5000 . ɡ ɿ -14.
-14 50000 .
-14
cosmic rays ѡ . ɡ -14 . -14 . -14 ( ) 5730 .
n + 14N → 14C + 1H
14 (B) . 5730 . 14
14 14 .
14
14 -14 . -12 -14 . -14 1012 -12 -14 .
-14 .


-14 -14 -12 -14 -14 . -12 . -14 -12 .



t = [Ln (Nf/No) / (-0.693) ] x t1/2

Ln Nf/No -14 . t1/2 -14 5730 .

-14 10% :

t = [ Ln (0.10) / (-0.693) ] x 5,700 years

t = [ (-2.303) / (-0.693) ] x 5,700 years

t = [ 3.323 ] x 5,700 years

t = 18,940 years old






-14 5730 -14 60000 . -14 -40 1.3x109 . -238 4.5x109 -232 14x109 -87 49x109 .

.

-14 1940 -12 -14