What does the prefix giga mean in the C system? Optical power in diopters and lens magnification. Applying decimal prefixes to binary units

Convert micro to milli:

1. Select the desired category from the list, in in this case"SI prefixes".
2. Enter the value to be converted. Basic arithmetic operations, such as addition (+), subtraction (-), multiplication (*, x), division (/, :, ÷), exponent (^), parentheses and π (pi), are already supported currently.
3. From the list, select the unit of measurement of the value being converted, in this case “micro”.
4. Finally, select the unit of measurement you want the value to be converted to, in this case "milli".
5. After displaying the result of an operation, and whenever appropriate, an option appears to round the result to a certain number of decimal places.

With this calculator, you can enter the value to be converted along with the original measurement unit, for example, "538 micro". In this case, you can use either the full name of the unit of measurement or its abbreviation. After entering the unit of measurement you want to convert, the calculator determines its category, in this case "SI Prefixes". It then converts the entered value into all the appropriate units of measurement that it knows. In the list of results you will undoubtedly find the converted value you need. Alternatively, the value to be converted can be entered as follows: "55 micro to milli", "76 micro -> milli" or "43 micro = milli". In this case, the calculator will also immediately understand into which unit of measurement the original value needs to be converted. Regardless of which of these options is used, the hassle of searching through long selection lists with countless categories and countless supported units is eliminated. All this is done for us by a calculator that copes with its task in a split second.

In addition, the calculator allows you to use mathematical formulas. As a result, not only numbers such as "(64 * 77) micro" are taken into account. You can even use multiple units of measurement directly in the conversion field. For example, such a combination might look like this: “538 micro + 1614 milli” or “80mm x 84cm x 28dm = ? cm^3”. The units of measurement combined in this way must naturally correspond to each other and make sense in a given combination.

If you check the box next to the "Numbers in scientific notation" option, the answer will be represented as an exponential function. For example, 8.352099923995 9×1030. In this form, the representation of the number is divided into an exponent, here 30, and the actual number, here 8.3520999239959. In devices that have disabilities display numbers (for example, pocket calculators), the method of writing numbers 8,352 099 923 995 9E+30 is also used. In particular, it makes it easier to see very large and very small numbers. If this cell is unchecked, the result is displayed using the usual way recording numbers. In the example above, it would look like this: 8,352,099,923,995,900,000,000,000,000,000 Regardless of the presentation of the result, the maximum accuracy of this calculator is 14 decimal places. This accuracy should be sufficient for most purposes.

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1 micro [μ] = 1000 nano [n]

Initial value

Converted value

without prefix yotta zetta exa peta tera giga mega kilo hecto deca deci centi milli micro nano pico femto atto zepto yocto

Metric system and International system units (SI)

Introduction

In this article we will talk about the metric system and its history. We will see how and why it began and how it gradually evolved into what we have today. We will also look at the SI system, which was developed from the metric system of measures.

For our ancestors, who lived in a world full of dangers, the ability to measure various quantities in their natural habitat made it possible to get closer to understanding the essence of natural phenomena, knowledge of their environment and the ability to somehow influence what surrounded them. That is why people tried to invent and improve various measurement systems. At the dawn of human development, having a measurement system was no less important than it is now. Fulfill different measurements was necessary when building housing, sewing clothes different sizes, cooking and, of course, trade and exchange could not do without measurement! Many believe that the creation and adoption of the International System of SI Units is the most serious achievement not only of science and technology, but also of human development in general.

Early measurement systems

IN early systems In all measures and number systems, people used traditional objects to measure and compare. For example, it is believed that decimal system appeared due to the fact that we have ten fingers and toes. Our hands are always with us - that's why since ancient times people have used (and still use) fingers for counting. Still, we haven't always used the base 10 system for counting, and the metric system is a relatively new invention. Each region developed its own systems of units and, although these systems have much in common, most systems are still so different that converting units of measurement from one system to another has always been a problem. This problem became more and more serious as trade between different peoples developed.

