Why is the Sun Yellow and the Sky Blue?

In this video from MinutePhysics, Henry Reich looks at the truth about what color the sky and Sun really are and why we think they are blue and yellow respectively. If you like this video, go check out and subscribe to MinutePhysics here. You can also join us in supporting Henry’s efforts to make more videos like this by donating via MinutePhysics’ Patreon page here.

If you liked this video, you might also enjoy:

Bonus Sun Facts:

  • The energy required to stop the Earth orbiting the Sun then is about 2.6478 × 1033 joules or 7.3551 × 1029 watt hours or 6.3285*1017 megatons of TNT. For reference, the largest nuclear explosion ever detonated (the Tsar Bomba by the Soviet Union) “only” produced 50 megatons of TNT worth of energy. So it would take about 12,657,000,000,000,000 of those nuclear bombs detonated at the correct location to stop the Earth from orbiting the Sun.
  • Along with orbiting around the Sun at 66,600 mph, the Earth is also rotating at its axis at about 1,070 miles per hour. So you are simultaneously hurtling around the sun at 66,600 mph while sitting on a rock that is spinning at 1,070 mph. On top of that, our whole solar system is rocketing through space around the center of the Milky Way at around 559,234 mph. On top of that, our galaxy is hurtling through space at around 671,080 mph, with respect to our local group of galaxies. On top of that, for all we know, our entire Universe is hurtling through some unknown medium at some other ridiculous speed.
  • Once regarded by astronomers as a small and relatively insignificant star, the Sun is now known to be brighter than about 85% of the stars in the Milky Way.
  • Light travels from the Sun to the Earth in about 8 minutes and 19 seconds, yet it actually takes about 10,000-170,000 years for a photon to travel from the core of the Sun to the surface.
  • The Sun does not have enough mass to go supernova and explode.  However, in about 5 billion years it will enter a red giant phase steadily expanding until it consumes the Earth.  But fear not, the Earth will already be dead in about 1 billion years due to the fact that the Sun becomes about 10% brighter every billion years; so in 1 billion years the Earth’s surface temperature will be such that no liquid water will be able to exist unprotected on the surface of the Earth.
  • It takes approximately 225 million Earth years for our solar system to make one trip around the Milky Way.
  • Each second about four million metric tons of matter is converted to energy within the Sun’s core.  This gives the Sun a lifetime as a main sequence star of about 10 billion years with about 5 billion years to go.
Share the Knowledge! Facebooktwittergoogle_plusredditpinteresttumblrmailFacebooktwittergoogle_plusredditpinteresttumblrmail
Print Friendly
Enjoy this article? Join over 50,000 Subscribers getting our FREE Daily Knowledge and Weekly Wrap newsletters:

Subscribe Me To:  | 
  • TRX

    The sky is blue because oxygen is blue. Nitrogen is transparent.

    Just look into a container of liquid oxygen. It’s blue.