Grant Sanderson AKA 3blue1brown posted a great video visualization of the Fourier Transform. I would have loved to have encountered this when I first began exploring its mysteries in the 1980’s (when I could only find droll texts on the subject)!
Grant visually explores decomposition, winding, motivations for use of the complex plane, and the inverse transformation (however was a little disappointed that they chose not to mention the original thermodynamic motivations).
I plan to share Grant’s videos with my 7 year old to lay the groundwork for new ways to examine the world.
I am also excited to explore manim, the author’s python based animation library used to create the graphics in this and other of his videos.