Back in 1777, German physicist Professor Georg Lichtenberg made a curious discovery; when dust in the air settled on electrically charged plates, beautiful tree-like “dust figures” formed. Lichtenberg believed that these figures showed the motion of the electric field. The figures, which were later named Lichtenberg figures, sparked a great amount of interest in scientists and philosophers because they believed they demonstrated the true nature of the electric field. Today, we know that Lichtenberg figures are branching patterns that may be created when high voltage electrical discharges pass either along the surface or through insulating materials.

Check out these awesome images of Lichtenberg figures:

Lichtenberg figure in plexiglass. Image credit: Bert Hickman, via Wikimedia Commons.

Three dimensional Lichtenberg figure. Image credit: Bert Hickman, via Wikimedia Commons.

Check out this awesome YouTube video of trapping lightning in a block:

So, we've established Lichtenberg figures are pretty damn cool, but what is perhaps more intriguing is that they can actually occur on people that are struck by lightning. Lightning, which is a huge discharge of static electricity resulting from an imbalance in electrically charged regions between the Earth's surface and a cloud, is one of the leading causes of weather-related death and injury in the U.S.; between 1959 and 2003, 3, 696 people died from being struck by lightning and although rates are falling around 30 people per year still die from this. Around 10% of lightning-stroke victims die, and 70% will suffer serious long-term problems such brain damage and personality changes.

Interestingly, when lightning strikes some people they develop Lichtenberg figures across their skin. For example, a 2000 report from the New England Journal of Medicine described the case of a 54-year-old man who was struck by lightning. He was initially stuporous, but by the time he got to the emergency room he seemed well and upon further examination it was discovered that he had a fern-leaf pattern of painless cutaneous marks across his arm, back and leg. The marks disappeared just two days later.

This striking skin pattern, as pictured below, is likely caused by the rupture of capillaries beneath the skin from the electrical discharge. They are sometimes called "lightning flowers" or "skin feathering" but the medical terms are arborescent (tree-like) erythema or keraunographic markings.

Image credit: Domart and Garet, NEJM.

Another man, called Winston Kemp, was struck by lightning back in 2011 whilst saving his pumpkins from a storm. The man, who ironically is an electrician, didn't even notice he was struck until the marks appeared on his arm around an hour after he returned indoors. His arm then started to feel sore and blisters appeared. His marks lasted for over a month, although they faded within the first month to a pale pink color.

Winston Kemp's Lichtenberg figure, via BBC news.

Although these marks look pretty damn cool, they are extremely rare, and most people come off much worse when struck by lightning! So don't try to recreate them at home by shocking yourself.