: Many observers notice the sky appears bluer in autumn. This is due to lower humidity and fewer pollutants like dust or pollen, which allows for cleaner scattering.
: The United Nations observes the International Day of Clean Air for blue skies every September 7 to raise awareness about air pollution. Research & Innovation Blue Skies
: This refers to curiosity-driven scientific research without immediate real-world applications. Proponents from platforms like PMC argue that this fundamental research often leads to serendipitous breakthroughs, such as the development of solar energy and quantum theory. : Many observers notice the sky appears bluer in autumn