February 9, 2026
Blue clues, red sunsets, green drama
Why Is the Sky Blue?
Why the sky is blue sparks memes, butterfly facts, and “it’s raining” chaos
TLDR: Air scatters blue light more, so the sky looks blue; at sunset, blue gets bounced away and reds shine through. Comments turned into a meme-and-science brawl over violet vs blue, the missing “green” sky, butterfly optics, and one legendary “it’s raining” reality check.
The internet just found a new thing to argue about: why the sky is blue. The article says tiny bits of air bounce blue light around more than other colors, so the whole sky glows blue. Cue the “ackshually” crowd linking a YouTube demo and Wikipedia on Rayleigh scattering — fancy words for “light gets ping‑ponged by air” — thanks to ranger_danger and this explainer. Meanwhile, one commenter crashed the science party with pure chaos: “It’s not. It’s raining here,” turning the thread into weather therapy. The nerdiest twist? Blue butterflies aren’t really blue — their wings use tiny ridges to reflect blue light, no dye needed. That parallel had everyone saying the sky and butterflies are both “optical illusions,” courtesy of [KellyCriterion]. Meme patrol showed up with obligatory xkcd on sky color and Rayleigh jokes, because of course they did. The spiciest debate: if daytime is blue and sunset is red, why isn’t the sky green in between? [justin_dash] lit it up, and replies said the colors blend, our eyes favor certain shades, and violet gets filtered and ignored — so the “green zone” gets lost in the mix. Sunsets stayed dramatic; the thread stayed messier than a storm cloud.
Key Points
- •Color perception depends on the wavelengths of photons entering the eye, often as mixtures interpreted as a single color.
- •In Earth’s atmosphere, blue photons scatter more than other colors, distributing blue light across the sky.
- •Photon interactions with nitrogen and oxygen induce electron cloud oscillations that are stronger near resonant frequencies.
- •For N2 and O2, the lowest resonant frequencies are in the ultraviolet, so scattering increases toward shorter visible wavelengths.
- •Rayleigh scattering scales with the fourth power of frequency; violet scatters far more than red (about tenfold).