05 May 2006

Billion-year-old carbon on the Tree of Life

each human branch
on the Tree of Life
entwines countless carbon atoms
ingested as food
excreted as CO2
recycled continually
from branch to branch
participating in
billions of lives

each atom uniquely traceable
(in theory)
across the surface of island Earth
for four billion years, back
past the origin of the solar system

when it was captured by
Earth's new gravity
from the interstellar void
where it had drifted
for unknown billions of years

since the supernova that destroyed
its birth star

each carbon atom
with its own moment of birth
from hydrogen and helium
in one or another
unknown star's
fusion reactor

most likely within a few billion years
of the Big Bang itself
13.7 billion years ago