The curious origins of imperial and metric units

Summary

This video explores the fascinating history and etymology of measurement systems, from the quirky decimal time and calendar of revolutionary France to the enduring imperial and US customary units. It traces the origins of feet, inches, miles, pounds, and gallons back to Ancient Egypt, Rome, and medieval England, revealing how body parts, land, and everyday objects shaped these units. The video then contrasts this with the metric system, highlighting its logical, Earth-based standardization and global dominance. Along the way, it touches on curious linguistic roots, cultural adoption, and modern usage, making measurement both informative and surprisingly entertaining.

Takeaways

• 🇫🇷 France once experimented with a decimal time system with 10-hour days and 100-minute hours, alongside a 10-day week calendar, but it lasted less than a decade.
• 📏 The metric system, including metres, litres, and grams, emerged from the French Revolution and is now the globally dominant measurement system.
• 🦵 Many imperial or US customary units trace back to human body measurements, such as fingers, hands, cubits, and feet, originating from Ancient Egypt, Greece, and Rome.
• 📐 The Roman foot was divided into 12 unciae, giving rise to the inch and ounce, which historically were also units of time.
• 🌾 England standardized the inch in the 1300s using three barleycorns, showing early attempts at consistent measurement.
• 🐴 Units like the hand, yard, pole, furlong, and acre evolved from human and animal-based measurements and agricultural practices.
• 🚢 Fathoms, miles, and nautical miles have historical and practical roots, including maritime navigation and Roman distance measures.
• ⚖️ Weights like pounds, ounces, and tons have evolved from Roman and medieval systems, with variations between the US and UK, highlighting inconsistencies prior to metrication.
• 🌍 The metric system defines units based on immutable natural constants, such as the metre being one ten-millionth of the distance from the North Pole to the equator.
• 🔢 Metric prefixes combine Latin (for divisions) and Greek (for multiples) to create a logical and consistent system for measurement scaling.
• 🇺🇸 Despite official adoption of metric systems, the US and UK still use imperial units widely in daily life, from road distances to pints and feet.
• 💡 Both imperial and metric systems have unique appeal: imperial relates measurements to everyday human experience, while metric connects them to universal natural standards.

Q & A

What was the decimal day introduced in France during the French Revolution?

The decimal day in France was a 10-hour day, divided into 100 minutes, each of 100 seconds. It was part of the revolutionary effort to decimalize time, along with a 10-day week called a 'décade'.

How did ancient units like the inch, foot, and cubit originate?

Many ancient units were based on human body parts. For example, a 'digit' represented the width of a finger, a 'palm' the width of a hand, and a 'cubit' the length from elbow to the tip of the middle finger. These measures evolved from Ancient Egypt through Greece and Rome.

What is the historical connection between the Roman 'uncia' and modern units?

The Roman 'uncia' was a twelfth of a foot, and its name evolved into the modern 'inch'. It also influenced the ounce as a unit of weight, which originally had 12 ounces to a pound before the avoirdupois system introduced 16 ounces per pound.

How was the modern British foot standardized?

Around 1300, King Edward I of England standardized the foot by defining it as three grains of barley, dry and round, placed end to end. This helped unify various foot measurements in use at the time.

What is the origin and meaning of the word 'furlong'?

A furlong comes from 'furrow-long', historically referring to the distance a pair of oxen could plough before needing a rest. It equals 220 yards.

How did the metric system define the metre?

The metre was defined as one ten-millionth of the distance from the North Pole to the equator along a meridian passing through Paris. This Earth-based standard aimed to provide a precise, immutable unit of length.

What is the difference between Latin and Greek prefixes in the metric system?

In the metric system, Latin prefixes are used for divisions (e.g., milli, centi, deci) and Greek prefixes for multiples (e.g., kilo, mega, giga, tera). Exceptions like micro- and nano- are Greek.

Why is the abbreviation for pound 'lb'?

The abbreviation 'lb' comes from the Latin 'libra', which referred to the Roman pound. 'Libra pondo' literally means 'pound by weight', linking the term to both weight and currency.

How did Queen Elizabeth I standardize the mile?

Queen Elizabeth I fixed the mile at 8 furlongs, or 5,280 feet, standardizing it from the earlier London mile of approximately 5,000 feet. This made the mile divisible by many smaller numbers, even if it wasn’t a round figure.

What is the significance of the metric system compared to imperial units?

The metric system is based on universal, consistent measurements derived from the Earth, making calculations and conversions simpler. In contrast, imperial units often originated from human or animal-based measurements, which varied regionally and historically.

How did the avoirdupois system change the pound?

The avoirdupois system, introduced in 14th century England, redefined the pound to consist of 16 ounces instead of the traditional 12 ounces, based on a Middle French term meaning 'goods by weight'.

What is a hand in measurement and its modern equivalent?

A hand is one-third of a foot, traditionally used to measure horse height. In metric terms, it equals just over 10 centimeters.