I was reading Creation - Life and How to Make It by Steve Grand. (This is the book that inspired Jeff Bezos to start the AWS initiative. ) In it he makes the following statement:

Anyhow, by now I hope you have thought of an experience from yoru childhood. Something you remember clearly, something you can see, feel, maybe even smell, as if you were really there. After all, you really were there at the time, weren't you? How else would you remember it? But here is the bombshell: you weren't there. Not a single atom that is in your body today was there when that event took place. Every bit of you has been replaced many times over (which is why you eat , of course)....

That didn't sound quite right to me. How could the atoms in your bones be replaced? Aren't your nerves pretty much fixed in place?

My question is: Are all the atoms in your body replaced with others over a 30 year period?

  • $\begingroup$ Bones, although they are hard, are very dynamic. They are literally in continual resorption and reconstitution, even in adult life when there is no growth. So you shouldn't be too surprised. And, in principle, yes, after a given period of time, all the atoms in your body would be "replaced". If you like that kind of thing, look up the Theseus paradox. $\endgroup$
    – Maljam
    Commented Apr 7, 2016 at 10:46
  • $\begingroup$ The lens of your eye is not replaced, IIRC. $\endgroup$
    – gilleain
    Commented Apr 7, 2016 at 13:10
  • 3
    $\begingroup$ There is no solid scientific evidence that this is true. It's sensational, and is likely true for much of the body (though I don't know the timeframe.) While many proteins and even some entire tissues turn over, some do not. Tooth enamel, for example, does not regenerate or get replaced. That makes carbon dating - to the year of birth +/- months - possible. $\endgroup$ Commented Apr 7, 2016 at 15:17


You must log in to answer this question.

Browse other questions tagged .