Viewers like you help make PBS (Thank you

Support us on Patreon! https://patreon.com/eons

Tyrannosaurus rex was big, Tyrannosaurus rex was vicious, and Tyrannosaurus rex had tiny arms. The story of how T-Rex lost its arms is, itself, pretty simple. But the story of why it kept those little limbs, and how it used them? Well, that’s a little more complicated.

Thanks as always to Nobumichi Tamura for allowing us to use his wonderful paleoart: http://spinops.blogspot.com/

Produced in collaboration with PBS Digital Studios: http://youtube.com/pbsdigitalstudios

Super special thanks to the following Patreon patrons for helping make Eons possible:
Aldo Espinosa Zúñiga, Svetlana Pylaeva, Colin Sylvester, Philip Slingerland, John Vanek, Jose Garcia, Noah offitzer, Eric Vonk, Tony Wamsley, Henrik Peteri, Jonathan Wright, Wilco Verweij, Jon Monteiro, James Bording, Brad Nicholls, Miles Chaston, Addison Baker, Michael McClellan, Elysha Nygård, Jeff Graham, Maria Humphrey, Southpoint, Connor Jensen, Ehit Dinesh Agarwal, Sapjes, Dave, Daisuke Goto, Zachary Winkler, Hubert Rady, Yuntao Zhou, Gregory Kintz, Tyson Cleary, Chandler Bass, Maly Lor, Joao Ascensao, Mario Morales, Tsee Lee, Sarah Fritts, phil parker, Ruben Winter, Ron Harvey Jr, Joshua Mitchell, Johnny Li, Katie Fichtner, Budjarn Lambeth, Jacob Gerke, Katie M Vasilescu, Brandon Burke, Alex Yan, Jordon Sokoll

Want to follow Eons elsewhere on the internet?
Facebook - https://www.facebook.com/eonsshow
Twitter - https://twitter.com/eonsshow
Instagram - https://www.instagram.com/eonsshow/

References:
Baron, Matthew G., David B. Norman, and Paul M. Barrett. "A new hypothesis of dinosaur relationships and early dinosaur evolution." Nature 543.7646 (2017): 501.
Bates, Karl T., and Peter L. Falkingham. "Estimating maximum bite performance in Tyrannosaurus rex using multi-body dynamics." Biology Letters (2012): rsbl20120056.
Brusatte, Stephen L., and Thomas D. Carr. "The phylogeny and evolutionary history of tyrannosauroid dinosaurs." Scientific Reports 6 (2016): 20252.
Burch, Sara. Osteological, Myological, and Phylogenetic Trends of Forelimb Reduction in Nonavian Theropod Dinosaurs. Diss. The Graduate School, Stony Brook University: Stony Brook, NY., 2015.
Carpenter, Kenneth. "Forelimb biomechanics of nonavian theropod dinosaurs in predation." Senckenbergiana lethaea 82.1 (2002): 59-75.
Erickson, Gregory M., et al. "Bite-force estimation for Tyrannosaurus rex from tooth-marked bones." Nature 382.6593 (1996): 706.
Fowler, Denver W., et al. "Reanalysis of “Raptorex kriegsteini”: a juvenile tyrannosaurid dinosaur from Mongolia." PLoS One 6.6 (2011): e21376.
Gillingham, James C., and Jeffrey A. Chambers. "Courtship and pelvic spur use in the Burmese python, Python molurus bivittatus." Copeia 1982.1 (1982): 193-196.
Gould, Stephen Jay, and Richard C. Lewontin. "The spandrels of San Marco and the Panglossian paradigm: a critique of the adaptationist programme." Proc. R. Soc. Lond. B 205.1161 (1979): 581-598.
Hutchinson, John R., and Stephen M. Gatesy. "Dinosaur locomotion: beyond the bones." Nature 440.7082 (2006): 292.
Makovicky, Peter J. "A new small theropod from the Morrison Formation of Como Bluff, Wyoming." Journal of Vertebrate Paleontology 17.4 (1997): 755-757.
MIDDLETON, KEVIN M., and STEPHEN M. GATESY. "Theropod forelimb design and evolution." Zoological Journal of the Linnean Society 128.2 (2000): 149-187.
Personal communication, Amy Atwater & Dr. John Scanella, Museum of the Rockies
Pontzer, Herman, et al. "Control and function of arm swing in human walking and running." Journal of Experimental Biology 212.4 (2009): 523-534.
Ruiz, Javier, et al. "The hand structure of Carnotaurus sastrei (Theropoda, Abelisauridae): implications for hand diversity and evolution in abelisaurids." Palaeontology 54.6 (2011): 1271-1277.
Sellers, William I., et al. "Investigating the running abilities of Tyrannosaurus rex using stress-constrained multibody dynamic analysis." PeerJ 5 (2017): e3420.
Sereno, Paul C., et al. "Tyrannosaurid skeletal design first evolved at small body size." Science 326.5951 (2009): 418-422.
Stanley, Steven M. “Evidence that the Arms of Tyrannosaurus rex were not functionless but adapted for vicious slashing.” Geological Society of America Annual Meeting 2017.
Sullivan, Corwin, et al. "The asymmetry of the carpal joint and the evolution of wing folding in maniraptoran theropod dinosaurs." Proceedings of the Royal Society of London B: Biological Sciences (2010): rspb20092281.
Therrien, François, and Donald M. Henderson. "My theropod is bigger than yours… or not: estimating body size from skull length in theropods." Journal of Vertebrate Paleontology 27.1 (2007): 108-115. [108:MTIBTY]2.0.CO;2
USAMI, Yoshiyuki, and Ryuta KINUGASA. "A Possibility of Fast Running of TYRANNOSAURUS." DEStech Transactions on Engineering and Technology Research amma (2017).
Xu, Xing, et al. "A basal tyrannosauroid dinosaur from the Late Jurassic of China." Nature 439.7077 (2006): 715.

