Basic HTML Version
1
'
1
1
\ \ ¡
,¡
Cosmic roys bombord upper otmo–
sphere. As
o
result, fost-movil'!g
neutrons ore produced.
Neutrons collide with otmospheric
nitrogen otoms. Moin reoction
produces corbon-14.
Corbon-14 combines with oxygen os does
ordinory corbon to produce corbon diox–
ide. This corbon dioxide with its rodioactive
carbon· 14 component is diffused through
otmosphere.
CARBON- 14
Trees, gross and other vegetotion absorb corbon
dioxide contoining carbon-14 during photo·
synthesis.
All animal llfe feeds on vegetotion,
Corbon-14 is added to their bodies.
Mon also eats vegetation ond onimals
having carbon-14 in their bodies. All life
contains equal amounts of carbon-14.
indicated radiocarbon years were the
same as actual calendar years.
And what about dating objects older
than
5000
ycars?
"There was only one way to check
the reliability of radiocarbon dating
over a longer span," said archaeologist
Edward S. Deevey, Jr., "and that was to
test it on thc materials of geology and
prehistoric archaeology. The age of such
materials is not 'known' in the same
sense
as
that of mummy cases or trees"
(Edward S. Deevey, Jr., "Radíocarbon
Dating,"
Srientific American,
Vol.
186,
No.
2,
February,
1952,
p.
25).
There wcre no dates historically fixed
Ambo...,clor Co/lege Arl
with which to check. Radiocarbon was
enti rely alone.
In the more recent historie period,
radiocarbon dates generally seemed to
agree with historical dates. With the
apparent success of radio::arbon dating
in the historie period, Libby very cau–
tiously stated: "In terms of physical
principies of course, a mcthod which
works for three thousand years might
extend all thc way to
fifty
thou–
sand...."
He did warn: "However, this is
MERE
CONJI:CTURE."
(Willard
f.
Libby, "History of Radiocarbon Dat–
ing,"
Symflo.rimn
011
Racliottrlit•e Dating
23
a11d
¡',[ethod.r
of
Lote Leve/ Cotmting,
March, 1967, page 24.)
Dr. Libby vcry heavily qualificd his
staternents. But most writers simply
glossed over such points. Laymen were
led to believe thc method was infallible.
Basic Asswnptions
The entire radiocarbon method stands
on certain basac assumptions which have
ncver been proveo to be truc. Experi–
mental evidence indicates rather cJearly
that some of thc assumptions, may in
fact,
be
wrong.
For examplc, has the amount of
radiocarbon in the atmosphere remained
fairly constant in past ages?
Scientists are not sure.
"An assumption on the constancy of
atmospheric radiocarbon conccntration
in the past is hasic for radiocarbon dat–
ing. However, the atmosphcric radio–
carbon conccntration depcnds on the
production r,\tc of radiocarbon
by
cos–
mic rays in the stratosphere and the car–
bon cycle on the earth, and there is
NO
I!VIOENCE
that cither was constant in
the past" (Kunihiko Kigoshi and
Hiroichi Hasegawa, "Secular Variation
of
Atmospheric Radiocarbon Concentra–
tion and Its Dependence on Geornag–
nctism,"
Jollrnrtl of
GeophyJical
Research,
Vol.
71,
No.
4,
Fcbruary
15,
1966,
p.
1065).
That assumption is recognizcd by sci·
entists but ignored by laymen who
::tlmost superstitiously accept radio–
carbon dates as true calendar years.
Suppose cosmic radiation varied for a
considerable time and magnitude in the
past? Suppose some shielding effcct
negated the cosmic shower's production
of
rad ioca rbon?
What would be the result if thc car–
bon-containing ocean reservoir had been
disturbed? What about extreme volcanic
activity ami mountain building -
would they have affected this crucial
relationship? Had some catastrophic
series of evcnts dwnped old nonradioac–
tive carbon dioxide into the atmos·
phere? How drastically would these
affect the apparent ages of specimens?
Suppose thesc and
¡
or other factors
had distmbcd the critica! relationship of
radioactive carbon-14 to ordmary car–
bon-12?
In spite
of
the attractivc:ness of