The accuracy of the first systems of weights and measures directly depended on the size of the objects that surrounded the people who developed these systems. It is clear that the measurements were inaccurate, since the “measuring devices” did not have exact dimensions. For example, parts of the body were commonly used as a measure of length; mass and volume were measured using the volume and mass of seeds and other small objects whose dimensions were more or less the same. Below we will take a closer look at such units.

Length measures

In ancient Egypt, length was first measured simply elbows, and later with royal elbows. The length of the elbow was determined as the distance from the bend of the elbow to the end of the extended middle finger. Thus, the royal cubit was defined as the cubit of the reigning pharaoh. A model cubit was created and made available to the general public so that everyone could make their own length measures. This, of course, was an arbitrary unit that changed when a new reigning person took the throne. Used in Ancient Babylon similar system, but with minor differences.

The elbow was divided into smaller units: palm, hand, zerets(ft), and you(finger), which were represented by the widths of the palm, hand (with thumb), foot and finger, respectively. At the same time, they decided to agree on how many fingers there were in the palm (4), in the hand (5) and in the elbow (28 in Egypt and 30 in Babylon). It was more convenient and more accurate than measuring ratios every time.

Measures of mass and weight

Weight measures were also based on the parameters of various objects. Seeds, grains, beans and similar items were used as measures of weight. A classic example of a unit of mass that is still used today is carat. Carats are now used to measure mass. precious stones and pearls, and once the weight of carob seeds, otherwise called carob, was determined as a carat. The tree is cultivated in the Mediterranean, and its seeds are distinguished by their constant mass, so they were convenient to use as a measure of weight and mass. IN different places different seeds were used as small units of weight, and larger units were usually multiples of smaller units. Archaeologists often find similar large weights, usually made of stone. They consisted of 60, 100 and other numbers of small units. Because the single standard the number of small units, as well as their weight, was missing, this led to conflicts when sellers and buyers who lived in different places met.

Volume measures

Initially, volume was also measured using small objects. For example, the volume of a pot or jug ​​was determined by filling it to the top with small objects relative to the standard volume - like seeds. However, the lack of standardization led to the same problems when measuring volume as when measuring mass.

Evolution of various systems of measures

The ancient Greek system of measures was based on the ancient Egyptian and Babylonian ones, and the Romans created their system based on the ancient Greek one. Then, through fire and sword and, of course, through trade, these systems spread throughout Europe. It should be noted that here we are talking only about the most common systems. But there were many other systems of weights and measures, because exchange and trade were necessary for absolutely everyone. If there was no written language in the area or it was not customary to record the results of the exchange, then we can only guess at how these people measured volume and weight.

There are many regional variations in systems of measures and weights. This is due to their independent development and the influence of other systems on them as a result of trade and conquest. Various systems were not only in different countries, but often within the same country, where each trading city had its own, because local rulers did not want unification in order to maintain their power. As travel, trade, industry, and science developed, many countries sought to unify systems of weights and measures, at least within their own countries.

Already in the 13th century, and possibly earlier, scientists and philosophers discussed the creation unified system measurements. However, it was only after the French Revolution and the subsequent colonization of various regions of the world by France and others European countries, which already had their own systems of weights and measures, a new system was developed, adopted in most countries of the world. This new system was decimal metric system. It was based on the base 10, that is, for any physical quantity there was one basic unit in it, and all other units could be formed in a standard way using decimal prefixes. Each such fractional or multiple unit could be divided into ten smaller units, and these smaller units could in turn be divided into 10 even smaller units, and so on.

As we know, most early measurement systems were not based on base 10. The convenience of a system with base 10 is that the number system we are familiar with has the same base, which allows us to quickly and conveniently, using simple and familiar rules, convert from smaller units to big and vice versa. Many scientists believe that the choice of ten as the base of the number system is arbitrary and is connected only with the fact that we have ten fingers and if we had a different number of fingers, then we would probably use a different number system.

