The molecules

Our drop is composed of many molecules of water.

They did not all start their descent to earth simultaneously.

Some have been added on the way

and others which were originally together left the road.

Water molecules are continuously added to the drop

from the gaseous state of water vapour in the atmosphere
while other molecules evaporate from the surface and pass
from the liquid to the gas state.

Πλαίσιο κειμένου: The "fate" however of each of these molecules was, according to our strong deterministic agreement, absolutely predetermined.

As a molecule that was initially

inside the drop came to the
surface this didn’t happen
on its "own initiative".

Some other molecules pushed it  

during the incessant thermal
motion, this total "pushing"
that prevails in nature, which
is something we usually forget.

And when another molecule left the surface,

this was because some of the interior
molecules gave it such a strong "nudge"
that provided the energy needed.

The same goes for condensation.

Collisions of molecules in the gas
state are those that led a molecule
to pass into the liquid state.

The "crowd" of molecules in a gas may not be

as large as in a liquid, but the crashes
are again the norm.

A gas molecule under normal conditions "flies"

at the speed of a very fast airplane,
but it can’t "enjoy" this speed.

Πλαίσιο κειμένου: It goes from crash to crash.
It suffers about 10 billion 
collisions per second.

The fate of the last seconds

of the molecules of our drop
is, except for gravity,
determined by collisions.

Collisions with air molecules (which we call friction),

collisions with water molecules which
result in addition or removal of material.

What happened then before that?

Exactly the same.

Collisions brought a molecule of the ocean
first to the surface and then to evaporation.

Collisions led it then, perhaps after months, to the
atmosphere at that point where the drop was formed.

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