Opposite Day: Radical Life Extension

Matthias has decided to come back for another round. This time he's here to grumble about the trouble with immortality.

Unlike most people, I don't think there's anything remotely outlandish about the ideas of people like Aubrey de Grey. I have no doubt that humans will eventually solve the engineering problem of aging, and I am utterly dreading the prospect. My break with the SENS boosters is simply that I don't think longer life is intrinsically good. What does it matter to you if you live 80 years or 8000, so long as it's a good time either way? When you're dead you're in no position to care.

Of course, on my view that just makes length of life neutral, but I'm going to come out and say that immortality would be downright bad for the human race. Max Planck put the problem eloquently in The Philosophy of Physics: "An important scientific innovation rarely makes its way by gradually winning over and converting its opponents: it rarely happens that Saul becomes Paul. What does happen is that its opponents gradually die out and that the growing generation is familiarized with the idea from the beginning."

Mutational variation is the driving force of memetic evolution just as it is in biological evolution: progress requires innovation. Innovation is overwhelmingly the province of the young, and humans tend to become increasingly set in their ways and resistant to new ideas as they get older. Not only that, but some generations we simply don't want to keep around. Frankly I know I can't be the only one who thinks we'll all be better off once (if?) the boomers kick the bucket.

Throw in the declining birthrates and the fact that immortality effectively removes much of the remaining emotional impetus to have children (i.e. living on through your offspring), and you've got a recipie for societal stagnation. I find immense irony in self-styled "dynamists" being so enthusiastic about creating a world full of immortal fuddy-duddies. But I know it's inevitable, sadly, so I'll be taking my suicide pills at 70 and leaving you to that horrid fate.

(Yes, I know that "Opposite Day" is a misnomer and no, it doesn't matter.)

Share this

OTH, most of us don't live

OTH, most of us don't live long enough to get rid of The Stupids.

I don't know that this is

I don't know that this is really true. There's nothing about growing older that necesarily means being set in your ways. Indeed, this might have more to do with the process of aging or be tied directly to lifespans. I wouldn't doubt that a radically longer life would also lead to radically different opportunities and increased chance of self-reinvention. After all, if I expected to live another 8,000 years I'd be more inclined to rethink my entire life every 20 years or so because it would not be as if I'd just "thrown away my best years."

There are a lot of unstated

There are a lot of unstated assumptions in Matthias's 4 paragraphs that I think are ripe for questioning.

1. He seems to think that the discovery of immortality is imminent. However, similar to the current state of AI research, it seems the more we learn, the more we realize how little we actually know. As such, the likelihood that an effective anti-aging technology is discovered before we're all too dead to benefit from it is very high, IMHO. Keep in mind that we still don't have good treatments for Acne, so why assume a cure for senescence is just around the corner?

2. Why is "societal evolution" intrinsically "better" than personal immortality? If the price of personal immortality is "stagnation" then I'll pick the former any day of the week. What I do with my time is *my* business, thank you, and if that means all I do with the rest of enternity is listen to ABBA over and over again, then what of it?

3. What's so wonderful about "the emotional impetus to have children," anyway?

Enjoy your pills!

I am getting more set in my

I am getting more set in my ways as I get older. For reasons of efficiency. I don't have the energy I had in previous decades of my life. Give me back that energy and I'll start innovating again.

One thing that makes me tired is people who whine about the prospect of restoring youth. I want to tell them to get a life, but the point seems to be that they're not really sure they want one. Did I mention that this kind of crap makes me tired?

And grouchy too.

It's a pity Matthias is on

It's a pity Matthias is on agreement with Matt on the likelihood of radical life extension. The desirability of radical life extension is really a secondary matter and one which approaches irrelevance the less likely RLE is.

It's not so long ago you admitted this was one of your "absurd" ideas, one which most intelligent people wouldn't share. Why not try and make your best argument against the likelihood of RLE and see if you are still convinced?

