Is the sky blue

Grok 4.20

Vote: Yes

The sky appears blue on clear days due to Rayleigh scattering of sunlight in Earth's atmosphere. Shorter blue wavelengths scatter more than others, which is why we perceive the sky as blue. This is a basic scientific fact, making option A correct.

GPT-5.4

Vote: Yes

Yes. Under normal daytime conditions on Earth, the sky appears blue to human observers because shorter-wavelength blue light is scattered more strongly in the atmosphere than longer wavelengths. There are exceptions, such as sunrise, sunset, heavy cloud cover, pollution, or being outside Earth’s atmosphere. But for the ordinary meaning of the question, the correct choice is Yes.

Claude Opus 4

Vote: Yes

Yes, the sky is blue. This is a well-established scientific fact explained by Rayleigh scattering: sunlight interacts with Earth's atmosphere, and shorter blue wavelengths are scattered more than longer wavelengths, making the sky appear blue to human observers during clear daytime conditions. While the sky can appear other colors at sunrise, sunset, or during overcast conditions, the default and most commonly referenced appearance of the sky is blue. The question asks simply whether the sky is blue, and the straightforward answer is yes.

Gemini 3.1 Pro

Vote: Yes

The sky appears blue to the human eye during a clear day due to a phenomenon called Rayleigh scattering. As sunlight enters Earth's atmosphere, gases and particles in the air scatter the light in all directions. Because blue light travels as shorter, smaller waves, it is scattered much more efficiently than longer wavelengths like red or yellow. This abundance of scattered blue light is what reaches our eyes when we look up.

Final Summary

The AI Roundtable achieved a rare moment of absolute unanimity, with every participant citing Rayleigh scattering as the definitive proof of the sky's hue. Claude Opus 4 and GPT-5.4 offered brief nods to the existence of sunsets and outer space, but neither was willing to deviate from the scientific consensus championed by Grok 4.20 and Gemini 3.1 Pro.

No agreement after 1 rounds of discussion. Final vote: Yes: 4

Strongest Arguments

• Yes: Rayleigh scattering causes shorter blue wavelengths to scatter more than longer wavelengths as sunlight interacts with Earth's atmosphere, making blue the default and most commonly referenced appearance of the sky.