The word "second" is what? Meaning and definition
Second - this is something that in everyday haste weusually do not pay attention, considering it something petty 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 look more closely at the meaning and origin of this term. After all, he has not one but several interpretations.
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 to find out what it is.
This word refers to the measure of durationexistence of all objects in the universe. In addition, it is a characteristic of a consistent change in the state of each and every object in processes (including the processes themselves), their change and development.
Time is also 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 irreversible current from the past to the future through the present.
Second - what is this?
Having considered that such time, it is necessary to pass to a second. It is its unit of measurement. And it is used both in metric and in American measuring systems.
The abbreviated notation of a second is a lowercase letter "c" in Cyrillic and "s" in Latin. Sometimes the option "sec" or "sec" is 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 a few 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 one more method of interpretation. The second agreeable to him is the second stage of the diatonic scale and at the same time the interval between his neighboring notes.
- In addition to all of the above, the termis a unit by means of which plane angles are measured. In this case, the second is indicated by the symbol "" "" above the figure, like the degree: 26 "". This second is the angular minute (1/60) or angular degree (1/3600).
- Sometimes the nounis used in artistic speech to refer to a very short time interval. 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 described event 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 part, etc.
- Among other things, this term together withunits of length is used to measure speed ("V"). Depending on the system, the units of length used differ. If this CGS - V system 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 noun
The term in question has come to all modernlanguages from Latin. It was formed from the word secund, which means "second / second" (hence the ordinal numeral second). By the way, in this sense the term remained in music (the second stage, the second musical instrument).
How is the numeral and time interval related? 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 gradually began to be called in honor of the very method of division - "seconds".
In medieval Latin, which was somewhatis far from the original language of the Romans, other expressions have been 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.
Widely distributed as a titleThe studied noun acquired throughout the world only in the seventeenth to eighteenth centuries. However, in England this term was used by scientists in the thirteenth century.
Intervention history seconds
Throughout the history of the science of the Ancient Worldin the calculation of time, scientists isolated small intervals of time. They made it possible to calculate processes invisible to the eye, such as chemical or physical reactions, etc.
The first clock with a second hand appeared already in the sixteenth century. However, in those years the size of the second was constantly fluctuating.
As a unit for measuring time intervals in exact sciences, the second was first used in 1832. A similar idea belonged to the German mathematician Karl Friedrich Gauss.
However, in order for this innovation to be acceptedother scientific men, it took another thirty years, after which the British Scientific Association decided all its members to use this unit of time.
In the future, after England, the whole of Europegradually shifted to seconds. The first countries that did actively develop science. 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 is known, some compounds can exist and do not disintegrate in just a few seconds. To be able to distinguish and study them, it was necessary to clearly know the time of their "life".
In the coming years, the unit in question became so popular that it was gradually incorporated into many measurement systems:
- GHS (centimeter - gram - second);
- ISS (meter-kilogram-second);
- ISSA or Georgie's system (meter-kilogram-second-ampere) and others.
It is worth noting that at that time a solar second was still used, calculated on solar days.
Second of Atomic Time
By the mid-twentieth century. scientists have experimentally proved that the Earth rotates around its axis and the Sun is not always uniformly, as was previously thought.
It then slows down, then on the contrary it accelerates in the formirregular jumps. Because of this, in different periods of time the magnitude of the seconds could be different. To correct this omission, the most eminent mathematicians and physicists tried to calculate the average solar year or to make tables of variation in its length.
However, in the future the situation was resolved in a simpler way. In the early sixties, as a standard for measuring time, not the sunny day and their longer units, but atomic ones, were used.
They were measured with the help of so-called atomic clocks. This device calculated the time, focusing on the vibrations associated with the reactions occurring in atoms and molecules.
With the help of this innovation was changeddetermining the size of one second. Beginning in 1967, to this day, this value is 9 192 631 770 plus / minus 20 emission periods from the cesium-133 element at a temperature of 0 Kelvin, without the influence of external fields.
It is worth noting that the modern atomic second is slightly shorter than the previous solar one. However, this difference did not have a particular effect on larger units of time.
Minutes, hours and days
Being a unit of time, the second is related to such concepts as minutes, hours and days.
It is worth paying special attention to the fact that inThis case is not a decimal system, but a sexagesimal system. According to her, one minute is 60 seconds, and one hour is 3600 seconds (60 minutes).
Since there are not sixty days, but only twenty-four hours, it turns out that they have 86400 seconds.
If desired, we can relate theThe value with larger units like the week (604800 s), the month (2,678,400 s or 2,592,000 s), the year (31,557,600 s, when it comes to 365.25 days). However, the numbers turn out to be too large and inconvenient for calculations.
Multiple seconds in the SI system
In addition to the calendar units, the term in questionalso correlates with the SI system and its elements. Since it is based on the decimal method of calculation, the above method of translating seconds in minutes or hours is not acceptable for SI. To find 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 apply kiloseconds (103), megaseconds (106), gigaseconds (109) and teraseconds (1012).
Less often - petaseconds (1015), the exacus (1018), zetaseconds (1021) and iotasecond (1024).
Also scientists have allocated decaseconds (101) and hectoseconds (102), but in practice they are almost never used.
Sub-units
Although the second itself is very tiny, in the SI system, even smaller subunits are allocated from it.
The most famous of them are milliseconds (10-3), microseconds (10-6) and nanoseconds (10-9).
Picoteconds are used less often (10-12), femtoseconds (10-15), attoseconds (10-18), a sec- onsecond (10-21) and Icseconds (10-24).
And almost inapplicable in practice - deciseconds (10-1) and centiseconds (10-2).
