To the Moon in No Time!

Exponential growth is a funny thing. It starts out real slow and then all of the sudden it shoots up big time. You know all about it, but how would you explain this topic to a fellow at a party?

Doing It the Nerdy Way

You could just grab a napkin and draw a little sketch.

That’s the fast and simple approach. It will probably make you appear quite nerdy, but if you don’t mind looking the part, then that’s a decent option. Just throw in a few sentences about how stuff keeps getting doubled all the time and you’re basically done, but chances are you’ve been boring your counterpart to death.

If you want to torture the poor questioner some more, just keep talking about compound interest or bacterial growth. Your fellow partygoer will walk away a bored and wiser man. Or woman. Whoever made the mistake of asking the question in the first place.

Trying Your Luck With Chess and Rice

Alright, napkin scribbles and nerdy talk didn’t really work all that great. So next time you’re asked the same question you remember the story about a king and his jester. One day, the jester didn’t have much to do and ended up inventing the game of chess. The king loved it and the jester was granted a wish.

Since the he wasn’t just a funny dude but also quite a smart one, the king’s jester knew all about exponential growth. So he asked for rice. One grain on the first square, and twice the amount of the previous one for all the other squares.

That’s a pretty solid story, and your listener will probably be quite impressed to learn that this actually makes for a grand total of more than just a single bag of rice. In fact, it’s an incredibly large number.

Nobody needs to be a genius to know that’s a lot of rice. Guess what’s for dinner…

When Moon? Soon!

Chess and rice is definitely less boring than function graphs and compound interest, but you can do way better!

Let’s take a single standard sheet of paper with a thickness of 0.1 millimeters. Now just ask how many times one needs to fold it until its height would at least cover the distance to the moon. While folding the sheet eventually turns into mission impossible, the theoretical answer is almost guaranteed to shock your questioner.

Even though you didn’t asked the ultimate question of life, the universe and everything, the correct answer is 42 nonetheless. Let’s quickly do the math.

Since the maximum Earth-Moon distance is 405,696 km, folding the sheet 42 times will always do the trick. Will this little story turn people into math aficionados? Probably not, but it certainly is one of the more stunning examples of exponential growth and it most likely won’t bore your audience.

When it comes to math, just grabbing people’s attention is very difficult. Wowing them is almost impossible. Going by my own experience, this moon example usually accomplishes both. Even better, sometimes people even want to see the actual math behind it, and that’s about all you can possibly hope for. After all, it must be a good story if the answer is 42, right?