Linear vs. Exponential Growth
There are two main ways quantities increase:
- 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…
- 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 cm) as we fold it.
| Folds () | Calculation | Thickness () | Comparison |
|---|---|---|---|
| 0 | 0.001 cm | Sheet of paper | |
| 10 | cm | Notebook | |
| 17 | cm | 4-year-old child | |
| 27 | km | Small Mountain | |
| 30 | km | Cruising altitude of jets | |
| 46 | km | Distance 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!