WEWilliams at smcm.edu (Bill Williams) wrote in message
news:<arheb8$2u7$1 at mercury.hgmp.mrc.ac.uk>...
> At 3:02 PM +0000 11/20/02, Mick wrote:
> >I'm trying to find out about some purported facts which were in
> >tonight's plot on Law and Order: Criminal Intent (this is in
> >Australia, BTW - I don't know what lag we have on episodes). Any help
> >will be appreciated.
>> >Has there
> >been an increase in radiation of enough significance (or perhaps of a
> >specific type) that would make recently manufactured linseed oil
> >noticeably different to linseed oil made pre-1945? If you're unsure
> >the radiation change - does it make sense that the oil would be
> >noticeably different if we accept that hypothesised radiation change?
>> My guess is that they're not referring to radiation per se, but to
> the changed levels of 14C. The atomic testing (not just Hiroshima and
> Nagasaki) done in the late 40s and early 50s did significantly
> increase the atmospheric concentration of 14C ("carbon 14"),
Thanks a lot for all this. Great stuff. I managed to find useful pages
once I entered 'carbon 14 1945 atmospheric concentration' in Google -
This one takes a while to load but halfway down it under 'Bomb
Effects' there's a quick summary of how significant the increase in
14C has been.
This is Chinese research on correlation of date with 14C in collagen
of teeth extracted from 1920-1977.
> since all living things are made of carbon that ultimately comes from
> atmospheric CO2, the ratio of 14C to other carbon isotopes is, in
> fact, quite measurably higher in organic material made since then.
> Carbon 14 is radioactive, but the change in total radiation caused by
> these increased levels is extremely small and requires very
> specialized procedures (similar to carbon dating) to detect. But it
> can definitely be done.
Thank you very much, William. Now I'll start with 'carbon 14 art
forgery' and see what I get :)
> William E. Williams WEWilliams at smcm.edu> Biology Department
> Saint Mary's College of Maryland
>> Academic year 2002-2003:
> c/o Dr. Marilyn Ball
> Australian National University
> Canberra, ACT 0200
> Phone: (02) 6125 4405 (international +61 2 6125 4405)
> FAX: (02) 6125 5095 (international +61 2 6125 5095)
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