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Light can exhibit properties of both [[wave]]s and [[particles]].  This property is referred to as [http://en.wikipedia.org/wiki/Wave%E2%80%93particle_duality wave-particle duality].  The study of light, known as [[optics]], is an important [[research]] area in modern [[physics]].

Light can exhibit properties of both [[wave]]s and [[particles]].  This property is referred to as [http://en.wikipedia.org/wiki/Wave%E2%80%93particle_duality wave-particle duality].  The study of light, known as [[optics]], is an important [[research]] area in modern [[physics]].

<center>For lessons on the [[topic]] of '''''Light''''', follow [http://nordan.daynal.org/wiki/index.php?title=Category:Light this link].</center>

<center>For lessons on the [[topic]] of '''''Light''''', follow [https://nordan.daynal.org/wiki/index.php?title=Category:Light this link].</center>

==Speed of light==  

==Speed of light==  

The ''speed of light'' in a [http://en.wikipedia.org/wiki/Free_space vacuum] is exactly 299,792,458 Metres per second|m/s (about 186,282.397 miles per second). The speed of light depends upon the [[medium]] in which it is [[traveling]], and the [[speed]] will be lower in a [[transparent]] medium. Although commonly called the "velocity of light", technically the word ''[[velocity]]'' is a [[vector]] [[quantity]], having both [[magnitude]] and direction.  ''Speed'' refers only to the [[magnitude]] of the velocity vector.  This fixed definition of the speed of light is a result of the modern attempt, in [[physics]], to define the basic [[unit]] of length in terms of the speed of light, rather than defining the speed of light in terms of a length.  

The ''speed of light'' in a [http://en.wikipedia.org/wiki/Free_space vacuum] is exactly 299,792,458 Metres per second|m/s (about 186,282.397 miles per second). The speed of light depends upon the [[medium]] in which it is [[traveling]], and the [[speed]] will be lower in a [[transparent]] medium. Although commonly called the "velocity of light", technically the word ''[[velocity]]'' is a [[vector]] [[quantity]], having both [[magnitude]] and direction.  ''Speed'' refers only to the [[magnitude]] of the velocity vector.  This fixed definition of the speed of light is a result of the modern attempt, in [[physics]], to define the basic [[unit]] of length in terms of the speed of light, rather than defining the speed of light in terms of a length.  

[[Mind]] is a [[phenomenon]] connoting the [[presence]]-activity of living ministry in addition to varied energy systems; and this is true on all levels of [[intelligence]]. In [[personality]], mind ever intervenes between spirit and [[matter]]; therefore is the [[universe]] illuminated by three kinds of light: material light, [[intellect|intellectual]] insight, and [[spirit]] luminosity.

[[Mind]] is a [[phenomenon]] connoting the [[presence]]-activity of living ministry in addition to varied energy systems; and this is true on all levels of [[intelligence]]. In [[personality]], mind ever intervenes between spirit and [[matter]]; therefore is the [[universe]] illuminated by three kinds of light: material light, [[intellect|intellectual]] insight, and [[spirit]] luminosity.

Light--spirit [[illumination|luminosity]]--is a [[word]] [[symbols|symbol]], a figure of speech, which connotes the [[personality]] manifestation [[character]]istic of spirit [[being]]s of diverse orders. This luminous emanation is in no respect related either to [[intellect]]ual insight or to physical-light manifestations.[http://nordan.daynal.org/wiki/index.php?title=The_foreword#VI._ENERGY_AND_PATTERN]

Light--spirit [[illumination|luminosity]]--is a [[word]] [[symbols|symbol]], a figure of speech, which connotes the [[personality]] manifestation [[character]]istic of spirit [[being]]s of diverse orders. This luminous emanation is in no respect related either to [[intellect]]ual insight or to physical-light manifestations.[https://nordan.daynal.org/wiki/index.php?title=The_foreword#VI._ENERGY_AND_PATTERN]