The story of sloths is one of astounding ecological variability, with some foraging in the seas, others living underground, and others still hiding from predators in towering cliffs. So why are their only living relatives in the trees?

Thanks to Ceri Thomas for allowing us to use few sloth reconstructions! Check out more of Ceri's paleoart at http://alphynix.tumblr.com and http://nixillustration.com

And thanks as always to Franz Anthony and everyone at http://252mya.com for their great paleoart.

Produced in collaboration with PBS Digital Studios: http://youtube.com/pbsdigitalstudios

Super special thanks to the following Patreon patrons for helping make Eons possible:

Katie Fichtner, Aldo Espinosa Zúñiga, Anthony Callaghan, Esmeralda Rupp-Spangle, Gregory Donovan, Ehit Dinesh Agarwal, الخليفي سلطان, Gabriel Cortez, Marcus Lejon, Anel Salas, Robert Arévalo, Robert Hill, Kelby Reid, Todd Dittman, Betsy Radley, PS, Colin Sylvester, Philip Slingerland, John Vanek, Jose Garcia, Noah offitzer, Eric Vonk, Tony Wamsley, Henrik Peteri, Jonathan Wright, Jon Monteiro, James Bording, Brad Nicholls, Miles Chaston, Michael McClellan, Jeff Graham, Maria Humphrey, Nathan Paskett, Connor Jensen, Sapjes, Daisuke Goto, Hubert Rady, Yuntao Zhou, Gregory Kintz, Tyson Cleary, Chandler Bass, Maly Lor, Joao Ascensao, Tsee Lee, Sarah Fritts, Ruben Winter, Ron Harvey Jr, Jacob Gerke, Alex Yan

If you'd like to support the channel, head over to http://patreon.com/eons and pledge for some cool rewards!

Want to follow Eons elsewhere on the internet?
Facebook - https://www.facebook.com/eonsshow
Twitter - https://twitter.com/eonsshow
Instagram - https://www.instagram.com/eonsshow/

