How do astronomers make sense out of the vastness of space? How do they study things so far away? Today Phil talks about distances, going back to early astronomy. Ancient Greeks were able to find the size of the Earth, and from that the distance to and the sizes of the Moon and Sun. Once the Earth/Sun distance was found, parallax was used to find the distance to nearby stars, and that was bootstrapped using brightness to determine the distances to much farther stars.
Table of Contents
Ancient Greeks Finding the Size of the Earth 1:07
Earth/Sun Distance Began Our Use of Parallax 5:39
Brightness Relation to Distance 9:07
PBS Digital Studios: youtube.com/pbsdigitalstudios
Follow Phil on Twitter: twitter.com/badastronomer
Want to find Crash Course elsewhere on the internet?
Facebook - www.facebook.com/YouTubeCrashCourse
Twitter - www.twitter.com/TheCrashCourse
Tumblr - thecrashcourse.tumblr.com
Support CrashCourse on Patreon: www.patreon.com/crashcourse
Lunar Ecplise www.slate.com/content/dam/slate/blogs/bad_astronomy/2014/04/15/lunareclipse_partial_apr142014_spica.jpg.CROP.original-original.jpg [credit: Phil Plait]
Venus & Mercury [credit: Phil Plait]
Venus Transit www.youtube.com/watch?v=34mXua1n_FQ [credit: NASA]
Black Drop Venus Transit en.wikipedia.org/wiki/Black_drop_effect#mediaviewer/File:BlackDrop-Venus-Transit.jpg [credit: Wikimedia Commons, H. Raab, Johannes-Kepler-Observatory]
New Horizons Approaching Pluto and Charon en.wikipedia.org/wiki/New_Horizons#/media/File:15-011a-NewHorizons-PlutoFlyby-ArtistConcept-14July2015-20150115.jpg [credit: NASA/JHU APL/SwRI/Steve Gribben]
Radio Telescopes Diagram scitechdaily.com/images/Radio-Telescopes-Settle-Controversy-Over-Distance-to-Pleiades.jpg [credit: Alexandra Angelich, NRAO/AUI/NSF]
61 Cygni archive.stsci.edu/cgi-bin/dss_search?v=poss1_red&r=21+06+54.60&d=%2B38+44+44.9&e=J2000&h=30&w=30&f=gif&c=none&fov=NONE&v3= [credit: Caltech / National Geographic Society / STScI]
Proxima Centauri www.spacetelescope.org/images/potw1343a/ [credit: ESA/Hubble & NASA]
Dying Star www.nasa.gov/images/content/64884main_image_feature_211_jwfull.jpg [credit: NASA, ESA, HEIC, and The Hubble Heritage Team (STScI/AURA)]
Exploding Star www.nasa.gov/multimedia/imagegallery/image_feature_1604.html [credit: NASA, ESA, J. Hester, A. Loll (ASU)]
Animation of a Variable Star www.spacetelescope.org/videos/heic1323j/ [credit: NASA, ESA, M. Kornmesser]
Hubble's High-Definition Panoramic View of the Andromeda Galaxy hubblesite.org/newscenter/archive/releases/2015/02/image/a/ [credit: NASA, ESA, J. Dalcanton, B.F. Williams, and L.C. Johnson (University of Washington), the PHAT team, and R. Gendler]
In this Crash Course series, marvel at the wonders of astronomy with your host for this intergalactic adventure, the Bad Astronomer himself -- Phil Plait. In just 40 short lessons, you will learn the basics of the oldest science known to humanity.
Be sure to check out links to relevant Photos in the description for each video.