The NS article is issue 2556 of New Scientist magazine, 19 June 2006, page 50
the actual published work is Cell, vol 122, p 133 What he measured was the age of carbon in DNA, which is only a tiny fraction of the total number of atoms making up a cell. So I guess you are right in your more restricted meaning of "same". Cheers On Sun, Oct 08, 2006 at 11:52:49AM +1000, Stathis Papaioannou wrote: > > Russell Standish writes: > > > On Sun, Oct 08, 2006 at 12:35:44AM +1000, Stathis Papaioannou wrote: > > > This is > > > literally true, given that from moment to moment, even in the absence of > > > teleportation > > > etc., the atoms in your body turn over such that after a certain time > > > none of the > > > matter in your body is the "same", and before this time the fact that > > > some of the > > > matter in your body is the "same" is accidental and makes no difference > > > to your > > > conscious experience. > > > > > > > We _really_ need to dispell this myth. It turns out that A bomb tests > > prior to the partial test ban treaty provides a unique clock that > > allows one to measure when a particular cell was born. It turns out > > that whilst this statement is true of various organs (eg the gut in > > particular), neurons turn out to have an average age just two years > > less than the age of the person (as measured in cadavers), ie most are > > born during the rapid brain expansion that occurs during the first two > > years of life. > > > > This is crucial, because I would suspect that neurons have far more > > relevance to one's person, than do gut cells. > > > > I posted on this before - it was reported in a recent New Scientist. I > > can dig out the reference if people are interested. > > I'd be interested in the reference. However, I wasn't referring to turnover > of cells, but > to turnover of components of cells. Water and electrolytes are freely and > continuously > turned over while proteins and other structural components are continuously > breaking > down and being replaced. I'm not sure of the numbers but I would guess that > only a tiny > percentage of the matter in a neuron would be the same years later. If there > are trillions > of radioactive atoms to begin with then by chance some of them will persist > in a particular > cell provided it does not die. What is actually preserved in a neuron which > survives over > the course of a person's life is a rough template and physical continuity, > not the matter it > is comprised of. But for a few lucky atoms, ordinary living is equivalent to > destructive > teleportation. > > Stathis Papaiaonnou > _________________________________________________________________ > Be one of the first to try Windows Live Mail. > http://ideas.live.com/programpage.aspx?versionId=5d21c51a-b161-4314-9b0e-4911fb2b2e6d > -- *PS: A number of people ask me about the attachment to my email, which is of type "application/pgp-signature". Don't worry, it is not a virus. It is an electronic signature, that may be used to verify this email came from me if you have PGP or GPG installed. Otherwise, you may safely ignore this attachment. ---------------------------------------------------------------------------- A/Prof Russell Standish Phone 0425 253119 (mobile) Mathematics UNSW SYDNEY 2052 [EMAIL PROTECTED] Australia http://parallel.hpc.unsw.edu.au/rks International prefix +612, Interstate prefix 02 ---------------------------------------------------------------------------- --~--~---------~--~----~------------~-------~--~----~ You received this message because you are subscribed to the Google Groups "Everything List" group. To post to this group, send email to [email protected] To unsubscribe from this group, send email to [EMAIL PROTECTED] For more options, visit this group at http://groups.google.com/group/everything-list -~----------~----~----~----~------~----~------~--~---
