An estimate of 600 years sounds reasonable. There is only so long you can live a normally active life and not fall down a sinkhole, be hit by lightning, shot by a close relative, or have a flying car fall on top of you. So now to the sociological implications.
My aside in the original post was motivated partly by many comments over the years from one Dr Karl Kruszelnicki, who is roughly Aus’s equivalent to the USA’s Bill Nye or the UK’s Brian Cox. Like this:
http://blogs.unimelb.edu.au/sciencecommunication/2012/09/14/life-death-and-disagreeing-with-dr-karl/
There is some famous American futurist whose name escapes me who has similar views, to wit: Methusalechian lifespans (I’m claiming credit on that coinage, by analogy with “Noachian”) will be great, and we will probably achieve them before the end of the century. Things will be fine.
I just don’t think they have thought it through. In 1900 world life expectancy was about 32, in 2000 it was about 67. We have coped with that doubling, but what happens if life expectancy multiplies by tenfold? To sharpen my parameters, here is what I’ll the call Kruszelnicki Scenario:
[ul]
[li]A treatment (the Methusaleh pill or M-pill) is invented that will stop normal cell ageing.[/li][li]It will give you an expected lifespan of 600 years if you live a healthy lifestyle. [/li][li]This implies concurrent medical discoveries that will prevent you getting cancer or degenerative diseases or whatnot. These discoveries will not prevent you drinking yourself to death if you so choose, or save you from a falling flying-car.[/li][li]We can implement the M-pill over a relatively short time, decades (like polio vaccination) not centuries (like improving sanitation).[/li][/ul]
Apart from the obvious issues of food, energy production, and pollution for a burgeoning population, I’d like to canvas a few social impacts that have struck me.
You Get to Work For Centuries
Forget retirement. The retirement insurance industry has collapsed. You have to keep working for century after century.
Do you love your job? That’s great! You won’t mind staying. You may have many people under you who want your great job. But they aren’t getting it, are they? Because you will be there for centuries. And you are not getting your boss’s even better job for exactly the same reasons. You are going no where: for centuries.
My Brain is Exploding
There is only so much information and so many memories the human brain can store. I rather like Elvis today, but in 600 years will my brain remember what an Elvis is? Me 600 years from now will have a completely different stock of memories. Parents? Gone. First girlfriend, first house, first fifty friends. Gone. Except in the sense that my physical body has stayed the same for 600 years, I will be a completely different person.
What’s Your Name Again?
Through human history, living grandparents have been uncommon. With a life expectancy of around 35, you might expect to see your children produce a toddler or two, but that’s about it. In developed countries today, grandparents are common.
But now you live to 600 years of age. Average length of marriage in the USA and Australia is 9, call it 10, years. Over 600 years you might be married/partnered up to 55 times, call it 25 times if you include the long single gaps. 25 times. How much will you remember of the first 15 spouses?
Say each marriage produces a single child. How much connection will you have with your 25 children? And there are your 20 generations of descendants. What possible connection could you have with your descendants 20 generations hence, people born 570 years after you were? How many birthday presents is that?
In My Day
How involved are you with the culture of people 20, 30 or more years younger than you? Keep up with their slang? Watch the videos that watch? Eat the food they eat? Buy the products they buy? Follow the trends they do? Follow the celebrities they do? Do you neuronically upfeed your BrainTwizzle every minute?
I thought not. After a certain point in life, you just say “Frack it, I’m happy; and I don’t know or care what BrainTwizzle is”. Ignoring BrainTwizzle may be viable for a few decades, but after 400 years you will be decidedly medieval. Not that you will care.
**
We Need More Prisons**
With the M-pill, a life sentence means some 600 years of taxpayer-funded incarceration. You’ll be paying for that.
Insurance
Life insurance premiums will collapse, so that’s good. But any insurance scheme that involves paying lifetime benefits, such as worker’s compensation or motor vehicle accident insurance will also collapse. To nothing. After the M-pill, if you become severely incapacitated through negligence, no insurance system or court order on the planet will pay you for the next 580 years of your life in a wheelchair. You are on your own!
