Staggering scales

Guesstimating the number of atoms on earth

Part of the Guesstimation series
Tue, Dec 28, 2021

Hello, curious minds! Welcome to post number 3 in this series on guesstimation. If this is your entry point into the world of guesstimation then please go back to the first post in this series to get some more context as to what we are trying to do in this series.

Today, we’re embarking on an exciting scientific journey that will take us from the dizzying heights of our magnificent planet Earth down to the infinitesimally small world of atoms. Our mission? To unravel a mind-boggling question: How many atoms are there on Earth? 🌍

We’ll be using guesstimation as a tool of choice for solving this “impossible problem”. As we saw in the last post, guesstimation our best friend when faced with problems that seem too big to tackle. We’re dealing with a colossal task here. The Earth is huge, atoms are tiny, and the sheer number we’re after is so enormous, it’s beyond our everyday comprehension. But, that’s where the fun begins 🤓.

And, we get to add another tool to our toolbox today - scientific notation1. It might sound a little complicated if you’re new to it, but trust me, you’ll soon see its charm. It’s a tool that enables us to write enormous or minuscule numbers in a compact form, making our calculations not only manageable but also enjoyable.

I won’t spoil the fun and give you the answer here – we’re going to explore, ponder, calculate and finally arrive at it together. So, buckle up and prepare for an adventure that transcends scales and delves into the mysteries of our planet and its atomic constituents. I promise, by the end of it, you’ll never look at Earth - or an atom - the same way again 😀.

Now, let’s get guesstimating!


  1. Scientific notation resources: Maths is fun, Lehman College, Khan Academy ↩︎