The collisions
The history of the
material of our drop is
in reality nothing
other than the story 
of a great many consecutive collisions.
If every particle
that makes up our drop
has suffered so many
collisions
then how many
collisions have 
determined the history of our drop? 
It would be not easy,
and it is not the purpose
of these considerations,
to find the true 
number of these collisions.
Only one thing is
for sure.
It would not be sufficient
to multiply the number 
of particles in our drop with the number 
of collisions suffered by each particle.
That would just be
the sum of the collisions
suffered by all the
particles in our drop.

In order for the
result of a collision to be exactly determined 
the motion of each
of the participating
particles must be completely defined.
This movement however
is affected by the last collision
with another
particle, which most likely is not in 
our drop, and whose movement is shaped through 
its previous collisions with others "foreign" particles 
and so on.

If, as we accepted
it, there exists
a deterministic sequence
from the 
beginning of the Cosmos to the moment
when we consider the drop,
the outcome of all these collisions must be
exactly determined
with absolute 
mathematical accuracy.
If only the
smallest uncertainty
existed about the
outcome of the collisions
the result
would be different.
It would not be deterministic!
Now that we have
studied in greater detail
such a simple phenomenon
as the fall of
a raindrop, the conclusion to which our
decision to accept the absolute accuracy
in the power of Natural Law led us, 
begins to seem unbelievable.
Were we perhaps
a bit rushed to 
reach this decision in chapter
5?
Maybe it would be advisable
before we take such
a serious decision about
the determinism in Nature, to deal in more detail 
with the predictability of collision which is shown 
to be the major cause of the phenomena.
Before doing this, however,
let's take a look at the second example.