(upbeat music)
- [Narrator] To ‘be’ means to be in motion.
Movement is inherent in
every aspect of existence...
From the smallest single-cell organism,
to the most complex...
from the hidden processes
that make a flower possible
to the Earth’s many waters,
teeming with life,
from the migration of birds, clouds, people,
even to societies; nothing is static.
Compared to other planets,
that so far show no signs of life,
one glance at the Earth from space
will tell you she’s different.
She just looks…alive.
But what regulates or
maintains this lively planet?
In the 1970s, two scientists, James Lovelock
and Lynn Margulis, suggested that life itself
plays a role in regulating
or maintaining the climate
and the atmosphere at an
optimum level for life to continue.
They called their hypothesis Gaia,
after a Greek primordial goddess,
Mother of the Earth.
They compared Earth’s homeostasis,
the ability to remain at a steady state,
to processes in our own bodies
that regulate our temperature,
electrochemical balance,
blood chemistry, and so on.
Gaia is the study of the Earth’s geophysiology,
how it functions as an organism.
Think of the Earth’s oceans
and rivers as her blood;
the oxygen-producing forests as her lungs;
the four layers of soil as her skin;
and all living creatures, meaning you,
as the Earth’s senses.
Today, there are many variations
of the Gaia hypothesis.
Some scientists disagree that
the Earth is actually alive,
but admit that life on
Earth significantly impacts
planetary processes.
Others go further and claim
the entire Universe is alive!
Look around. How do you define life?
By your definition, is the Earth alive?
