Canada & The United States (Bizarre Borders Part 2). What if the Holy Roman Empire Reunited Today? Why Countries Are Landlocked + Canals. How Big Can Animals Get? What the Most Powerful Magnet in the Universe is Capable of: Magnetars Explained. Every Country in the World (Part 1). How many countries are there in the world? Tallest Buildings in Each U.S. State. The Hardest We've Ever Pushed Matter. What is the LOUDEST Sound Ever Heard?