To a sceptic, it doesn't look at all like current technology has "cracked" mortality. It seems to me that, as with much of the cutting edge of techno-boosterism, the cognitive biases are going the wrong way. The reverse naturalistic fallacy (Something ought to be true, therefore it is true) is a pretty tenacious cognitive bias. I'd suggest this makes it difficult for someone excited about this possibility to evaluate the evidence with a clear head. After all, it's not as if humans haven't been anticipating a "cure" for mortality for thousands of years.

"...so I’ll be taking my

"...so I’ll be taking my suicide pills..."

Promises, promises...

By the time we have radical

By the time we have radical life extension technology, we'll probably also have advance neuro-pharmaceuticals and techniques for engineering more intelligent offspring. Today, old people manage to remain in power without accepting new ideas. If they try to do that in the future, they'll just be swept aside. Old people don't adapt to new ideas unless they're forced, but I think forcing them to adapt would be easier than you think it would be.

I know it'll be pretty

I know it'll be pretty darned easy for my Adrian Barbobot body, with her chainsaw hands and D-cups of justice!

Mattias assumes that we will

Mattias assumes that we will have the technology for radical life extension, but not the technology to restore neural plasticity to youth-like levels. It seems unreasonable to so readily accept the first and reject the second.

p.s. For a SF treatment of this topic, see Bruce Sterling's _Holy Fire_

John, stop dropping

John, stop dropping context!

Patri gets the kewpie for putting his finger on the flaw in the argument most precisely. Steve came close, but he didn't really address the neurophysical issues directly. XLM gets honourable mention for making a significant and closely related point, but unfortunately it was weakened by the fact that he didn't consider the argument that birth rates would also fall dramatically, making cognitive enhancements to new children moot since there'd hardly be any.

For the doubters Einzige and Frank: please note that Matthias made no commitment about the actual timeline of radical life extension. He said simply that it would happen eventually, which seems a pretty safe bet to me considering the human track record for overcoming engineering problems. Considering that nobody's taken up Aubrey's $20K challenge to debunk his ideas, I'd say it's incumbent on the critics to explain why radical life extension is implausible in principle. There's a lot of money in it for you.

For my part, I do harbour a faint belief that I'll end up living for an extremely long time. While this could certainly turn out to be wrong, I don't think it's crazy. Saying that "current technology [hasn't] 'cracked' mortality" is rather beside the point; the relevant question is rather whether advances within the next 60 years will be enough to get the echo boomers such as myself into escape velocity. Even more beside the point are comments like "it’s not as if humans haven’t been anticipating a 'cure' for mortality for thousands of years" because -- correct me if I'm wrong here -- humans have never had anywhere near as much understanding of their own biology as we do today, and that understanding is growing rapidly.

(Of course, I still plan to save for my retirement. Which is certainly a tacit admission that I don't believe this strongly enough to bet everything on it...)

I’d say it’s incumbent

I’d say it’s incumbent on the critics to explain why radical life extension is implausible in principle.

Not at all, this is just a convenient dodge. I never maintained that such a thing is implausible in principle. The problem is that there are always things which are plausible in principle - like, as Dennett puts it, building a ladder to the moon - but practically impossible. There is no particular reason to believe that RLE is possible in practice currently (and by "currently" I mean the next few decades).

Even more beside the point are comments like “it’s not as if humans haven’t been anticipating a ‘cure’ for mortality for thousands of years” because – correct me if I’m wrong here – humans have never had anywhere near as much understanding of their own biology as we do today, and that understanding is growing rapidly.

Ok, I'll correct you then. For starters, the reference to this tenacious belief was merely intended tas a reminder that this is a longstanding deep-seated cognitive bias. In any case, the claim in that last sentence could have been made plenty of times over the last two thousand years and it would have been true. It doesn't really say all that much about the state of current technology to say that we know more than we did before - well, d'uh, that's kind of the point of time's arrow and the conservation of knowledge.

The question is whether we know enough now about human biology (as einzege puts it above, as with AI, the more we learn, the more intractable some of the problems become) and have the technology or some outline of a possible realistic future technology to "defeat" mortality. The fact is, and there's pretty much a scientific consensus on this, we don't. All that's left is wishful thinking.

