The Giant’s Causeway is a rock formation that is so otherworldly that it seems like it was made by supernatural beings. But these incredible hexagonal columns of rock aren’t the result of giant masons. They formed through a quirk of volcanic activity that shows that hexagons really are the bestagons! Cooling lava naturally creates hexagonal cracks to evenly relieve stress When lava cools and turns into rock, it contracts and builds up tension, particularly when held in place by the surrounding landscape. Just as drying mud cracks, initial cracks in the rock are random, but quickly organize into a hexagonal pattern, which scientists consider the most space-efficient shape.
Note: the presentation talks about lava cooling from the top down, but it also cools upward from the bottom where it flowed onto a cooler land surface. In our area we typically see columns underlying a more chaotically fractured “entablature”. It is generally thought that because the entablature section is exposed to the air and precipitation, that results in rapid cooling that produces chaotic fracturing. The columnar section which is cooling upward from the base, would experience a much slower and more even rate of cooling, allowing it to better organize into an optimal, space-efficient “bestagonal” shape.
Found via SciShow, hosted by: Niba @NotesbyNiba