What Does Second Mean
We explain what a second is in the measurement of time, how long it lasts and the history of its definition. Also, how long is a minute.
What is a second?
Second is called the base unit for the measurement of time in the International System of Units (SI). This unit is also shared with the Cegesimal System of Units and the Technical System of Units.
It is represented by the letter s (without a period or capital letter, as it is not an abbreviation). The incorrect use of sec is common . , sec or s. as abbreviations, none of which are formally accepted.
According to the International System, seconds can be divided into smaller units, such as the millisecond (ms) equivalent to 10 -3 seconds; the microsecond (μs) equivalent to 10 -6 seconds and the nanosecond (ns) equivalent to 10 -9 seconds, just to name their three best-known submultiples.
There are also increasing multiples such as decaseconds (days) or hectoseconds (hs), but generally for these cases, larger units of time , such as minutes, are preferred .
See also: Time in physics
History of the second
The ancient Romans were the first to divide the hours into minutes and seconds , which is why these words come from Latin. They divided each hour into 60 smaller portions that they called pars minuta prima or "first small part", hence the term minute was imposed .
At the same time, they divided the minutes into 60 again, which were logically called pars minuta secunda or “second small part”, which ended up being called “second”. Ultimately, the name of the second comes from the Latin sequire , "to follow."
To this should be added the Hebrew heritage in Western culture, whose fervor by the number twelve (12) as the number sacred led to so divide the hours of the day, exit to the start of the Sun , considering that it is still used today in day. Thus, each of the twelve hours has 60 minutes and these in turn 60 seconds, which means that in an hour there are 3600 seconds.
How long is a second?
The definition of what a second is comes from centuries past, and was subject to debate and inaccuracies until it was defined as one eighty-six thousand four hundredth (1 / 86,400) of an average solar day between 1750 and 1890. This seemed to settle the subject with an acceptable margin of error.
However, in 1967 the need for even more exact measurements imposed a redefinition, no longer based on astronomical time but on atomic time. Thus, today we understand that a second has the duration of 9,192,631,770 oscillations of the radiation emitted by the isotope 133 of cesium ( 133 Cs) at a temperature of 0 Kelvin (0 K).
How long is a minute?
According to the International System, a minute has the exact duration of 60 seconds , that is, according to atomic time, of 551,557,906,200 oscillations of the radiation of a cesium 133 atom at 0 degrees Kelvin.
How many hours and minutes are there in a year?
Extending the previously handled figures to a whole year of time, we will have that this represents 525,600 minutes, equivalent to 8760 hours . These figures correspond to a “typical” or average year, since not all years are exactly identical in size.
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