Calculations grounded in physics, chemistry, biology, and the wider natural sciences
We count everything from building and furniture doors to bacterial flagellar motors, one category at a time, using Merriam-Webster as the only ruler. The lead changes hands three times, and the shakiest reversal comes down to how many Hot Wheels cars are still rolling around somewhere.
The Book of Joshua describes six days of marching once around Jericho's walls, then seven laps on the seventh — 13 laps in all. How far did that add up to for one person, how long did it take, and how much metabolic energy did 40,000 marchers burn doing it? We reverse-engineer the city's size from archaeology, weigh three guesses at how far back from the wall they actually walked, and convert the total into joules — and, just for scale, into tons of TNT.
One avocado (100 g flesh) gets dissected through three lenses: water, carbon, and nutrition efficiency. The math checks the popular "200-320 liters of water" claim against the primary dataset, tests how much transport mode swings the carbon footprint, and ranks avocado's nutrient-per-liter efficiency against four other fruits.
Adjust melt rates of Greenland ice sheet, Antarctic ice sheet, and mountain glaciers to calculate sea level rise directly. An interactive calculator covering IPCC low/high emission scenarios through complete melting, where you can explore different futures by adjusting sliders.
A 10 km commute by car uses far more energy per passenger than a bus — unless the bus is nearly empty. We break down energy intensity (MJ per passenger-km) across eleven transportation modes, from walking to electric cars to rockets, then apply it to one real trip — New York to Los Angeles, about 3,940 km (2,450 mi) — to see which one actually wins, and how badly occupancy and grid mix can reverse the rankings.