Solargraph tracks the sun's six-month path across the sky

What's incredible about this stunning photograph isn't just that it captures the path the sun appears to take across the sky from the summer solstice to the winter solstice. It's that it was taken with such a simple device: a pin-hole camera made from a drink can.

This view of the University of Hertfordshire's Bayfordbury Observatory is called a solargraph, an image that uses pinhole photography to track the apparent movement of the sun. A drink can-camera was fixed to a single spot from June 21, 2011, to December 21, 2011, letting the sun's path burn into its photosensitive paper. The gaps in the arcs represent times when the camera's view was blocked by cloud cover. Fortunately, this autumn was one of the UK's nicest on record, so we get a fairly clear view of those glowing trails.

[APOD]