Math in the world around us: coffee, seasons, pi and power lines
Curiosities with real arithmetic inside. Each one starts from something you can see or touch and ends with a number you can check.
5 pages in this section
- GuideHow Fast Does Coffee Cool? Newton's Law of CoolingCoffee cools fast at first and slower later. The law behind it, how to find your cup's cooling constant, measured data, and what milk and lids change.
- GuideHow Much Gold Is in an Oscar? The Plating MathAn Oscar is cast bronze with a thin 24-karat gold plating. See the plating math: about 0.5 to 6.5 grams of gold, and why solid gold would cost about $414,000.
- ReferenceWhat Is Pi? Meaning, Value, Uses and HistoryPi is a circle's circumference divided by its diameter, about 3.14. See the formulas, how many digits you need, what pi is used for, and its history.
- GuideWhy Power Lines Use High Voltage: The Math of Line LossHigh voltage means low current, and heat loss grows with the square of the current. Worked example, transformers, HVDC and underground cables explained.
- StoryWhy Seasons Happen: Earth's Tilt, Sun Angle and DaylightEarth's 23.44 degree tilt causes the seasons, not distance from the Sun. See the sun-height math, daylight by latitude, and why the tilt slowly changes.