Aleiha's parabolic solar cooker. The paraboloid is an interesting shape with some amazing qualities. It has the power to concentrate light, electronic waves, sound, etc. to its focus at the center. To find the focal point of a paraboloid, one must use the formula, , where p is a constant. The variable y is the depth of the dish, and x measures the distance from the center axis to the maximum circumference of the dish. You have to pretend that there is an x axis going through the center of the base of the dish and a perpendicular y-axis passing from the center of the base of the dish to the focal point. The two numbers, x and y, represent a point on the paraboloid, and from that, you are able to determine where the focus is.
Parabolic cookers have been used for centuries now. The idea to concentrate light using curved mirrors was developed by the Greeks, Aztecs, Incas, Romans and Chinese. The Incas used bronze and gold for their mirrors and they built structures that were several stories high. This technology seems to have appeared around the same time for each of the civilizations. It is thought that Archimedes harnessed the technologyW to defend Syracuse from invading Roman fleets in 212 BC.
Appropriate technology (AT) is technology that is designed with special consideration to the context of its use - including environmental, ethical, cultural, social, political, and economical aspects of the community it is intended for. With these goals in mind, AT proponents claim their methods require fewer resources, are easier to maintain, and have less of an impact on the environment compared to techniques from mainstream technology, which they contend is wasteful and environmentally polluting.
The term is usually used to describe simple technologies proponents consider suitable for use in developing nations or less developed rural areas of industrialized nations. This form of "appropriate technology" usually prefers labor-intensive solutions over capital-intensive ones, although labor-saving devices are also used where this does not mean high capital or maintenance cost. In practice, appropriate technology is often something described as using the simplest level of technology that can effectively achieve the intended purpose in a particular location. In industrialized nations, the term appropriate technology takes a different meaning, often referring to engineering that takes special consideration of its social and environmental ramifications.