Find out how Lichtenberg Figures (Frozen Lightning sculptures) are created in the  NPL Linear Accelerator.

The interior of Plexiglas samples are irradiated by an electron beam from a 10 million electron volt (MeV) particle accelerator; the excess negative charge is discharged and the electrons escape with a bright flash and loud bang. The hot, lightning-like discharges create a fractal pattern of fractures inside the acrylic.