Why Does a Cold Spread Through the Whole Class So Fast?
Why Does a Cold Spread Through the Whole Class So Fast? — Even small changes, stacked by "multiplying," grow beyond imagination. That's why one hand-wash, one mask, makes a big difference. Understand the power of exponents and you'll see why small habits matter so much.
One classmate catches a cold, and a few days later the whole class is coughing. It started with one person — how does it spread so fast? If it grew one at a time, it couldn't possibly be this quick.
There's an old Indian legend. A king offered a reward to the inventor of chess, who asked: "One grain of rice on the first square, two on the second, four on the third… for all 64 squares." The king laughed: "Just rice?" But doubling each square, the 64th square needed more rice than the entire kingdom could grow! Only then did the king grasp the terror of "doubling."
The key is the difference between "adding" and "multiplying." Growing by one a day (1→2→3→4) is adding — slow. But if one person infects two, and those two each infect two more (1→2→4→8→16), that's multiplying! This is exponential growth. It seems trivial at first, then suddenly explodes. That's why colds and flu spread so fast, and why COVID swept the globe. So scientists watch one crucial number: "how many people, on average, does one person infect?" Above 1, it spreads; below 1, it dies down.
- Predicting epidemic spread (COVID and flu containment policy)
- A video "blowing up" on social media (going viral)
- How bank interest (compounding) and investments grow
- Population growth, bacterial reproduction
增 (jeung) shows earth (土) piled up higher and higher — the 增 of "increase." One becoming two, two becoming four — the explosion of exponential growth is exactly the math of 增.
Meet this hanja in Cheonjamun →Even small changes, stacked by "multiplying," grow beyond imagination. That's why one hand-wash, one mask, makes a big difference. Understand the power of exponents and you'll see why small habits matter so much.
