Telescopes: Crash Course Astronomy #6

Today Phil explains how telescopes work and offers up some astronomical shopping advice.

How Telescopes Work 1:07
Refractors vs Reflectors 2:50
Technology and the Light Spectrum 7:45

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Rafał Kukuła says:

I love the JWST on the shelf behind 🙂

G Bendicion says:

Great video Crash Course! This is a great explanation of telescopes and is very helpful to students and more people who are interested.

Wish to see much more videos! 😀

Ahmed Mansi says:

The Arabic scientist Ibn Sina has investigated Gravity long before Sir Isaac Newton and Hook.

noonesflower says:

why don’t you use any real views through the telescope’s eyepiece as examples? Why do you use only paintings of

D.K. Gonzales says:

I’ve always loved looking up at the sky at night. Especially now that I’m learning Astronomy thanks to you guys. I now make it a habit to walk my way home so I can look up and see the stars and the moon while listening to my favorite tunes. One of the best feelings in the world.

Aaron O Donovan says:

getting my first telescope for christmas so i thought id learn a bit about astronomy. these videos are great!

Sharven Mahendren says:

really helped.. and was very useful.. thanks Crash Course

Need leopard says:

I’m from America so that car scene made me nervous XD

Zom Bee Nature says:

My telescope is actually just a pretty cheap mini pair of binoculars and that makes them sad… [weeps piteously]
Everyone, please watch my tiny nature videos. There is no talking in them. It is hard to find quiet places to record. Shhh!

Matt Kroeker says:

“Hey Phil! Who does your hair?!”

shreya jain says:

Wow. U r so amazing. U just motivated me to visit my city’s planetarium

Charles Glisson says:

Great job

Ferber Person says:

“Look at your eyes… well, that’s tough, so let’s think about our eyes for a moment.” this is why I love this series

thomaaas_ says:

Mr Telescope invented it

Masth Malang says:


Vivek Tripathi says:

awesome series !!..I find this very very helpful in understanding the basics of astronomy.

Paul Aldrich says:

Unfortunately light pollution in my area renders stargazing obsolete. On a good night there are no more than 50 visible stars. I do still keep track of the moon and the visible planets 🙂 once a year I go on a holiday to a rural part of nsw to look up at night. I love being able to see both the large and small maggelanic clouds as they orbit our galaxy

Vladimir Morar says:

Size matters

Max Sainz says:

Well, my refractor doesn’t flip the image. my reflector does.

Jaison Sam says:


Ahsan Arifeen says:

the picture of the eye looked scary

Branden Loveless says:

Phil plait, you’re on the science channel. How the universe works

Lynda Williams says:

more diagrams!

Julia marshmello says:

I have a science exam tumorrow. this vid saved my life

Team Gamers says:

Thank you Phil Plait for such fun and informative videos. I learnt a lot of things which I did not know.

D.K. Gonzales says:

Aggressive self-marketing sometimes pays off.

Branden Loveless says:

I want to get a PhD in astronomy when I’m older. I want to work for NASA when I’m older. I want to get a PhD in electrical engineering and computer science. I know about Galileo galilei. please respond to this comment.

kmm says:

Phil, I must say that you are one of the funnest teachers I’ve heard! These episodes have been inspiring and make me excited to learn more about astronomy!

Red Coin says:

Phil, who does your hair?

Arz Bshara says:

Who else is watching this in 2017?

Arch3rAc3 says:

8:59 Wait, 19FPS? That’s pretty low.

Branden Loveless says:

Galileo discovered some moons on the planets in the solar system which he thought were satellites

Alex Altair says:

Wait… you have *two* model of the James Webb Space Telescope on the shelf behind you? And with mirrors oriented differently?

friggingbomb88 says:

boring episode!

TigerShark says:


Joey Sullivan says:

You can “look at your eyes”, by looking in a mirror. Just sayin’.

Kaz Pdx says:

You’re a genius

SZECHUAN diping sauce says:

if a was a teacher these series would be my lesons


Its very satisfiable to understand the sciences through your videos ….

Pablo Herrera says:


phatcrayonz says:

i love this stuff


Hi! I am going to 6th grade. I want to see the planet by a telescope. So what kind of telescope should my parents buy for me?

Red Fox Nalie says:

this channel reminds me of ted ed

allison 180181 says:

Amazing work, love these videos/lessons

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