Metric system

In the early days of the metric system, man-made prototypes were used as measures of length and weight, as in previous systems. The metric system has evolved from a system based on material standards and dependence on their accuracy to a system based on natural phenomena and fundamental physical constants. For example, the time unit second was initially defined as a fraction of the tropical year 1900. The disadvantage of this definition was the impossibility experimental verification this constant in subsequent years. Therefore, the second was redefined as a certain number of periods of radiation corresponding to the transition between two hyperfine levels of the ground state of the radioactive atom of cesium-133, which is at rest at 0 K. The unit of distance, the meter, was related to the wavelength of the line of the radiation spectrum of the isotope krypton-86, but later The meter was redefined as the distance that light travels in a vacuum in a period of time equal to 1/299,792,458 of a second.

The International System of Units (SI) was created based on the metric system. It should be noted that traditionally the metric system includes units of mass, length and time, but in the SI system the number of base units has been expanded to seven. We will discuss them below.

International System of Units (SI)

The International System of Units (SI) has seven basic units for measuring basic quantities (mass, time, length, luminous intensity, amount of matter, electric current, thermodynamic temperature). This kilogram(kg) to measure mass, second(c) to measure time, meter(m) to measure distance, candela(cd) to measure luminous intensity, mole(abbreviation mole) to measure the amount of a substance, ampere(A) to measure electric current, and kelvin(K) to measure temperature.

Currently, only the kilogram still has a man-made standard, while the remaining units are based on universal physical constants or natural phenomena. This is convenient because the physical constants or natural phenomena on which the units of measurement are based can be easily verified at any time; In addition, there is no danger of loss or damage to standards. There is also no need to create copies of standards to ensure their availability in different parts of the world. This eliminates errors associated with the accuracy of making copies of physical objects, and thus provides greater accuracy.

Decimal prefixes

To form multiples and submultiple units, differing from the base units of the SI system by a certain integer number of times, which is a power of ten, it uses prefixes attached to the name of the base unit. The following is a list of all currently used prefixes and the decimal factors they represent:

For example, 5 gigameters is equal to 5,000,000,000 meters, while 3 microcandelas is equal to 0.000003 candelas. It is interesting to note that, despite the presence of a prefix in the unit kilogram, it is the base unit of the SI. Therefore, the above prefixes are applied with the gram as if it were a base unit.

At the time of writing this article, there are only three countries that have not adopted the SI system: the United States, Liberia and Myanmar. In Canada and the UK, traditional units are still widely used, even though the SI system is the official unit system in these countries. It’s enough to go into a store and see price tags per pound of goods (it turns out cheaper!), or try to buy building materials measured in meters and kilograms. Will not work! Not to mention the packaging of goods, where everything is labeled in grams, kilograms and liters, but not in whole numbers, but converted from pounds, ounces, pints and quarts. Milk space in refrigerators is also calculated per half-gallon or gallon, not per liter milk carton.

Do you find it difficult to translate units of measurement from one language to another? Colleagues are ready to help you. Post a question in TCTerms and within a few minutes you will receive an answer.

Calculations for converting units in the converter " Decimal prefix converter" are performed using unitconversion.org functions.

Multiples of units- units that are an integer number of times greater than the basic unit of measurement of some physical quantity. The International System of Units (SI) recommends the following decimal prefixes to represent multiple units:

Application of decimal prefixes to units of measurement in binary notation

Main article: Binary prefixes

In programming and the computer-related industry, the same prefixes kilo-, mega-, giga-, tera-, etc., when applied to powers of two (e.g. byte), may mean the multiplicity is not 1000, but 1024 = 2 10. Which system is used should be clear from the context (e.g. in relation to the volume random access memory the multiplicity of 1024 is used, and in relation to the volume of disk memory introduced by hard drive manufacturers - the multiplicity of 1000).

To avoid confusion in April 1999 International Electrotechnical Commission introduced new standard on naming binary numbers (see Binary prefixes).

Prefixes for submultiple units

Submultiple units, constitute a certain proportion (part) of the established unit of measurement of a certain value. The International System of Units (SI) recommends the following prefixes for denoting submultiple units:

Origin of consoles

Most prefixes are derived from Greek words Soundboard comes from the word deca or deka(δέκα) - “ten”, hecto - from hekaton(ἑκατόν) - “one hundred”, kilo - from chiloi(χίλιοι) - “thousand”, mega - from megas(μέγας), that is, “big”, giga is gigantos(γίγας) - “giant”, and tera - from teratos(τέρας), which means "monstrous". Peta (πέντε) and exa (ἕξ) correspond to five and six places of a thousand and are translated, respectively, as “five” and “six”. Lobed micro (from micros, μικρός) and nano (from nanos, νᾶνος) are translated as “small” and “dwarf”. From one word ὀκτώ ( októ), meaning “eight”, the prefixes yotta (1000 8) and yokto (1/1000 8) are formed.

