Day 1

Band of the day: They might be giants

Nother's Theorem

Above: Photo of a salt crystal (from wikipedia) and a cartoon of the microscopic structure of a crystal.

Above: The unit cell does not have to be a single atom. This examples shows crystals made out of biological proteins.

Metals atoms arrange themselves into crystals. This is a photo of gallium which crystallizes into large grains. Other metals have smaller crystal grains (need a microscope to see).
One of the most important materials for modern technology!
Transmission electron microscope image of a graphene lattice. Graphene is a two-dimensional periodic structure made entire from carbon atoms.

Above: Image of opal and a cartoon of the microscopic structure of the material. Source: the wikipedia article about opals.

Unit cell animation: Cesium Chloride is a good example.