We live in a unique cosmic era when we can observe the cosmic microwave background and distant galaxies, but the accelerating expansion of the Universe will make this impossible for future generations. This video explores how dark matter determines the dynamics of our Local Group and why a collision with Andromeda in billions of years is inevitable.

Timestamps:
00:00 Introduction
01:28 From Earth to the Milky Way
03:00 The Structure of the Milky Way
08:03 Galaxy Rotation and the Cosmic Year
09:07 The Spiral Arms of the Milky Way
11:44 Globular Clusters — Galactic Relics
13:05 Satellite Galaxies and the Magellanic Clouds
15:58 The Tarantula Nebula: Extreme Star Formation
18:04 Dim Dwarf Satellites of the Milky Way
19:17 The Problem of Missing Satellites
21:07 The Andromeda Galaxy: A Giant Nearby
25:22 Andromeda Flying Toward Us
26:43 The Fate of the Solar System during a Merger
27:19 A Spectacle of a Merger in the Night Sky
28:02 The Triangulum Galaxy (M33)
29:28 Dwarf Galaxies of the Local Group
30:17 The Scale of the Local Group: An Analogy
32:14 The Local Group - Our Home
32:37 Intergalactic Void
33:37 Matter Density in the Void
34:33 Dynamics of the Local Group
35:53 The GAIA Mission: A Map of Motions
36:56 Hubble and the Andromeda Collision
37:30 The Local Group in the Virgo Supercluster
40:13 The Cosmic Web
41:22 The Role of Dark Matter
43:37 From the Big Bang to the First Stars
45:56 Formation of the Milky Way and the Local Group
46:46 History of the Discovery of the Extragalactic World
48:41 Hubble's Discovery of Extragalactic Scale
50:30 The Growth of Galaxies through Cannibalism
51:31 Ancient Merger Revealed by Gaia
52:15 The Milky Way in the Process of Absorption
56:26 Why the Local Group?
58:57 Our Place in the Universe and Life
01:00:58 Earth — Smaller than an Atom in a Brick
01:02:34 Amazing: We Measured the Cosmos
01:03:44 Flight Time to Andromeda — Billions of Years
01:05:15 Andromeda — Light from the Past
01:08:10 The Unpredictability of the Future of the Local Group
01:09:38 The Ubiquity of Planets and Star Systems
01:13:01 Observing Andromeda from Earth
01:14:53 The Role of Dark Matter in the Fate of the Group
01:16:38 The Local Group as an Eternal Home
01:17:20 Measuring Cosmic Distances
01:22:20 Stellar Streams in the Halo of Andromeda
01:24:03 Comparison of the Halos of the Milky Way and Andromeda
01:25:02 Evidence and the Mystery of Dark Matter
01:28:38 Invisible Light: X-Rays from Hot Gas
01:30:25 Mapping Hydrogen: The 21-Centimeter Line
01:31:49 The Future: Colliding Galaxies and Dark Energy
01:36:53 The Computational Revolution in Cosmology
01:39:41 The Local Group as a Laboratory
01:40:37 Light as a Message from the Past
01:46:07 Future Merger and Solitude
01:48:09 The Uniqueness of the Current Era
01:49:04 Stellar Spectroscopy and Chemistry
01:53:56 True Scale and Perception
01:56:27 The Local Group and the Scale of the Cosmos
01:56:56 A Unique Awareness of Our Smallness