Editing Ibn al-Haytham (section)

=== Law of reflection ===
{{Main|Specular reflection}}
Alhazen was the first physicist to give complete statement of the law of reflection.<ref>{{Cite book |last=Stamnes |first=J. J. |url=https://books.google.com/books?id=dGQ-DwAAQBAJ&dq=alhazen+law+of+reflection&pg=PT15 |title=Waves in Focal Regions: Propagation, Diffraction and Focusing of Light, Sound and Water Waves |date=2017 |publisher=Routledge |isbn=978-1-351-40468-6 |language=en |access-date=22 February 2023 |archive-date=31 March 2023 |archive-url=https://web.archive.org/web/20230331171120/https://books.google.com/books?id=dGQ-DwAAQBAJ&dq=alhazen+law+of+reflection&pg=PT15 |url-status=live }}</ref><ref>{{Cite book |last=Mach |first=Ernst |url=https://books.google.com/books?id=7dPCAgAAQBAJ&dq=alhazen+incident+ray+reflected+ray+lie+on+same+plane&pg=PA29 |title=The Principles of Physical Optics: An Historical and Philosophical Treatment |date=2013 |publisher=Courier Corporation |isbn=978-0-486-17347-4 |language=en |access-date=22 February 2023 |archive-date=31 March 2023 |archive-url=https://web.archive.org/web/20230331172406/https://books.google.com/books?id=7dPCAgAAQBAJ&dq=alhazen+incident+ray+reflected+ray+lie+on+same+plane&pg=PA29 |url-status=live }}</ref><ref>{{Cite book |last=Iizuka |first=Keigo |url=https://books.google.com/books?id=h9n6CAAAQBAJ&dq=alhazen+law+of+reflection&pg=PA7 |title=Engineering Optics |date=2013 |publisher=Springer Science & Business Media |isbn=978-3-662-07032-1 |language=en |access-date=22 February 2023 |archive-date=31 March 2023 |archive-url=https://web.archive.org/web/20230331171118/https://books.google.com/books?id=h9n6CAAAQBAJ&dq=alhazen+law+of+reflection&pg=PA7 |url-status=live }}</ref> He was first to state that the incident ray, the reflected ray, and the normal to the surface all lie in a same plane perpendicular to reflecting plane.{{sfn|Selin|2008|p=1817}}<ref>{{Cite book |last=Mach |first=Ernst |url=https://books.google.com/books?id=7dPCAgAAQBAJ&dq=alhazen+first+incident+ray+reflected+ray+lie+on+same+plane&pg=PA29 |title=The Principles of Physical Optics: An Historical and Philosophical Treatment |date=2013 |publisher=Courier Corporation |isbn=978-0-486-17347-4 |language=en |access-date=22 February 2023 |archive-date=31 March 2023 |archive-url=https://web.archive.org/web/20230331171118/https://books.google.com/books?id=7dPCAgAAQBAJ&dq=alhazen+first+incident+ray+reflected+ray+lie+on+same+plane&pg=PA29 |url-status=live }}</ref>