The tale of the two giants…
According to Irish mythology, there once lived a pair of giants, Finn McCool (or Fionn Mac Cumhaill) in Northern Ireland and Benandonnar across the channel in Scotland. The two giants were aware of each other, and loathed each other, especially since their countrymen held them up as their respective champions, boasting incessantly of their own man’s superiority.
One day, Benandonnar, the Scottish giant, began to hurl insults at his rival. In rage, Finn McCool scooped a mound of dirt and threw it at Benandonnar, symbolic of throwing down a gauntlet and challenging him to a fight. (By some accounts, the dirt he scooped up created the crater for Northern Ireland’s largest lake, Lough Neagh, and in falling into the sea, the Isle of Man.) Benandonnar, in turn retaliated by throwing an immense rock at Finn, and bellowing, “You don’t know how lucky you are. If I were a strong swimmer, I would come over and give you a thorough thrashing!” As the argument escalated, Finn decided to take up Benandonnar on his threat. He hauled dirt into the channel, and created a causeway for the Scotsman to come and face him “…if, that is, you have the gall.” But in building the causeway, Finn found himself on the Scottish shore, where he could spy his foe. To his shock and horror, the Scottish giant was considerably bigger than he was! Accordingly, he made a hasty retreat, but only to look back and see that Benandonnar was trailing behind him, crossing the channel to Ireland also.
Here, Finn’s wife came to the rescue. She instructed Finn to immediately jump into his bed, and to pretend to be asleep. When Benandonnar arrived, Finn’s wife invited the Scottsman into the house, and explained, “My husband is away. And if you are not quiet, you will wake up our baby sleeping in the crib.” When Benandonnar saw Finn under the covers, his head sticking out from one end, his feet from the other, he realized, “If their baby is that big, how big is the father! Clearly, he must be much bigger than I.” This time it was Benandonnar who made a hasty retreat, running across the causeway, and tearing it up in the process. “And that is how,” the myth goes, “… Giant’s Causeway was created!”
A Geologic Wonderland…
The shafts (or columns) of stones rising from the ground resemble giant cigarettes, closely packed, their hexagonal cross sections fitting together to weave a colossal mass. Geologists and material scientists investigating the composition, concluded that there exist approximately 40,000 shafts of different length, that they are basaltic rocks and mostly six-sided (hexagonal). It is known that they were created by magma extruding upward from volcanic activity in the ground 60 million years ago. Plate tectonic action was powered by the internal dynamics inside the earth, creating geologic faults, trenches and ridges. As the magma cooled and solidified, it also began to crack, as water seeped in. Under ideal conditions, joints form at 120° to one another in basalt, explaining the preponderance of hexagonal pattern seen in the cross sections. Because of flaws in the material, however, they are not all six sided, but other polygons can be seen, including five, seven, eight, or even nine sides. The photo does not include any identifiable scale, such as a meter stick or a person. But the shafts can be as long as 12 meters (36 ft) or as tall as a four-story building.
Following the theoretical (mathematical) analysis by applied mathematician L. Mahadevan in Harvard University’s Material Sciences Department, and simple experiments using starch and water by physicists Stephen Morris and Lucas Goehring at the University of Toronto convincing evidence emerged that in the growth of these columns, their cross sectional size was determined by the time it took for the material to cool down. The longer the cooling period the larger will be the cross section. The phenomenon is also seen in the mud in parched river and lakebeds during drought conditions.
Giant’s Causeway is the best known of columnar basalts in the world, but similar geological sites do exist especially in areas of tectonic activity. First there is the eponymous Fingal’s Cave on the uninhabited Isle of Staffa, Scotland, closely related to Giant’s Causeway in its gestation, as a creation by Paleocene basalt flow. Although conceived 60 Million years ago, they were both uncovered by receding ice sheets at the end of the last Ice Age 15,000 years ago. The cave, discovered in 1770 and known for its haunting echoes reminiscent of an organ, served as the inspiration for Mendelssohn’s overture, “New Hebrides” (1829). Futurist Jules Verne cited the cavern in his book “Le Rayon Vert,” and again in his novels “Journey to the Center of the Earth.” Nineteenth century poets and writers, including William Wordsworth, John Keats and Alfred Lord Tennyson wrote about them. And artist Turner created his painting, “Staffa, Fingal’s Cave.”
Other basaltic pillars include Devil’s Postpile in California; Narooma Basalt, Narooma, New South Wales, Australia; and the massive Devil’s Tower, Wyoming, USA.