You are aware of the havoc that cognitive biases play on our intuitions, why not have a crack at goring your own ox and see if it's still standing - after all, isn't that what Popper would recommend?

Patri gets the kewpie for

Patri gets the kewpie for putting his finger on the flaw in the argument most precisely.

So is that a tacit admission that you agree with Matthias, then, that a society without "progress" is not a "good" society, and that anyone who disagrees is "wrong"? Shouldn't the real issue be cautioning against the tendency to rail against people who don't share your values? If the price of "progress" is slavery to one man's - or one group's - view of how the world "should" be, then isn't that too high?

OTOH, It does seem that Matthias's main point is the most common argument made against the desirability of longevity - the one originally (?) made by Jonathan Swift - and I'll confess to not understanding it. Why would anyone assume that advocates of RLE are suggesting that the world be populated by a bunch of oldsters hobbling around in a hazy stupor? But for some reason people do.

XLM gets honourable mention for making a significant and closely related point...

And what was that? I guess I missed it amongst all the mental masturbation and talk of übermenschen going on.

...please note that Matthias made no commitment about the actual timeline of radical life extension.

Au contraire! He announced that he'll be taking pills at 70, giving the arrival of the technology an upper limit of 50ish years.

50 years ago they thought that today we'd have intelligent robot servants, we'd have colonies on the Moon and Mars, and we'd be exploring the outer solar system. Just 12-15 years ago some of the more optimistic in the San Francisco Extropian community thought that we'd have advanced nanotechnology by today, and that the singularity wasn't much farther off. What was Drexler's prediction in Engines of Creation? I don't remember offhand and I don't have the book at this point. Maybe he didn't actually offer a timeline. Funny, though, how the big stuff always seems to remain about 15-50 years out.

Frank, Shaky anaolgies seem

Frank,

Shaky anaolgies seem to abound. RLE is not like a ladder to the moon, because there's demand for it -- once you've admitted that it's a tractable engineering problem and that people would pay a lot to get it, you're basically only quibbling over the timeline. RLE is also not like AI, because our understanding of intelligence is nowhere near our understanding of cellular biology -- and I think you'd be hard pressed to contend that the former isn't a much harder problem than the latter.

In any case, you put the question correctly, almost: "whether we know enough now about human biology ... and have the technology or some outline of a possible realistic future technology to 'defeat' mortality." The only thing that's wrong with this is that last part. We don't need to "defeat" mortality in the next 60 years, just push it back far enough that some people alive now will then live long enough to see the day when it is effectively "defeated." It's perfectly reasonable to be skeptical that this will happen for people alive today, but it's also unreasonable to dismiss the possibility out of hand.

"The fact is, and there’s pretty much a scientific consensus on this, we don’t."

Huh? Says who? And how can you have a "scientific consensus" about research that's still ongoing? This is approximately like asserting in 1940 that there's no way we could have a powerful computer you could fit in a briefcase by the end of the century.

Yes, I am well aware of what a bugger cognitive biases can be, and I am quite prepared to believe that I'm too bullish on this subject. But frankly I don't think it's possible to make a dispositive argument either way, precisely because it's so tricky to predict technological advances. History is riddled seemingly obvious predictions about it that turned out to be comepletely wrong. Which is why in spite of my optimism, I hedge.

Einzige,

Settle down, keep your Alans on. If I told you why the poetry of Wordsworth is rubbish, would you start babbling about slavery and ubermenschen? One would think you ought to be able to tell the difference between saying "you ought not desire X" and "you ought not be permitted to obtain X", but evidently not. In any case, no I do not agree with Matthias argument -- hello, that's why it's opposite day!

"Why would anyone assume that advocates of RLE are suggesting that the world be populated by a bunch of oldsters hobbling around in a hazy stupor?"

Nobody is assuming that. The argument is that new humans tend to disproportionately provide fresh perspectives and new ideas, and that attrition is the main way by which humanity gives up old errors.

"He announced that he’ll be taking pills at 70, giving the arrival of the technology an upper limit of 50ish years."

