Careful what you wish for. Aging and death are woven deeply into the fabric of society, indeed, into the fabric of life itself. Old growth needs to be periodically swept away to make room for new growth.
The only logically possible outcome of immortality is that sooner or later the entire biomass of the planet is consumed by immortals, at which point all growth must stop. Imagine being the last person born into such a world, doomed forever to be the youngest, least experienced, least powerful member of a static society where no one ever ages and no new people are ever born. Is that really a life you would want to lead?
This is not immortality, this is eternal youth, until you die for some reason (war, an accident, suicide, whatever) .
Thermal engines were a radical change in society, it let us do things that were impossible before, like flying. There will be new changes in the world, like nuclear fusion, DNA editing(with actual understanding of it not like we do today), symbiosis between man and machine with high bandwidth communication...
With nuclear fusion you could irrigate the Sahara dessert, you could irrigate Australia. Take Google Earth and look how big those places are. Those places are bigger than Europe and the USA.
With nuclear fusion you could LED grow plants without pesticides and almost without using water(you recycle it).
You can grow food or live in space, mine asteroids and planets like Saturn( do you know how big is Saturn?).
> The only logically possible outcome of immortality is that sooner or later the entire biomass of the planet is consumed by immortals, at which point all growth must stop.
You seem to be using the word "immortal" in some kind of fantasy meaning of "it keeps living forever no matter what". That's very clearly impossible.
Revise your definition to state instead: "keeps living indefinitely unless prevented by accident or disease, or is killed on purpose". Now see how your conclusions change.
Preventing and/or reversing aging is definitely good. If too long a life becomes a problem for some reason and you feel burdened by it, that's easily dealt with, just get a piece of rope, find a tree, and solve your own "problem".
> Is that really a life you would want to lead?
Your reaction is typical for a surprisingly large number of people. It's just a strategy to deal with the uncomfortable outcome of your own death, nothing more. To be able to cope with that, many people end up believing all sorts of bizarre things, such as "death is part of life", or "you don't want to live in that kind of world". Bullshit. You're just brainwashing yourself because otherwise you'd find the prospect of mortality intolerable.
An attitude that's a lot more honest is to recognize that aging and death are things we ought to fight, even though as of right now we're losing that battle.
> You're just brainwashing yourself because otherwise you'd find the prospect of mortality intolerable.
As someone who has suffered from suicidal depression and recovered from it, I am intimately familiar with the subjective sensations both of feeling like death would suck, and feeling like it would be desirable. Your subjective sensation that death sucks has nothing to do with the objective truth, it's just a reflection of the fact that genes that build brains that think that death sucks tend to reproduce better than genes that build brains that think that death is awesome. This does not change the empirical and theoretical fact that death is in fact an integral part of life.
When we say we are interested in immortality, people say that's because of the 'fear of our own death'.
Sorry, but it's wrong.
When something is inevitable (given our current technology, it is) there is no need to be afraid.
However, when it becomes evitable, then it is time to fear. People are are brainwashing themselves because they find the prospect of their own mortality intolerable make me think they know we we will eventually have the technology, so try to feel better for living in the wrong time and place.
Immortals will still die occasionally due to accidents and other non-age related causes. Unless risk is totally eliminated from the world, there will always be a positive replacement fertility rate.
Actually, I think the greatest risk in a society of immortals would be murder. Everyone would constantly be eyeing each other as a potential resource to allow themselves to reproduce.
Given technological progress and human nature I think that might be a temporary or worst case scenario but unlikely to be a long term status quo.
What about exploration or just plain old boredom? There might be more radical escapes (VR, brain upload), more extreme sports or more people leaving this planet in search of something else.
1000 years is a long time. Forever is a lot longer than that..
I think immortality and living for a few million/billion/trillion years are essentially interchangeable, for all we can appreciate it - I mean, yes we'll die eventually, but nobody thinks a million years ahead. Hell, Most people don't even think 3 years ahead, from what I've seen of elections.
Risk of violent death is mainly an issue because it's not worth investing in - you're going to be die for sure before age 130 currently, why bother with the smidgen of a chance of death by comet when AGING is around? Remove aging-related death and people will put a whole lot more effort into preventing other things.
As for the human aspects:
Replacing teeth should be easy, since we can already do full implants (we just don't bother much, since most people die before their teeth fall out, if they brush/floss properly) and we'll have a long time to figure it out if we really want the normal type.
Marriage isn't forever currently, and I don't see how immortality would change that.
Or, we could limit reproduction for those that choose not to age, so that you can only reproduce when you're next in line with and someone dies, keeping a consistent population.
> you can only reproduce when you're next in line with and someone dies
A system similar to that has historically been employed in lines of royal succession, where the number of thrones available places a hard limit on how many people can be kings. It has generally not ended well.
> The only logically possible outcome of immortality is that sooner or later the entire biomass of the planet is consumed by immortals, at which point all growth must stop.
Growth is not a discontinuous function, it's continuous. Resources will become scarce, wars will be fought over them thus further slowing the decline, unless of course biomass growth is encouraged. Fortunately, this is quite simple.
We're already growing meat in labs far more efficiently than the natural process, and without the harmful environmental emissions that accompany raising cows.
Your scenario is fear-mongering, and not at all realistic IMO.
