Yes, I did leave time out of it for the purpose. Our civilization is so young, but we already can easily replace almost every body part we have, not to mention better ways of getting new ones [1].
In the near future, not only we will continue to stretch average life expectancy, but we will continue to mesh technology with living tissue. Today we can have metal bones, joints, metal plates in human brain, porcelain teeth, all sort of signal strengtheners (fake eye, hearing devices, etc), nothing tells we will stop developing those more in the future. No, we have a long way before we could live forever, but definitely mechanical devices that can least 500 years (fake heart, lever, lungs, etc etc) will stretch our lives X-fold. I would assume if some civilization flies UFO crafts, they most likely advanced on other fields as well.
In the near future, not only we will continue to stretch average life expectancy, but we will continue to mesh technology with living tissue. Today we can have metal bones, joints, metal plates in human brain, porcelain teeth, all sort of signal strengtheners (fake eye, hearing devices, etc), nothing tells we will stop developing those more in the future. No, we have a long way before we could live forever, but definitely mechanical devices that can least 500 years (fake heart, lever, lungs, etc etc) will stretch our lives X-fold. I would assume if some civilization flies UFO crafts, they most likely advanced on other fields as well.
[1] http://blog.ted.com/2011/03/07/printing-a-human-kidney-antho...