Question

why does sky looks blue

Answer 1

Sky is not blue but it looks blue because the molecules in the air scatter blue light more than any other colour

Answer 2

In truth, the reason the sky is blue is because of three simple factors put together: that sunlight is made out of light of many different wavelengths, that Earth’s atmosphere is made out of molecules that scatter different-wavelength light by different amounts, and the sensitivity of our eyes. Put these three things together, and a blue sky is inevitable. Here’s how it all comes together.