Why is darkness 'black'?

Hello science enthusiasts, Gerd Dani here, professional blogger and director at freeastroscience.com. I'm thrilled to invite you on a journey of scientific discovery, exploring the enigmatic world of color perception. Written especially for you, let's delve into our understanding of colors, our perception of 'black' in the dark, and the fascinating concept of 'Eigengrau'.

The celebrated physicist, Isaac Newton (1642-1726), conducted an array of experiments with a prism, transforming white light into a spectrum of seven distinct colors. He documented his findings on light, color, and what he termed as 'inflection' phenomena in his 1704 publication, "Opticks". 

The colors we discern are a result of our brains' sophisticated interpretation system. Cones in our retinas absorb and cipher different wavelengths from visual stimuli. These are then transported as electrical signals via the optic nerve to the visual cortex. This process involves not just the visual cortex and hippocampus but also the limbic system which holds our emotional areas. Therefore, our perception of color is more than a mere neural process; it's an intricate blend of physiology and emotion.

Have you ever considered the color you see in complete darkness? It's a slightly brighter shade than black that German term as 'Eigengrau' or 'proper gray', produced by spontaneous activation of specific photosensitive cells in our eyes. It's a physiological trick our eyes play on us, creating a perception of 'something' that doesn't quite match reality. 

We all experience such biological illusions like the 'Eigengrau', and hypnagogic and hypnocampus hallucinations which accompany transitions between sleep and wakefulness. Our visual system, in a state of confusion, produces these optical illusions. 

The hexadecimal code for Eigengrau is #16161d, while black is represented by #0000. It's a result of the instability of a photosensitive protein composed of opsin and vitamin A in our rods, which can trick the brain into believing it has detected a photon of light. The color is unstable and can vary among individuals and over time. Although it might be unfamiliar, 'Eigengrau' has been widely acknowledged within the scientific community since Gustav Theodor Fechner, a Teutonic psychologist, coined it in the mid-19th century.

Join us at freeastroscience.com, as we continue to unravel the intriguing mysteries of the universe.  Our team of experts delves into the depths of science, exploring topics such as optical illusions and the workings of human perception.