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.
>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 of
>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"), and
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.
William E. Williams WEWilliams at smcm.edu
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)