Imagine students’ amazement when they actually see sunlight melt a penny with the Atomic Penny Vaporizer! This demonstration clearly illustrates the vast amount of energy illuminating the Earth’s surface. In rough numbers: 70% of the Sun’s incident energy on our outer atmosphere is reflected back into space – only about 30% actually gets to the Earth’s surface. But, as we experience, this is still a substantial quantity of energy.
Fortunately, this energy (I. R. – Visible – U. V.) is rather uniformly distributed over the Earth’s surface – thus its overall intensity is such that we have a habitable environment. However, as we all know, we can concentrate some ‘area’ of this energy to increase the ‘energy per area’ (a measure of this is the temperature of the area of concentrated energy). A common magnifying lens (2-4 in. diameter) will concentrate sufficient energy to burn paper or other objects with a low flash point. Read the rest of this entry »