Viewers like you help make PBS (Thank you

Viewers like you help make PBS (Thank you

Viewers like you help make PBS (Thank you

Viewers like you help make PBS (Thank you

For more than 10 million years, Megalodon was at the top of its game as the oceans’ apex predator...until 2.6 million years ago, when it went extinct. So, what happened to the largest shark in history?

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

And thanks to Joschua Knüppe and Studio 252mya for the illustration of Piscobalaena. You can find more of Joschua's work here: https://www.deviantart.com/hyrotrioskjan

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, Neil H. Gray, Marilyn Wolmart, Esmeralda Rupp-Spangle, Gregory Donovan, Ehit Dinesh Agarwal, سلطان الخليفي, 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, 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

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References:
https://www.researchgate.net/p....rofile/John_Barron3/
https://www.researchgate.net/p....ublication/312500230
https://journals.plos.org/plos....one/article?id=10.13
https://onlinelibrary.wiley.co....m/doi/abs/10.1111/j.
https://www.ncbi.nlm.nih.gov/pubmed/28586693
https://www.ncbi.nlm.nih.gov/pubmed/27381883
https://www.ncbi.nlm.nih.gov/p....mc/articles/PMC45415
https://www.ncbi.nlm.nih.gov/pubmed/29754903
http://sciencepress.mnhn.fr/si....tes/default/files/ar
https://www.ncbi.nlm.nih.gov/pubmed/27620830
https://onlinelibrary.wiley.co....m/doi/full/10.1111/j
https://www.nature.com/articles/nature09067
https://www.sciencedirect.com/....science/article/pii/
https://journals.plos.org/plos....one/article?id=10.13
http://science.sciencemag.org/content/327/5968/993
https://journals.plos.org/plos....one/article?id=10.13
https://www.nature.com/articles/ngeo2813
https://www.researchgate.net/p....ublication/233681377
http://ufdc.ufl.edu/UFE0042397/00001

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This week on Crash Course Economics, we're talking about monetary policy. The reality of the world is that the United States (and most of the world's economies) are, to varying degrees, Keynesian. When things go wrong, economically, the central bank of the country intervenes to try aand get things back on track. In the United States, the Federal Reserve is the organization that steps in to use monetary policy to steer the economy. When the Fed, as it's called, does step in, there are a few different tacks it can take. The Fed can change interest rates, or it can change the money supply. This is pretty interesting stuff, and it's what we're getting into today.

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2,000 Years of Chinese History! The Mandate of Heaven and Confucius:
Crash Course World History #7

In which John introduces you to quite a lot of Chinese history by
discussing the complicated relationship between the Confucian scholars
who wrote Chinese history and the emperors (and empress) who made it.
Included is a brief introduction to all the dynasties in Chinese
history and an introduction to Confucius and the Confucian emphasis on
filial piety, the role the mandate of heaven played in organizing
China, and how China became the first modern state.

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In which John Green teaches you about Harper Lee's famous (and only) novel, To Kill a Mockingbird. John will cover a bit about Harper Lee's personal life, (seeing as this novel has some autobiographical elements) and her long association with Truman Capote, who figures as a character in the book. You'll get an overview of the plot, and we'll talk a bit about Mockingbird as an example of bildungsroman (again(man, this description is heavy on parentheses)) and Southern Gothic, and look into the novel as a commentary on the racism and patriarchy of the Alabama in which Harper Lee grew up.

Hank takes you on a tour of your two-part autonomic nervous system. This episode explains how your sympathetic nervous system and parasympathetic nervous system work together as foils, balancing each other out. Their key anatomical differences - where nerve fibers originate and where their ganglia are located - drive their distinct anatomical functions, making your sympathetic nervous system the "fight or flight" while your parasympathetic nervous system is for "resting and digesting."

--

Table of Contents
The Basic Two-Part System of the Autonomic Nervous System 0:48
Sympathetic Nervous System 2:33
Parasympathetic Nervous System 2:54
Their Nerve Fibers Originate in Different Parts of the Body 3:22
Sympathetic Ganglia Are Close to the Spinal Cord 4:36
Parasympathetic Ganglia Are Close to Their Effectors 4:59


***

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This episode of Crash Course Physics is supported by Prudential. Go to www.raceforretirement.com to learn how, if you start saving today, you can continue to enjoy the things you love tomorrow.

So we've all heard of relativity, right? But... what is relativity? And how does it relate to light? And motion? In this episode of Crash Course Physics, Shini talks to us about perspective, observation, and how relativity is REALLY weird!


