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\begin{document}

%-------------------------------------------------------------------


\section*{friction}

\hypertarget{idea}{}\subsection*{{Idea}}\label{idea}

(some discussion should eventually go here, for the moment this entry just serves as a container for the (maybe) interesting piece of ancient history of thought recorded below)

\hypertarget{history}{}\subsection*{{History}}\label{history}

Aristotle may have been either ignorant or dismissive of friction but in the Epicurean school exemplified in the writings by Lucretious it is not, he says that atoms `are in perpetual motion at enormous speed, since in the void they get no resistance from the medium, and when they collide they can only be deflected, not halted'.

This is in the lines 80-332 in Book 2, section 4 of

\begin{itemize}%
\item Lucretius, \emph{De Rerum Natura} (\href{http://classics.mit.edu/Carus/nature_things.2.ii.html}{web})

\end{itemize}
The author there argues that atoms are in constant motion (all in the English translation by William Leonard):

\begin{quote}%
For far beneath the ken of senses lies

The nature of those ultimates of the world;

And so, since those themselves thou canst not see,

Their motion also must they veil from men


\end{quote}
and that they are constantly colliding with another:

\begin{quote}%
Inveterately plied by motions mixed,

Some, at their jamming, bound aback and leave

Huge gaps between, and some from off the blow

Are hurried about with spaces small between.


\end{quote}
But they're able to be stay together to form compounds, but they're still in motion:

\begin{quote}%
And all which, brought together with slight gaps,

In more condensed union bound aback,

Linked by their own all intertangled shapes,-

These form the irrefragable roots of rocks

And the brute bulks of iron


\end{quote}
and that the motion must be unpredictable, (Empson uses the word swerve here), for otherwise they'd never collide and nothing would be then created.

\begin{quote}%
For were it not their wont

Thuswise to swerve,

down would they fall, each one,

Like drops of rain, through the unbottomed void;

And then collisions ne'er could be nor blows

Among the primal elements; and thus

Nature would never have created aught


\end{quote}


\end{document}