Page 193 - For Men of Understanding

possible only with the establishment of thousands of physical and ecological
balances. Moreover, the establishment of those conditions alone on our planet
is not sufficient for the continuation of life on earth. If the world were to exist
in its present state with its geophysical structure and its motion in space, yet
have a different position in the galaxy, the balance would still be upset.
For instance, a smaller star instead of the sun would cause the earth to grow
extremely cold, and a bigger star would scorch the earth.
It is sufficient to look at the dead planets in space in order to understand
that the earth is not a result of random coincidence. The conditions essential
for life are too complicated to have been formed "on their own" and at ran-
dom, and, certainly within the solar system, the earth alone is especially cre-
ated for life.

THE NITROGEN BALANCE AND BACTERIA
The nitrogen cycle is another evidence that the earth is especially designed
for human life.
Nitrogen is one of the basic elements found in the tissues of all living organ-
isms. Although 78% of the atmosphere consists of nitrogen, human beings and
animals cannot absorb it directly. It is the main function of bacteria to meet our
need for nitrogen.
The nitrogen cycle starts with the gas nitrogen (N ) in the air. Bacteria liv-
2
ing in some plants transform nitrogen in the air into ammonia (NH ). Other
3
Nitrogen is con-
verted to ammo-
nia by lightning,
and dissolves in
the soil.
Nitrogen in the air

Animals eat plants

Plants use
nitrate Animal faeces and
dead animals
Bacteria convert some Dead plants
amounts of nitrogen Bacteria use a certain
into ammonia amount of nitrate,
which again is con-
verted to nitrogen
Becomes nitrate (NO )
3
Ammonia (NH ) Bacteria convert
3
ammonia
Decomposition
Bacteria convert amino acids
into ammonia

The Earth 191