Want more Crash Course in person? We'll be at NerdCon: Nerdfighteria in Boston on February 25th and 26th! For more information, go to http://www.nerdconnerdfighteria.com/

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This week Jacob and Adriene teach you about marginal analysis, which you're using RIGHT NOW! The video is coming from inside the house! Or something. You'll learn how marginal analysis guides the decision making if cities, nations, companies, and amusement park enthusiasts. We'll also look at the idea of elasticity, and what people are willing to pay for certain stuff based on the supply. Why is a Van Gogh worth more than an OBEY poster? (hint: it's because they're still cranking out the OBEY posters, and Vincent is dead) All this and more on Crash Course Economics!

***

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

Mark, Eric Kitchen, Jessica Wode, Jeffrey Thompson, Steve Marshall, Moritz Schmidt, Robert Kunz, Tim Curwick, Jason A Saslow, SR Foxley, Elliot Beter, Jacob Ash, Christian, Jan Schmid, Jirat, Christy Huddleston, Daniel Baulig, Chris Peters, Anna-Ester Volozh, Ian Dundore, Caleb Weeks

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In which John Green teaches you about European Imperialism in the 19th century. European powers started to create colonial empires way back in the 16th century, but businesses really took off in the 19th century, especially in Asia and Africa. During the 1800s, European powers carved out spheres of influence in China, India, and pretty much all of Africa. While all of the major (and some minor) powers in Europe participated in this new imperialism, England was by far the most dominant, once able to claim that the "sun never set on the British Empire." Also, they went to war for the right to continue to sell opium to the people of China. Twice. John will teach you how these empires managed to leverage the advances of the Industrial Revolution to build vast, wealth-generating empires. As it turns out, improved medicine, steam engines, and better guns were crucial in the 19th century conquests. Also, the willingness to exploit and abuse the people and resources of so-called "primitive" nations was very helpful in the whole enterprise.

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

So, how many different kinds of intelligence are there? And what is the G-Factor? Eugenics? Have you ever taken an IQ Test? All of these things play into the fascinating and sometimes icky history of Intelligence Testing. In this episode of Crash Course Psychology, Hank talks us through some of the important aspects of that history... as well as Nazis. Hey, I said some of it was icky.

--
Table of Contents

Defining Intelligence 00:00:00
Types of Intelligence 01:22:09
G-Factor 01:37:05
Sherlock Holmes 04:44:12
Intelligence Testing 02:26:23
IQ Scores 08:00:21
Eugenics 07:47:05
Intelligence Controversy 09:05:17

--
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In which John Green teaches you about the Gilded Age and its politics. What, you may ask, is the Gilded Age? The term comes from a book by Mark Twain and Charles Dudley Warner titled, "The Gilded Age." You may see a pattern emerging here. It started in the 1870s and continued on until the turn of the 20th century. The era is called Gilded because of the massive inequality that existed in the United States. Gilded Age politics were marked by a number of phenomenons, most of them having to do with corruption. On the local and state level, political machines wielded enormous power. John gets into details about the most famous political machine, Tammany Hall. Tammany Hall ran New York City for a long, long time, notably under Boss Tweed. Graft, kickbacks, and voter fraud were rampant, but not just at the local level. Ulysses S. Grant ran one of the most scandalous presidential administrations in U.S. history, and John will tell you about two of the best known scandals, the Credit Mobilier scandal and the Whiskey Ring. There were a few attempts at reform during this time, notably the Civil Service Act of 1883 and the Sherman Anti-trust act of 1890. John will also get into the Grange Movement of the western farmers, and the Populist Party that arose from that movement. The Populists, who threw in their lot with William Jennings Bryan, never managed to get it together and win a presidency, and they faded after 1896. Which brings us to the Progressive Era, which we'll get into next week!

Hey teachers and students - Check out CommonLit's free collection of reading passages and curriculum resources to learn more about the events of this episode. The Gilded Age was marked by the success of the richest coupled with inequality and corruption. Repeated factory disasters, such as the triangle shirtwaist factory fire revealed the unsafe working conditions of the urban poor: https://www.commonlit.org/text....s/the-triangle-shirt
Meanwhile, workers began to join unions and strike for better working conditions: https://www.commonlit.org/text....s/the-coeur-d-alene-

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In which John Green teaches you about the Progressive Presidents, who are not a super-group of former presidents who create complicated, symphonic, rock soundscapes that transport you into a fantasy fugue state. Although that would be awesome. The presidents most associated with the Progressive Era are Theodore Roosevelt, William Taft, and Woodrow Wilson. During the times these guys held office, trusts were busted, national parks were founded, social programs were enacted, and tariffs were lowered. It wasn't all positive though, as their collective tenure also saw Latin America invaded A LOT, a split in the Republican party that resulted in a Bull Moose, all kinds of other international intervention, and the end of the Progressive Era saw the United States involved in World War. If all this isn't enough to entice, I will point out that two people get shot in this video. Violence sells, they say.

