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You know that feeling when you learn something amazing about the world and just have to try it out yourself? That's how I felt after learning about Eratosthenes and his incredible method for measuring the Earth's circumference using just shadows and some simple math. It might sound crazy, but with a bike, two sticks, and a whole lot of curiosity, I set out to prove the Earth is round – and measure it myself!
A Bike Ride Through Saskatchewan (for Science!)
My journey started in Regina, Saskatchewan, a place known for its flat prairies – the perfect setting for this experiment. My trusty bike and I hit the open road, heading down a perfectly straight highway for 138 kilometers. Why Saskatchewan? Well, to accurately recreate Eratosthenes' experiment, you need a long, straight stretch of land, and Saskatchewan definitely delivered!
The Sundial Setup
Now, let's talk about the tools of the trade. I had two identical sundials, simple but effective tools for measuring the sun's angle. One sundial stayed in Regina with my friend Casey, carefully positioned and leveled. The other sundial? That one hitched a ride with me, strapped securely to my bike.
The Science Behind the Shadows
Here's where the real magic happens. Because the Earth is curved, the angle of the sun's rays will differ slightly depending on your location. By measuring the length of the shadows cast by our sundials at the exact same time, we could calculate the difference in those angles. And with that difference, we could unlock the secret of the Earth's size!
Crunching the Numbers (and Biking Some More)
After a long bike ride and careful measurements, here's what we found:
- My sundial's shadow in Stoughton: 66.1 cm
- Casey's sundial's shadow in Regina: 70 cm
- Difference in shadow length: 3.9 cm
Using some trigonometry (don't worry, I'll spare you the details!), we calculated the angle difference between our two locations to be 1.5 degrees. This tiny angle, representing 1/240th of a circle, was the key to unlocking the Earth's circumference.
Since I biked 138 kilometers, which represented 1/240th of the Earth's circumference, all we had to do was multiply 138 by 240. The result? A calculated Earth circumference of 33,120 kilometers!
Was I Spot On?
The actual circumference of the Earth is about 40,075 kilometers. So, my measurement was about 17% off. Not perfect, but considering I used a bike and some sticks, I was pretty thrilled! Eratosthenes, with his ancient units of measurement, was only off by about 16%!
The Beauty of Experimentation
This experiment wasn't just about getting the perfect measurement. It was about proving that the Earth is, indeed, round. It was about following in the footsteps of a scientific pioneer and experiencing the thrill of discovery firsthand.
So, the next time you're feeling adventurous and want to connect with the world around you, grab a friend, some simple tools, and see what wonders you can uncover. You might be surprised by what you learn!
"The Earth is something we can experiment on and learn about."
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