Unit converter

Humanity faced the need to use measures at the dawn of civilization. It was necessary to somehow measure distances, determine weight, temperature, area, time, speed.

To do this, units of measurement were introduced: first, primitive and conditional (finger, elbow, fathom), and then standard ones - meter, yard, foot. For example, today density can be measured and expressed in liters, kilograms / cubic meters or pounds / cubic meters, and time - in seconds, minutes, hours.

History of units

Length measurement

Initially, the length was measured by parts of the human body: palms, fingers, elbows, feet. Since each person has slightly different proportions and sizes, such measurements were very arbitrary and not highly accurate. Especially if it was about measuring large multiples, for example, a kilometer road, which, depending on the characteristics of a person, can be either 1250 or 1450 steps.

Primitive length units were used in different countries during antiquity and the Middle Ages, and only in the XIV century, the English king Edward II introduced a relatively accurate way to determine the dimensions and distances. The usual unit of measurement - an inch, which was previously measured as the width of the thumb of an adult, he proposed to measure with barley grains. So, since the XIV century, an inch is three barley grains laid in a ruler one after another. Since the size of all barley seeds is approximately the same, this provided a much higher measurement accuracy.

At the same time, measures such as the foot, yard, and qubit continued to be used. The first was equal to the length of the human foot, the second - the length of the male belt, and the third - the distance from the ends of the fingers to the elbow. Even ancient scientists understood that the error in using such measures was huge, but the need to switch to more accurate units of measurement arose much later - in the 16th-17th centuries, as the exact sciences developed.

Weight measurement

Before our era, weights were determined very conditionally and with low accuracy - in the equivalent of pebbles, grains and seeds of approximately the same size. In ancient Babylon, this led to the creation of the first units of measurement: shekels, mines and talents. Later, they were borrowed first by the Israelites, and then by the Greeks and Romans. The latter renamed the mine into a liter, which corresponds to the modern pound.

A much more precise system was used in ancient India. According to her, the basic unit of mass was 28 grams (analogue of an ounce), and all other quantities were repelled from it. The maximum unit was 500 base and the minimum was 0.05 base.

The same weights differed in different historical eras. For example, the same mine in one period of the history of Babylon was 640 grams, and in another - 978 grams. At the same time, for many centuries it remained the main unit of mass measurement: not only in Babylon itself, but also in most other civilized countries.

American history also speaks of the inaccuracies of the measures, where, until the middle of the 19th century, gold mines established their own units of weight measurement. In California, they were brought to a common standard only in 1850.

Volume measurement

The main measures for determining volumes in the ancient world were containers and vessels. For example, in ancient Greece, clay amphoras were used for this. They contained from 2 to 26 liters (by modern standards) and made it possible to accurately measure liquids and bulk materials. The former most often were water, oil and wine, and the latter were crops.

Transition to a unified measurement system

It's hard to believe, but the confusion in units of measurement (often conditional and inaccurate) continued until the 18th century. And only in the 1790s in France were the first standards of mass (kilogram) and length (meter) made. They formed the basis for the Le Système International d'Unités (SI) system of units, commonly known today as the SI. The first version of the international metric system began to be used in Europe from the beginning of the 19th century.

Measurement standards were also sent to the United States, but the ship was captured by British privateers along the way. This is one of the reasons why the United States still uses its own metric system (yards, feet and miles), and the SI system remains only an alternative / fallback.

A complete official description of the international system is contained in the SI Brochure published since 1970. Since 1985, it has been published in English and French, and in May 2019 it underwent the last (at the moment) edition. Material objects used for comparisons were removed from the system, and the definitions of measures received new official wording.

Interesting facts

• In 1875 in Paris, seventeen countries signed the Meter Convention (Convention du Mètre) - an international treaty that serves to ensure the unity of metrological standards in different countries.
• The International System of Units (SI) was introduced in 1960, it contained six basic units (meter, kilogram, second, ampere, kelvin, candela) and 22 more derived units.
• In Ray Bradbury's Fahrenheit 451, this is the temperature at which paper burns. In terms of temperature in Celsius, this is 232.78 ° C. Paper actually burns at 843.8 degrees Fahrenheit (451°C).
• The English like to describe the size of geographical objects in non-traditional units. In the papers, there are "bus length", "football field" and "Olympic pool".
• Radiation can be measured in bananas. Each banana contains about 0.1 μSv. This is a safe dose to get irradiated, like after the explosion at Fukushima-1, you need to eat 76 million bananas. The comparison with a banana is used when they want to point out a negligible dose of radiation.

With the help of the converter, you can convert various units of mass, length, volume, area and much more. The service provides adaptation of units of different systems. You can easily recognize measurements in inches and centimeters, distances in miles and kilometers, weight in pounds and grams.