I can see how it might come off that way, but it was actually intended as a facetious allusion to Matthias' disdain for living too long.

Shaky anaolgies seem to

Shaky anaolgies seem to abound. RLE is not like a ladder to the moon, because there’s demand for it – once you’ve admitted that it’s a tractable engineering problem and that people would pay a lot to get it, you’re basically only quibbling over the timeline.

Well no actually. The ladder to the moon analogy is to llustrate that there are plenty of things which are possible in principal but come up against real physical barriers which make them practically impossible . In fact, "in principle" impossibility is almost as elusive as absolute verification. But just like we don't need absolute verification to adopt a working hypothesis that something is "true", we don't need "in principle" impossibility to determine practical impossibility.

This is approximately like asserting in 1940 that there’s no way we could have a powerful computer you could fit in a briefcase by the end of the century.

Well, the thing is that the type of things people were predicting would happen didn't, and the type of things that nobody anticipated did. RLE is one of those things that people have been anticipating for centuries, millenia. Just because one thing which seemed wildly improbable in 1940 (when there was no such thing as a computer btw) happened while hundreds of other predictions didn't, doesn't suggest that one improbable prediction today will share the same fate.

We don’t need to “defeat” mortality in the next 60 years, just push it back far enough that some people alive now will then live long enough to see the day when it is effectively “defeated.

The development of RLE technology is under no obligation to follow a smooth curve. The possibility that an extension of a couple of decades might be achievable doesn't entail that after those decades, further extensions might be available. When Armstrong walked on the moon, I'm sure those who expected space colonisation to follow a smooth curve will have been disappointed with progress to date

In any case, you've succeeded in dragging the dicussion towards the merits of RLE per se and away from my original point. Look at another way, forget for a moment that I'm skeptical of RLE. This is something which you admit you "believe" in. It seems to me that a better use of Matthias might be to air the best arguments you can muster - and there are plenty - against RLE and see if it affects how you think about it. If what you "believe" is reasonable and isn't the result of a cognitive bias that disposes you to relax your skepticism towards exciting scientific possibilities (and particularly ones from which you might stand to benefit) you ought to be at least able to rule it out. Wouldn't that be worthwhile?

Settle down, keep your Alans

Settle down, keep your Alans on. If I told you why the poetry of Wordsworth is rubbish, would you start babbling about slavery and ubermenschen?

I take issue with the idea that I was "babbling" about anything, but I am settled.

One would think you ought to be able to tell the difference between saying “you ought not desire X” and “you ought not be permitted to obtain X", but evidently not.

Good point.

Frank, We seem to be using

Frank,

We seem to be using "in principle" in two different ways. If there's a physical barrier preventing something from occurring then it's not possible in principle in the sense that I mean it. But neither you nor anyone else has yet demonstrated (or even argued persuasively) why there should be some physical reason that SENS is a fundamentally impractical engineering progam.

"Just because one thing which seemed wildly improbable in 1940 (when there was no such thing as a computer btw) [Oh yes there was. -- Matt] happened while hundreds of other predictions didn’t, doesn’t suggest that one improbable prediction today will share the same fate."

I agree, it doesn't suggest that; by the very same token it doesn't suggest that your prediction is on any better footing. The point was merely that it makes no sense to look at the state of technology as it is now and then say there's not going to be very much progress on it for the next several decades, particularly when there's already a whole lot known about what the technical challenges are. (And I'm still waiting for evidence of that "scientific consensus" of yours!)

"The development of RLE technology is under no obligation to follow a smooth curve. The possibility that an extension of a couple of decades might be achievable doesn’t entail that after those decades, further extensions might be available. When Armstrong walked on the moon, I’m sure those who expected space colonisation to follow a smooth curve will have been disappointed with progress to date"

Again, this is not a very good analogy. How much of a market is/was there for space travel? And yes, I know it's under no obligation to follow any particular sort of curve, but then I never said it was (don't take the "escape velocity" metaphor too literally). Most technological breaththroughs come in discontinuous and unpredictable bursts. I just think there's good reason to be moderately bullish about the prospects, though by no means certain.

