Phasons in Quasicrystals

In 2025, researchers studied a quasicrystal forged in a hypervelocity asteroid collision 600 million years ago—and found that it contains ‘phasons’! It’s not a perfect icosahedral quasicrystal: it’s slightly distorted. 6 gentle ‘phason waves’ run through it, oriented along the 6 fivefold symmetry axes of an icosahedron. These waves were locked in when the alloy quickly cooled after impact, and they’ve been sitting there frozen in the structure ever since. This quasicrystal is made of ‘icosahedrite’. The easiest way to describe this is the ‘slice and project’ method. You start with a lattice in 6 dimensions, choose a 3d slice, thicken that up a bit, take the lattice points that lie in the thickened slice, and project them down to 3d space. The atoms in the icosahedrite are exactly the projections of the 6d lattice points that happen to fall inside the thickened slice. But now imagine wiggling the slice gently—letting it ripple in the other three dimensions, the ones perpendicular to…