New research reveals longevity gains slowing, life expectancy of 100 unlikely

If you had full understanding of human cell and how they contribute to homeostasis, you could reprogram the cell to rejuvenate them endlessly without turning into cancer (many cancers have unlimited lifespan). You would also need to find ways to remove all cruft that gradually accumulates even in healthy body, like heavy metals etc.

How do you know that you could? That’s the question! If we did understand biology perfectly it may be that we would then prove no organism can live forever and reproduction is the only way.

Because there's absolutely no reason to believe that's the case? Like I don't know what the point of this argument is: maybe it's impossible. Sure, great. Okay. But you know...let's actually find out, because it looks very possible if hard from our current vantage point.

There's also no reason to believe the opposite is the case.

> Like I don't know what the point of this argument is

The point of the argument is to stop people like you from making declarations about what is possible without any evidence

> Sure, great. Okay. But you know...let's actually find out

Can you show me where anyone said we shouldn't find out?

> because it looks very possible

There's absolutely no reason to believe that's the case

Reproduction is not physically special. If it is physically possible to create a new organism with a longer lifespan than its parent (which it is), then it is physically possible to extend the lifespan of an existing organism. This may be impractical, but we cannot prove that no organism can live ≈forever, because it's not a physical impossibility. (Assuming a source of power remains present: it looks like the universe won't last forever, so we can trivially assert that no organism can live forever.)

This is perhaps the single worst form of argument I've ever seen. It does not help, it does not engage with anything scientific, it doesn't promote any new ideas (an example of an idea worth exploring is 'how can a cancer cell live indefinitely but other cells cannot' or 'why do different animals live for different lengths of time and what triggers this process'?). Things not worth exploring include whatever you're engaging in.

Do you believe this limit on lifespan is a uniquely human condition? or do you believe that it's impossible for any animal whatsoever to have a long lifespan (let's say 400 years for the sake of argument here).

Reproduction doesn't create whole new cells from nothing (except in the ship of Thesius sense). It's existing cells getting reprogrammed to do new things.

Reproduction does result in new matrix/scaffolding being built but the cells build that (and can rebuild it if so directed).

Of course some things "we" care about exist exclusively in the matrix (configurations of neurons, learned behaviors, memories, etc) so that could well be a limit for those parts of the body where we care primarily about preserving the matrix.

Anyway my point is that "reproduction" doesn't create whole new life, it's just a continuation.

Some cells are literally hundreds of millions of years old.

That’s not forever and it required a very specific environment, but biological degradation on that timescale can be effectively zero.

You know what a chaotic system is, don't you? That goes for a simple double pendulum.

There is no "full understanding" of a complex system.

yes precisely. that's why I picked 400 years

I mean I also feel like people would be pretty happy with the average lifespan of a tree, or a Greenland Shark, etc.

Also, some few (fairly primitive) animals are "biologically immortal," for example, lobsters (which are motile and vaguely resemble us more than, say, sponges and jellyfish) don't experience senescence.

That being said, I think we have a long way to go if we want to make any progress at all, and I doubt I will live to see it.

> Anyway my point is that "reproduction" doesn't create whole new life, it's just a continuation.

Then you're just arguing that we're already immortal, after all we reproduce, but I don't think that's what we're talking about when we talk about longevity. Longevity is the continued existence of a particular being, not its continuation through descendants.

> it is physically possible to extend the lifespan of an existing organism.

This is not at all guaranteed until we actually manage to do it. And that's exactly what we're discussing, you can't just say "but it must be possible". There's no rule of the universe that says it should, and given life has been around for 4 billion years and there's no single species (specially animals which is what we really should consider here if we're talking about human lifespan) that manages to live for more than a few hundred years, I think that's strong evidence that life is approaching a fundamental limit here. Someone else said "maybe that's enough" - well, why?? Maybe 100 years is already quite enough then??

> Because there's absolutely no reason to believe that's the case?

The fact we haven't seen an organism live forever is strong evidence that that's the case. You're the one making the case without any evidence!

Take the existing organism apart, fix all the problems, put the organism back together. No laws of physics prevent this, so by the totalitarian principle it's physically possible. Principles of engineering might make it impractical, and even if it is practical we might never discover how to do it, but it's possible.

The point is that a fundamental assumption that "reproduction" does anything that can't be done by regeneration is just a hunch that so far isn't actually supported by anything in microbiology. The existence of reproduction is irrelevant to the question.

> This is perhaps the single worst form of argument I've ever seen.

It's because you didn't understand it

> 'how can a cancer cell live indefinitely but other cells cannot'

Cancer cells are damaged cells mutating without regard for function. It's pretty obvious that there is a difference between "living indefinitely in a mutated form devoid of original function" is different from a cell performing a specific function

> Do you believe this limit on lifespan is a uniquely human condition

No

> or do you believe that it's impossible for any animal whatsoever to have a long lifespan

Let's pick an arbitrary timeframe and declare that as long

No, I don't think anything is impossible when you pick dates "for the sake of argument"

if you claim to think that 4x your current max-ish lifespan isn't long, then you're not having an argument in good faith, are you?