How “thousand” is translated is the prefix milli, which goes back to lat. mille. Latin roots also have the prefixes centi - from centum(“one hundred”) and deci - from decimus(“tenth”), zetta - from septem("seven"). Zepto ("seven") comes from lat. words septem or from fr. sept.

The prefix atto is derived from date atten("eighteen"). Femto goes back to date And norwegian femten or to other-nor. fimmtan and means "fifteen".

The prefix pico comes from either fr. pico(“beak” or “small amount”), either from Italian piccolo, that is, “small”.

Rules for using consoles

Prefixes should be written together with the name of the unit or, accordingly, with its designation.

The use of two or more prefixes in a row (eg micromillifarads) is not permitted.

The designations of multiples and submultiples of the original unit raised to a power are formed by adding the appropriate exponent to the designation of the multiple or submultiple unit of the original unit, where the exponent means the exponentiation of the multiple or submultiple unit (together with the prefix). Example: 1 km² = (10³ m)² = 10 6 m² (not 10³ m²). The names of such units are formed by attaching a prefix to the name of the original unit: square kilometer (not kilo-square meter).

If the unit is a product or ratio of units, the prefix, or its designation, is usually attached to the name or designation of the first unit: kPa s/m (kilopascal second per meter). Attaching a prefix to the second factor of a product or to the denominator is allowed only in justified cases.

Applicability of prefixes

Due to the fact that the name of the unit of mass in SI- kilogram - contains the prefix “kilo”; to form multiple and submultiple units of mass, a submultiple unit of mass is used - a gram (0.001 kg).

Prefixes are used to a limited extent with units of time: multiple prefixes are not combined with them at all - no one uses “kilosecond”, although this is not formally prohibited, however, there is an exception to this rule: in cosmology the unit used is " gigayears"(billion years); sub-multiple prefixes are attached only to second(millisecond, microsecond, etc.). In accordance with GOST 8.417-2002, the names and designations of the following SI units are not allowed to be used with prefixes: minute, hour, day (time units), degree, minute, second(flat angle units), astronomical unit, diopter And atomic mass unit.

WITH meters of the multiple prefixes, in practice only kilo- is used: instead of megameters (Mm), gigameters (Gm), etc. they write “thousands of kilometers,” “millions of kilometers,” etc.; instead of square megameters (Mm²) they write “millions of square kilometers”.

Capacity capacitors traditionally measured in microfarads and picofarads, but not millifarads or nanofarads [ source not specified 221 days ] (they write 60,000 pF, not 60 nF; 2000 µF, not 2 mF). However, in radio engineering the use of the nanofarad unit is allowed.

Prefixes corresponding to exponents not divisible by 3 (hecto-, deca-, deci-, centi-) are not recommended. Widely used only centimeter(being the basic unit in the system GHS) And decibel, to a lesser extent - decimeter and hectopascal (in weather reports), and hectare. In some countries the volume guilt measured in decalitres.

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1 kilo [k] = 0.001 mega [M]

Initial value

Converted value

without prefix yotta zetta exa peta tera giga mega kilo hecto deca deci santi milli micro nano pico femto atto zepto yocto

Ferromagnetic fluids

Metric system and International System of Units (SI)

Introduction

In this article we will talk about the metric system and its history. We will see how and why it began and how it gradually evolved into what we have today. We will also look at the SI system, which was developed from the metric system of measures.

For our ancestors, who lived in a world full of dangers, the ability to measure various quantities in their natural habitat made it possible to get closer to understanding the essence of natural phenomena, knowledge of their environment and the ability to somehow influence what surrounded them. That is why people tried to invent and improve various measurement systems. At the dawn of human development, having a measurement system was no less important than it is now. It was necessary to carry out various measurements when building housing, sewing clothes of different sizes, preparing food and, of course, trade and exchange could not do without measurement! Many believe that the creation and adoption of the International System of SI Units is the most serious achievement not only of science and technology, but also of human development in general.

