Anders Celsius

Hello! My name is Anders Celsius. I was born a very long time ago, on November 27th, 1701, in a beautiful town called Uppsala in Sweden. My house was always full of books and exciting ideas because my dad and both of my grandfathers were scientists! I loved listening to them talk about stars, numbers, and how the world works. It made me want to become a scientist, too.

My favorite thing to study was the night sky. The stars and planets seemed like a giant puzzle waiting to be solved. When I grew up, I became a professor of astronomy at Uppsala University in 1730. That means I got to teach students all about space! I even helped build a special building with a giant telescope called the Uppsala Astronomical Observatory in 1741. It was our window to the universe, where we could see far-away planets and twinkling stars up close.

Besides looking at stars, I liked to solve everyday problems. Back then, it was hard for people to agree on how hot or cold something was. So, in 1742, I came up with an idea. I made a special thermometer with a scale of 100 steps, or degrees. I used water to set the points. But here’s a funny secret: my first scale was upside down! I made 0 the boiling point of water and 100 the freezing point. It was a brand new way to measure temperature!

I lived to be 42 years old, and my work continued even after I passed away in 1744. Other scientists thought my temperature scale was a great idea, but they decided to flip it around. So now, 0 degrees is for freezing and 100 degrees is for boiling. Today, when you hear someone say the temperature in degrees Celsius, you’ll know they’re talking about the little idea I had so long ago in Sweden.