Unfortunately, our bodies are made of certain types of material that just has a difficult time lasting forever. Our heart tissue works really hard each and every day, and it's difficult to keep it in the groove for so long! One way to prolong life might be to always keep trying to replace old tissue with younger, more vital stuff. This could be difficult, though, since you would have to continuously monitor the status of every component of your body for, presumably, hundreds, maybe even thousands of years. One missed check-up at Speed BioLube could mean certain death. (How many times have you missed the 3,000 mile lube job for your car?) What if we gave up on our body all together after it whithers away? How could we still "stay alive"? Risking getting too philosophical here, we might consider a technology that could maintain not our entire body, but at least the part that matters most to keeping the "I" in ourselves alive: the brain. Keep your brain active and those neurons firing, and it doesn't matter if you heart tissue has rotted, or your fingers don't twitch anymore. If you really found it necessary to walk around to be happy for thousands of years, then you could even replace all that stuff with mechanical elemtents. Even if this sort of technology were available, would you even want to "stay alive" without the rest of your natural body in tact? Could you be happy only as an active brain on a stick? (Let's assume your active brain was connected to input/output devices that allowed you to interact with the world around you... so, you could still talk and see, and have access to all of your senses, but the only 'original' part left is your brain.) Matthew