Early measurement systems

In early measurement and number systems, people used traditional objects to measure and compare. For example, it is believed that the decimal system appeared due to the fact that we have ten fingers and toes. Our hands are always with us - that's why since ancient times people have used (and still use) fingers for counting. Still, we haven't always used the base 10 system for counting, and the metric system is a relatively new invention. Each region developed its own systems of units and, although these systems have much in common, most systems are still so different that converting units of measurement from one system to another has always been a problem. This problem became more and more serious as trade between different peoples developed.

The accuracy of the first systems of weights and measures directly depended on the size of the objects that surrounded the people who developed these systems. It is clear that the measurements were inaccurate, since the “measuring devices” did not have exact dimensions. For example, parts of the body were commonly used as a measure of length; mass and volume were measured using the volume and mass of seeds and other small objects whose dimensions were more or less the same. Below we will take a closer look at such units.

Length measures

In ancient Egypt, length was first measured simply elbows, and later with royal elbows. The length of the elbow was determined as the distance from the bend of the elbow to the end of the extended middle finger. Thus, the royal cubit was defined as the cubit of the reigning pharaoh. A model cubit was created and made available to the general public so that everyone could make their own length measures. This, of course, was an arbitrary unit that changed when a new reigning person took the throne. Ancient Babylon used a similar system, but with minor differences.

The elbow was divided into smaller units: palm, hand, zerets(ft), and you(finger), which were represented by the widths of the palm, hand (with thumb), foot and finger, respectively. At the same time, they decided to agree on how many fingers there were in the palm (4), in the hand (5) and in the elbow (28 in Egypt and 30 in Babylon). It was more convenient and more accurate than measuring ratios every time.

Measures of mass and weight

Weight measures were also based on the parameters of various objects. Seeds, grains, beans and similar items were used as measures of weight. A classic example of a unit of mass that is still used today is carat. Nowadays, the weight of precious stones and pearls is measured in carats, and once upon a time the weight of carob seeds, otherwise called carob, was determined as a carat. The tree is cultivated in the Mediterranean, and its seeds are distinguished by their constant mass, so they were convenient to use as a measure of weight and mass. Different places used different seeds as small units of weight, and larger units were usually multiples of smaller units. Archaeologists often find similar large weights, usually made of stone. They consisted of 60, 100 and other numbers of small units. Since there was no uniform standard for the number of small units, as well as for their weight, this led to conflicts when sellers and buyers who lived in different places met.

Volume measures

Initially, volume was also measured using small objects. For example, the volume of a pot or jug ​​was determined by filling it to the top with small objects relative to the standard volume - like seeds. However, the lack of standardization led to the same problems when measuring volume as when measuring mass.

Evolution of various systems of measures

The ancient Greek system of measures was based on the ancient Egyptian and Babylonian ones, and the Romans created their system based on the ancient Greek one. Then, through fire and sword and, of course, through trade, these systems spread throughout Europe. It should be noted that here we are talking only about the most common systems. But there were many other systems of weights and measures, because exchange and trade were necessary for absolutely everyone. If there was no written language in the area or it was not customary to record the results of the exchange, then we can only guess at how these people measured volume and weight.

There are many regional variations in systems of measures and weights. This is due to their independent development and the influence of other systems on them as a result of trade and conquest. There were different systems not only in different countries, but often within the same country, where each trading city had its own, because local rulers did not want unification in order to maintain their power. As travel, trade, industry, and science developed, many countries sought to unify systems of weights and measures, at least within their own countries.

Already in the 13th century, and possibly earlier, scientists and philosophers discussed the creation of a unified measurement system. However, it was only after the French Revolution and the subsequent colonization of various regions of the world by France and other European countries, which already had their own systems of weights and measures, that a new system was developed, adopted in most countries of the world. This new system was decimal metric system. It was based on the base 10, that is, for any physical quantity there was one basic unit, and all other units could be formed in a standard way using decimal prefixes. Each such fractional or multiple unit could be divided into ten smaller units, and these smaller units could in turn be divided into 10 even smaller units, and so on.

