White light is made up of all the different colors of light added together. When white light shines through a prism, it splits up into different colors, becoming a spectrum. The spectrum contains all of the wavelengths of light that we can see. Red light has the longest wavelength, and violet (purple) light has the shortest. Buser, Pierre A.; Imbert, Michel (1992). Vision. MIT Press. p. 50. ISBN 978-0-262-02336-8 . Retrieved 11 October 2013. Light is a special class of radiant energy embracing wavelengths between 400 and 700 nm (or mμ), or 4000 to 7000 Å.

In physics, the term light sometimes refers to electromagnetic radiation of any wavelength, whether visible or not. [2] [3] This article is about visible light. Read the electromagnetic radiation article for the general concept. Reference Solar Spectral Irradiance: Air Mass 1.5". Archived from the original on 12 May 2019 . Retrieved 12 November 2009. Sunlight provides the energy that green plants use to create sugars mostly in the form of starches, which release energy into the living things that digest them. This process of photosynthesis provides virtually all the energy used by living things. Some species of animals generate their own light, a process called bioluminescence. For example, fireflies use light to locate mates and vampire squid use it to hide themselves from prey. Spectrum and the Color Sensitivity of the Eye" (PDF). Thulescientific.com. Archived (PDF) from the original on 5 July 2010 . Retrieved 29 August 2017. Main article: Refraction Due to refraction, the straw dipped in water appears bent and the ruler scale compressed when viewed from a shallow angle.The fact that light could be polarized was for the first time qualitatively explained by Newton using the particle theory. Étienne-Louis Malus in 1810 created a mathematical particle theory of polarization. Jean-Baptiste Biot in 1812 showed that this theory explained all known phenomena of light polarization. At that time the polarization was considered as the proof of the particle theory. Fokko Jan Dijksterhuis, Lenses and Waves: Christiaan Huygens and the Mathematical Science of Optics in the 17th Century, Kluwer Academic Publishers, 2004, ISBN 1-4020-2697-8 a b Newcomb, Simon (1911). "Light" . In Chisholm, Hugh (ed.). Encyclopædia Britannica. Vol. 16 (11th ed.). Cambridge University Press. p. 624.

Solar Sails Could Send Spacecraft 'Sailing' Through Space". NASA. 31 August 2004. Archived from the original on 21 October 2012 . Retrieved 30 May 2008. Light is a form of electromagnetic radiation. It is the natural agent that stimulates sight and makes things easy to see. Antognozzi, M.; Bermingham, C. R.; Harniman, R. L.; Simpson, S.; Senior, J.; Hayward, R.; Hoerber, H.; Dennis, M. R.; Bekshaev, A. Y. (August 2016). "Direct measurements of the extraordinary optical momentum and transverse spin-dependent force using a nano-cantilever". Nature Physics. 12 (8): 731–735. arXiv: 1506.04248. Bibcode: 2016NatPh..12..731A. doi: 10.1038/nphys3732. ISSN 1745-2473. S2CID 52226942.where θ 1 is the angle between the ray and the surface normal in the first medium, θ 2 is the angle between the ray and the surface normal in the second medium and n 1 and n 2 are the indices of refraction, n = 1 in a vacuum and n> 1 in a transparent substance. Svitil, Kathy A. (5 February 2004). "Asteroids Get Spun By the Sun". Discover Magazine. Archived from the original on 9 October 2012 . Retrieved 8 May 2007. NASA team successfully deploys two solar sail systems". NASA. 9 August 2004. Archived from the original on 14 June 2012 . Retrieved 30 May 2008. To explain the origin of colours, Robert Hooke (1635–1703) developed a "pulse theory" and compared the spreading of light to that of waves in water in his 1665 work Micrographia ("Observation IX"). In 1672 Hooke suggested that light's vibrations could be perpendicular to the direction of propagation. Christiaan Huygens (1629–1695) worked out a mathematical wave theory of light in 1678 and published it in his Treatise on Light in 1690. He proposed that light was emitted in all directions as a series of waves in a medium called the luminiferous aether. As waves are not affected by gravity, it was assumed that they slowed down upon entering a denser medium. [36] Christiaan Huygens Thomas Young's sketch of a double-slit experiment showing diffraction. Young's experiments supported the theory that light consists of waves. Nichols, E.F; Hull, G.F. (1903). "The Pressure due to Radiation". The Astrophysical Journal. 17 (5): 315–351. Bibcode: 1903ApJ....17..315N. doi: 10.1086/141035. Archived from the original on 8 October 2022 . Retrieved 15 November 2020.