View full lesson: http://ed.ted.com/lessons/thesunss...

Suppose you placed a camera at a fixed position, took a picture of the sky at the same time every day for an entire year, and overlaid all of the photos on top of each other. What would the sun look like in that combined image? A stationary dot? A circular path? Neither. Oddly enough, it makes a ‘figure 8’ pattern, known as the Sun’s analemma. Gordon Williamson explains why.

Lesson by Gordon Williamson, animation by TEDEd.