Tree circles!

 "Tree circles" ?  A glance at the namesake for this weblog's URL.

  Here's a picture, showing how the source of light may be hidden from view, but it is revealed in a thousand reflections,  if you realize they form a bulls-eye pattern around it.

Light coming from a lamp hidden by the tree trunk is reflected into a pattern of concentric circles among the tree’s wet branches. Photo: Bob King / Duluth News Tribune

 ( posted by AstroBob: https://astrobob.areavoices.com/2008/11/06/funnel-of-radiance/ )

 

 

The tree and light seen from a different angle.
Photo: Bob King

source:  https://www.thenakedscientists.com/forum/index.php?topic=54452.0