A second is something that we usually don’t pay attention to in our daily rush, considering it something small and frivolous. At the same time, the most powerful minds of the past worked to learn how to correctly determine its length. Therefore, let's try to more carefully consider the meaning and origin of this term. After all, he 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, it is worth knowing what it is.
This word is a measure of the duration of the existence of all objects in the universe. In addition, this is a characteristic of the successive change of 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 in the framework of the theory of relativity.
From the point of view of philosophy, this term refers to an irreversible flow from the past to the future through the present.
What is a second?
Having considered what time is, it’s worth moving on to the second. She is his unit of measurement. Moreover, it is used both in metric and in American measuring systems.
The abbreviated designation of the second is the lowercase letter “s” in Cyrillic and “s” in Latin. The “sec” or “sec” option is sometimes used, but only a few 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 second musical instrument in the orchestra. For example: flute second.
- Also in music, the term in question has another way of interpretation. The second consonant with it is the second stage of the diatonic scale and at the same time the interval between its neighboring notes.
- In addition to all of the above, this term is a unit with which flat angles are measured. In this case, the second is indicated by the “'” icon at the top of the number, as the degree: 26'. This second is the fractional value of the angular minute (1/60) or angular degree (1/3600).
- Sometimes the considered noun is used in fiction for 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 with happiness." In both cases, the incident described could have lasted 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 unit of length used differs depending on the system. If it is a GHS System - V is measured in centimeters per second (cm / s). If the SI system - in meters per second, the speed is measured (m / s).
The origin of the studied noun
The term in question has come to all modern languages from Latin. It was formed from the word secund, which means "second / second" (hence the ordinal numeral second is preserved in English). By the way, in this sense the term remained in the music (second stage, second musical instrument).
How is the numeral and the time span connected? Very simple. The fact is that in ancient Rome, one hour was divided twice into 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 were gradually called in honor of the very method of division - “seconds”.
In medieval Latin, which was somewhat far from the original language of the Romans, other expressions began to be used: pars minuta prima (“the first small part”) and pars minuta secunda (“the second small part”). It was also about dividing the hour into minutes and seconds.
The studied noun gained wide distribution as the name of the time span throughout the world only in the seventeenth and eighteenth centuries. However, in England, this term was used by scientists in the thirteenth century.
Second injection history
Throughout the history of the science of the Ancient World, when calculating time, scientists distinguished small intervals 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 in the sixteenth century. However, in those years, the size of a second constantly fluctuated.
As a unit of measuring time intervals in the exact sciences, second was first used in 1832. A similar idea belonged to the German mathematician Karl Friedrich Gauss.
However, for this innovation to be accepted by other pundits, it took another thirty years, after which the British Scientific Association decided that all its members use this unit of time.
Subsequently, after England, all of Europe gradually switched to seconds. The first to do this was the countries in which science was actively developing. After all, 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 just a few seconds. In order to be able to isolate and study them, it was necessary to clearly know the time of their "life."
In future years, the unit in question became so popular that it was gradually included in many measurement systems:
- GHS (centimeter - gram - second);
- ISS (meter - kilogram - second);
- ISS or Georgie system (meter - kilogram - second - ampere) and others.
It is worth noting that then the solar second, calculated by sunny days, was still used.
Atomic time second
By the middle of the twentieth century. Scientists have experimentally proved that the Earth does not always rotate around its axis and the Sun evenly, as previously thought.
It either slows down, or vice versa accelerates in the form of irregular jumps. Because of this, in different periods of time, the magnitude of the seconds could be different. To correct this omission, the most prominent mathematicians and physicists tried to calculate the average solar year or to make tables of changes in its length.
However, in the future the situation was resolved in a simpler way. In the early sixties, the standard for measuring time was not atomic days and their fractional units, but atomic ones.
They were measured using the so-called atomic clocks. This device calculated time, focusing on vibrations associated with reactions occurring in atoms and molecules.
With the help of this innovation, the definition of the size of one second was changed. Starting from 1967 to this day, this value is equal to 9 192 631 770 plus / minus 20 periods of radiation from the cesium-133 element at a temperature equal to 0 Kelvin, without exposure to external fields.
It is worth noting that the modern atomic second is slightly shorter than the solar one preceding it. However, this difference did not have a special effect on larger units of time.
Minutes, hours and days
As a unit of time, a second is related to concepts such as minutes, hours, and days.
It is worth paying special attention to the fact that in this case the decimal system of calculus is not in effect, but the six-decimal system. According to it, one minute is 60 seconds, and one hour is 3600 seconds (60 minutes).
Since the day is not sixty, but only twenty-four hours, it turns out that they have 86,400 seconds.
If you wish, you can correlate the considered value with larger units like a week (604800 s), a month (2 678 400 s or 2592000 s), year (31 557 600 s, if we are talking about 365.25 days). However, the numbers are too large and inconvenient for calculations.
Multiple units of a second in the SI system
In addition to calendar units, the term in question is also related to the SI system and its elements. Since it is based on the decimal method of calculus, the above method of converting seconds to minutes or hours is not acceptable for SI. To find the multiple units, you need to multiply not by sixty, but by ten.
Let's look at the most famous multiple units of a second. Most often, in calculations in physics and astronomy, kiloseconds (10 3 ), megaseconds (10 6 ), gigaseconds (10 9 ) and teraseconds (10 12 ) are used.
Less commonly, petaseconds (10 15 ), exaseconds (10 18 ), zettaseconds (10 21 ) and iottaseconds (10 24 ).
Scientists also identified decaseconds (10 1 ) and hectoseconds (10 2 ), but in practice they are almost never used.
Share units
Although the second itself is very tiny, even smaller fractional units stand out from it in the SI system.
The most famous of them are milliseconds (10 -3 ), microseconds (10 -6 ) and nanoseconds (10 -9 ).
Picoseconds (10 -12 ), femtoseconds (10 -15 ), attoseconds (10 -18 ), zeptoseconds (10 -21 ) and ioctoseconds (10 -24 ) are used a little less often.
And almost inapplicable in practice - deciseconds (10 -1 ) and centiseconds (10 -2 ).