Darzu wrote...
Real immortality is not something physical, the best you could hope for is extened longevity.
Immortality is literally:
"To live forever."
To live forever... An example of a real immortal is none other than Achilles.
To become immortal is to immortalize your name, your existence. And Achilles achieved that feat.
Achilles of that time, of that name, now lives on forever. Thus, he is figuratively and literally immortal.
This. Immortality is very nearly impossible. Not even the universe will last forever. The Universe will end in a Big Crunch where gravity wins, or a Big Rip where the universe accelerates so much that even atoms rip apart. Look it up for more detail.
But extending human longevity is possible. And I think it is very much worth it. Imagine a nano-machine that can detect cancerous cells and destroy it immediately. Or a nano-machine that can repair damage to a chromosome in an unborn child. Even a machine that can repair damage to the spine that would otherwise leave a person paralyzed. So much potential for good, yet also for evil. Cybernetic humans would be susceptible to computer viruses and hackers just like Ghost in the Shell.
If it can save lives, then humans should try it.