References:
https://link.springer.com/arti....cle/10.1007/s10722-0
https://www.tandfonline.com/do....i/abs/10.1080/004382
http://www.pnas.org/content/102/33/11763
https://www.cambridge.org/core..../journals/journal-of
https://www.jstor.org/stable/2400207
https://onlinelibrary.wiley.co....m/doi/abs/10.1111/j.
https://www.tandfonline.com/do....i/abs/10.1080/104209
https://palaeo-electronica.org..../2009_3/189/index.ht
https://link.springer.com/arti....cle/10.1007/s10914-0
https://eurekamag.com/research..../020/408/020408865.p
https://www.tandfonline.com/doi/abs/10.1671/2429b
https://link.springer.com/arti....cle/10.1007/s10914-0
https://link.springer.com/arti....cle/10.1007/s10914-0
https://link.springer.com/arti....cle/10.1007/s10914-0
https://www.ncbi.nlm.nih.gov/p....mc/articles/PMC39732
http://www.bioone.org/doi/abs/....10.1671/0272-4634(20
https://academic.oup.com/zooli....nnean/article/140/2/
https://link.springer.com/arti....cle/10.1007/s10914-0
https://www.ncbi.nlm.nih.gov/pubmed/25861559
https://peerj.com/articles/5600/
https://www.tandfonline.com/do....i/abs/10.1671/0272-4
https://www.researchgate.net/p....ublication/233548931

The California condor is the biggest flying bird in North America, a title that it has held since the Late Pleistocene Epoch. It's just one example of an organism that we share the planet with today that seems lost in time, out of place in our world.

Thanks as always to Studio 252mya for their wonderful paleoart. You can check out more of their work here: https://252mya.com

Produced in collaboration with PBS Digital Studios: http://youtube.com/pbsdigitalstudios

Super special thanks to the following Patreon patrons for helping make Eons possible:

Katie Fichtner, Anthony Callaghan, XULIN GE, Po Foon Kwong, Larry Wilson, Merri Snaidman, Renzo Caimi, Ordenes, John Vanek, Neil H. Gray, Marilyn Wolmart, Esmeralda Rupp-Spangle, Gregory Donovan, Ehit Dinesh Agarwal, الخليفي سلطان, Gabriel Cortez, Marcus Lejon, Robert Arévalo, Robert Hill, Kelby Reid, Todd Dittman, Betsy Radley, PS, Philip Slingerland, Jose Garcia, Eric Vonk, Tony Wamsley, Henrik Peteri, Jonathan Wright, Jon Monteiro, James Bording, Brad Nicholls, Miles Chaston, Michael McClellan, Jeff Graham, Maria Humphrey, Nathan Paskett, Connor Jensen, Daisuke Goto, Hubert Rady, Gregory Kintz, Tyson Cleary, Chandler Bass, Maly Lor, Joao Ascensao, Tsee Lee, Sarah Fritts, Ron Harvey Jr, Jacob Gerke, Alex Yan

If you'd like to support the channel, head over to http://patreon.com/eons and pledge for some cool rewards!

Want to follow Eons elsewhere on the internet?
Facebook - https://www.facebook.com/eonsshow
Twitter - https://twitter.com/eonsshow
Instagram - https://www.instagram.com/eonsshow/

References: https://bit.ly/2HdL2V7

Viewers like you help make PBS (Thank you

You can check out Google's Science Journal app at https://makingscience.withgoog....le.com/science-journ

We traveled to Bozeman, Montana to meet with Dr. Ellen-Thérèse Lamm who explores ancient life by studying it at the cellular level. Kallie and Dr. Lamm discuss how she does this, and what she’s learned by putting dinosaur bones under a microscope.

Check out the Museum of the Rockies - Paleohistology Lab website: https://www.morhistologylab.org/

Produced in collaboration with PBS Digital Studios: http://youtube.com/pbsdigitalstudios

Want to follow Eons elsewhere on the internet?
Facebook - https://www.facebook.com/eonsshow
Twitter - https://twitter.com/eonsshow
Instagram - https://www.instagram.com/eonsshow/

Viewers like you help make PBS (Thank you

As more and more fossil ancestors have been found, our genus has become more and more inclusive, incorporating more members that look less like us, Homo sapiens. By getting to know these other hominins--the ones who came before us--we can start to answer some big questions about what it essentially means to be human.

