Page history
September 26, 2018
December 1, 2017
April 7, 2017
October 28, 2016
September 26, 2016
July 13, 2016
January 23, 2013
May 6, 2012
no edit summary
+19
grammar fix
m-5
see talk page: diffraction is something only waves do!
-97
a good point was made on the talk page, but it did not justify wholesale deletion of a parapraph, which can remain with this minor tweak
+343
no edit summary
-336
fix category
mimproved
+737