Well, we could always start small, and I can resurrect a small piece of "Thunderbolts Forum 1.0" history. IE, known lightning scars... All the thumbnails link to larger versions in my science pics stash(es). Often with additional expository or suggestive text or links back to original sources where possible (I've tried to list as many as I could recall or re-find).
First off, let's take a look at Lichtenberg figures.
("Positive" and "Negative" figures)http://scienceservice.si.edu/pages/044138e.htm
(Example of a sparse, filamentary discharge in acrylic [a dielectric insulator])
(Example of a more dense / "feathery" discharge)
Next, let's take a look at some real-world examples of electrical damage:
(Multi-spot arc traces to stainless steel; note similarity across scales.)
The above appears related to or a subset of the process known as "diffusion limited aggregation
." Possibly part of the process of dielectric breakdown is dependent on or related to DLA?
(Compare this photo of golf course lightning to the sparse filamentary discharge captured in acrylic above. A distinct replication of one of the major characteristic "Lichtenberg figure" morphologies.)
(Another example of golf course lightning. This one is a bit denser and gets somewhat featherier at the tips.)
(An extremely impressive, extremely big, extremely feathery and dense lightning strike to another golf course.)
(Nowhere near as well-defined as the others, this lightning strike was a bit of a messy one. But tore up the turf pretty well.)
So far we've seen a few relatively "stationary" strikes, with a center and radiating filaments. (Likely from charge locked up in the ground? then catastrophically released as in the production
of Lichtenberg acrylic pieces.)
However, lightning can wander too, leaving what are often called "rilles" on moons. But around here tend to be a bit smaller and look a bit like churned up troughs:
(Trench cut by lightning; photographed circa 1950)
(Trench cut by lightning, damaged the concrete curb too; reported circa 2002)
(A lightning strike fused this double [fulgurite] trackway in the ground.)
Fulgurites are the physical evidence sometimes left by lightning strikes when they pass through the ground. They generally consist of fused materials from the soil. Especially sandy soils. Fulgurites are generally quite brittle and glassy. Though in the case of longer lasting electrical energizing of the soil or surrounding materials (usually from a live downed power line resting on soils for extended periods of time), more durable products can be formed. Some of these have been termed "clinkers
Interestingly, such a feature strongly resembles certain fossils! Such as sea shells trapped in a stony matrix, but otherwise mostly unmolested, etc...
(Lightning strikes can also apparently produce spherules not unlike those produced by CJ Ransom in the lab
Getting back to lightning damage, I might as well point to a few instances of damage to concrete!
(Either lightning or a downed power pole in Minneapolis, MN.)
(A closer look.)
(Damage to either a sidewalk or patio in Pico Rivera, CA)
(A closer shot; notice the darkening around the periphery. Wouldn't be surprised if some electrical/chemical process was going on to change the materials or otherwise scorch the area.)
Well, that's all been something of a walk down memory lane. The last bit isn't for the squeamish. Known as "lightning flowers," or more clinically as "electrical burns," the following images show what happens when people get hit by lightning or by industrial strength discharges.
(An example of a lightning strike to the shoulder. Probably lucky to be alive...? Seeing as it appears to have been the left shoulder! Ouch!)
(Something of a more extensive lightning strike / burn.)
(Industrial electrical burn; whether it's "industrial" electricity or "natural" electricity, the results come out about the same.)
Hope this trip down memory lane has been useful for some folks...