Solar forge
From Wikipedia, the free encyclopedia
A solar forge is a device that uses the power of the sun to melt materials, such as asphalt. A large Fresnel lens, usually rectangular and several feet long on each side, is positioned as a lid of a hollow standing cylinder. The lens focuses the sun's radiation to a point inside the cylinder, where the material to be melted is placed. The effect is the same as a magnifying glass used to burn a dry leaf, except that the heat achieved is much greater.
Solar forges work best in desert areas where there is plenty of sunlight. They are dangerous to approach because of the great heat and light generated. A safe way to handle the danger is to cover the lens when not in use. Solar forges are easy to build, because they consist of only two parts. Other optional parts are : a cover, a pollution-control device (for the smoke), a vent, a temperature gauge, protective fire-proof clothing, and gas masks. Solar forges have the benefit of cheap construction and no fuel cost, unlike other forges. However, they cannot achieve the higher temperatures that other forges can. They are good for melting materials with low melting points.
[edit] Theoretical future uses
Solar forges can achieve higher temperatures in space or in celestial bodies with no atmosphere to block solar radiation such as the moon, asteroids, or the planet Mercury. There, they can melt denser materials with higher melting points. If the solar forge is not hot enough, multiple lenses in a row can be used. They have also been considered for use on space stations and space mining colonies in the future. The beam produced by the solar forge could theoretically melt through rock, making mining on other planets and moons easier, with no fuel cost or machine work. The solar forge might melt moon rocks, creating smoke that contains mineral gas, carbon, trapped air (nitrogen and oxygen), and water (hydrogen and oxygen). The smoke could be filtered to separate air and water to be used by colonists for drinking, farming, bathing, washing clothes and dishes, and other uses. By releasing water from a dry planet, solar forges could aid in colonization and terraforming (just as the earth's original carbon dioxide atmosphere was created by the smoke of molten rock ejected by primeval volcanoes).