As we know, most early measurement systems were not based on base 10. The convenience of a system with base 10 is that the number system we are familiar with has the same base, which allows us to quickly and conveniently, using simple and familiar rules, convert from smaller units to big and vice versa. Many scientists believe that the choice of ten as the base of the number system is arbitrary and is connected only with the fact that we have ten fingers and if we had a different number of fingers, then we would probably use a different number system.

Metric system

In the early days of the metric system, man-made prototypes were used as measures of length and weight, as in previous systems. The metric system has evolved from a system based on material standards and dependence on their accuracy to a system based on natural phenomena and fundamental physical constants. For example, the time unit second was initially defined as a fraction of the tropical year 1900. The disadvantage of this definition was the impossibility of experimental verification of this constant in subsequent years. Therefore, the second was redefined as a certain number of periods of radiation corresponding to the transition between two hyperfine levels of the ground state of the radioactive atom of cesium-133, which is at rest at 0 K. The unit of distance, the meter, was related to the wavelength of the line of the radiation spectrum of the isotope krypton-86, but later The meter was redefined as the distance that light travels in a vacuum in a period of time equal to 1/299,792,458 of a second.

The International System of Units (SI) was created based on the metric system. It should be noted that traditionally the metric system includes units of mass, length and time, but in the SI system the number of base units has been expanded to seven. We will discuss them below.

International System of Units (SI)

The International System of Units (SI) has seven basic units for measuring basic quantities (mass, time, length, luminous intensity, amount of matter, electric current, thermodynamic temperature). This kilogram(kg) to measure mass, second(c) to measure time, meter(m) to measure distance, candela(cd) to measure luminous intensity, mole(abbreviation mole) to measure the amount of a substance, ampere(A) to measure electric current, and kelvin(K) to measure temperature.

Currently, only the kilogram still has a man-made standard, while the remaining units are based on universal physical constants or natural phenomena. This is convenient because the physical constants or natural phenomena on which the units of measurement are based can be easily verified at any time; In addition, there is no danger of loss or damage to standards. There is also no need to create copies of standards to ensure their availability in different parts of the world. This eliminates errors associated with the accuracy of making copies of physical objects, and thus provides greater accuracy.

Decimal prefixes

To form multiples and submultiples that differ from the base units of the SI system by a certain integer number of times, which is a power of ten, it uses prefixes attached to the name of the base unit. The following is a list of all currently used prefixes and the decimal factors they represent:

For example, 5 gigameters is equal to 5,000,000,000 meters, while 3 microcandelas is equal to 0.000003 candelas. It is interesting to note that, despite the presence of a prefix in the unit kilogram, it is the base unit of the SI. Therefore, the above prefixes are applied with the gram as if it were a base unit.

At the time of writing this article, there are only three countries that have not adopted the SI system: the United States, Liberia and Myanmar. In Canada and the UK, traditional units are still widely used, even though the SI system is the official unit system in these countries. It’s enough to go into a store and see price tags per pound of goods (it turns out cheaper!), or try to buy building materials measured in meters and kilograms. Will not work! Not to mention the packaging of goods, where everything is labeled in grams, kilograms and liters, but not in whole numbers, but converted from pounds, ounces, pints and quarts. Milk space in refrigerators is also calculated per half-gallon or gallon, not per liter milk carton.

Do you find it difficult to translate units of measurement from one language to another? Colleagues are ready to help you. Post a question in TCTerms and within a few minutes you will receive an answer.

Calculations for converting units in the converter " Decimal prefix converter" are performed using unitconversion.org functions.

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1 milli [m] = 1000 micro [µ]

Initial value

Converted value

without prefix yotta zetta exa peta tera giga mega kilo hecto deca deci santi milli micro nano pico femto atto zepto yocto

Optical power in diopters and lens magnification

Metric system and International System of Units (SI)

Introduction

In this article we will talk about the metric system and its history. We will see how and why it began and how it gradually evolved into what we have today. We will also look at the SI system, which was developed from the metric system of measures.