Thanks as always to Nobu Tamura for allowing us to use his wonderful paleoart: http://spinops.blogspot.com/

Thanks to Julio Lacerda and Studio 252mya for the hominin illustrations. You can find more of Julio's work here: https://252mya.com/gallery/julio-lacerda

Produced in collaboration with PBS Digital Studios: http://youtube.com/pbsdigitalstudios

Super special thanks to the following Patreon patrons for helping make Eons possible:

Katie Fichtner, Anthony Callaghan, Renzo Caimi Ordenes, John Vanek, Neil H. Gray, Marilyn Wolmart, Esmeralda Rupp-Spangle, Gregory Donovan, Ehit Dinesh Agarwal, الخليفي سلطان , Gabriel Cortez, Marcus Lejon, Robert Arévalo, Robert Hill, Kelby Reid, Todd Dittman, Betsy Radley, PS, Colin Sylvester, Philip Slingerland, Jose Garcia, Eric Vonk, Tony Wamsley, Henrik Peteri, Jonathan Wright, Jon Monteiro, James Bording, Brad Nicholls, Miles Chaston, Michael McClellan, Jeff Graham, Maria Humphrey, Nathan Paskett, Connor Jensen, Daisuke Goto, Hubert Rady, Yuntao Zhou, Gregory Kintz, Tyson Cleary, Chandler Bass, Maly Lor, Joao Ascensao, Tsee Lee, Sarah Fritts, Ruben Winter, Ron Harvey Jr, Jacob Gerke, Alex Yan

If you'd like to support the channel, head over to http://patreon.com/eons and pledge for some cool rewards!

Want to follow Eons elsewhere on the internet?
Facebook - https://www.facebook.com/eonsshow
Twitter - https://twitter.com/eonsshow
Instagram - https://www.instagram.com/eonsshow/

References:
http://humanorigins.si.edu/evi....dence/human-fossils/
http://humanorigins.si.edu/evi....dence/human-fossils/
http://humanorigins.si.edu/evi....dence/human-fossils/
http://humanorigins.si.edu/evi....dence/human-fossils/
http://humanorigins.si.edu/evi....dence/human-fossils/
http://humanorigins.si.edu/evi....dence/human-fossils/
http://humanorigins.si.edu/evi....dence/behavior/footp
http://humanorigins.si.edu/evi....dence/human-fossils/
https://australianmuseum.net.a....u/learn/science/huma
https://www.earthmagazine.org/....article/redefining-h
https://medium.com/@johnhawks/....the-plot-to-kill-hom
Antón, S. C., Potts, R., & Aiello, L. C. (2014). Evolution of early Homo: an integrated biological perspective. Science, 345(6192), 1236828.
Gibbons, A. (2015). Deep roots for the genus Homo.
Haile-Selassie, Y., Latimer, B. M., Alene, M., Deino, A. L., Gibert, L., Melillo, S. M., ... & Lovejoy, C. O. (2010). An early Australopithecus afarensis postcranium from Woranso-Mille, Ethiopia. Proceedings of the National Academy of Sciences, 107(27), 12121-12126.
Leakey, L. S., Tobias, P. V., & Napier, J. R. (1964). A new species of the genus Homo from Olduvai Gorge.
Schwartz, J. H., & Tattersall, I. (2015). Defining the genus Homo. Science, 349(6251), 931-932.
Susman, R. L. (1994). Fossil evidence for early hominid tool use. Science, 265(5178), 1570-1573.
Villmoare, B., Kimbel, W. H., Seyoum, C., Campisano, C. J., DiMaggio, E. N., Rowan, J., ... & Reed, K. E. (2015). Early Homo at 2.8 Ma from Ledi-Geraru, Afar, Ethiopia. Science, 347(6228), 1352-1355.
Wood, B. (1992). Origin and evolution of the genus Homo. Nature, 355(6363), 783.
Wood, B. (1999). 'Homo rudolfensis' Alexeev, 1986-fact or phantom?. Journal of human evolution, 36(1), 115.
Wood, B. (2014). Human evolution: Fifty years after Homo habilis. Nature News, 508(7494), 31.
Wood, B., & Collard, M. (1999). The human genus. Science, 284(5411), 65-71.

Hank introduces us to the "simplest" of the animals, complexity-wise: beginning with sponges (whose very inclusion in the list as "animals" has been called into question because they are so simple) and finishing with the most complex molluscs, octopuses and squid. We differentiate them by the number of tissue layers they have, and by the complexity of those layers.

