Fourier Series ean Baptiste Joseph Fourier(1768-1830) Fourier series are useful in countless applications today, ranging from vibration analyn to image processing-virtually any field in which a frequency analysis is important Fo example, Fourier series help scientists characterize and better understand he chemical composition of stars or how the vocal tract produces spe Before French mathematician Joseph Fourier discovered his famous ser accompanied Napoleon on his 1798 expedition of Egypt, where Fourier spent several years studying Egyptian artifacts Fourier's research on the mathematical theory of began around 1801 when he was back in France, and in 1807 he had completed his important memoir on the Propagation of Heat in Solid Bodies. One of his interests was heat diffusion in different shapes. For these problems, researchers are usually given the temperatures at points on the surface, as well as at its edges, at time t introduced a series with sine and cosine terms in order to find solutions to these kinds of problems. More generally, he found that any differentiable function can be represented to arbitrary accuracy by a sum ofsine and cosine functions, no matter how bizarre the function may look when graphed Biographers Jerome Ravetz and I. Grattan-Guiness note, "Fourier s achievement can be understood by leonsidering] the powerful mathematical tools he invented for the solutions of the equations, which yielded a long series of descendents and raised problems in mathematical analysis that motivated much of the leading work in that field for the rest of the century and beyond British physicist Sir James Jeans(1877-1916) remarked, "Fourier's theorem tells us that every curve, no matter what its nature may be, or in what way it was originally obtained, can be exactly reproduced by superposing a sufficient number of simple harmonic curves in brief, every curve can be built up by piling up waves SEE ALso Bessel Functions(IS17), Hammonic Analyzer(1876), and Differential Analyzer(1927