How we know the distances to the planets, stars, and faraway galaxies.
Instead of sponsored ad reads, these lessons are funded directly by viewers: https://3b1b.co/support
FAQ with added details and corrections: https://terrytao.wordpress.com/2025/02/13/cosmic-distance-ladder-video-with-grant-sanderson-3blue1brown-commentary-and-corrections/

An equally valuable form of support is to simply share the videos.

Terry and his collaborator Tanya have an Instagram about the cosmic distance ladder: https://www.instagram.com/cosmic_distance_ladder/

Artwork of Guillaume Le Gentil by Kurt Bruns
Artwork of Antonia Maury and Henrietta Leavitt by Talia Gershon: https://bit.ly/taliagershonart
Several of the great cosmological animations where by Paul Dancstep

Timestamps:
0:00 – Intro
1:04 – Distance to Venus
7:30 – Speed of light
10:08 – Nearby stars
13:20 – The Milky Way
18:14 – Nearby Galaxies
19:44 – Distant Galaxies
22:42 – Lingering mysteries

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These animations are largely made using a custom Python library, manim. See the FAQ comments here:
https://3b1b.co/faq#manim
https://github.com/3b1b/manim
https://github.com/ManimCommunity/manim/

All code for specific videos is visible here:
https://github.com/3b1b/videos/

The music is by Vincent Rubinetti.
https://www.vincentrubinetti.com
https://vincerubinetti.bandcamp.com/album/the-music-of-3blue1brown
https://open.spotify.com/album/1dVyjwS8FBqXhRunaG5W5u

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3blue1brown is a channel about animating math, in all senses of the word animate. If you’re reading the bottom of a video description, I’m guessing you’re more interested than the average viewer in lessons here. It would mean a lot to me if you chose to stay up to date on new ones, either by subscribing here on YouTube or otherwise following on whichever platform below you check most regularly.

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