I Love My Children
In the middle-class developed world, people die in their 70s and 80s. They leave a modest or more sum to their two, three, or four children; the family home, if nothing else. These late middle-aged children may use this decent sum of money to pay off their own mortgages, and the cycle repeats.
Not if you live to 600 years. You won’t even be able to remember the names of your 25 kids, let alone their 20 generations of descendants. The inheritance you leave to be divided amongst the 25 will pay for some jellybeans, not help their mortgages.
The Rupert Murdoch Effect
Rupert Murdoch is 82. He loves running News Corp. He will still love running it when he is 600. One man, 600 years. 600 years of an 80-year old’s views.
Max Planck said that science progresses one funeral at a time. But if there are no funerals, what happens to innovation? The venerable oldies on all those boards are not going anywhere-- they can’t afford to. If Thomas Edison were still alive today and in charge of his corporate children, would he still be wearing an “I Hate Tesla!” t-shirt let alone 500 years hence? How would the future politics of the United States be altered if every President for the past 500 years was alive, hale, hearty, and deeply bored after centuries in retirement?
Dr Garry
ummmmm…If people remain married for a thousand years, it’s possible that a lot more of them will be at risk of being killed by their spouse.
just sayin’ 
(chappachula…who forgot to take the garbage out last night…again.
Human brains do not have an infinite capacity to store information. They will all get saturated at some point, maybe in 200-300 years, and stop being able to process information meaningfully any more. Unless people are ‘born-again’ in a much more literal sense - they get their brain backed up to storage and then wiped clean. In that case no one would be more than say 300 years old in terms of memory and experiential learning, though the body may endure 3000 years.
Bravehearts that try to avoid a brain backup will die slowly as their brain loses capacity to deal with life and eventually shuts down; very similar to extreme and prolonger sleep deprivation.
I think some people would work for centuries, but some people would save up enough to retire in 30 or 40 years and live off the interest for the rest of their 600 years. (some would start businesses, fail and return to the workforce) Some people wouldn’t save and would feel “forced” to work forever, just as some people work into their 70’s and 80’s now. I think eventually you’d see even more economic disparity between the savers and the spenders than we have now. The “life of leisure and luxury” class would grow dramatically, but so would the working class of people who barely make ends meet each month. The middle class would be nearly nonexistent.
I don’t think memories work in quite this fashion. Surely the details of the oldest events fade, but you wouldn’t completely forget the old stuff. Think of your earliest childhood memories now. You may no longer have the clarity of memory you had as a child, but you still have a basic idea of what happened, even if only what you are remembering is the last time you recalled the memory. Memory is very efficient in this way. Your brain simply reduces the storage of an old, rarely-accessed memory, down to a simple bullet point.
Interesting, perhaps life sentences are replaced by sentences of 100 years. Or perhaps death penalties become much more common?
The market will adjust to these changes. There will still be term and whole life insurance. Long-term disability insurance would become a LOT more expensive for the “lifetime” option.
Not necessarily. This will vary according to the saving/spending of the deceased, just as it does now. Many people continue to make more than they spend until they die. And the wealth doesn’t have to be spread so thinly. Typically the bulk goes to the offspring and only a token gift is left to grandchildren.
In his excellent book The Face of Battle, historian John Keegan points out that the death rate for alpine mountain climbers historically approached or exceeded the death rate in modern industrialized warfare. Thus the German phrase for falling rocks, “mountain artillery,” was peculiarly apt. Indeed, most of the mountain climbers back then were young men of military age. He drew an analogy between alpine climbing (which in the 20th century morphed from walking holiday-style up steep grades into prolonged “campaigns” to scale sheer faces by means of technical hardware) and warfare (which during the same period evolved into increasingly large-scale campaigns in which individual humans would be trapped in a hostile environment for long periods).
If he’s right, and mountain climbing (at least back then) was as hazardous as total war, that implies it’s pretty hazardous.
Well, people in economically comfortable circumstances in First World societies have been increasingly less and less willing to serve in war. The assumption I’ve seen most often is that a potentially long, comfortable life leads people to value it all the more and be less willing to risk it.
So I’d guess that super-long-lived people would very much NOT see life as cheap, and would abjure risk and view early death as an even greater tragedy than we do today.