How would you repair a piece of metal ... how do you replace "a muscle" The huge difference between repairing a piece of metal, and repairing a living tissue,

How would you repair a piece of metal ... how do you replace "a muscle" The huge difference between repairing a piece of metal, and repairing a living tissue, is, obviously, the living tissue can repair itself. The mechanisms of self-repair are built in, and they are extremely effective. The problem is these mechanisms break down with age, so the task becomes figuring out how to re-enable them. Yes, we don't know how to do that yet, but keep in mind - just 10 years ago we didn't know how to do things like CRISPR gene editing and now we can do something like this: https://www.bbc.com/news/health-63859184 https://www.bbc.com/news/health-63859184. The point is, we are making progress towards the goal of controlling all the processes in our bodies. There's absolutely no reason to believe this progress will stop any time soon. Even if we can't do it today, things like organ or limb regeneration do not sound like science fiction any more, it's a question of when, not if. Yes, it's quite likely every one of us Millennials will grow old and die, but I'm much less sure about our kids, and our grand kids will most likely be able to stay forever young if they so desire.