What I have right over here, this picture, this is Egyptian hieroglyphs. And Egyptian hieroglyphs are over 5,000 years old. So you could write 5,000 years before the present. But even when you have writing, it's not enough. As we'll see, not only in this video, but in many videos as we study history and world history, it's really a lot of science and a lot of detective work to make sense of what has happened. And that understanding will constantly evolve. For example, we didn't know what these hieroglyphs said until 1799 when we found the Rosetta Stone.