Description
Lava Stone
Lava is rock in liquid form. Once magma reaches the Earth's surface or the seabed, it is called lava. Due to differences in magma composition, outflow rate, temperature, and chemical and mineralogical composition, there are several types of lava, each with its own behavior and characterized by a porous structure. Lava can have a destructive effect, but at the same time, it also has a creative effect. For instance, new land can be formed by lava; this is how the Hawaiian Islands in the Pacific Ocean were formed. Furthermore, cooled lava—after several centuries of weathering—is very fertile and can therefore be used effectively as agricultural land. The word 'lava' originates from the Italian language and is likely derived from the Latin word labes, which refers to the sliding or gliding of lava. The word was first used in its current meaning by Francesco Serao, a professor of medicine at the University of Naples, when he described the eruption of Mount Vesuvius in the period from May 14 to June 4, 1737. Serao believed that lava was a mixture of sand and earth that had been melted by the heat of the volcanic fire. He described “a stream of fiery lava” in comparison to the water and mud that flow down the volcano after heavy rain. Cooling viscous lava often accumulates in a volcanic shaft. Due to this blockage and the presence of gases in the lava, pressure builds up in the shaft. Eventually, an eruption occurs, producing large clouds of volcanic ash and gas, as well as pyroclastic flows. The most explosive eruptions are followed by a quieter period during which lava is expelled. If the lava is rich in silica, a slowly growing lava dome forms—a large, cushion-like structure full of cracks and fissures. The top and edges of a lava dome are usually covered with rock fragments, breccia, and ash. The hardened rock that forms from lava is called extrusive rock. The appearance and composition of different extrusive rocks vary greatly. If a lava flow of rhyolite cools rapidly, it can become obsidian. However, if it is filled with gas bubbles, it can also become pumice. If the same lava cools slowly, it becomes a light-colored solid rock simply called rhyolite.
The Kama Sutra is considered the most important Indian textbook on the art of love. It was compiled by Vatsyayana, probably in the second century CE. It discusses in detail and in a didactic manner many topics of eroticism. The book was a guide for (newly) married couples to discover each other and to find pleasure in a time when arranged marriages could seriously disrupt romance. It teaches the man to please the woman he has married and thus win her love. The Buddha also taught a Kama Sutra, dated to the fourth century BC. It does not discuss how to obtain pleasure, but how the pursuit of sensual pleasure leads to both pleasure and unhappiness, and that one is therefore better off avoiding sensual pleasure and focusing on the search for Nirvana.