Crash Course Biology is now available on DVD! http://dft.ba/-8css

Like CrashCourse on Facebook: http://www.facebook.com/YouTubeCrashCourse
Follow CrashCourse on Twitter: http://www.twitter.com/TheCrashCourse

Table of Contents:
1) Porifera 1:33
2) Cnidaria 2:36
a) Diploblasts 2:48
3) Platyhelminthes 3:33
a) Triploblasts 3:56
b) Coelom 4:36
4) Biolography 5:36
5) Nematoda 7:26
6) Rotifera 7:57
7) Molusca 8:33

References for this episode can be found in the Google document here: http://dft.ba/-2V_c

crash course, biology, anatomy, animal, simple, complex, tissue complexity, tissue, sponge, development, porifera, multicellular, eukaryotic, eukaryote, species, cnidaria, jellies, anemone, hydra, coral, germ layer, body cavity, endoderm, ecotoderm, dipoloblast, stinging cell, cnidocyst, platyhelminthes, fluke, triploblast, coelom, acoelomate, biolography, cambrian explosion, adaptation, fossil, evolution, diversity, nematoda, pseudocoelomate, hookworm, rotifera, mollusca, chitin, snail, bivalve, octopus, squid, visceral mass, foot, mantle, radula, gastropod, cephalopod Support CrashCourse on Subbable: http://subbable.com/crashcourse

In which John covers the long, long history of ancient Egypt, including the Old, Middle and New Kingdoms, and even a couple of intermediate periods. Learn about mummies, pharaohs, pyramids and the Nile with John Green.

Crash Course World History is now available on DVD!
http://store.dftba.com/product....s/crashcourse-world-

Resources:

Mummies!: https://goo.gl/BvAdmj

Pyramids!: http://goo.gl/aCov2j


Follow us!
@thecrashcourse
@realjohngreen
@raoulmeyer
@crashcoursestan
@saysdanica
@thoughtbubbler

Like us! ‪http://www.facebook.com/youtubecrashcourse
Follow us again! ‪http://thecrashcourse.tumblr.com
Support CrashCourse on Patreon: https://www.patreon.com/crashcourse

Want more videos about psychology every Monday and Thursday? Check out our sister channel SciShow Psych at https://www.youtube.com/scishowpsych!

What exactly is Consciousness? Well... that's kind of a gray area. In this episode of Crash Course Psychology, Hank gives you the basic ideas of what Consciousness is, how our attention works, and why we shouldn't text and drive... ever... no, really, NEVER!
--
Table of Contents

Defining Consciousness 00:00:00
Neuroimaging 02:16:01
Dual Processing 03:45:18
Selective Attention 04:22:16
Selective Inattention 05:46:21
Change Blindness 06:12:08
--
Want to find Crash Course elsewhere on the internet?
Facebook - http://www.facebook.com/YouTubeCrashCourse
Twitter - http://www.twitter.com/TheCrashCourse
Tumblr - http://thecrashcourse.tumblr.com
Support CrashCourse on Subbable: http://subbable.com/crashcourse

You can directly support Crash Course at https://www.patreon.com/crashcourse Subscribe for as little as $0 to keep up with everything we're doing. Free is nice, but if you can afford to pay a little every month, it really helps us to continue producing this content.

In which John Green teaches you about the poetry of Sylvia Plath. When a lot of people think about Sylvia Plath, they think about her struggles with mental illness and her eventual suicide. Her actual work can get lost in the shuffle a bit, so this video really tries to focus on the poetry. You'll learn about Sylvia Plath's role as a feminist poet, and you'll also learn about her extraordinary ability to recreate the experiences of real life in beautiful and relatable way.

Hear John read all of Sylvia Plath's "Lady Lazarus" here:
https://www.youtube.com/watch?v=auP1bHAglU0&feature=youtu.be

You can directly support Crash Course at http://www.subbable.com/crashcourse Subscribe for as little as $0 to keep up with everything we're doing. Also, if you can afford to pay a little every month, it really helps us to continue producing great content.

Continuing our look at Nuclear Chemistry, Hank takes this episode to talk about Fusion and Fission. What they mean, how they work, their positives, negatives, and dangers. Plus, E=mc2, Mass Defect, and Applications of Fission and Fusion in the real world!

