Lithium fluoride (LiF) has long been recognised for its ability to host radiation-induced colour centres, which are point defects in the crystal lattice that absorb and emit light when excited. These ...

We road-tested it not just on straight-forward, all over grade 1 buzzcuts, but on DIY fades and longer hair too (iStock/The Independent) For many people, Wahl is the first brand of hair clippers they ...