The reason I can't properly do an opposite day job on the practicality of RLE (though I wouldn't mind it) is that it would require me to go deeper into the technical literature than is worth my time. I went for the desirability of it because that's a much more easily discussed question that doesn't require any expert knowledge. But by all means Frank, I'd be happy for you to point me in the direction of the plenty of arguments against the technical feasibility of it that you seem to be hiding behind your back. ;)

Matt, You really have it bad

Matt,

You really have it bad don't you? I mean, I thought you were above a line like this:

But neither you nor anyone else has yet demonstrated (or even argued persuasively) why there should be some physical reason that SENS is a fundamentally impractical engineering progam

Well, you're the one making extravagant claims, I'm simply being skeptical. The null hypothesis is that we age, we die. This is pretty much well borne out by empirical evidence. There are no physical impediments to small extensions of lifespan through better diet, exercise, plus advances in medicine etc. But, the technology required to vastly slow down ageing isn't here, nor is there any sign of it. You are presenting a manifesto based on wishful thinking and asking me to disprove it.

Where does one start? How about: where's the cure for cancer? Considering that 1 in 3 of us get it at some stage, and plenty of people die of other things before they get the chance to get cancer so you'd expect that proportion to rise with an "ordinary" extension of life. You'd think that a programme for RLE would need at minimum to have cancer nailed. As the SENS website puts it: "all we need to do is develop a really really good cure for cancer". Oh, is that all? Now, you might respond with the claim that cancer will be cured in the next few decades. Maybe it will, for my sake, I hope it is, but there's no basis for believing it will. Note that this is not a "prediction" that cancer won't be cured, but rather a statement that a prediction that cancer will be cured is not based on empirical evidence but on faith.

And by the way, that's just cancer. There's much more over at SENS where the assumption seems to be that we have nailed all of these problems already.

by the very same token it doesn’t suggest that your prediction is on any better footing.

But I don't have a prediction. To clarify:

1) Positive prediction: There will be a red car parked outside tomorrow morning
2) Positive counter-prediction: There definitely won't be a red car parked outside tomorrow morning
3) Skepticism about 1): I have no reason to believe there will be a red car parked outside.

(by the way this seems to be a little habit of thought you've picked up at gnxp where it's quite common to cast skepticism about an extravagant claim as if such skepticim represented a positive counter-claim in itself).

The point was merely that it makes no sense to look at the state of technology as it is now and then say there’s not going to be very much progress on it for the next several decades, particularly when there’s already a whole lot known about what the technical challenges are.

If it makes no sense to say there's not going to be "very much progress" (and I agree which is why I'm not making that claim) it also makes no sense to say that progress is going to follow a particular path according to a particular timeline.

(And I’m still waiting for evidence of that “scientific consensus” of yours!)

Oh, come on. Just throw a rock in a roomful of scientists and when you've finished applying the icepack, ask the scientist you struck whether she has any reason to think that RLE (i.e. "negligible sensescence", practical immortality) is around the corner. There's a reason why Aubrey de Grey is somewhat of a marginal figure.

Again, this is not a very good analogy. How much of a market is/was there for space travel?

Give me a break. You don't think there would be a market for space tourism if the technology was available? And I thought you were being the techno-booster here. In any case, the analogy works fine - look at the development of space travel technology: In 1968, it would have looked reasonable that the "technical challenges" associated with further space travel would be "cracked" over the next few decades. Just look at all the science fiction films over the two decades following the Moon landing, all of them envisaged that space travel would be routine by now.

But by all means Frank, I’d be happy for you to point me in the direction of the plenty of arguments against the technical feasibility of it that you seem to be hiding behind your back.

Well, gee Matt, where are all the fantastic arguments for RLE and maybe I could assess them. The best argument against RLE-boosters is that it is based on wishful thinking. It is a nonscientific theory of what might happen were a series of "technical challenges" (as you put it) addressed. The problem is that we haven't got past addressing those particular technical challenges yet.

