Online research in philosophy

Light is strangely absent from most accounts of the environment. From photosynthesis to vitamin D, however, light is central to human well-being. Human circadian rhythms are keyed the alternation of dark and light. Erosion of the ozone layer makes skin cancer a growing threat from excess ultraviolet radiation. Light plays a significant role in health and illness. In changing historical circumstances, light continues to evoke and to express significant issues of value.

Neural impulses from the senses to the brain convey information, not sensation. The direct electrical stimulation of the cortex produces sensations. Hence, such sensations are evoked in the brain, and not received from the senses, nor from the outside world through the senses. More specifically, the experience of light is evoked in the brain and not received from the eyes. Consequently, the born blind, too, would experience light in response to electrical brain stimulation. The luminosity of light is not a property of electromagnetic radiation. If the experience of light is private, then so are the visual observations it makes possible.

This paper aims to cast new light on one of our main sources for ancient science, Sextus Julius Frontinus; to cast new light on the science of the Graeco-Roman period; and to contribute ancient materials to present discussions on the relations between power and knowledge, and/or science and empire.

The phenomenological tradition has always had a peculiar preoccupation with light. This paper will attempt to determine how and why light appears as it does, and what this can tell us about the phenomenological understanding of light and its relevance. This will be carried out through a systematic analysis covering Husserl's study of light as "circumstance of apperception," Heidegger's interpretation of Plato's use of light as "symbol for the unsayable," and Levinas' interest in light as "rival to the 'there is'." This survey will allow us to see how light has been treated by phenomenology as a concept of central importance in the realms of perception, epistemology, and ontology. It is this multiform use that has allowed for the distinction between the concepts of "light" and "lighting" to become blurred, and has thus problematized any attempt at something like a phenomenology of light.

It is still perhaps not widely appreciated that in 1905 Einstein used his postulate concerning the ‘constancy’ of the light-speed in the ‘resting’ frame, in conjunction with the principle of relativity, to derive numerical light-speed invariance. Now a ‘weak’ version of the relativity principle (or, alternatively, appeal to the Michelson—Morley experiment) leads from Einstein's light postulate to a condition that we call universal light-speed constancy. which is weaker than light-speed invariance. It follows from earlier independent investigations (Robertson [1949]; Steigler [1952]; Tzanakis and Kyritsis [1984]) that this condition is none the less sufficient to derive the Lorentz transformations up to a scale factor, given the well-known kinematic principle of ‘reciprocity’. In this paper, we follow Robertson and explore the kinematics consistent with universal light-speed constancy without imposing reciprocity, and we recover the Lorentz transformations by further appeal only to the weak relativity principle and spatial isotropy.

: This paper critiques enlightenment notions of representation and rehearses an alternative model of mapping that is grounded in performance. Working from her own practice as a landscape painter, Bolt argues that the particular experience of the "glare" of Australian light fractures the nexus between light, form, knowledge, and subjectivity. This rupture prompts a move from shedding light ON the matter to shedding light FOR the matter and suggests an emergent rather than a representational practice.

The rediscovery of meaning -- Dream, myth, and philosophical double vision -- The meaning of 'literal' -- Poetic diction and legal fiction -- The harp and the camera -- Where is fancy bred? -- The rediscovery of allegory (I) -- The rediscovery of allegory (II) -- Imagination and inspiration -- Language and discovery -- Matter, imagination, and spirit -- Self and reality -- Science and quality -- The coming trauma of materialism -- Participation and isolation: a fresh light on present discontents -- Form and art in society -- Philology and the incarnation -- The Psalms of David -- The "Son of God" and the "Son of Man".

At the age of sixteen, Einstein imagined chasing after a beam of light. He later recalled that the thought experiment had played a memorable role in his development of special relativity. Famous as it is, it has proven difficult to understand just how the thought experiment delivers its results. It fails to generate problems for an ether-based electrodynamics. I propose that Einstein’s canonical statement of the thought experiment from his 1946 “Autobiographical Notes,” makes most sense not as an argument against ether-based electrodynamics, but as an argument against “emission” theories of light.

Light is puzzling in modern physics–witness wave-particle duality, the two-slit experiment, and the invariant speed of light. These puzzles are not intrinsic to light but arise from overly narrow views of light. Disregarding the expansive, unitary nature of light that informs everyday experience, modern physics treats light as if it were self-bounded and separable. Further, physics assumes that light is not complicit with observations of light, that the two are separable. By likening light to light-illuminated entities, these attitudes set the stage for puzzles. When,however, conceptions of light are aligned with visual experience, those puzzles become occasions of understanding.This is because visual experience already embodies that aspect of light which physics finds so anomalous: nonseparability. Light's interactive vastness shows up wherever light shows up, and because no observer can back away from light or step outside its integrative embrace, different parts of light (photons) cannot be lifted out ofthe observation as distinct – i.e., distinctly-observed – entities.