We aren’t machines, but as a thought experiment lets pretend that’s an accurate metaphor.

You can repair a machine, and science, not religion, has come up with amazing repair techniques that have significantly extended our lives. Our “machines” now last twice as long as they did just a couple of centuries ago. But eventually, no matter how often and how carefully you repair it, every machine reaches a point where it’s so broken down, so fatigued and so worn out that that further repairs are impossible.

Posted: November 27th 2008

See all questions answered by Dave Hitt

Humans and all other living organisms are like machines. It’s a metaphor. People are clearly more complicated than eggs, but nobody wonders why you can’t un-make an omelet.

Look into the second law of thermodynamics.

Posted: November 13th 2008

See all questions answered by George Locke

Aubrey de Grey lists the challenges for repair in the following excerpt from this article:

SENS is a seven-point plan for the comprehensive repair and maintenance of the body at the molecular and cellular level. Each point addresses one of the types of intrinsic “damage” — ongoing, lifelong accumulating side-effects of our normal metabolism that contribute to eventual age-related pathology and disease. The seven types of damage are cell loss, cell death-resistance, chromosomal mutations, mitochondrial mutations, indigestible molecules inside the cell, indigestible molecules outside the cell, and crosslinking of long-lived extracellular proteins.

Another interesting excerpt from the same article:

The general consensus among biologists who study aging is that aging does not serve any evolutionary purpose, no — that it happens by default. We have plenty of in-built, automatic anti-aging machinery, but perfect anti-aging machinery would be infinitely elaborate, so in practice it’s only as good as was needed in the Stone Age to keep us from dying of old age before we died of other hazards like predation and starvation.

Posted: November 13th 2008

See all questions answered by logicel

It probably could be, but there’s no mechanic who’s good enough yet.

We can repair the body after clinical death, with CPR and adrenaline. So that’s a start.

We can keep most of the body alive almost indefinitely. Read the news: there’s a controversy every time someone’s brain has checked out but their heart and lungs are kept running by a machine. The underlying question is whether or not the person is actually dead. Without the machine, there’d be no question.

The brain’s the thing we can’t repair with any confidence. Every minute the brain is deprived of oxygen after the heart stops beating, important cells die and unique neural connections which run the rest of the body are permanently wiped. We have no way to rewrite them at present, although this may change as our understanding of neural networks increases and we gain the ability to grow brain cells from stem cells.

Alternatively, when various parts are beyond repair they can be replaced, like hips, bones and even hearts. The procedure for each is extremely difficult, and we certainly haven’t got the hang of brain transplants for example. Nobody ever said it was eternally impossible, though.

Look at it this way. Once a car has sat in a backyard for a few years, it reaches a level of decay where the world’s best auto mechanic would tell you it’ll never run again. You could still fix it, but you’d have to replace every single part so it hardly counts. After a human dies, various parts of the human body reach an equivalent level of decay in hours. The brain gets there in minutes. There’s no procedure to salvage all the essential parts in that time. Yet.

Posted: November 12th 2008

See all questions answered by SmartLX