If we want to avoid a climate disaster, we need much more radical leadership, says Jim Snabe, who knows a thing or two about leadership as chairman of the world's largest maritime shipping company. In a stirring talk, he encourages...

We often think of quantum mechanics as only affecting only the smallest scales of reality, with classical reality taking over at some intermediate level. But in his 1944 book, What is Life?, the quantum physicist Erwin Schrödinger...

Alice Dreger works with people at the edge of anatomy, such as conjoined twins and intersexed people. In her observation, it's often a fuzzy line between male and female, among other anatomical distinctions. Which brings up a huge...

What's salty and cold and cool as heck? Brinicles, a rarely seen undersea phenomenon the combines ice and saltwater to become every sea star's worst nightmare! Actually, they're not that scary, just awesome. Hank explains within.

This is it! The final episode of CC Literature season 4 is a deeper look at Jane Austen's Pride and Prejudice. Today we'll explore the novel's take on materialism, and we'll talk about whether the novel has a liberal or conservative...

In which John Green teaches you about Reconstruction. After the divisive, destructive Civil War, Abraham Lincoln had a plan to reconcile the country and make it whole again. Then he got shot, Andrew Johnson took over, and the...

This is it! The final episode of CC Literature season 4 is a deeper look at Jane Austen's Pride and Prejudice. Today we'll explore the novel's take on materialism, and we'll talk about whether the novel has a liberal or conservative...

Temperatures are rising, and greenhouse gases are being emitted faster than ever. What's a planet to do? Hank explains the recommendations of some of the world's top scientists to stem global warming.

Daniel Libeskind builds on very big ideas. Here, he shares 17 words that underlie his vision for architecture -- raw, risky, emotional, radical -- and that offer inspiration for any bold creative pursuit.

Neuroscience is abound with debates over the nature of consciousness. Which makes sense, because it’s a very abstract idea. We know we are conscious, but theories of why, how and what brain activity causes it are still simply that:...

In which John Green teaches you about various reform movements in the 19th century United States. From Utopian societies to the Second Great Awakening to the Abolition movement, American society was undergoing great changes in the first...

Throughout this series we’ve mostly talked about pairs of electrons, but electrons don’t always have a buddy. An atom or group of atoms with a single unpaired electron is called a radical. In this episode of Crash Course Organic...

Jimmy Wales recalls how he assembled "a ragtag band of volunteers," gave them tools for collaborating and created Wikipedia, the self-organizing, self-correcting, never-finished online encyclopedia.

We’ve already learned a lot about electrophilic aromatic substitution (EAS) and benzene, but guess what? There’s even more to learn! In this episode of Crash Course Organic Chemistry we’ll revisit our old friends the Friedel-Crafts...

So far in this series we’ve focused on molecules with tens of atoms in them, but in organic chemistry molecules can get way bigger! Polymers are molecules that contain hundreds, thousands, or even millions of identical subunits. In this...

When humanity first landed on the moon in 1969, the typeface Futura was right there with them. In this fascinating history of typography, designer Douglas Thomas shares Futura's role in launching the Apollo 11 spacecraft -- and how it...

A video entitled "Rearrange Radicals and Rationals" that shows how to use inverse operations to isolate various variables in equations.

Pupil outcome: I can multiply and divide with surds. Key learning points: - The multiplication of surds can be generalised. - √a × √b=√ab and √a × √(1/b) = √(a/b) = √a ÷ √b - You may be able to simplify this product.

Pupil outcome: I can identify the highest square factor of any term including those written with algebra. Key learning points: - Numbers can be classified as surds or not surds. - Square factors of numerical and algebraic terms can be...

Pupil outcome: I can appreciate the structure that underpins multiplication of surds. Key learning points: - The square root operation is equivalent to the exponent 0.5 where the base is the term under the square root. - You can deduce...

Pupil outcome: I can appreciate the structure that underpins addition of surds. Key learning points: - An unknown value is represented by a letter. - An unevaluated surd can be thought of as an unknown value. - Each simplified surd has a...

Pupil outcome: I can identify, from their equations or graphs, whether two lines are perpendicular. Key learning points: - If two equations are written in the form y = mx + c then you can identify if they are perpendicular. - If the...

Pupil outcome: I can explain how William Blake presents power in society in 18th century London. Key learning points: - Blake’s poem ‘London’ is a condemnation of the inequality and oppression that pervaded society in 18th century...

How to simplify when you add, subtract, or multiply radical expressions