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Figure $$\PageIndex{1}$$: The tree-like branch patterns in this clear acrylic block are created by irradiating the block with an electron beam. This tree is known as a Lichtenberg figure, named for the German physicist Georg Christof Lichtenberg (1742–1799), who was the first to study these patterns. The “branches” are created by the dielectric breakdown produced by a strong electric field. Image used with permission (Bert Hickman).