Mathematics
Fourier Series for Solving Heat Equations
Quick fact
Joseph Fourier introduced his series while studying heat conduction, and his work was initially rejected by mathematicians because he claimed that even discontinuous functions could be represented by sums of smooth sine and cosine curves—a revolutionary idea that later became a cornerstone of modern analysis.
Why this is interesting
Why does a hot metal rod cool down in that smooth, predictable way? And what do musical tones have to do with it?