Logo
Overview

Exponential Growth

April 10, 2024
1 min read

Linear vs. Exponential Growth

There are two main ways quantities increase:

  1. Linear Growth (Additive): Adding a fixed amount each step.
    • Example: Walking up a ladder. Each step adds 20 cm to your height.
    • Sequence: 20, 40, 60, 80…
  2. Exponential Growth (Multiplicative): Multiplying by a fixed amount each step.
    • Example: Cell division or folding paper. Each step doubles the previous value.
    • Sequence: 1, 2, 4, 8, 16…

The Paper Folding Experiment

Let’s look at the thickness of paper (assumed 0.0010.001 cm) as we fold it.

Folds (nn)CalculationThickness (2n×0.0012^n \times 0.001)Comparison
0202^00.001 cmSheet of paper
102102^{10}1.02\approx 1.02 cmNotebook
172172^{17}131\approx 131 cm4-year-old child
272272^{27}1.3\approx 1.3 kmSmall Mountain
302302^{30}10.7\approx 10.7 kmCruising altitude of jets
462462^{46}70,368,744\approx 70,368,744 kmDistance to Moon (approx)
Tip

Key Insight: Linear growth adds up slowly. Exponential growth starts slow but explodes very quickly. This is why just 46 folds can reach the moon!

Visualizing the Difference

Start

Linear: +2

Exponential: x2

2

4

6

8

2

4

8

16