The majority of the universe is made up of a currently mysterious entity that pervades space: dark energy. We don’t know exactly what it is, but we do know that dark energy accelerates the expansion of space. We think this means the Universe will expand forever, even as our view of it shrinks while space expands faster all the time.

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

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GEOMETRY OF THE UNIVERSE RESOURCES
Geometry:
abyss.uoregon.edu/~js/cosmo/lectures/lec15.html
starchild.gsfc.nasa.gov/docs/StarChild/questions/question35.html

Expanding faster than light:
curious.astro.cornell.edu/legal-information/104-the-universe/cosmology-and-the-big-bang/expansion-of-the-universe/616-is-the-universe-expanding-faster-than-the-speed-of-light-intermediate

General expansion:
en.wikipedia.org/wiki/Metric_expansion_of_space

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Table of Contents
Majority of the Universe is Made of Dark Energy 4:35
Dark Energy Accelerates the Expansion of Space 3:42
We Think The Universe Will Expand Forever 5:20

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PHOTOS/VIDEOS
The Big Bang svs.gsfc.nasa.gov/cgi-bin/details.cgi?aid=10128 [credit: NASA]
Collision Scenario for Milky Way and Andromeda Galaxy Encounter www.nasa.gov/images/content/654284main_i1220bw.jpg [credit: NASA; ESA; A. Feild and R. van der Marel, STScI]
Artist's impression of vampire star www.spacetelescope.org/videos/astro_bn/ [credit: ESO/M. Kornmesser]
Host Galaxies of Distant Supernovae www.nasa.gov/sites/default/files/images/593872main_hs-2006-52-a-print.jpg [credit: NASA, ESA, and A. Riess (STScl)]
Dark Energy Expands the Universe svs.gsfc.nasa.gov/cgi-bin/details.cgi?aid=10135 [credit: NASA]
Expanding Universe www.spacetelescope.org/videos/hst15_expanding_universe/ [credit: ESA/Hubble (M. Kornmesser & L. L. Christensen)]
Hubble Ultra Deep Field 2014 hubblesite.org/newscenter/archive/releases/2014/27/image/a/ [credit: NASA, ESA, H. Teplitz and M. Rafelski (IPAC/Caltech), A. Koekemoer (STScI), R. Windhorst (Arizona State University), and Z. Levay (STScI)]

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.