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!

View full lessonf='https://ed.ted.com/lessons/the-hidden-network-that-makes-the-internet-possible-sajan-saini' target='_blank' rel='nofollow'>lesson↵↵In 2012, a team of researchers set a world record, transmitting 1 petabit of data—...

Hank takes us on a trip around the body - we follow the circulatory and respiratory systems as they deliver oxygen and remove carbon dioxide from cells, and help make it possible for our bodies to function.

The mirror test is supposed to be a way to figure out when an animal is self-aware, but there might be only one particular animal this test works well on: humans.

There's a region of Earth's atmosphere known as the South Atlantic Anomaly, and it’s one of the most dangerous near-Earth areas of space, both for satellites and humans.

Socrates, one of the founding fathers of Western philosophical thought, was on trial. Many believed he was an enemy of the state, accusing the philosopher of corrupting the youth and refusing to recognize their gods. But Socrates wasn't...

Ancient Egyptians believed that in order to become immortal after death, a spirit must first pass through the underworld - a realm of vast caverns, lakes of fire, and magical gates. Needless to say, one needed to come prepared. But how?...

Your mortal enemy has captured you and hooked you up to a bizarre experiment. He's extended your nervous system with one very long neuron to a target about 70 meters away. At some point, he's going to fire an arrow. If you can then think...

It's an increasingly common sight in hospitals around the world: a nurse measures our height, weight, blood pressure, and attaches a glowing plastic clip to our finger. Suddenly, a digital screen reads out the oxygen level in our...

People have been grappling with the question of artificial creativity -- alongside the question of artificial intelligence -- for over 170 years. For instance, could we program machines to create high quality original music? And if we...

When it was ratified in 1789, the US Constitution didn't just institute a government by the people _ it provided a way for the people to alter the Constitution itself. And yet, of the nearly 11,000 amendments proposed in the centuries...

As different as we humans are from one another, we all age along the same great sequence, and the shared patterns of our lives pass into the pages of the books we love. In this moving talk, journalist Joshua Prager explores the stages of...

In this shorts video we will determine which graph is a linear function. We will first determine which of the four graphs is linear by understanding linear means a straight line. We will then learn how to determine which graph is a...

In this shorts video we will answer a standardized math test questions about a function: true or false. We will use the vertical line test to examine each of the four graphs. We will understand that the vertical line test is when you...

In this video Bill Thisdell examines the period known as Personal Rule, when Charles I governed without Parliament. How revolutionary was this practice? Why was personal rule a problem? Part of our English Civil War series of videos.

Trump demands end to Senate filibuster after off-year election lossesCredit: The White House/YouTube

In this video, explore the recommended practice exams available on Teachable to help you assess your readiness for the CCNA exam.

In this video, we offer recommended practice tests to help you assess your readiness for the CCNA 200-301 certification exam.

In this video, you will learn how to display all categories.

In this video, you will learn about deleting a category.

This video describes various ways that species change over time such as variation, binary fission, adaption, mutation, envirvonmental changes, and extinction.

This Science 6 instructional video discusses natural selection and evolution.

Science Kids Animal Parenting V1-0003

This video explores the fascinating and diverse birthing styles of male seahorses and octopuses. Male seahorses undergo a unique process where they carry and give birth to fully formed...

Acts of kindness can help heal the world and people can show kindness in a variety of ways. Frankly, any way is a good way. Watch this kindness social experiment by these two young people Jared Tang-Alejandro and Samantha Lynn...