Many researchers through the ages have taken up the challenge of finding out “What is Light?”
Optics is known as the oldest discipline along with mechanics.
The progress of the study of light has been made by the great scholars from different fields introduced here while leading other discipline and closely involved with the growth of industry and culture.

5th-3rd B.C.
“The essence of light is white light.
Colors are made up of a mixture
of lightness and darkness.”
Era of Ancient Greece (Aristotle)

10th-11th centuries
“Why does the moon appear larger near 
the horizon than it does
when higher up in the sky ?”
Ibn al-Haytham (Alhazen) 965-1040




17th-18th centuries
“Light is comprised of colored particles.”
Sir Isaac Newton 1643-1727
(English physicist, mathematician, and astronomer.)

“Light is a wave.”
Christiaan Huygens, 1629-1695
(Dutch mathematician, physicist, and astronomer)

18th-19th centuries
“Proof of the wave theory of light”
Thomas Young, 1773-1829
(English physicist, classical scholar, and archeologist)

“Predicted the existence
of electromagnetic waves”
James Clerk Maxwell, 1831-1879
(Scottish theoretical physicist)
20th century

“Light is a photon”

Albert Einstein, 1879-1955

(German-born theoretical physicist) 
Einstein is called the greatest physicist of the 20th century because of three groundbreaking research results announced in 1905 that had a great impact on physics. Those three papers were on the photoelectric effect theory where light is made up of particles called photons, the theory of Brownian motion utilizing kinetic theory of molecules, and the theory of special relativity. The theory of relativity in particular was a new discovery about space and time expressed in the relativity principle of electromagnetism and which resolved the ether problem in 19th century physics.
Einstein is famous for his research on the theory of relativity yet his work on theoretically revealing the photoelectric effect based on the light quantum hypothesis won him the Nobel Prize in physics in 1921.

 

Through the researches accumulated over 2,000 years of time, the true nature of light or namely the photon was discovered. The photon has many mysterious physical properties such as possessing the dual properties of a wave and a particle. Revealing facts of these properties may lead us to using light more effectively than ever before.

The photon is a substance that is seen as the key to the origins of space and life. For human beings, history of light and optics research may have only just begun.

Through the researches accumulated over 2,000 years of time, the true nature of light or namely the photon was discovered. The photon has many mysterious physical properties such as possessing the dual properties of a wave and a particle. Revealing facts of these properties may lead us to using light more effectively than ever before.

The photon is a substance that is seen as the key to the origins of space and life.

For human beings, history of light and optics research may have only just begun.