese herbalist that lived more than 250 years. 1. https://en.wikipedia.org/wiki/Li_Ching-Yuen https://en.wikipedia.org/wiki/Li_Ching-Yuen
- furgooswft13 8y ago> claimed lifespans, of 197 and 256 years Ah! Clearly the human age register is only 8 bits and when it overflowed his body crashed. Try to plan ahead a little better when designing human 2.0 God!
- opportune 8y agoWhat's more likely: this guy actually lived to be twice the age of the oldest (confirmed) person ever - or the guy overstated his age to make people more inclined to buy his medicine?
- tomrod 8y agoAny time I see these kinds of claims, I like to take a step back and think through a few points. Does it happen frequently? How much evidence would I need to shift my prior from unlikely to likely? Is someone trying to sell me something, literally or metaphorically? This skepticism is borne from living a life of being gaslighted and conned in a high-demand religion, and breaking away. I don't doubt there are occasionally a few long-tail events that skepticism causes one to miss its reality, but as far as seeking mysticism or a hidden reality (hidden by whatever underlying power, be it gods or billionaires, pick your poison) I find life much less stressful and more fulfilling with a healthy dose of skepticism.
- SketchySeaBeast 8y agoIt's a 50/50 change once 105, and given that the odds of 32 coin tosses all coming up heads is 1 in 4,294,967,296 does that mean there's a 137 year old person running around somewhere?
- vinceguidry 8y agoMethuselah lived 969 years, so there's that data point. ducks
- SketchySeaBeast 8y agoI'm only in my early 30's and I am already considering myself 35, at 969 you'd think you'd round up to an even thousand. I'll only believe that exact time if someone counts the rings.
- vinceguidry 8y agoThe Hebrews took from the Egyptians a great love of numbers and numerology. 969 probably rolled off the tongue really well in their language. It was all originally passed orally in verse.
- stan_rogers 8y agoI once took up the Ussher chronology thing, wading through the begats, just to see if there was any sort of basis on which a person could legitimately convince themselves they were doing a proper chronology. Turns out that 969 means ol' Meth drowned in the Flood his grandson was known for - or at least kicked off in the few months preceding it. I'm thinking "drowned in the Flood" is something you're supposed to carry away from the tale, in much the same way as he's listed as somebody's son and somebody's father, without any accomplishments worth mentioning, nor any notable piety. There's probably another part of the tale, now lost, that folks were originally supposed to know.
- tpeo 8y agoProbably not running, and probably not within our time. World population in 1881 was a couple of billion short of that.
- jkingsbery 8y agoA 50% mortality rate per year translates into there being a <0.1% chance of living for 10 years. How does that translate into there being "no limit to longevity?" I seriously don't get the claim.
- tpeo 8y agoIt means that mortality rate doesn't approach 100% around some given age, which would be the hypothetical biological limit. I don't see the issue.
- repsilat 8y agoRight. "You don't get worse at living after a certain point." Sounds like big news to me even if the "half life" was shorter.
- Rantenki 8y agoIt's not a valid claim IMHO. If you look at the sample size that they're basing it on, you can see that it's shrinking at the attrition rate for what they are measuring. Once you get to 117 years old, there are only a few people worldwide that can be used to determine that survival rate, and those people are already subject to a selection bias of people that are exceedingly long-lived.
- mrfusion 8y agoIf this is true shouldn’t we see the maximum lifespan increasing as population has doubled several times?
- olavk 8y agoYes, but not much. Since mortality is about 50% for people over 100 (according to the article), doubling the population of humans should only see an increase of one year.
- sixdimensional 8y agoI wonder if there is something like the study I heard of once that said, if an electronic or mechanical device lasts at least X years, it will almost always last X + Y years where Y is a much longer period of time. I heard that related to design, manufacturing process and material selection. If it's true for things, it makes sense it might be true for humans.
- fjsolwmv 8y agoThis is well known in humans as the "infant mortality rate" vs "adult life expectancy".