For our ancestors, who lived in a world full of dangers, the ability to measure various quantities in their natural habitat made it possible to get closer to understanding the essence of natural phenomena, knowledge of their environment and the ability to somehow influence what surrounded them. That is why people tried to invent and improve various measurement systems. At the dawn of human development, having a measurement system was no less important than it is now. It was necessary to carry out various measurements when building housing, sewing clothes of different sizes, preparing food and, of course, trade and exchange could not do without measurement! Many believe that the creation and adoption of the International System of SI Units is the most serious achievement not only of science and technology, but also of human development in general.

Early measurement systems

In early measurement and number systems, people used traditional objects to measure and compare. For example, it is believed that the decimal system appeared due to the fact that we have ten fingers and toes. Our hands are always with us - that's why since ancient times people have used (and still use) fingers for counting. Still, we haven't always used the base 10 system for counting, and the metric system is a relatively new invention. Each region developed its own systems of units and, although these systems have much in common, most systems are still so different that converting units of measurement from one system to another has always been a problem. This problem became more and more serious as trade between different peoples developed.

The accuracy of the first systems of weights and measures directly depended on the size of the objects that surrounded the people who developed these systems. It is clear that the measurements were inaccurate, since the “measuring devices” did not have exact dimensions. For example, parts of the body were commonly used as a measure of length; mass and volume were measured using the volume and mass of seeds and other small objects whose dimensions were more or less the same. Below we will take a closer look at such units.

Length measures

In ancient Egypt, length was first measured simply elbows, and later with royal elbows. The length of the elbow was determined as the distance from the bend of the elbow to the end of the extended middle finger. Thus, the royal cubit was defined as the cubit of the reigning pharaoh. A model cubit was created and made available to the general public so that everyone could make their own length measures. This, of course, was an arbitrary unit that changed when a new reigning person took the throne. Ancient Babylon used a similar system, but with minor differences.

The elbow was divided into smaller units: palm, hand, zerets(ft), and you(finger), which were represented by the widths of the palm, hand (with thumb), foot and finger, respectively. At the same time, they decided to agree on how many fingers there were in the palm (4), in the hand (5) and in the elbow (28 in Egypt and 30 in Babylon). It was more convenient and more accurate than measuring ratios every time.

Measures of mass and weight

Weight measures were also based on the parameters of various objects. Seeds, grains, beans and similar items were used as measures of weight. A classic example of a unit of mass that is still used today is carat. Nowadays, the weight of precious stones and pearls is measured in carats, and once upon a time the weight of carob seeds, otherwise called carob, was determined as a carat. The tree is cultivated in the Mediterranean, and its seeds are distinguished by their constant mass, so they were convenient to use as a measure of weight and mass. Different places used different seeds as small units of weight, and larger units were usually multiples of smaller units. Archaeologists often find similar large weights, usually made of stone. They consisted of 60, 100 and other numbers of small units. Since there was no uniform standard for the number of small units, as well as for their weight, this led to conflicts when sellers and buyers who lived in different places met.

Volume measures

Initially, volume was also measured using small objects. For example, the volume of a pot or jug ​​was determined by filling it to the top with small objects relative to the standard volume - like seeds. However, the lack of standardization led to the same problems when measuring volume as when measuring mass.

Evolution of various systems of measures

The ancient Greek system of measures was based on the ancient Egyptian and Babylonian ones, and the Romans created their system based on the ancient Greek one. Then, through fire and sword and, of course, through trade, these systems spread throughout Europe. It should be noted that here we are talking only about the most common systems. But there were many other systems of weights and measures, because exchange and trade were necessary for absolutely everyone. If there was no written language in the area or it was not customary to record the results of the exchange, then we can only guess at how these people measured volume and weight.

There are many regional variations in systems of measures and weights. This is due to their independent development and the influence of other systems on them as a result of trade and conquest. There were different systems not only in different countries, but often within the same country, where each trading city had its own, because local rulers did not want unification in order to maintain their power. As travel, trade, industry, and science developed, many countries sought to unify systems of weights and measures, at least within their own countries.

