We’ve heard that the sky is blue because it’s a reflection of Lord Krsna’s body. Modern science probably wouldn’t agree. Here are some things Srila Prabhupada said about this (excerpted from a lecture in Srimad Bhagavatam 7.9.9 in Montreal on 4 July 1968: “Yes. Krsna is bluish. Krsna’s color is the sky. When you see the clear sky, bluish sky, are you not very happy? …Krsna’s body, there is a ray, brahmajyoti. That brahmajyoti is reflected in the sky. That brahmajyoti is outside this material sky, but that is being reflected. Therefore the sky’s color, it appears bluish….”