"...the sun instead of revealing things would hide them with light..."
- Clarice Lispector, from The Besieged City, translated from the Portuguese by Johnny Lorenz, New York, New Directions: 2019 (1949).
There have been many ingenious and even fanciful ideas about the source and significance of light. I like this one from Brazilian writer Clarice Lispector (1920-1977) who drew on Jewish Kabbaleh and mysticism more generally in her work of receptive illumination. Light does conceal sometimes, a phenomenon that frustrated early critics of French Impressionist paintings who wanted final answers. What were those disconnected daubs of color doing there ? Introducing the aspect of light seen through frozen water only intensifies the headache of uncertainty. And this particular uncertainty has a long history.
Light can be both wave and particle as we now know thanks to the synthesis known as quantum theory put forward by Max Planck in 1900. Technically, Planks' theorum posited that light is an electromagnetic wave that is emitted in quanta (packets) of radiation. A few years later Planck delivered the opinion that "science proceeds one funeral at a time." Given the circuitous path that detoured some of the greatest thinkers of earlier times and their sometimes diffidence toward each other, Planck knew what he was talking about. Pythagorus, Empedocles, Epicurus, and Euclid, to drop a few names, all got entangled in thickets of their own making
Other theories of light, even if superseded, have their charms. Although ancient Greeks are credited for the ray theory of light mostly they got themselves hung up on the mechanisms of the eye as the source of light. It was Ibn-al-Haytham, (born in what is now modern Basra, Iraq) who in 1038 correctly defined vision as the passive reflection of light rays. For this achievement the title of "father of modern optics" was bestowed on him.
The year 1690 saw the publication of competing theories, from the Dutch astronomer Christiaan Huygens whose theory that light traveled in long waves was parried by Isaac Newton 's that light was emitted from its source as small particles. Newton argued that light could not be a wave because we can heard sound originating from behind an object but we cannot see it. Since light can travel through a vacuum as sound cannot Huygens then asserted that light traveled through a substance he called "aether."
Image: Vittorio Gianella - Glacon gelee (Frozen Ice, color positive print, circa 2010-2014, Alinari Archives, Florence.