When researching the close packing of tetrahedrons I came across a reasonably new discovery, The Quasicrystal. Its current impact or potential impact can be gauged by the fact that Dan Shechtman, who made the finding, was this year awarded the Nobel Prize in Chemistry.
“Quasicrystals are a fascinating aspect of chemical and material science – crystals that break all the rules of being a crystal at all.”
So what is a Quasicrystal?
Basically they are formed when tetrahedra are compressed into a given volume. In Dan Shechtman’s discovery, the packing achieves an efficiency which fills 82% of space, higher than any previous effort. The close packing of the tetrahedron forms these intricately complicated and amazingly complex structures. A normal crystal is a material structure which repeats periodically however one of the really interesting things about Quasicrystals is that they don’t actually repeat exactly, despite its regularity. Quasicrystals represent a class of solids which lack translational symmetry, but nevertheless exhibit perfect long-range order and reveal well defined fivefold rotational symmetries. Translational symmetry is when an image or object can be divided into a sequence of identical repetitions which are translated about a given vector. So without this form of symmetry the Quasicrystal is non-periodic.
Aperiodic and Penrose tiling’s can also be found within Quasicrystals which themselves can be found in medievil Islamic mosaics.
The model shown in the second image is made up of 4000 x 1cm long struts, built thanks to 3D printing!
For further information follow the link below.
http://www.nobelprize.org/nobel_prizes/chemistry/laureates/2011/press.pdf
