Comment on Fuck you in particular
PrimeMinisterKeyes@leminal.space 6 months agoSerious question: If his black is the blackest and absorbs all light, why does that gadget/ trinket in the second video on this site cast a gray shadow? To my understanding, it should either cast a completely black shadow, or no shadow at all.
I don’t know where you got that idea.
Your logic assumes there’s only one light source, no atmospheric dispersion, light is a particle, and everything around the object is non-reflective. And it’s moved to a white background, something we know reflects light.
On the backdrop you mean? That would be from light refracting off of other places in the background and converging behind the gadget, partially illuminating the shadow.
The reason the shadow is gray is because light is bouncing off the other surfaces in the environment. The shadowed area isn’t receiving direct light, but it is receiving reflected indirect light.
Krudler@lemmy.world 6 months ago
Actual reason
en.wikipedia.org/…/Umbra%2C_penumbra_and_antumbra