The 2019 AAPT calendar contains an incorrect description of the December
photograph. The photograph is incorrectly explained as the inverted,
virtual image of a real tree produced by a plane mirror. A plane mirror
will always produce an erect virtual image of a real object. The mirror
must be a concave mirror in order to produce the inverted image displayed
in the calendar.
Bob Sciamanda
Physics, Edinboro Univ of PA (em)
treborsciamanda@gmail.com
www.sciamanda.com