--
Table of Contents

E=mc2
Mass Defect
Fission vs. Fusion
Applications in the Real World

--
Want to find Crash Course elsewhere on the internet?
Facebook - http://www.facebook.com/YouTubeCrashCourse
Twitter - http://www.twitter.com/TheCrashCourse
Tumblr - http://thecrashcourse.tumblr.com
Support CrashCourse on Subbable: http://subbable.com/crashcourse

Hank gives us a tour of the most important table ever, including the life story of the obsessive man who championed it, Dmitri Mendeleev. The periodic table of elements is a concise, information-dense catalog of all of the different sorts of atoms in the universe, and it has a wealth of information to tell us if we can learn to read it.

Like Crash Course? http://www.facebook.com/YouTubeCrashCourse
Follow Crash Course! http://www.twitter.com/TheCrashCourse
Tumbl Crash Course: http://thecrashcourse.tumblr.com

Table of Contents
Dmitri Mendeleev - 0:45
Mendeleev's Organization of the Periodic Table - 2:31
Relationships in the Periodic Table - 5:03
Why Mendeleev Stood Out from his Colleagues - 7:09
How the Periodic Table Could be Improved - 8:28

More info. about the cylindrical periodic table of elements: http://www.av8n.com/physics/periodic-table.htm Support CrashCourse on Subbable: http://subbable.com/crashcourse

You can directly support Crash Course at http://www.subbable.com/crashcourse Subscribe for as little as $0 to keep up with everything we're doing. Also, if you can afford to pay a little every month, it really helps us to continue producing great content.

How did we get here? Well, in terms of Atomic Chemistry, Hank takes us on a tour of the folks that were part of the long chain of other folks who helped us get to these deeper understandings of the world. From Leucippus to Heisenberg to you - yes, YOU - the story of Atomic Chemistry is all wibbly-wobbly... and amazing.

--
Table of Contents

Leucippus, Democritus & Atomic Theory 0:09
Discharge Tubes 1:52
Ernest Rutherford & The Nucleus 4:22
Chemistry = Math 7:22
Niels Bohr Model 5:32
Heisenburg & Quantum Theory 6:35
--
Want to find Crash Course elsewhere on the internet?
Facebook - http://www.facebook.com/YouTubeCrashCourse
Twitter - http://www.twitter.com/TheCrashCourse
Tumblr - http://thecrashcourse.tumblr.com
Support CrashCourse on Subbable: http://subbable.com/crashcourse

Dihydrogen monoxide (better know as water) is the key to nearly everything. It falls from the sky, makes up 60% of our bodies, and just about every chemical process related to life takes place with it or in it. Without it, none of the chemical reactions that keep us alive would happen - none of the reactions that sustain any life form on earth would happen - and the majority of inorganic chemical reactions that shape the surface of the earth would not happen either. Every one of us uses water for all kinds of chemistry every day - our body chemistry, our food chemistry and our laundry chemistry all take place in water.
In today's Crash Course Chemistry, we use Hank's actual dirty laundry (ew) to learn about some of the properties of water that make it so special - it's polarity and dielectric property; how electrolytes can be used to classify solutions; and we discover how to calculate a solution's molarity as well as how to dilute a solution using the dilution equation.

Table of Contents
Polarity 02:40
Dielectric Property 04:13
Electrolytes 04:29
Molarity 08:46
Dilution 10:56

Want to find Crash Course elsewhere on the internet?
Facebook - http://www.facebook.com/YouTubeCrashCourse
Twitter - http://www.twitter.com/TheCrashCourse
Tumblr - http://thecrashcourse.tumblr.com Support CrashCourse on Subbable: http://subbable.com/crashcourse

Now that we’ve finished our tour of the planets, we’re headed back to the asteroid belt. Asteroids are chunks of rock, metal, or both that were once part of smallish planets but were destroyed after collisions. Most orbit the Sun between Mars and Jupiter, but some get near the Earth. The biggest, Ceres is far smaller than the Moon but still big enough to be round and have undergone differentiation.

CORRECTION: In the episode we say that 2010 TK7 is 800 km away. However, 2010 TK7 stays on average 150 million kilometers from Earth, but that can vary wildly.
Sorry about that!

