the.com/opaque
the bouncer of the light spectrum, refusing every photon at the door.
means Not letting light pass through, so you can't see what's behind it — and, by extension, hard to understand or see into.
from From Latin 'opacus,' meaning shaded, shadowy, or dark — the kind of word you'd use for a tree's deep shade. It came into English through French, and early on it actually got spelled 'opake' for a while, before the Latin spelling muscled its way back in. The figurative sense of 'unclear, impenetrable to the mind' is a later stretch from the literal blocking of light.
- latin root
- opacus meant shaded or dark, like deep forest
- opposite spectrum
- transparent, translucent, opaque: light's three exit options
- figurative use
- describes prose nobody can actually understand
- physics
- opacity depends on wavelength, not just thickness
- finance
- opaque markets hide prices to favor insiders
frosted glass windows — blocks light transmission while allowing diffuse illumination, used in bathrooms and privacy partitions worldwide
tungsten filament light bulbs — tungsten metal becomes opaque at high temperatures, glowing but not transparent, standard before leds
human skin — melanin and hemoglobin make skin opaque to visible light, blocking uv penetration to deeper tissues