Giudice F
Nuncius. 2000;15(1):3-49. doi: 10.1163/221058700x00447.
The object of this study is Leonhard Euler's physical optics as it is formulated in Nova theoria lucis et colorum (1746). The focus is on this particular work by Euler for two reasons: 1) Nova theoria represents undoubtedly the most comprehensive and systematic medium theory of the 18th century; 2) it contains the basic principles of Euler's conception of the nature of light, which he later maintained. The works of the most important advocates of this tradition (Huygens, Malebranche and Johann II Bernoulli) are here analyzed to give a historical frame to Euler's role in the medium tradition. Though these authors try to elaborate a theory of light alternative to the emission theory, they never realize the contrast between the medium and the emission traditions. From this perspective, Nova theoria is a real transition point: Euler is fully aware of the antithesis between the two traditions; he compares them, he refutes the arguments in favor of emission theory and formulates an alternative one, that will substantially be the first and the most significant antagonist of emission model. The essay examines also the central questions of Euler's theory of light, i.e. how pulses are generated and propagated, the nature of the rays of light and the relations among pulse distance, frequency, and velocity.
本研究的对象是莱昂哈德·欧拉在《光与色的新理论》（1746年）中阐述的物理光学。之所以关注欧拉的这部特定著作，有两个原因：1）《新理论》无疑代表了18世纪最全面、系统的介质理论；2）它包含了欧拉关于光的本质的基本概念，他后来一直秉持这些概念。这里分析了这一传统最重要的倡导者（惠更斯、马勒伯朗士和约翰二世·伯努利）的著作，以便为欧拉在介质传统中的角色提供一个历史框架。尽管这些作者试图阐述一种不同于发射理论的光理论，但他们从未意识到介质传统与发射传统之间的差异。从这个角度来看，《新理论》是一个真正的转折点：欧拉充分意识到这两种传统之间的对立；他对它们进行比较，反驳支持发射理论的论据，并提出了一种替代理论，这实质上是发射模型的首个也是最重要的对手。本文还考察了欧拉光理论的核心问题，即脉冲是如何产生和传播的、光线的本质以及脉冲距离、频率和速度之间的关系。
