The MEaSURE Project

The corners of each triangle are draggable, and it only works for angles in the first quadrant.

24.10.2025 19:24 — 👍 0    🔁 0    💬 0    📌 0

Angle Sum Identity

Here's a visualizer I made in Desmos to show to my students!

www.desmos.com/calculator/m...

24.10.2025 19:22 — 👍 2    🔁 0    💬 1    📌 0

MEaSURE Measuring Earth's Size Using a Revision of Eratosthenes

If you made a measurement this past equinox and haven't submitted it yet, please do! I will include it and update the results accordingly.

If you find this project worthwhile or interesting, good news! There's another equinox in the spring!

sites.google.com/view/themeas...

23.09.2025 23:27 — 👍 0    🔁 0    💬 0    📌 0

This is a table of values of Earth's radius, calculated by the MEaSURE Project. The average value is 6,162 km, which has a -3.28% error.

This histogram shows a tight cluster of values around the accepted mean radius of 6,371 km.

With three measurers come three PAIRS of measurements. This means three independent calculations of Earth's radius.

23.09.2025 23:27 — 👍 0    🔁 0    💬 1    📌 0

Three locations: northeastern USA, eastern Canada, and Europe submitted measurements so far.

Not unexpected, but participation is starting off slowly. I am hopeful that participation now will encourage more participation later. The best part is, every equinox's astronomical conditions are identical, so previous entries can still be part of the calculation!

We have three data points so far.

23.09.2025 23:27 — 👍 1    🔁 0    💬 1    📌 0

MEaSURE - Results and analysis Results and analysis

Happy 2nd day of Fall! Fortunately I had the day off today (Happy Rosh Hashanah) so I was able to process the data and crunch the numbers.

The results and data are available at my website now, but if you want to see a summary, read the thread!
sites.google.com/view/themeas...

23.09.2025 23:27 — 👍 0    🔁 0    💬 1    📌 1

🥳 First response! Thanks for participating!

22.09.2025 17:57 — 👍 1    🔁 0    💬 0    📌 0

A satellite image showing clouds over central Maryland and Pennsylvania

An image of the sky over my school. It is overcast and the sun doesn't appear through the clouds.

Unfortunately, it's cloudy where I am today. I was prepared to take three classes outside to measure shadows! But I won't be able to contribute any measurements today. I'll try again in the spring!

22.09.2025 15:28 — 👍 1    🔁 0    💬 1    📌 1

Oh my goodness, these are awesome!

15.06.2025 16:02 — 👍 1    🔁 0    💬 0    📌 0

1. Find a flat, level surface
2. Set up a vertical ruler
3. Find true North (northern hemisphere) or true South (Southern hemisphere)
4. Wait for the equinox
5. Measure the length of the shadow at solar noon
6. Record the time of solar noon (UTC)
7. Go to the MEaSURE website and submit your data

13.06.2025 03:05 — 👍 3    🔁 1    💬 0    📌 1

Math teachers! I have your lesson plan for the next equinox...Monday, September 22.

Join a global experiment to calculate Earth's radius!
youtu.be/myvEWdLU_1E
#iteachmath #math #maths #teach

10.06.2025 14:57 — 👍 0    🔁 1    💬 0    📌 2

New short! First short, actually 😅
youtube.com/shorts/r9rtr...

01.06.2025 21:40 — 👍 1    🔁 0    💬 0    📌 1

@petraschwer.bsky.social Thank you for sharing my post! This experiment's first attempt was done with help from a school in Leinfelden-Echterdingen, not far from you!

31.05.2025 14:11 — 👍 1    🔁 0    💬 0    📌 0

Hello STEM teachers! As the school year wraps up and you begin to make plans for next year, I've got something you might like to check out!

This experiment can be done anywhere in the world, from elementary to advanced. See the video for details!
youtu.be/myvEWdLU_1E

31.05.2025 11:46 — 👍 0    🔁 1    💬 0    📌 1

MEaSURE Measuring Earth's Size Using a Revision of Eratosthenes

To organize participation and distribute resources, I've built a simple website.

Whether you're curious or you want to participate, come check it out!
sites.google.com/view/themeas...

03.05.2025 17:02 — 👍 0    🔁 0    💬 0    📌 1

Hello! This is The MEaSURE Project.

I am organizing a bi-annual experiment among schools, students, and lifelong learners to measure Earth's radius.

Please watch this informational video. Consider participating, and spread the word!
youtu.be/myvEWdLU_1E

03.05.2025 16:56 — 👍 0    🔁 1    💬 0    📌 1