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Pbs Learning Media: Crash Course Ecology: Pollution
Hank talks about the last major way humans are impacting the environment: pollution. Pollution takes many forms - from the simplest piece of litter to the more complex endocrine distruptors - and ultimately, humans are responsible for it...
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Pbs Learning Media: Crash Course Astronomy: Meteors
Meteors are small bits of interplanetary debris broken off from asteroids or comets. When the Earth plows through the stream emitted by a comet, we get a meteor shower. Meteors burn up about 100 km above the Earth, but some survive to...
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Pbs Learning Media: Crash Course Astronomy: Cycles in the Sky
Take a look at the cyclical phenomena at work in the universe. Learn about the subtle changes in the sky that take place over time as the Earth circles the sun, following along the ecliptic. Learn how the tilt of the Earth's axis has a...
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Pbs Learning Media: Crash Course Us History: War and Expansion
In which John Green teaches you about the Mexican-American War in the late 1840s and the expansion of the United States into the western end of North America. Famous Americans abound in this episode, including James K Polk (Young...
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Pbs Learning Media: Crash Course Us History: Colonizing America
John Green teaches you about the (English) colonies in what is now the United States. He covers the first permanent English colony at Jamestown, Virginia, the various theocracies in Massachusetts, the feudal kingdom in Maryland, and even...
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Pbs Learning Media: Crash Course Us History: Westward Expansion
In which John Green teaches you about the Wild, Wild, West, which as it turns out, wasn't as wild as it seemed in the movies. When we think of the western expansion of the United States in the 19th century, we're conditioned to imagine...
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Pbs Learning Media: Crash Course Anatomy and Physiology: Vision
Next stop on our tour of the sensory systems is vision. With a little help from an optical illusion, we take a look inside your eyes to try to figure out how your sense of vision works-and how it can be tricked. [9:38]
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Pbs Learning Media: Crash Course Astronomy: Gamma Ray Bursts
Gamma-ray bursts are not only incredible to study, but their discovery has an epic story all its own. Today Phil takes you through some Cold War history and then dives into what we know. [13:51]
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Pbs Learning Media: Crash Course Astronomy: Galaxies, Part 1
Galaxies contain gas, dust, and billions of stars or more. They come in four main shapes: elliptical, spiral, peculiar, and irregular. Galaxies can collide, and grow in size by eating each other. [11:51]
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Pbs Learning Media: Crash Course Astronomy: Galaxies, Part 2
Active galaxies pour out lots of energy, due to their central supermassive black holes gobbling down matter. Galaxies tend not to be loners, but instead exist in smaller groups and larger clusters. Our Milky Way is part of the Local...
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Pbs Learning Media: Crash Course Us History: Women's Suffrage
In which John Green teaches you about American women in the Progressive Era and, well, the progress they made. So the big deal is, of course, the right to vote women gained when the 19th amendment was passed and ratified. But women made...
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Pbs Learning Media: Crash Course Astronomy: Star Clusters
Last week we covered multiple star systems, but what if we added thousands or even millions of stars to the mix? A star cluster. [10:21]
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Pbs Learning Media: Crash Course Astronomy: Low Mass Stars
Today we are talking about the life-and death-of stars. Low mass stars live a long time, fusing all their hydrogen into helium over a trillion years. More massive stars like the Sun live shorter lives. They fuse hydrogen into helium, and...
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Pbs Learning Media: Crash Course Astronomy: The Oort Cloud
Out past Neptune are vast reservoirs of icy bodies that can become comets if they get poked into the inner solar system. The Kuiper Belt is a donut-shaped region beyond the planets that is aligned with the plane of the solar system. The...
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Pbs Learning Media: Crash Course Us History: Age of Jackson
John Green teaches you about the presidency of Andrew Jackson. Jackson's election was more democratic than any previous presidential election. More people were able to vote, and they picked a doozie. Jackson was a well-known war hero,...
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Pbs Learning Media: Crash Course Astronomy: High Mass Stars
Massive stars fuse heavier elements in their cores than lower mass stars. This leads to the creation of heavier elements up to iron. Iron robs critical energy from the core, causing it to collapse. The resulting supernova creates even...
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Pbs Learning Media: Crash Course Astronomy: Jupiter's Moons
Before moving on from Jupiter to Saturn, we're going to linger for a moment on Jupiter's moons. There are 67 known moons, and four huge ones that we want to explore in greater detail. Ganymede is the largest - larger, in fact, than any...
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Pbs Learning Media: Crash Course Us History: The War of 1812
John Green teaches you about the War of 1812. The War of 1812 was fought between the United States and its former colonial overlord England. John will take you through the causes of the war, tell you a little bit about the fighting...
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Pbs Learning Media: Crash Course Us History: The Roaring 20s
In which John Green teaches you about the United States in the 1920s. They were known as the roaring 20s, but not because there were lions running around everywhere. In the 1920s, America's economy was booming, and all kinds of social...
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Pbs Learning Media: Crash Course Astronomy: Uranus & Neptune
We complete our planetary tour with a review of the ice giants Uranus and Neptune. Both have small rocky cores, thick mantles of ammonia, water, and methane, and atmospheres that make them look greenish and blue. Uranus has a truly weird...
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Pbs Learning Media: Crash Course Astronomy: Exoplanets
There are other planets out there, and astronomers have a lot of methods for detecting them. Nearly 2000 planets have been found so far. The most successful method for finding them is using transits, where a planet physically passes in...
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Pbs Learning Media: Crash Course Astronomy: Telescopes
Host Phil Plait explains how telescopes work and offers up some astronomical shopping advice. In this episode, we learn how telescopes do two things: collect light, and increase our ability to resolve details. Learn the difference...
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Pbs Learning Media: Crash Course Astronomy: Dark Matter
Today on Crash Course Astronomy, Phil dives into some very dark matters. The stuff we can actually observe in the universe isn't all there is. Galaxies and other large structures in the universe are created and shifted by a force we...
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Pbs Learning Media: Crash Course Astronomy: Black Holes
Stellar mass black holes form when a very massive star dies, and its core collapses. 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...