250, wow! I remember the first time I heard of Fourier, was when I was learning about the digital signal processing equipment for our RADAR, when I was in the Navy. The engineer who was teaching us kept mentioning FFT. Finally I asked him what it meant. He told me Fast Fourier Transform, then I had to know what that was. He gave me the brief overview. Later in life, at college: I learned a lot more about Fourier Transforms and DFTs / FFTs