Opposites, Radical Life

Opposites, Radical Life Extension at Catallarchy
A conversation on concepts and views of radical life extension - and the steps to get us there - is underway over at one of Catallarchy's opposite days: Shaky analogies seem to abound. [Radical life extension] is not like a ladder to the moon, because...

Shorter McGahon: 'We aren't

Shorter McGahon: 'We aren't immortal yet and no one can predict the future.' Well spotted, Frank.

Anyway, I've been trying to find evidence for your claim that humans have been anticipating a cure for mortality for 'centuries, millenia'. Care to point me in the right direction? It's just that I'm a little sceptical.

Cheers
ab

I’ve been trying to find

I’ve been trying to find evidence for your claim that humans have been anticipating a cure for mortality for ‘centuries, millenia’. Care to point me in the right direction? It’s just that I’m a little sceptical.

Wikipedia wouldn't be a bad place to start, try the pages on Elixir of Life, Philosopher's stone or Fountain of Youth.

Frank It's one thing making

Frank

It's one thing making predictions about the probility of a group of cavemen standing next to a chasm gaping of crossing it, and another thing when you replace them with a bunch of enginees and a parking lot full of what it takes to build a bridge.

Even if they've never built bridges across chasms but only burrowed tunnels, I'd put my null hypothesis on the engineers getting, sooner or later, to the other side.

Let's look at the facts, at our "group of engineers inspecting the chasm" and in spite of this never having been attempted before on a similar scale, attempt to gauge their capacity to access the other side.

1. Unlike before, the problems underpinning ageing have been defined and laid out as engineering problems.
2. Unlike before, humanity is now in an era where manufacture and tooling on the nano-scale exists and is gaining lots of traction in a multitude of fields. We're poking at things at the molecular and atomic levels. This is possible at ever decreasing costs. We can make *stuff* do what we please. And we're all made of the same stuff. This has never been the case before.
3. Unlike before, we are more and more empowered by computers to resolve bioinformatics problems. The mind-boggling amounts of data and computational problems such as that tackled by the Folding@Home project are, over time, matched by ever-increasing amounts of CPU cycles. As long as Moore's "law" (observation really) keeps up, it's not the computational problems that'll be keeping us back.
4. Demand, belief in what can be achieved and the money that follows.

While we are moving, the target, engineered solutions to ageing side-effects, is a sitting duck.

This is the real null hypothesis dictated by our empiric evidence.

It's just a matter of time before this happens. As was stated here before, we're only squabbling about the timeline.

And by the way. A ladder to the moon is a non-starter for two simple reasons:

1. Because the moon is in an elliptical orbit.

2. Because you don't need one. Build an elevator that will stretch 1/4 the distance to the moon and you can get a pound in orbit for under 100$. Build many, and you can get there at under 10$ a pound. And you can fling your payload as far as Jupiter without any serious onboard propulsion. I kid you not.

All you have to do is come up with a material that won't tear under its own weight - such as, for example, carbon nanotubes, and then figure out how to make a ribbon from that material that will retain a decent proportion of the tensile strength of its individual carbons.

NASA seems to think more of this idea than you do. They're sponsoring it in their centennial challenges :-)
Check it out at www.elevator2010.org

I'm not a biologist (though I am on my way to becoming one), but to my laymen's eyes it seams that at least several of the technologies required for De-Grey's 7 killers require no serious "revolutions", only evolution of existing capabilities and understanding, much like the space elevator requires us to improve our ability to produce and weave nearly-ideal carbon nanotubes up to a predetermined and static red line rather than the invention of something yet unknown. In both cases, we know where we're going and we're in motion.

And if gradual evolution of existing technology is all (or at least a major portion of) what stands between us and RLE, It's basis enough for reserved optimism.

>> "... of its individual

>> "... of its individual carbons"
Of its individual *molecules*. My neurons getting ahead of themselves.

"Wikipedia wouldn’t be a

"Wikipedia wouldn’t be a bad place to start, try the pages on Elixir of Life, Philosopher’s stone or Fountain of Youth."

I would think that the differences between looking/hoping for a magic place/item and anticipating a future engineering breakthrough would be rather obvious, but maybe that's just me.