--

Table of Contents
Asteroids Are Chunks of Rock, Metal, or Both 1:45
Most Orbit the Sun Between Mars and Jupiter 7:16
Ceres is Far Smaller Than the Moon, But Large Enough to be Round 3:43

--

PBS Digital Studios: http://youtube.com/pbsdigitalstudios

Follow Phil on Twitter: https://twitter.com/badastronomer

Want to find Crash Course elsewhere on the internet?
Facebook - http://www.facebook.com/YouTubeCrashCourse
Twitter - http://www.twitter.com/TheCrashCourse
Tumblr - http://thecrashcourse.tumblr.com
Support CrashCourse on Patreon: http://www.patreon.com/crashcourse

--

PHOTOS/VIDEOS
Timelapse of Asteroid 2004 FH's flyby http://en.wikipedia.org/wiki/F....ile:Asteroid_2004_FH [credit: NASA/JPL Public Domain]
Asteroid Discovery Video https://www.youtube.com/watch?v=2k2vkLEE4ko [credit: Scott Manley - scottmanley1972@gmail.com]
Inner Solar System http://en.wikipedia.org/wiki/F....ile:InnerSolarSystem [credit: Wikimedia Commons]
Kirkwood gaps http://commons.wikimedia.org/w....iki/File:Kirkwood-ga [credit: Wikimedia Commons]
Ceres, Earth & Moon size comparison http://en.wikipedia.org/wiki/F....ile:Ceres,_Earth_%26 [credit: NASA]
Dawn Glimpses Ceres’ North Pole http://www.jpl.nasa.gov/news/n....ews.php?release=2015 [credit: NASA/JPL-Caltech/UCLA/MPS/DLR/IDA]
Ceres cutaway http://commons.wikimedia.org/w....iki/File:Ceres_Cutaw [credit: NASA, ESA, and A. Feild (STScI)]
Bright Spot on Ceres Has Dimmer Companion http://www.jpl.nasa.gov/spacei....mages/details.php?id [credit: NASA/JPL-Caltech/UCLA/MPS/DLR/IDA]
Vesta http://en.wikipedia.org/wiki/4...._Vesta#/media/File:V [credit: NASA/JPL-Caltech/UCAL/MPS/DLR/IDA]
Lutetia http://en.wikipedia.org/wiki/2....1_Lutetia#/media/Fil [credit: ESA]
Gaspra http://commons.wikimedia.org/w....iki/File:Galileo_Gas [credit: NASA]
Steins http://neo.ssa.esa.int/image/image_gallery?uuid=db747cf5-9d21-405e-bcdb-e70fe475edc9&groupId=10157&t=1340734455649 [credit: ESA/Osiris]
Mathilde http://neo.jpl.nasa.gov/images/mathilde1.jpg [credit: NEAR Spacecraft Team, JHUAPL, NASA]
Ida http://en.wikipedia.org/wiki/2....43_Ida#/media/File:2 [credit: NASA/JPL]
Kleopatra http://apod.nasa.gov/apod/ap000510.html [credit: Stephen Ostro et al. (JPL), Arecibo Radio Telescope, NSF, NASA]
An artist's conception of two Pluto-sized dwarf planets in a collision around Vega. http://en.wikipedia.org/wiki/M....ethods_of_detecting_ [credit: NASA/JPL-Caltech/T. Pyle (SSC)]
Itokawa http://apod.nasa.gov/apod/ap140209.html [credit: ISAS, JAXA]
An artist's illustration showing two asteroid belts and a planet orbiting Epsilon Eridani http://en.wikipedia.org/wiki/E....psilon_Eridani#/medi [credit: NASA/JPL-Caltech]
Near-Earth Asteroids http://www.jpl.nasa.gov/images..../asteroid/20130204/a [credit: NASA/JPL-Caltech]
Lagrange Points Diagram http://en.wikipedia.org/wiki/T....rojan_(astronomy)#/m [credit: Wikimedia Commons]
TK7 http://en.wikipedia.org/wiki/2....010_TK7#/media/File: [credit: NASA/JPL-Caltech/UCLA]
165347 Philplait http://www.slate.com/content/d....am/slate/blogs/bad_a [credit: Larry Denneau/Pan-STARRS via Amy Mainzer]

In which Jacob Clifford and Adriene Hill teach you about Economic Systems and Macroeconomics. So, economics is basically about choices. We'll look at some of the broadest economic choices when we talk about the difference between planned economies and market economies. We'll get into communism, socialism, command economies, and capitalism. We'll look at how countries choose the kind of system they're going to use (spoiler alert: many end up with mixed economies). We'll also look into how individuals make economic choices.

