> Girls born since 2000 in the developed world are more likely than not to reach the age of 100,

You have posted this false statement multiple times in the past on HN. Please stop. This is what I wrote last time:

> the support for this supposed fact is very dubious. You link to one article by Vaupel in Nature who, in making this claim, cites only this paper

> http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2810516/

> by Christensen et al. The paper says, in the abstract,

   If the pace of increase in life expectancy in developed countries over the past two 
   centuries continues through the 21st century, most babies born since 2000 in France, 
   Germany, Italy, the UK, the USA, Canada, Japan, and other countries with long life 
   expectancies will celebrate their 100th birthdays.

>Very few medical researchers are likely to find that "if" statement at all plausible, so this claim about most newborn girls living to 100 is bogus. If you have a better source for this claim, please present it. Otherwise, stop posting it.

Anyone wanting to read your very unconvincing rebuttal can go back to that thread:

https://news.ycombinator.com/item?id=7533774

Hi Jess -- good on you for being skeptical. Honestly curious about two things:

1. Why do you think OP's wrong? You don't really state, in either this thread or that one.

2. What our your sources for OP being incorrect? Semi-anonymous internet posters can keep trashing each other ad infinitum, and without any sources (that I saw, maybe I am wrong) you don't present a convincing argument against.

Thank you!

I wasn't citing a source that conflicts with tokenadult's claims, I was just pointing out that if you actually track down his citations you find that none of them point to actual data supporting his broad claim. Rather, he takes a speculative statement based on a hypothetical scenario that is very unlikely to hold, and then presents it as fact.

That's all I should really need to do to convince a reader that they can't trust him to represent his sources fairly, but for completeness you can just read that the World Bank's life expectancy predictions for a child born today in the US is 79 and in the UK 82.

http://data.worldbank.org/indicator/SP.DYN.LE00.IN

Indeeed, this news article

http://www.telegraph.co.uk/health/healthnews/10511865/Two-th...

explicitly describes where the funny business arises:

   The most commonly quoted life expectancy figures for the UK say that the current 
   generation of baby girls will live on average until they are just 82.7 while boys 
   will survive just 79 years. But using the ONS’s alternative “cohort life
   expectancy” method – which assumes that survival rates will continue to improve 
   at the current rate – today’s baby girls are already expected to live to 93.9 
   years while boys would reach 90.6 years, taking them well into the 22nd Century

The only way to get this ridiculous claim about people routinely living to 100 is by assuming that the historic rise in life expectancies will continue, but this is extremely unlikely to happen as confirmed by any official source or actuary table you care to consult.

> Semi-anonymous internet posters

I know what you mean, but I think I'm about as non-anonymous as you can get on the internet. My HN user page contains a link to my personal website, which has my legal name, photographs of me, my place of employment, email address, and mailing address. (And my personal webpage links back to my HN account.)

Hey, that's really helpful. Thank you for the well thought out answer.

Vaupel is a respected voice in the field. You might look through his publication history.

I don't think it's particularly controversial at this point that life expectancy at birth is trending upwards at ~2.5 years/decade and adult life expectancy at ~1 year/decade. Vaupel is far from the only researcher publishing studies of life expectancy trends, and the actuarial community is in a state of what passes in their staid halls for great upheaval for some years now, issuing ever more politely alarmed statements about their growing inability to predict the future longevity upside.

But none of that is relevant, as it is the result of medical advances in absence of any attempt to intervene deliberately in the aging process. What will distinguish the medicine of the past fifty years from the medicine of the next fifty years is exactly that. In the future researchers will be trying to slow or reverse the causes of aging, whereas in the past they achieved life extension through only inadvertent impact on those causes or expensive compensation strategies for the end results that do little to fix things.

> ...and the actuarial community is in a state of what passes in their staid halls for great upheaval for some years now, issuing ever more politely alarmed statements about their growing inability to predict the future longevity upside.

I'm not sure what this is supposed to mean, but it sounds like you're admitting that essentially all actuarial tables, across many nations, industries, and governments, agree that this trend cannot continue.

> In fact, newborn children in high-income countries can expect to live to more than 100 years.

Not sure if you used the correct word (and if I interpret it correctly), but I find the expected age of 100 a bit hard to believe, given that (1) humans don't live longer than about 120 years, and (2) many die much younger than 80.

Do people younger than 80 die of old age?

I would hope that over the next 50 years, heart disease and cancer, for example, become treatable. We should be lifting weights and maintaining our strength into our 80's:

http://www.usatoday.com/story/news/nation/2014/11/28/77-year...

In the past half century, the life expectancy for the UK has risen a decade to 81.5. And that's across disparate demographics. I expect it will rise more in the next half century.

I have aunts and uncles who have lived a long time, with two of them in fine health above age 90, so I find this a bit more believable. My maternal grandmother, their mother, lived to be 99.

Anyway, on the issue you doubt, Vaupel and other professional demographers "show the work" in their professional publications.

Life expectancy simply means that 50% of those people will be dead by 100. It could be that 99% of them are dead by 110.

That's a perfectly plausible distribution. Japan, for example, has over 50k 100+ inhabitants (and probably 0 over 120).

No, it doesn't. From Wikipefia:

> Life expectancy is a statistical average of the number of years a human lives

Therefore, if 3 people live until 110, and the fourth dies at 30, life expectancy is 90 years.

In another part of his comment, tokenadult mentioned another estimate that means what you're describing:

> Girls born since 2000 in the developed world are more likely than not to reach the age of 100

>humans don't live longer than about 120 years

That's not a hard limit. There are a number of promising avenues of research likely to push human lifespan substantially higher.

Actually, it's a pretty hard limit based on cell death. You can never predict when an amazing breakthrough will come about, but without it you're not going to see people living to 150.