A little over a hundred hundred years ago, you could have made the same arguments over flight:

FG's earlier incarnation: "For thousands of years, people have been anticipating human flight"

Anyone with a bit of foresight and knowledge of history: "Huh?"

FGEI: "Just look in the Enyclopedia Britannica under 'Daedalus', 'Icarus', 'tower jumpers', etc."

PS While your points about the expectations regarding space flight in the 1950's and 60's vs today's reality are well taken, I hope you would agree that that is simply a matter of timeframe.

I would think that the

I would think that the differences between looking/hoping for a magic place/item and anticipating a future engineering breakthrough would be rather obvious, but maybe that’s just me.

Jim, I'd just like to point out that the reason I mentioned this in the first place was as evidence for a longstanding cognitive bias in humans - to look overly favourably on the prospect for immortality - and not, in itself, as any kind of "proof" of the impossibility of RLE. I would have thought that was rather obvious, but maybe that's just me.

Frank, I'm going to

Frank,

I'm going to (belatedly) backtrack a bit and say that we need to seperate two distinct claims:

1. It is highly likely at some time in the future that humanity will find ways to reverse the aging process(es) and find cures for all deadly diseases like cancer.

2. It is moderately likely that (1) will happen rapidly enough for some people alive today to effectively live "forever."

Skepticism toward (2) is entirely reasonable, but I think anyone who disagrees with (1) is arguing against the weight of evidence. I know you disagree with (2), but I'm having a hard time pinning down where you stand on (1).

In any case, I don't think it's reasonable to say that (my) belief in either of the above statements is based on "faith" any more than it is to say that my belief that it is going to rain today is based on "faith." I don't know for sure that it will rain, but looking at the way it looks outside right now I think it's a pretty good bet. But I'm willing to revise my priors up or down given new evidence, which I should think is the opposite of a faith-based stance.

(And BTW, "skepticism" toward these kinds of Bayesian probability statements is just another way of saying you think these things are not likely, which is indeed a positive counterclaim. You cannot avoid standing somewhere. Unless of course you want to disavow the use of these kinds of subjective probabilities altogether, which is a whole other can of worms...)

It's also a bit disingenuous to snip out that short quote from de Grey without acknowledging that he gives it in the context of sketching out a promising research avenue for curing cancer, which he has been discussing openly with other scientists and for which part of the necessary technology already exists (repopulation of stem cells in the blood and gut). As Mik points out, there's nothing in the core of the SENS program that requires any kind of massive revolution, just incrimental advances in areas we're already pretty familiar with. His "can-do" attitude may be excessively optimistic about the technical challenges, but it's not as if there's nothing holding it up.

De Grey's views are undoubtedly outside the mainstream, but that tells us nothing because he's the first person to seriously tackle aging as an engineering problem head-on. The mere fact that a majority of scientists believe X does not constitute a scientific consensus about X in any relevant sense -- for there to be what we'd call a scientific consensus, the scientists would have to have detailed, evidence-based arguments for X. Mere balking at a new and alien point of view doesn't suffice. De Grey publishes regularly in peer-reviewed journals and is being taken increasingly seriously even by those in his field who disagree with him strongly, so you can't exactly write him off as some kind of crank.

And no, I honestly don't think people would be as willing to pay for space travel as they would for RLE, any more than they'd be willing to pay for vacation cruises more than they'd be willing to pay for antibiotics. Space travel is a luxury good, but the desire to live longer and healthier is much more visceral and urgent desire.

ab:"Anyway, I’ve been

ab:"Anyway, I’ve been trying to find evidence for your claim that humans have been anticipating a cure for mortality for ‘centuries, millenia’. Care to point me in the right direction? It’s just that I’m a little sceptical."

The Emperor QinShiHuang from the Qin Dynasty of China (~200+ BC), had been searching for it, even built a whole vast tomb for it. He died of ingesting the wrong elixir pill I think. And there is good literature evidence that those ancient buddhist monks had been searching for immortality for centuries/thousand years way before that time, ever since they had invented symbols to record history.