Crash Course is now on Patreon! You can support us directly by signing up at http://www.patreon.com/crashcourse

Thanks to the following Patrons for their generous monthly contributions that help keep Crash Course free for everyone forever:

Mark Brouwer, Jan Schmid, Anna-Ester Volozh, Robert Kunz, Jason A Saslow, Christian Ludvigsen, Chris Peters, Brad Wardell, Beatrice Jin, Roger C. Rocha, Eric Knight, Jessica Simmons, Jeffrey Thompson, Elliot Beter, Today I Found Out, James Craver, Ian Dundore, Jessica Wode, SR Foxley, Sandra Aft, Jacob Ash, Steve Marshall

TO: Everyone
FROM: Martin

To gild refined gold is just silly.


TO: Dana
FROM: Cameron

Still holding out. We're going to make it!

Thank you so much to all of our awesome supporters for their contributions to help make Crash Course possible and freely available for everyone forever:

Raymond Cason, Marcel Pogorzelski, Cowgirlgem, Chua Chen Wei, Catherine Emond, Victoria Uney, Robin Uney, Damian Shaw,
Sverre Rabbelier

Want to find Crash Course elsewhere on the internet?
Facebook - http://www.facebook.com/YouTubeCrashCourse
Twitter - http://www.twitter.com/TheCrashCourse
Tumblr - http://thecrashcourse.tumblr.com
Support Crash Course on Patreon: http://patreon.com/crashcourse

CC Kids: http://www.youtube.com/crashcoursekids

Hank bursts our ideal gas law bubble, er, balloon, and brings us back to reality, explaining how the constants in the gas law aren't all that constant; how the ideal gas law we've spent the past two weeks with has to be corrected for volume because atoms and molecules take up space and for pressure because they're attracted to each other; that Einstein was behind a lot more of what we know today than most people realize; and how a Dutch scientist named Johannes van der Waals figured out those correction factors in the late 19th century and earned a Nobel Prize for his efforts.

Table of Contents
Constants in the Gas Laws Aren't all that Constant 1:20
The Ideal Gas Law has to be Corrected for Volume and Pressure 3:26
Einstein was the Bomb 5:02
Van Der Waals Equation 9:38
Never Give Up! 10:08

--
Want to find Crash Course elsewhere on the internet?
Facebook - http://www.facebook.com/YouTubeCrashC...
Twitter - http://www.twitter.com/TheCrashCourse
Tumblr - http://thecrashcourse.tumblr.com Support CrashCourse on Subbable: http://subbable.com/crashcourse

You can directly support Crash Course at http://www.subbable.com/crashcourse Subscribe for as little as $0 to keep up with everything we're doing. Also, if you can afford to pay a little every month, it really helps us to continue producing great content.

In this episode, Hank goes over Reversible Reactions, the water dissociation constant, what pH and pOH actually mean, Acids, Bases, and Neutral Substances as well as the not-so-terrifying Logarithms, strong acids, weak acids, and how to calculate pH and pOH. Oh, and litmus paper!

***** AND NOW, A SUBBABLE MESSAGE! *****
"Daisy, we love you more than you love John and Hank!
From Mum and Nemo."

--
Table of Contents
Reversible Reactions 3:40
Water Dissociation Constant 5:00
Acids, Bases, & Neutral Substances 6:38
Strong and Weak Acids 7:43
Logarithms 1:46
Calculating pH and pOH 8:45
Cool Mathematical Connections 9:54

--
Want to find Crash Course elsewhere on the internet?
Facebook - http://www.facebook.com/YouTubeCrashCourse
Twitter - http://www.twitter.com/TheCrashCourse
Tumblr - http://thecrashcourse.tumblr.com
Support CrashCourse on Subbable: http://subbable.com/crashcourse