Already in the 13th century, and possibly earlier, scientists and philosophers discussed the creation of a unified measurement system. However, it was only after the French Revolution and the subsequent colonization of various regions of the world by France and other European countries, which already had their own systems of weights and measures, that a new system was developed, adopted in most countries of the world. This new system was decimal metric system. It was based on the base 10, that is, for any physical quantity there was one basic unit, and all other units could be formed in a standard way using decimal prefixes. Each such fractional or multiple unit could be divided into ten smaller units, and these smaller units could in turn be divided into 10 even smaller units, and so on.

As we know, most early measurement systems were not based on base 10. The convenience of a system with base 10 is that the number system we are familiar with has the same base, which allows us to quickly and conveniently, using simple and familiar rules, convert from smaller units to big and vice versa. Many scientists believe that the choice of ten as the base of the number system is arbitrary and is connected only with the fact that we have ten fingers and if we had a different number of fingers, then we would probably use a different number system.

Metric system

In the early days of the metric system, man-made prototypes were used as measures of length and weight, as in previous systems. The metric system has evolved from a system based on material standards and dependence on their accuracy to a system based on natural phenomena and fundamental physical constants. For example, the time unit second was initially defined as a fraction of the tropical year 1900. The disadvantage of this definition was the impossibility of experimental verification of this constant in subsequent years. Therefore, the second was redefined as a certain number of periods of radiation corresponding to the transition between two hyperfine levels of the ground state of the radioactive atom of cesium-133, which is at rest at 0 K. The unit of distance, the meter, was related to the wavelength of the line of the radiation spectrum of the isotope krypton-86, but later The meter was redefined as the distance that light travels in a vacuum in a period of time equal to 1/299,792,458 of a second.

The International System of Units (SI) was created based on the metric system. It should be noted that traditionally the metric system includes units of mass, length and time, but in the SI system the number of base units has been expanded to seven. We will discuss them below.

International System of Units (SI)

The International System of Units (SI) has seven basic units for measuring basic quantities (mass, time, length, luminous intensity, amount of matter, electric current, thermodynamic temperature). This kilogram(kg) to measure mass, second(c) to measure time, meter(m) to measure distance, candela(cd) to measure luminous intensity, mole(abbreviation mole) to measure the amount of a substance, ampere(A) to measure electric current, and kelvin(K) to measure temperature.

Currently, only the kilogram still has a man-made standard, while the remaining units are based on universal physical constants or natural phenomena. This is convenient because the physical constants or natural phenomena on which the units of measurement are based can be easily verified at any time; In addition, there is no danger of loss or damage to standards. There is also no need to create copies of standards to ensure their availability in different parts of the world. This eliminates errors associated with the accuracy of making copies of physical objects, and thus provides greater accuracy.

Decimal prefixes

To form multiples and submultiples that differ from the base units of the SI system by a certain integer number of times, which is a power of ten, it uses prefixes attached to the name of the base unit. The following is a list of all currently used prefixes and the decimal factors they represent:

For example, 5 gigameters is equal to 5,000,000,000 meters, while 3 microcandelas is equal to 0.000003 candelas. It is interesting to note that, despite the presence of a prefix in the unit kilogram, it is the base unit of the SI. Therefore, the above prefixes are applied with the gram as if it were a base unit.

At the time of writing this article, there are only three countries that have not adopted the SI system: the United States, Liberia and Myanmar. In Canada and the UK, traditional units are still widely used, even though the SI system is the official unit system in these countries. It’s enough to go into a store and see price tags per pound of goods (it turns out cheaper!), or try to buy building materials measured in meters and kilograms. Will not work! Not to mention the packaging of goods, where everything is labeled in grams, kilograms and liters, but not in whole numbers, but converted from pounds, ounces, pints and quarts. Milk space in refrigerators is also calculated per half-gallon or gallon, not per liter milk carton.

Do you find it difficult to translate units of measurement from one language to another? Colleagues are ready to help you. Post a question in TCTerms and within a few minutes you will receive an answer.

Calculations for converting units in the converter " Decimal prefix converter" are performed using unitconversion.org functions.