ABSTRACT
Tetrahedra may be packed together in infinitely many ways, since the manner in which the interstices are arranged and the aggregates are linked together is not fixed by any construction rule. Moreover, this is also the case during rapid cooling of our alloy, when tetrahedral aggregates form spontaneously and join together, unable to respect the symmetry of the tetrahedron on the boundaries. The short-range order which is generally present in glasses outlines the boundary between perfect order and total disorder: in glasses, the position of the atoms is neither fixed by a periodic rule as in a crystal, nor random as in a gas. Polymers will be the second example of amorphous packings. These materials consist of extended linear molecules, which are themselves formed by laying n monomers end to end. This laying end to end which necessitates the intervention of a catalyst is known as polymerisation.
