Prime Meridian

Imagine a giant, invisible line stretching all the way around the world, from the tippy-top North Pole to the bottomy-bottom South Pole. It’s like the main seam on a giant playground ball, holding everything together. Before people knew about me, they would look at their big, beautiful globe and wonder, where does the world begin? Is this side the front or the back? I am the world's starting line. I help everyone know if they are in the east or in the west. If you cross over me, you step from one side of the world to the other in a single hop. I run through oceans and over mountains, through busy cities and quiet fields, but you can’t see me with your eyes. I am an idea that connects everyone and helps us all understand our place on this big planet. You can call me the Prime Meridian.

A long time ago, things were very confusing. Imagine trying to play a game where everyone had a different starting line. That's what it was like for sailors and mapmakers. Each country drew its own maps with its own special starting line. A map from one country would look different from a map from another. Sailors would get their maps all mixed up. They would be sailing across the big blue ocean, thinking they were going one way, but their maps would tell them something different. It was a giant puzzle, and it made traveling very tricky. To solve this problem, smart people from 25 different countries decided to have a big meeting. They traveled all the way to a city called Washington, D.C., in the United States. In the year 1884, they all sat down in a big room to talk. Their goal was simple but very important: to agree on just one single starting line for the entire world, so that every map would be the same and no one would get lost again.

The big meeting was a huge success. After lots of talking and sharing ideas, on October 13th, 1884, everyone agreed. They chose me. They decided that the official starting line for the world would be the one that passed through a special place called the Royal Observatory in Greenwich, England. From that day on, I had two very important jobs. First, I divide the world into two halves, like an apple cut down the middle. One side is the Eastern Hemisphere, and the other is the Western Hemisphere. My second job is to help everyone with time. I am the starting point for all the time zones in the world. When the sun is shining directly over me, it’s noon. All other clocks are set based on my time. I am a reminder that even when people live far apart and speak different languages, they can work together to solve big problems. I help connect the whole world, every single day.