光学 (1704)

《光学》是艾萨克·牛顿的一本著作，英文版于1704年问世（拉丁文译本于1706年出版）。该著作通过棱镜与透镜的光折射实验、玻璃片的光衍射现象系统分析了光的基本性质。《光学》是牛顿在物质科学领域的第二部著作。

Opticks: or, A Treatise of the Reflexions, Refractions, Inflexions and Colours of Light is a collection of three books by Isaac Newton that was published in English in 1704 (a scholarly Latin translation appeared in 1706). The treatise analyses the fundamental nature of light by means of the refraction of light with prisms and lenses, the diffraction of light by closely spaced sheets of glass, and the behaviour of colour mixtures with spectral lights or pigment powders. Opticks was Newton's second major work on physical science and it is considered one of the three major works on optics during the Scientific Revolution (alongside Johannes Kepler's Astronomiae Pars Optica and Christiaan Huygens' Treatise on Light).

Overview

The publication of Opticks represented a major contribution to science, different from but in some ways rivalling the Principia, yet Newton's name did not appear on the cover page of the first edition. Opticks is largely a record of experiments and the deductions made from them, covering a wide range of topics in what was later to be known as physical optics. That is, this work is not a geometric discussion of catoptrics or dioptrics, the traditional subjects of reflection of light by mirrors of different shapes and the exploration of how light is "bent" as it passes from one medium, such as air, into another, such as water or glass. Rather, the Opticks is a study of the nature of light and colour and the various phenomena of diffraction, which Newton called the "inflexion" of light.

Newton sets forth in full his experiments, first reported to the Royal Society of London in 1672, on dispersion, or the separation of light into a spectrum of its component colours. He demonstrates how the appearance of colour arises from selective absorption, reflection, or transmission of the various component parts of the incident light.

The major significance of Newton's work is that it overturned the dogma, attributed to Aristotle or Theophrastus and accepted by scholars in Newton's time, that "pure" light (such as the light attributed to the Sun) is fundamentally white or colourless, and is altered into color by mixture with darkness caused by interactions with matter. Newton showed the opposite was true: light is composed of different spectral hues (he describes seven – red, orange, yellow, green, blue, indigo and violet), and all colours, including white, are formed by various mixtures of these hues. He demonstrates that colour arises from a physical property of light – each hue is refracted at a characteristic angle by a prism or lens – but he clearly states that colour is a sensation within the mind and not an inherent property of material objects or of light itself. For example, he demonstrates that a red violet (magenta) colour can be mixed by overlapping the red and violet ends of two spectra, although this colour does not appear in the spectrum and therefore is not a "colour of light". By connecting the red and violet ends of the spectrum, he organised all colours as a colour circle that both quantitatively predicts colour mixtures and qualitatively describes the perceived similarity among hues.

Newton's contribution to prismatic dispersion was the first to outline multiple-prism arrays. Multiple-prism configurations, as beam expanders, became central to the design of the tunable laser more than 275 years later and set the stage for the development of the multiple-prism dispersion theory.