It was a time when the greatest power the world had yet known suffered an attack on its primary city which seemed to signal the coming of an age of unstoppable decline.The once seemingly unopposable power no longer possessed control over its borders,it was threatened by upheaval in North Africa, unable to bring to heel the stubborn Iranians, or stem its relative decline. It was suffering under the impact of climate change, its politics infected with systemic corruption, its economy buckling under the weight of prolonged crisis.
“given the fact that such physical immortality, or something close to it, does not seem to violate any known laws of nature, then if there is not something blocking its appearance, say complexity, or more ominously, expense, we are likely to see something like the defeat of death if not in this century then in some further future that is not some inconceivable distance from us.”
Thats like a version of the basic compelling premise for why we should obviously support and help take on working for the achievement of indefinite life extension. If more people thought about that basic principle of the matter, then it seems more of them would much more readily come to support indefinite life extension, sooner than later.
“What does art mean in such a context where the world it addresses no longer exists not long after it has been made?”
Maybe cultures will adopt more timeless things into their fiber. Like the form of a rose is timeless. The symbolism of the grim reaper is timeless. The stars are timeless. The big questions about life are, like how we got here and how the universe got here, etc.
I do not see any reason why indefinite life extension is impossible in a biological sense though I do think it is likely to be a much harder problem than many of its more vocal proponents would like to admit. Evidence for precisely how hard a problem it might be can I think be seen in the fact that despite what an evolutionary break out it would be for the species whose genetics were rearranged in such a way as to bring indefinite lifespan about (as long, that is, that the species could continue to reproduce) after 4 billion years of evolution no multi-cellular organism with the exception of a very peculiar species of jellyfish has figured it out.
I think people in general are much less freaked out by talk of extending the human lifespan as they are ending human death and for good reasons. As Vinge points out in the interview I linked to in this post indefinite lifespan forces people to confront what it means to be alive and what it is to be a self. From the perspective of long periods of time none of the things you mention above actually remain timeless: the rose will evolve or be bred into something else, the grim reaper would be meaningless and the very stars in the sky would change….