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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.

Hey teachers and students - Check out CommonLit's free collection of reading passages and curriculum resources to learn more about the events of this episode. The era of progressive presidents began with Teddy Roosevelt, who felt that conservation was a national duty: https://www.commonlit.org/text....s/conservation-as-a-
Teddy Roosevelt is remembered for fighting hard for his causes, as exemplified in his famous “Man in the Arena” Speech: https://www.commonlit.org/text....s/the-man-in-the-are

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Metabolism is a complex process that has a lot more going on than personal trainers and commercials might have you believe. Today we are exploring some of its key parts, including vital nutrients -- such as water, vitamins, minerals, carbs, fats, and proteins -- as well as how anabolic reactions build structures and require energy, while catabolic reactions tear things apart and release energy.

Anatomy of Hank Poster: http://store.dftba.com/product....s/crashcourse-anatom

--

Table of Contents
Water, Vitamins, Minerals, Carbs, Fats and Proteins 3:47
Anabolic Reactions Build Structures and Require Energy 2:59
Catabolic Reactions Tear Things Apart and Release Energy 3:17
Metabolism 2:30

***

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

Mark , Elliot Beter, Moritz Schmidt, Jeffrey Thompson, Ian Dundore, Jacob Ash, Jessica Wode, Today I Found Out, Christy Huddleston, James Craver, Chris Peters, SR Foxley, Steve Marshall, Simun Niclasen, Eric Kitchen, Robert Kunz, Avi Yashchin, Jason A Saslow, Jan Schmid, Daniel Baulig, Christian , Anna-Ester Volozh

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In this episode of Crash Course Chemistry, Hank discusses what Molecules actually look like and why, some quantum-mechanical three dimensional wave functions are explored, he touches on hybridization, and delves into sigma and pi bonds.
--
Table of Contents
Molecules: Clumpy Globs... 0:18
Quantum-Mechanical Three-Dimensional Wave Functions 3:06
S & P Orbital Hybridization 5:27
Sigma & Pi Bonds 7:32
Hybridized Orbitals 5:52
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So, it turns out we have an easy time reading emotions in facial expressions, but emotions can straight up kill us! In this episode of Crash Course Psychology, Hank discusses stress, emotions, and their overall impact on our health.

--
Table of Contents:

How Emotions Work 00:00
Two-Dimensional Model of Emotional Experience 03:29
How Anger, Happiness, and Depression Affect Health 4:52
Stress, the Nervous System, and Chronic Stress 6:36

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In which John Green teaches you where American politicians come from. In the beginning, soon after the US constitution was adopted, politics were pretty non-existent. George Washington was elected president with no opposition, everything was new and exciting, and everyone just got along. For several months. Then the contentious debate about the nature of the United States began, and it continues to this day. Washington and his lackey/handler Alexander Hamilton pursued an elitist program of federalism. They attempted to strengthen the central government, create a strong nation-state, and leave less of the governance to the states, They wanted to create debt, encourage manufacturing, and really modernize the new nation/ The opposition, creatively known as the anti-federalists, wanted to build some kind of agrarian pseudo-paradise where every (white) man could have his own farm, and live a free, self-reliant life. The founding father who epitomized this view was Thomas Jefferson. By the time Adams became president, the anti-federalists had gotten the memo about how alienating a name like anti-federalist can be. It's so much more appealing to voters if your party is for something rather than being defined by what you're against, you know? In any case, Jefferson and his acolytes changed their name to the Democratic-Republican Party, which covered a lot of bases, and proceeded to protest nearly everything Adams did. Lest you think this week is all boring politics,you'll be thrilled to hear this episode has a Whiskey Rebellion, a Quasi-War, anti-French sentiment, some controversial treaties, and something called the XYZ Affair, which sounds very exciting. Learn all about it this week with John Green.

Hey teachers and students - Check out CommonLit's free collection of reading passages and curriculum resources to learn more about the events of this episode. Much of America's politics came from debates between democratic republican Thomas Jefferson and federalist Alexander Hamilton: https://www.commonlit.org/texts/alexander-hamilton
While Jefferson would go on to become president, Hamilton heavily influenced President George Washington who set many American political ideals in his farewell address that Hamilton helped craft: https://www.commonlit.org/text....s/washington-s-farew

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