Crash Course Recap: Lichtenberg Figures

 

Lichtenberg figures are named after German physicist Georg Christoph Lichtenberg, who originally discovered them. They’ve also been called Lichtenberg trees or “trapped lightning.”

If you’ve ever visited our facilities or stopped by our booth at a trade show, you might have seen some of our collection of Lichtenberg figures (and maybe even taken one home with you!). 

We create these Lichtenberg figures by shooting millions of electrons over 99% the speed of light into the top surface of an acrylic plaque. 

Because acrylic is such a great insulator, the electrons travel through and become trapped in the middle, forming a plane of excess negative charge. At this point, the acrylic still looks unaffected, even though it has millions of electrons teeming inside.

At some point, the electric field’s strength (which can reach millions of volts) exceeds the insulating strength of the acrylic and it discharges, creating a beautifully unique Lichtenberg figure. 

A manual discharge can also be achieved by striking the acrylic at the desired location, (using a heavily insulated tool, of course). In an instant, portions of the polymer abruptly become electrically conductive in a process called dielectric breakdown. Networks of branching channels form, creating – you guessed it – a Lichtenberg figure.

The branching pattern looks similar at various scales of magnification, suggesting that Lichtenberg figures might be mathematically described through fractal geometry. Similar fractal patterns are prevalent throughout nature, as seen in aerial views of rivers and their tributaries, branching tree limbs, snow, your body’s circulatory system, and of course in lightning.

We think this is a fun way of demonstrating the power of electrons!

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