Cosmology & Astronomy
Uncover the secrets of the universe from The Big Bang to Black Holes plus many more. Created by Khan Academy.
Average Course Length
15 hours
Skill Level
Beginner
Pick a lesson
1: Scale of Earth and Sun
2: Scale of Solar System
3: Scale of Distance to Closest Stars
4: Scale of the Galaxy
5: Intergalactic Scale
6: Hubble Image of Galaxies
7: Big Bang Introduction
8: Radius of Observable Universe
9: (Correction) Radius of Observable Universe
10: Red Shift
11: Cosmic Background Radiation
12: Cosmic Background Radiation 2
13: Cosmological Time Scale 1
14: Cosmological Time Scale 2
15: Four Fundamental Forces
16: Birth of Stars
17: Becoming a Red Giant
18: White and Black Dwarfs
19: A Universe Smaller than the Observable
20: Star Field and Nebula Images
21: Parallax in Observing Stars
22: Stellar Parallax
23: Stellar Distance Using Parallax
24: Stellar Parallax Clarification
25: Parsec Definition
26: Hubble's Law
27: Lifecycle of Massive Stars
28: Supernova (Supernovae)
29: Supernova clarification
30: Black Holes
31: Cepheid Variables 1
32: Why Cepheids Pulsate
33: Why Gravity Gets So Strong Near Dense Objects
34: Supermassive Black Holes
35: Quasars
36: Quasar Correction
37: Galactic Collisions
38: Earth Formation
39: Beginnings of Life
40: Ozone Layer and Eukaryotes Show Up in the Proterozoic Eon
41: Biodiversity Flourishes in Phanerozoic Eon
42: First living things on land clarification
43: Plate Tectonics-- Difference between crust and lithosphere
44: Structure of the Earth
45: Plate Tectonics -- Evidence of plate movement
46: Plate Tectonics -- Geological Features of Divergent Plate Boundaries
47: Plate Tectonics-- Geological features of Convergent Plate Boundaries
48: Plates Moving Due to Convection in Mantle
49: Hawaiian Islands Formation
50: Compositional and Mechanical Layers of the Earth
51: Seismic Waves
52: Why S-Waves Only Travel in Solids
53: Refraction of Seismic Waves
54: The Mohorovicic Seismic Discontinuity
55: How we know about the Earth's core
56: Pangaea
57: Scale of the Large
58: Scale of the Small
59: Detectable Civilizations in our Galaxy 1
60: Detectable Civilizations in our Galaxy 2
61: Detectable Civilizations in our Galaxy 3
62: Detectable Civilizations in our Galaxy 4
63: Detectable Civilizations in our Galaxy 5
64: Human Evolution Overview
65: Understanding Calendar Notation
66: Correction Calendar Notation
67: Development of Agriculture and Writing
68: Introduction to Light
69: Seasons Aren't Dictated by Closeness to Sun
70: How Earth's Tilt Causes Seasons
71: Milankovitch Cycles Precession and Obliquity
72: Are Southern Hemisphere Seasons More Severe?
73: Precession Causing Perihelion to Happen Later
74: What Causes Precession and Other Orbital Changes
75: Apsidal Precession (Perihelion Precession) and Milankovitch Cycles
76: Firestick Farming
77: Carbon 14 Dating 1
78: Carbon 14 Dating 2
79: Potassium-Argon (K-Ar) Dating
80: K-Ar Dating Calculation
81: Chronometric Revolution
82: Collective Learning
83: Land Productivity Limiting Human Population
84: Energy Inputs for Tilling a Hectare of Land
85: Random Predictions for 2060