"Increase and multiply"
I think it interesting to consider how our
population evolved on Earth,
so that we have a measure of the degree of our success and have
objective data to argue with.
How did our population in the world develop in the last 1000 years?
The diagram in Figure 1 gives the answer.
We can be proud
of our brilliant success.
Could we imagine an even bigger success?
The first remarkable thing is that starting about
one million years
ago, we were able to become some 300 million in the year 1000.
This is no small achievement, if we consider that
we started from very few individuals, maybe one
family only, as some anthropologists believe.
This success however appears not so great when we
compare it with our present results.
Today we have surpassed the 6 billion.
And the most important thing, the fact
which proves the ever-faster growth
(i.e., the growing evidence of our success)
If at the beginning we needed one million years to
"create" 300 million people, today we achieve the
same increase of the population in only 10 years.
In the seam way as the rich say:
"To make the first million, it took a long
Then it multiplied by itself".
The curve, which describes such phenomena, has exactly this form.
At the beginning it creeps almost horizontally
(imagine the curve of Figure 1 for a million years back. On
the scale of our drawing it couldn't be distinguished from zero),
without revealing the potential hiding inside it,
and finally shoots almost vertically upwards.
What, however, does such a curve describe?
What else but an explosion.
In this case the population explosion.
The increase happens more and more quickly,
the end is approaching at an accelerated speed.
But why the end?
Could not this increase proceed ever further?
Proceed where? To the infinite?
Is it possible to have
a development that
extends to the infinite?
Of course not.
In mathematics there is the concept of infinity.
In nature, in reality, in life there is no such thing.
For the specific case of population growth, it is
on a finite planet an infinite population cannot develop.
How many should we become?
As many, as cover the entire surface of the earth
packed so close to each other, as in the subway?
And what would we have to eat?
Where would we plant our crops?
There is a limit, which is evident purely from energy considerations.
If we filled the planet with humans, then they
would die of hunger,
because there would be no room to grow the plants that are absolutely
necessary to feed the population.
All of us, animals and plants,
acquire directly or indirectly from the sun
the energy that is necessary for life.