What Does “Exponential Growth” Really Mean, and How Does It Work?

When someone on TV says “XYZ is growing exponentially!” they usually mean it’s giiiinormous. But that’s not what “exponential growth” means.

Introduction

Human beings are surrounded by things that grow exponentially in so many parts of our lives:

• Semiconductor chip densities (“Moore’s Law”)
• Patient count during a pandemic
• Investments over time — whether it’s money in the stock market or in a savings account earning 2% per year
• Cancerous cells spreading throughout a human body
• A fire spreading through a building
• Sales of a popular product
• Weed growth in your backyard

Examples of exponential growth are everywhere. So it’s very helpful for people to have a sense of what “exponential growth” means and how it generally works.

That understanding helps us whether exponential growth is working to hurt us:

• virus growth and patient growth during a pandemic
• impact of carbon going up into the atmosphere on climate change
• cancerous cells spreading through a human body