A incrível história de como a França criou o sistema métrico decimal | Ouça 11 minutos
The Fascinating History of the Metric System in France
Introduction to the Metric System
- The report by Madwey Ramani from BBC Travel discusses how France created the metric system, highlighting a marble plaque at the Ministry of Justice in Paris that signifies its historical importance.
- Ken Alder, a history professor, emphasizes that measuring is often overlooked but has complex and controversial histories.
Pre-Metric Measurement Chaos
- Before the French Revolution, measurement systems varied widely not only between countries but also within France itself, with thousands of different units in use.
- The revolution aimed to fundamentally change society by abolishing old traditions and introducing new systems like the decimal calendar in 1793.
Establishing a New Measurement Standard
- Revolutionary leaders sought to create a uniform measurement system based on reason rather than tradition; thus, the meter was defined as one ten-millionth of the distance from the North Pole to the equator.
- Two astronomers were tasked with measuring this distance using triangulation techniques starting from Paris.
The Challenges Faced by Astronomers
- Delambre and Méchain faced significant challenges during their measurements due to political turmoil and public skepticism about adopting new standards.
- Their work took seven years instead of one, culminating in 1799 when they presented a platinum bar as the standard meter.
Resistance to Change
- Despite technological advancements, there was widespread reluctance among people to abandon traditional measures tied to local customs and economies.
- Authorities even sent police inspectors to enforce compliance with the new metric system due to public resistance.
Gradual Adoption of Metric System
- Although initially abandoned in 1812, it was reinstated in 1840. It took about 100 years for most French citizens to fully adopt it.
The Importance of Measurement Standards
Historical Context of the BIPM
- The Eiffel Tower was constructed for the 1889 World Fair in Paris, standing at 324 meters, making it the tallest man-made structure at that time. This event led to the establishment of one of the oldest international institutions, the International Bureau of Weights and Measures (BIPM), located in a serene suburb of Paris.
Role and Functionality of BIPM
- The BIPM is crucial for maintaining international measurement standards. It promotes uniformity across seven international units: meter, kilogram, second, ampere (electric current intensity), kelvin (temperature), mole (amount of substance), and candela (luminous intensity).
- Originally defined by a physical object—a platinum-iridium cylinder—the kilogram has undergone significant changes. In 1980, the meter was redefined based on light's travel distance in a vacuum over a specific time interval.
Redefinition of Measurement Units
- The original kilogram definition relied on a physical artifact until November 2018 when it was redefined using Planck's constant. This shift emphasizes precision and universality in measurements.
- The kilogram is now determined through the Kibble balance or watt balance method, which compares mechanical energy with electromagnetic energy. This approach ensures that measurements are consistent and not subject to loss or damage like physical objects.
Implications for Global Accessibility