Articles

Stories and guides about hard-to-picture quantities: areas, volumes of water, weights… always with the figure drawn to scale so it actually sinks in.

Distances

From the foot to the metre: why we measure distance the way we do

A kilometre is a thousand metres and a mile is 1,609.344: one of those numbers was chosen and the other was not. The table of every distance unit, the 0.2 mm error still inside the metre, and why a mile is 5,280 feet.

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Distances

How far away is the horizon?

From the beach the horizon is only 2.9 miles (4.7 km) away. The formula (1.22 × the square root of your height), a table by height, why mountains show up 60 miles out, and your horizon drawn to scale on a map.

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Liters

How many litres of water are in a bathtub?

A standard 170 × 70 cm bathtub is rated at 183 litres (48 gallons) and a real bath uses about 150. Capacities by size, how many minutes of shower equal a bath, and how to measure your own.

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Distances

How long is a marathon?

A marathon is 26.2 miles — 26 miles 385 yards, or 42.195 km — and a half marathon 13.11 miles. Why that odd figure, pace and finishing times, drawn to scale on a map.

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Distances

How long is a nautical mile?

A nautical mile is exactly 1,852 metres (1.852 km, 1.15 statute miles) — 15 % longer than a land mile. Why it measures that, what a knot is and a conversion table, drawn on a map.

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Distances

How far is 10,000 steps?

10,000 steps come to about 7.5 km (4.7 miles) — between 7 and 8 km. Where the figure comes from, how many steps you really need and how long it takes. See it drawn to scale on a map.

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Liters

How many litres of water are in an Olympic swimming pool?

An Olympic swimming pool holds about 2.5 million litres (2,500 m³): some 16,667 bathtubs or 83 tanker trucks. Official size, equivalents and what it costs to fill.

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