We’ve covered a lot of incredible stuff, but this week we’re talking about the weirdest objects in space: BLACK HOLES. Stellar mass black holes form when a very massive star dies, and its core collapses. The core has to be more than about 2.8 times the Sun’s mass to form a black hole. Black holes come in different sizes, but for all of them, the escape velocity is greater than the speed of light, so nothing can escape, not matter or light. They don’t wander the Universe gobbling everything down around them; their gravity is only really intense very close to them. Tides near a stellar mass black hole will spaghettify you, and time slows down when you get near a black hole — not that this helps much if you’re falling in.

Crash Course Astronomy Poster: store.dftba.com/products/crashcourse-astronomy-poster

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Table of Contents
How Stellar Mass Black Holes Are Formed 1:03
The Core 1:43
Nothing Can Escape Once It’s Inside 2:29
Gravity Intensifies The Closer You Get 3:33
Spaghettification 6:01
Time Will Slow Down Near A Black Hole 8:01

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PHOTOS/VIDEOS
White Dwarf Pulses Like a Pulsar www.nasa.gov/centers/goddard/news/topstory/2007/whitedwarf_pulsar.html [credit: NASA, Casey Reed]
Swift Reveals New Phenomenon in a Neutron Star www.nasa.gov/mission_pages/swift/bursts/new-phenom.html#.Vc4isflVhBd [credit: NASA's Goddard Space Flight Center]
Black Holes - Monsters in Space en.wikipedia.org/wiki/File:Black_Holes_-_Monsters_in_Space.jpg [credit: NASA/JPL-Caltech, Wikimedia Commons]
What if the Sun became a black hole? (artist's impression) www.spacetelescope.org/videos/hubblecast43g/ [credit: ESA/Hubble (M. Kornmesser)]
Black Hole Animation chandra.harvard.edu/photo/2003/0203long/animations.html [credit: NASA/SAO/CXC/D.Berry]
Star Destroyer svs.gsfc.nasa.gov/cgi-bin/details.cgi?aid=11065 [credit: Space Telescope Science Institute (STScI) and NASA's Goddard Space Flight Center]
Black hole deforms space www.spacetelescope.org/videos/hst15_blackhole_grid/ [credit: ESA/Hubble (M. Kornmesser & L. L. Christensen)]
Black hole close-up (artist's impression) www.spacetelescope.org/videos/heic0211c/ [credit: European Space Agency, NASA and Felix Mirabel (the French Atomic Energy Commission & the Institute for Astronomy and Space Physics/Conicet of Argentina)]

1. Introduction to Astronomy
2. Naked Eye Observations
3. Cycles in the Sky
4. Moon Phases
5. Eclipses
6. Telescopes
7. The Gravity of the Situation
8. Tides
9. Introduction to the Solar System
10. The Sun
11. The Earth
12. The Moon
13. Mercury
14. Venus
15. Mars
16. Jupiter
17. Jupiter's Moons
18. Saturn
19. Uranus & Neptune
20. Asteroids
21. Comets
22. The Oort Cloud
23. Meteors
24. Light
25. Distances
26. Stars
27. Exoplanets
28. Brown Dwarfs
29. Low Mass Stars
30. White Dwarfs & Planetary Nebulae
31. High Mass Stars
32. Neutron Stars
33. Black Holes
34. Binary and Multiple Stars
35. Star Clusters
36. Nebulae
37. The Milky Way
38. Galaxies, part 1
39. Galaxies, part 2
40. Gamma-Ray Bursts
41. Dark Matter
42. The Big Bang, Cosmology part 1
43. Dark Energy, Cosmology part 2
44. A Brief History of the Universe
45. Deep Time
46. Everything, The Universe...And Life
47. Explore The Solar System:

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.