Blue Sky

IMG_7131-1-1Have you ever wondered why the sky is blue, the sun is yellow and sunsets are red? This is due to Rayleigh scattering from the air molecules. They scatter more blue light than red so when looking at the sky it seems blue! Click through to learn more.



In the video below, Minute Physics cleverly explains why the scattering of light by the air molecules make the sky seem blue. This scattering, called Rayleigh scattering, also explains why the sun seems yellow and sunrises and sunsets are orange/redish. I highly reccomend taking the time to watch it :) This topic is on my to-do list for a future blog post with more in depth explanations and equations. I learned about Rayleigh scattering for the first time in a 3rd year Physics course during my undergrad studies and it has fascinated me ever since! :)

In the photograph below you can see that blue skies and fluffy clouds were the inspiration for this artwork at Sculptures by the Sea 2012. By the way, Sculptures by the Sea started today! Be sure to head down to the Bondi-Tamarama coastal walk in Sydney before the 9th of November to check it out!

Blue Sky at Sculptures by the Sea 2012
Blue Sky at Sculptures by the Sea 2012. Ana Andres-Arroyo Photography.

As was explained in the video, at sunset or sunrise “there is even more air for the light to scatter off of before it reaches you, hence, the even richer oranges and reds”. The picture below was taken in Jervis Bay in October 2013. It was just a few days after the huge bushfires that took place in the Blue Mountains, and a lot of ash was still in the air. This meant that there were even more particles to scatter the light, making the sunrise even more red!

Sunrise at Jervis Bay. Ana Andres-Arroyo Photography.
Sunrise at Jervis Bay. Ana Andres-Arroyo Photography.

I hope this post has piqued your interest in the how and why of blue skies and red sunsets. It’s all physics! Photography is light, light is physics :)

Thank you for reading!

xx Ana :)


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