- elihu 8y agoIt depends on the device, but there's also the phenomenon where failures go up after a certain amount of time just because parts wear out. https://en.wikipedia.org/wiki/Bathtub_curve https://en.wikipedia.org/wiki/Bathtub_curve
- bloak 8y agoI would have thought it's intuitively obvious that there's "no fixed limit on human longevity", and it's therefore obvious that mortality "flattens out": how else could it avoid going over 100%? It presumably is possible to say something interesting and non-trivial about the shape of the curve but it seems to be beyond the mathematical competence of the people writing these journalistic reports to do so. Looking at the Wikipedia list of longest-lived people (https://en.wikipedia.org/wiki/List_of_the_verified_oldest_people https://en.wikipedia.org/wiki/List_of_the_verified_oldest_pe...) I get the impression that the top two (Jeanne Calment and Sarah Knauss) don't fit, though I know that the case of Jeanne Calment is very well documented.
- mattnewton 8y agoI don’t find it obvious that there shouldn’t be some hard coded expiration mechanism- lots of insects have effective experation dates, for example.
- bloak 8y agoEven if there were a hard-coded expiration mechanism, that mechanism would presumably have limited precision and a non-zero failure rate (assuming it's implemented with biochemistry rather than magic). Looking at the list I linked to, it does rather look as if there were a cunning device to kill people towards the end of their 118th year, and that device failed in two cases... but I can't imagine why there should be such a device or how it might be implemented, so I don't really believe that. Even if the chances of surviving another year did stabilise around 50% after the age of 100, say, you still wouldn't have enough people living beyond 130 for you to be able to measure with reasonable accuracy the mortality rate of people aged over 130. So the hypothesis that a person aged 140 would still have a 50% chance of surviving another year would be totally untestable. If you think about it, there's also no hard limit for how tall or how short an adult human could be. Except the limit of zero for the height. Again, beyond a certain point there will be, in practice, no data available for testing any hypothesis about the distribution.
- fjsolwmv 8y ago
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- reasonattlm 8y agoThis really has nothing to do with limits to longevity in any practical sense. That's just the publicity machine at work, the first line in mangling and misrepresenting the relevance of research. This paper is to do with a long-running debate over whether or not mortality risk reaches a high, flat plateau in extreme old age. The difference between limit and high flat plateau is academic for those involved. The outcome is much the same. It does in flies, and there is very clear evidence for that. The evidence in humans to date is very sparse, and where people have done good work on the numbers, they have not seen signs of a plateau. So in that sense, that people have found a larger data set that shows it, that is fuel for the fire. No-one has the slightest idea as to how you can balance the fundamentals of reliability theory with a late life mortality plateau. If damage is accumulating, and no-one really believes it stops accumulating, then your risk of mortality should keep on going up. What sort of mechanisms in a highly damaged biology could buffer that underlying reality? And why in very late life versus other times? None of this, of course, has anything to do with efforts to treat aging or extend human life. It is an academic debate that will likely fade out before answers are found, made irrelevant by the advent of ways to treat aging and its causes. Methods of extending life will work by putting off or repairing the very damaged state. There will likely never be a large multiple of the present count of exceptionally physiologically aged individuals. Rejuvenation therapies are just around the corner.
- qwerty456127 8y agoWho wants to live long without staying young? I'd rather choose to die in my 40-es if I would get 25-yr-old body until the end of the life in exchange. Body/health (skin, brain, immune system, muscles etc.) anti-aging is the thing we need first, not longevity/immortality.
- grepthisab 8y agoOut of curiosity, how old are you now?
- qwerty456127 8y agoI'm in my early 30-ies. I'm alright generally (I also look rather young and the doctor says my health is great) but I already feel loss of vitality, stamina, flexibility and regeneration. I felt like an invincible superhuman when I was 24 and now, despite maintaining fairly healthy lifestyle, my knee and back hurt occasionally, I can't f-ck without making a pause every couple of minutes (used to do it for hours contiguously and vigorously until 28), I have to eat healthy to maintain satisfyingly low weight (no wildly bad diet could cause a fluctuation in my weight until 24) etc. I also feel very satisfied by the life I have lived and occasionally think I wouldn't mind to die happily at any time the G-d would decide my time on Earth to end (yet I absolutely do mind to live long enough to get Alzheimer's, cancer etc, I don't fear death yet I do fear senility). I have started to work-out vigorously to revitalize and develop my body and mind recently so perhaps everything is going to change as I achieve the results yet I doubt things like my knee are going to regenerate (this has been scientifically proven impossible in 2017 or 2016 as far as I can remember although I can't find a link to the paper now). It seems it's a fact that 30+-yr-old bodies are generally more fragile and less powerful than 20-yr-old ones.
