A second is something we usually don't pay attention to in our daily rush, considering it to be something small and frivolous. At the same time, the most powerful minds of the past worked to learn how to correctly determine its length. So let's try to take a closer look at the meaning and origin of this term. After all, it has not one, but several interpretations at once.
What is time
The concept under consideration is very closely related to such an important philosophical and physical category as time. Therefore, first of all, you should find out what it is.
This word refers to the measure of the duration of the existence of all objects in the universe. In addition, this is a characteristic of the sequential change in the state of each and every object in the processes (including the processes themselves), their change and development.
Also, time is one of the coordinates of a single space-time, which is considered within the framework of the theory of relativity.
From the point of view of philosophy, this term refers to the irreversibleflow from the past to the future through the present.
A second - what is it?
Having considered what time is, it is worth moving on to a second. It is its unit of measurement. Moreover, it is used both in metric and in American measuring systems.
The abbreviation for the second is the lowercase letter "s" in Cyrillic and "s" in Latin. Sometimes the variant "sec" or "sec" is used, but few people accept it.
Other meanings of the term
In addition to the temporal unit of measure, the noun in question also has several additional meanings:
- This is the name of the second or secondary musical instrument in the orchestra. For example: flute-second.
- Also in music, the term in question has another way of interpretation. The second according to it is the second degree of the diatonic scale and at the same time the interval between its adjacent notes.
- In addition to all of the above, this term is a unit by which flat angles are measured. In this case, the second is indicated by the “''” icon above the number, as a degree: 26 ''. Such a second is a fractional value of an arc minute (1/60) or an angular degree (1/3600).
- Sometimes the noun in question is used in artistic speech to denote a very short time period. For example: "Just a second passed, as I turned away - and he disappeared." Or “It seemed to me that at that moment my heart would jump out of my chest fromhappiness". In both cases, the described incident could last longer or vice versa less than the traditional unit of time. For example, not 1, but 5 seconds. Or vice versa - its half, quarter, sixth, etc.
- Among other things, this term, together with units of length, is used to measure speed ("V"). The length units used differ depending on the system. If it is the CGS System - V is measured in centimeters per second (cm/s). If the SI system is in meters per second, the speed is measured (m / s).
Origin of the studied noun
The term in question came to all modern languages from Latin. It was formed from the word secund, which means “second / second” (hence the ordinal number second has been preserved in English). By the way, in this sense the term remained in music (the second step, the second musical instrument).
How is the numeral and the interval of time related? Very simple. The fact is that in ancient Rome one hour was divided twice by sixty. The first such division (as a result of which minutes were allocated) was called prima divisio, and the second - secunda divisio. The parts of the hour formed in this way gradually began to be named after the very method of division - “seconds”.
In medieval Latin, which was somewhat distant from the original language of the Romans, other expressions began to be used: pars minuta prima ("first small part") and pars minuta secunda ("second small part"). It was also about dividing the hour into minutes and seconds.
Widethe noun under study acquired distribution as a name for a period of time throughout the world only in the seventeenth and eighteenth centuries. However, in England this term was used by scientists as early as the thirteenth century.
History of the implementation of the second
Throughout the history of science of the Ancient World, when calculating time, scientists singled out small periods of time. They made it possible to calculate processes invisible to the eye, such as chemical or physical reactions, etc.
The first watch with a second hand appeared already in the sixteenth century. However, in those years, the size of the second fluctuated constantly.
As a unit of measurement of time intervals in the exact sciences, the second was first used in 1832. A similar idea belonged to the German mathematician Carl Friedrich Gauss.
However, for this innovation to be accepted by other scientists, it took another thirty years, after which the British Scientific Association decided to all its members to use this unit of time.
In the future, following England, the whole of Europe gradually switched to seconds. The countries that actively developed science were the first to do this. Indeed, to conduct various experiments, it was necessary to know the exact time with seconds. Especially when you consider that by the end of the nineteenth century, scientists around the world were actively studying molecular and atomic chemistry and physics. And, as you know, some compounds are able to exist and not decay for just a few seconds. To be able to identify and study them, it was necessary to clearly know the time of their "life".
In the following years, the unit in question became so popular that it was gradually incorporated into many measurement systems:
- CGS (centimeter - gram - second);
- MKS (meter - kilogram - second);
- MKSA or Georgie system (meter - kilogram - second - ampere) and others.
It is worth noting that at that time the solar second was still used, calculated from solar days.
Atomic time second
By the middle of the twentieth century. scientists have experimentally proved that the Earth rotates around its axis and the Sun is not always uniform, as previously thought.
It either slows down, or vice versa accelerates in the form of irregular jumps. Because of this, the value of seconds could differ in different periods of time. To correct this omission, the most prominent mathematicians and physicists tried to calculate the average solar year or to compile tables of changes in its length.
However, in the future, the situation was resolved in a simpler way. In the early sixties, not solar days and their submultiple units, but atomic ones began to be used as a standard for measuring time.
They were measured using the so-called atomic clock. This instrument calculated time based on the fluctuations associated with reactions occurring in atoms and molecules.
With the help of a similar innovation, the definition of the size of one second has been changed. Since 1967 and to this day, this value is equal to 9,192,631,770 plus/minus 20 periods of radiation from the element cesium-133 attemperature of 0 Kelvin, without external fields.
It is worth noting that the modern atomic second is slightly shorter than the previous solar second. However, this difference did not have much effect on larger units of time.
Minutes, hours and days
As a unit of time, the second is related to minutes, hours and days.
It is worth paying special attention to the fact that in this case, not the decimal system, but sexagesimal. According to it, one minute is equal to 60 seconds, and one hour is equal to 3600 seconds (60 minutes).
Because there are not sixty hours in a day, but only twenty-four hours, it turns out that there are 86400 seconds in them.
If you wish, you can correlate the value in question with larger units like a week (604800 s), a month (2,678,400 s or 2,592,000 s), a year (31,557,600 s, if we are talking about 365, 25 days). However, the numbers are too large and inconvenient for calculations.
SI multiples of a second
In addition to calendar units, the term under consideration also correlates with the SI system and its elements. Since it is based on the decimal method of calculation, the above method of converting seconds into minutes or hours is not acceptable for SI. To find multiples of units, you need to multiply not by sixty, but by ten.
Let's look at the most famous multiple units of the second. Most often in calculations in physics and astronomy, kiloseconds (103), megaseconds (106),gigaseconds (109) and teraseconds (1012).
Rarely - petaseconds (1015), exaseconds (1018), zettaseconds (1021) and iottaseconds (1024).
Decaseconds (101) and hectoseconds (102) are also distinguished by scientists, but in practice they are almost never used.
Multiple units
Although the second itself is very tiny, in the SI system even smaller submultiple units are distinguished from it.
The most famous of them are milliseconds (10-3), microseconds (10-6) and nanoseconds (10 -9).
Slightly less commonly used picoseconds (10-12), femtoseconds (10-15), attoseconds (10 -18), zeptoseconds (10-21) and ioctoseconds (10-24).
And almost inapplicable in practice - deciseconds (10-1) and centiseconds (10-2).
