"If something is being measured, then someone needs it." Mayakovsky might have said so, but he was more interested in the stars. However, is everything inherent in the measure and is it always worth it to do it? Something must also be left to the poets.
To everything else, you can apply a meter and a caliper.
What was up to a unit of quantity of information?
Even primitive construction could not do without determining the length, width and height. The military operations that our ancestors engaged in even earlier than they started building something also required the calculation of distances, requirements for draft force, etc., etc.
But where to get the units? The inhabitants of the island, who, for happiness, lacked only a calendar, also asked this question, but to no avail. Although the solution lay on the surface.
In fact, the question is not so complicated. All the first units were provided by nature. People had arms and legs. No wonder the elbows and the feet first came up. "Man is the measure of all things" - a philosophical definition did not arise from scratch.
No precision required yet
At first, the approximation of measurements did not bother anyone. But already at the time of the pharaohs, builders began to use more advanced tools. If the pyramid collapsed, no one would be stroked on the head. But they still stand.
When it was first required to measure information, the wheel was not invented. Used the good old meters and kilograms. Because the information was recorded on paper. The paper had weight and volume.
There was no talk about the unit of quantity of information and could not be.
But then computers appeared
The question arose at the theoretical stage. Because measuring the amount of information in units of length and weight has become impossible.
And without this data, a computer could not be created. Although computing tools already existed and did an excellent job. Take, for example, Iron Felix, which is remembered only by those over fifty.
Number systems
How to count the number of sheep in a herd? It is easy if you know how many fingers are on the hand. One, two ... ten. Set aside one pebble to the side, repeat the process. This is how the first number system appeared.
And if our ancestors had six fingers instead of five? Would a duodecimal system arise? Rather yes than no. Although the remains of six-fingered homo sapiens have not yet been found, such a system was created. Artists from Babylon used the knuckles of one hand.
It gradually became clear that number systems can be any number. Hexadecimal will require 16 characters. An octal is enough 8. Binary and even less - only zero and one.
The Yin and Yang of the Digital World
The binary number system was the last. To come up with something simpler is simply impossible. But for a long time no one used it. What can you do, people used to count dozens.
That was until the first computers appeared. To count, you must have a number system. Then they remembered about zero and one. Because the tension is either there or not. There was nothing to invent. Everything was already available.
The binary system, as it turned out, was invented by the ubiquitous Chinese. Emperor Fu Xi, who was also a philosopher at the same time, defined the system 4 thousand years before Leibniz was born. An outstanding mathematician and reported in 1703 this tidbit of news.
But how many kilobytes per gigabyte, he could not say. There was neither one nor the other.
Beat and its author
The binary number algebra for the circuit in which current flows was first described by the American Claude Shannon in 1940. He managed to combine electricity and mathematics in his doctoral dissertation. In it, he applied Boolean algebra to describe relay circuits. Logical mathematics operates on two concepts: falsehood and truth. Relays and circuit breakers can either be turned on or off. Surprisingly, no one had come to mind to compare one with the other.
After 8 years, in 1948, he introduced a unit of quantity of information and called it bit. The short word, now known to almost everyone, he borrowed from John Tukey. He did not like long names and used the abbreviation bit instead of Binary digiT. This phrase is translated into Russian as "binary digit". So the world recognized the bit - the smallest unit of information.
In the most general sense, information refers to the degree of heterogeneity. A completely homogeneous space means a complete lack of information. By chance or not, the Lord began the creation of the world by separating light from darkness. At this point, information appeared, and it was equal to one bit.
Roulettes are different
Gamblers may be disappointed. Roulette is not understood here as what is betting on. There is also a measuring tool with the same name. Millimeters, centimeters, decimeters - units of length are applied on it.
Each next division on roulette is 10 times larger than the previous one. So, centimeters, decimeters, meters and kilometers are obtained. It is clear that such a gradation is associated with a system used to measure length.
And what about information roulette? Here I had to sacrifice principles. Binary digits do not correspond to decimal units. Because division is based on the power of 2.
What's the beat?
The next unit is called a byte. To understand how many bits are contained in 1 byte, you need to raise 2 to the third power. Get eight. The smallest number will be represented as 00000001, the largest 11111111.
Why is this length chosen for the byte? Partly because the number of possible combinations of zeros and ones is equal to 256. This turned out to be quite enough to encode numbers, alphabets and service symbols for teletype and telegraph.
But soon the byte was not enough. For a long time they didn’t. The familiar prefixes were assigned to all subsequent units: “kilo”, “mega”, “giga”, “tera” and so on. It became possible to calculate how many bytes per KB and answer how MB differs from GB.
But then the contradictions began.
How is a kilogram different from a kilobyte?
If we distract from the subject of measurement, then almost nothing. The prefix "kilo" means "thousand." In one case, we have a thousand grams, in the other as many bytes. Everything is simple and clear. So megabytes are a million, gigabytes are a billion, and terabytes are a trillion bytes.
The difference still exists. A kilogram is also a kilogram in Africa, but a kilobyte is not always 1 thousand bytes. The thing is that in the powers of two there is no number 1000. 2 9 = 512, and the next power, 2 10 , is already 1024. Therefore, a kilobyte should not contain a thousand, but 1024 bytes.
How to measure all the information in the world?
All other divisions of the byte scale are also obtained by raising the number 2 to a power multiple of 10:
- megabytes - 1024 Kb (2 20 );
- gigabyte - 1024 MB (2 30 );
- Terabytes - 1024 GB (2 40 ).
In what units the amount of information is measured can be seen in the figure.
The volume of all information in the world in 2009 was estimated at 0.8 zettabytes. And in 2020 it should increase to 44. Is it a lot or a little? If you imagine a video disc of this size, it would take 63 million years to watch all the films. Completes a number of iBytes. It contains 1024 zettabytes, or 2 80 bytes.