- BuuQu9hu 8y agoI'm not the person you're replying to, but I too would happily "die in my 40-es if I would get 25-yr-old body until the end of the life in exchange." I'm 36.
- landryraccoon 8y ago
- ilaksh 8y agoI always link to http://www.sens.org http://www.sens.org when aging comes up because their approach makes the most sense to me.
- jz_ 8y agoI've donated 300 USD to them this month.
- WhompingWindows 8y agoThe Italian study argues after a certain threshold age, lets say 105, Italians hit a constant, "mortality plateau, which was 50:50 odds of living to your next birthday, and thus since mortality is not increasing year on year, theoretically there is no upper bound on the age of a person. This may be true theoretically, but mathematical reasoning clarifies this somewhat. Even if you have 1 million humans aged 105 right now, which is probably a vast overstatement, they would diminish to 100,000 humans in less than 4 years, then diminishing to 1,000 humans aged 115 in 10 years' time. After this point, it's basically a question of statistics, as we keep halving the population yearly and get into statistically unsubstantial cohorts of humans. So, while it may be that some humans could live to 130-140 naturally, without fountain-of-youth innovations, the VAST majority of us will die much, much earlier. The low-hanging fruits of obesity, heart disease, and diabetes are calling to public health far more urgently than this pie in the sky limitless life.
- kbenson 8y ago> mortality plateau, which was 50:50 odds of living to your next birthday Isn't the question whether or not we can affect the odds here? If we can increase it to 75:25 at this plateau, then we also are also increasing the age longest lived of these people are predicted to live for immensely, and the last person of this example group of 1 million starting at age 105 you give would expect that last person to die not 10 years later (at 115) on average as with a 50:50 mortality, but around 48 years later, at 153. Every slight change in that mortality rate affects that long tail quite a bit, relatively speaking. I for one believe that might have an immense effect on how people view their health and longevity. If people believe that taking care of themselves might give them many decades of additional life instead of a few years, that could lead to a wider shift.
- Something1234 8y agoHow did you come to 48 years later? When I calculated it came to about 21 years. In [2]: def reduce_pop(pop, prob): ...: if pop <= 1: ...: return 1 ...: return 1 + reduce_pop(pop * prob, prob) ...: In [3]: reduce_pop(1000000, 0.5) Out[3]: 21 Where pop is the initial starting group, and prob is how many die off(with 50:50 I expected half of them die off each year). Please correct me if my math is wrong or if I'm miss interpreting how to calculate this.
- davesque 8y agoI'm sorry to say it, but I always feel incredibly cynical about longevity tech. If we had a treatment that could extend people's lives indefinitely, what would that do? It would essentially put a price tag on life in a more direct way than we've seen before. It's hard to imagine that the powers that be would want everyone to have fair access to it. Obviously, this kind of treatment wouldn't at first be widely available even if it worked. So how do we decide who gets it?
- vagab0nd 8y agoMay I ask, why you don't feel the same way for any other medical research that saves lives? What's so different about curing aging?
- davesque 8y agoWhy do you assume I don't feel the same way about the things you mention? In general, I think the economic incentives for medical tech are fucked up.
- vagab0nd 8y agoWell, you mentioned you "feel incredibly cynical about longevity tech", which seems to suggest that you feel differently on this particular type of research compared to others.
- visarga 8y agoAs we live, we forget stuff, we change, the situation around us changes. So it's as if we gradually die every day, to be replaced with a new self. The day we physically die is just the last time we die. Not to mention that we experience nothingness and coming back every night. By analogy, is a continually trained neural net the same as a previous version of itself? Is it a different one, especially after a long time? Did the old version end/die by continuous accumulation of changes?
- newman8r 8y agoReminds me of the ship of Theseus https://en.wikipedia.org/wiki/Ship_of_Theseus https://en.wikipedia.org/wiki/Ship_of_Theseus
- sgt101 8y agoContrast your idea to the ideas used in the search for life on Mars. The Martian atmosphere is very near its chemical equilibrium, the Earths atmosphere is dynamic; Mars is (more or less) dead, Earth is (not as) alive (as it should be if we weren't messing it up). My point is that change is life; stasis is death. On the day we die our body begins a journey to chemical equilibrium, our brains reach electrical equilibrium rather quickly. Then they stop there.
- llamaz 8y agoThis was the insight of the pre-Socratic philosopher Heraclitus: “No man ever steps in the same river twice, for it's not the same river and he's not the same man.”