Neil deGrasse Tyson Explains Why The Sky Is Blue

Have you ever wondered why the sky is blue? Neil deGrasse Tyson is here to help you answer that question alongside comic co-host Chuck Nice. And, you’re about to find out why the answer is easy to understand, but not that simple.

You’ll learn how the white light from the sun interacts with the atmosphere through a process called “Rayleigh scattering” that makes the sky blue. Neil tells us why the sky turns different shades as the day goes on, and why the sunset changes from blue to amber.

Discover why the reason we have a blue sky is the same reason you can’t see stars during the daytime. And, how this lead to the discovery of the operational definition of where the atmosphere ends and space begins. Neil explains why he thinks space should be defined by gravity and not by the circumstances of our atmosphere. Lastly, Neil gives us a lesson on the frailty of our atmosphere and our delicate place among the stars.

Follow StarTalk:

About StarTalk:
Science meets pop culture on StarTalk! Astrophysicist & Hayden Planetarium director Neil deGrasse Tyson, his comic co-hosts, guest celebrities & scientists discuss astronomy, physics, and everything else about life in the universe. Keep Looking Up!

#StarTalk #NeildeGrasseTyson

0:00 - Introduction
1:13 - The Composition Of The Atmosphere
1:44 - The 7 Colors Of The Spectrum
3:52 - How The Atmosphere Creates A Blue Sky
4:35 - Rayleigh Scattering
5:30 - Why Sunsets Are Red
6:18 - Why Can’t We See Stars During The Daytime?
7:11 - Where Is The Edge Of The Atmosphere?
9:38 - Neil’s Operational Definition Of Space

[EiRodri]

They went from "why is the sky blue?" to "we're all going to die" 😂

[elainebmack]

I once attended a lecture by Neil deGrasse-Tyson at the University of Chicago. This guy is so down-to-earth, yet brilliant.

[YouTuber-mcel]

Two things...first, I love how Neil can be so intelligent and in a blink can come down and enjoy humor that most of us share. Second, I had always thought that the sky was blue because sunlight was being reflected off our oceans into the atmosphere. Makes me start rethinking what else I have so drastically misunderstood.

[mr.balawis]

Elementary schools should have passionate teachers like him. That is how we build foundations for learning.

[drgswhk]

*Chuck*: "Why is the sky blue?"
*12 mins later* "We're all gonna die."

[ey]

This was so entertaining, educational, lighthearted, poking fun here, and there, and just a basket of joy. Thank you so much.

[chf]

What a great video, and a great channel. Honestly I’ll never see the sky or the sunset quite the same way again. Thank you so much

[karwansalih]

I remember adults telling me because the oceans are blue and the light reflects 🤣🤣🤣

[jeromelj]

I’d be a scientist if I had him as a teacher

[hanamantmunnolli]

One of the finest explainatons of a "technical subject" in "non-technical language".

[twatpopper]

I could sit and listen to Neil for hours on end. I love science, particularly his field of science and, I wanted to study physics in college but I couldn’t do the math.

[ryzenx]

I love how Neil can chuckle through the wise-cracks yet stay on topic AND not arrogantly sound like a know-it-all. The perfect balance for learning.

[pontiac]

Man, this dude has such a freaking gift of gab. He eases us in to a complex idea, then blows our minds, then brings us back down to earth and calmly wraps up his lesson. He literally teaches astrophysics to the layman without the slightest condescending tone and totally gets off on sharing the knowledge he's labored so intensely to acquire. Just... I dunno... what a gift. What a guy!

[TheGympert]

I remember my history teacher for ever. The only "teacher" I had during "middle school" (how we call it in the Netherlands) who could always keep the whole class curious every single time. He was a story teller and left it all to us what we thought of it. Bless him <3

[davidwilkinson]

"If we didn't need atmosphere, I would want to get rid of it" These guys are the best!! Thanks.

[mmbelle]

Throughout everything I've watched with Neil, every time Neil hits Chuck in the arm or anyone else, it means he's about to blow your mind with a scientific fact. It's like a 'shut up, immabout to educate you' hit. Not mad at it at all.

[mcwix]

I love how turnt Neil gets when talking about the color blue

[kennyhalltotga]

The sky’s blue is the light bouncing off & through the earth. A beautiful glow.

[maxfri]

Now this is what I call an efficient way of learning. It’s fun, engaging, easy to digest and informative. 👌🏻

[kitlangdon]

Thanks for this! I'm a science teacher and had the privilege of naming our first-born daughter, Rayleigh. She's heard me say several times that I'm reminded of her whenever I look up at our beautiful blue skies and our equally majestic sunrises and sunsets. She now has a much better understanding and appreciation for why that is.