I Learned This Today

#660 Is Earth an open or closed system?

Watch this on YouTube Is Earth an open or closed system? It is both. For some things it is open and for […]

Watch on YouTube Why were the Terracotta Warriors buried? They were buried to protect Qin Shi Huang, the first emperor of China, […]

Watch on YouTube Why is Broadway so long? Before it became a road it was originally the Wickquasgeck trail. Broadway is a […]

Watch on YouTube How do facial expressions work? There are 20 muscles in the face that can be moved in different combinations. […]

Watch on YouTube Are Inner and Outer Mongolia separate countries? Outer Mongolia is the country of Mongolia and Inner Mongolia is a […]

Watch on YouTube How was the meter (metre) defined? In 1791 it was defined as one ten-millionth of the distance from the […]

Watch on YouTube Why is the Grand Canyon so deep? Because of the power of the Colorado River, the amount of water […]

Watch on YouTube What will happen at the end of the universe? There will either be a Big Crunch, a Big Bounce, […]

Watch on YouTube Why does blood show up under UV light? Because it absorbs all of the light and appears completely black. […]

Watch on YouTube Why do stick insects look like plants? They have evolved to resemble the plants they live and feed on, […]