Why is the sky blue? (explainers.blog)

Article summary

The article explains why the sky appears blue and sunsets appear red, due to the scattering of light by small molecules in the atmosphere, such as nitrogen and oxygen. The scattering effect is more pronounced for shorter wavelengths like blue and violet, while longer wavelengths like red and orange are less affected. The article also discusses the color of the sky on Mars, which appears red due to the presence of iron-rich dust particles that absorb blue light. The author provides interactive demos and examples to illustrate the concepts.

Main themes

• Atmospheric scattering
• Light wavelength and color
• Planetary atmospheres
• Optical phenomena
• Color perception

What commenters say

• The color of the sky is determined by the scattering of light by small molecules in the atmosphere, which is a well-established scientific principle.
• The reason for the blue color of the sky is not just the size of the air molecules, but also their resonant frequency, which is closer to the frequency of blue and violet light.
• The use of emojis and reassuring language in technical explanations can be seen as either helpful or undermining, depending on the reader's perspective.
• The explanation for the color of the sky and sunsets is not just a matter of simple physics, but also involves complex interactions between light, atmosphere, and perception.
• The green color is not typically visible in the sky during sunset because it is overshadowed by the dominant red and yellow wavelengths.
• The concept of structural colors, where the color is created by the physical structure of a material rather than pigments, is relevant to the discussion of the sky's color and is also found in nature, such as in butterfly wings.
• The patent system allows for the combination of existing ideas in new ways, even if the individual components are not novel, which is relevant to the discussion of technological innovations inspired by natural phenomena.
• The color of the sky can be influenced by various factors, including atmospheric conditions, dust particles, and the observer's perspective, making it a complex and multifaceted topic.