Abstract
what, according to Newton, is a ray of light? And why do rays of light obey the laws of optics which he laid out so succinctly in Book I of his Optics? The next two chapters are drawn from Newton’s Queries included in Book III of his Opticks. These Queries take the form of rhetorical questions by which Newton articulates his theory of light. He begins slowly, exploring the relationship between light, heat and matter. In particular, in the first 24 Queries Newton suggests that when a body vibrates—whether due to heat, friction, percussion, or chemical action—it emits light. Conversely, when light strikes a substance it initiates vibrations within the substance. For instance, when light strikes the eye, vibrations arise in the vitreous humor; these vibrations, in turn, cause the visual perception of color. Likewise, when light strikes a transparent medium—such as water, air or even æther—vibrations arise in the medium; these vibrations, in turn, affect the trajectory of the light within the medium. Indeed, far from rejecting the existence of æther, Newton actually argued that its existence (or rather, inhomogeneities in its density) are responsible for the bending of light rays. Newton, however, carefully distinguishes light itself from vibrations of the æther. This is critical to Newton: vibrations of the æther can certainly affect the trajectory of a ray of light, but light is not a vibration of the æther. We join the discussion at Query 25, where Newton begins to articulate the specific properties that a ray of light must have in order to explain the curious phenomenon of birefringence observed in Iceland crystal.
Are not the Rays of Light very small Bodies emitted from shining Substances?
—Isaac Newton
Access this chapter
Tax calculation will be finalised at checkout
Purchases are for personal use only
Notes
- 1.
The orthogonality of light rays and wave-fronts is presented in Book IV of Huygens’ Treatise on Light; see Chap. 17 of the present volume. Notably, Erwin Schrödinger uses Huygens’ relationship between light waves and rays to explain wave-particle duality which is an essential features of quantum theory. See Schrödinger’s Nobel lecture, included in volume IV.
- 2.
See Chap. 12 of the present volume.
- 3.
Originally Newton included only 16 Queries; later Latin and English editions included all 31.
- 4.
The factum of the diameter and the velocity is just the product of the two.—[K.K.].
- 5.
For the present exercise, you may need to look up the density of air in the stratosphere. The effect of drag on falling bodies is discussed in Ex. 11.3 in the context of Galileo’s dialogue on projectile motion, included in Chap. 11 of volume II.
Author information
Authors and Affiliations
Corresponding author
Rights and permissions
Copyright information
© 2016 Springer International Publishing Switzerland
About this chapter
Cite this chapter
Kuehn, K. (2016). The Particle Theory of Light. In: A Student's Guide Through the Great Physics Texts. Undergraduate Lecture Notes in Physics. Springer, Cham. https://doi.org/10.1007/978-3-319-21816-8_18
Download citation
DOI: https://doi.org/10.1007/978-3-319-21816-8_18
Published:
Publisher Name: Springer, Cham
Print ISBN: 978-3-319-21815-1
Online ISBN: 978-3-319-21816-8
eBook Packages: Physics and AstronomyPhysics and Astronomy (R0)