Decade definition, a period of ten years: the three decades from 1776 to 1806. Define decade. Decade synonyms, decade pronunciation, decade translation, English dictionary definition of decade. A period of ten years. A group or series of ten. Dec′adal adj. A period of ten consecutive years 2. A group or series of ten deˈcadal adj n. Decade definition is - a group or set of 10: such as. How to use decade in a sentence. A group or set of 10: such as; a period of 10 years; a division of the rosary that consists primarily of 10 Hail Marys. DECADE's Statistical Portal will then select custom video content for you based on your statistical profile. New Content Weekly Unlike other stats tools on the market, DECADE will constantly bring you new video content on a weekly basis. Definition of decade in the Definitions.net dictionary. Meaning of decade. What does decade mean? Information and translations of decade in the most comprehensive dictionary definitions. Nov 14, 2019  As the decade comes to an end, Twitter users are debating what we all want to know: what is the best meme of the decade?Twitter user @GenePark. Any period of ten years is a 'decade'. For example, the statement that 'during his last decade, Mozart explored chromatic harmony to a degree rare at the time' merely refers to the last ten years of Wolfgang Amadeus Mozart 's life without regard to which calendar years are encompassed.

One decade (symbol dec^[1]) is a unit for measuring frequency ratios on a logarithmic scale, with one decade corresponding to a ratio of 10 between two frequencies (an order of magnitude difference).^[2][3] It is especially useful when describing frequency response of electronic systems, such as audio amplifiers and filters.

When Does The New Decade Start

A closely related unit is the octave, which corresponds to a ratio of 2 between two frequencies.

Calculations[edit]

The factor-of-ten in a decade can be in either direction: so one decade up from 100 Hz is 1000 Hz, and one decade down is 10 Hz. The factor-of-ten is what is important, not the unit used, so 3.14 rad/s is one decade down from 31.4 rad/s.

To determine the number of decades between two frequencies (${\displaystyle f_1}$ & ${\displaystyle f_2}$), use the logarithm of the ratio of the two values:

• ${\displaystyle {\log }_{10}(f_2/f_1)}$ decades^[2][3]

or, using natural logarithms:

• $\frac{{\displaystyle \ln f_2-\ln f_1}}{\ln 10}$ decades^[4]

How many decades is it from 15 rad/s to 150,000 rad/s?

${\displaystyle {\log }_{10}(150000/15)=4}$ dec

How many decades is it from 3.2 GHz to 4.7 MHz?

${\displaystyle {\log }_{10}(4.7\times {10}^6/3.2\times {10}^9)=-2.83}$ dec

How many decades is one octave?

One octave is a factor of 2, so ${\displaystyle {\log }_{10}(2)=0.301}$ decades per octave (decade = just major third + three octaves, 10/1 (Play) = 5/4)

To find out what frequency is a certain number of decades from the original frequency, multiply by appropriate powers of 10:

What is 3 decades down from 220 Hz?

${\displaystyle 220\times {10}^{-3}=0.22}$ Hz

What is 1.5 decades up from 10?

${\displaystyle 10\times {10}^{1.5}=316.23}$

To find out the size of a step for a certain number of frequencies per decade, raise 10 to the power of the inverse of the number of steps:

What is the step size for 30 steps per decade?

${\displaystyle {10}^{1/30}=1.079775}$ – or each step is 7.9775% larger than the last.

Graphical representation and analysis[edit]

Decades on a logarithmic scale, rather than unit steps (steps of 1) or other linear scale, are commonly used on the horizontal axis when representing the frequency response of electronic circuits in graphical form, such as in Bode plots, since depicting large frequency ranges on a linear scale is often not practical. For example, an audio amplifier will usually have a frequency band ranging from 20 Hz to 20 kHz and representing the entire band using a decade log scale is very convenient. Typically the graph for such a representation would begin at 1 Hz (10⁰) and go up to perhaps 100 kHz (10⁵), to comfortably include the full audio band in a standard-sized graph paper, as shown below. Whereas in the same distance on a linear scale, with 10 as the major step-size, you might only get from 0 to 50.

Electronic frequency responses are often described in terms of 'per decade'. The example Bode plot shows a slope of −20 dB/dec in the stopband, which means that for every factor-of-ten increase in frequency (going from 10 rad/s to 100 rad/s in the figure), the gain decreases by 20 dB.

See also[edit]

Sources[edit]

1. ^ISO 80000-3:2006 Quantities and Units – Space and time
2. ^ ^abLevine, William S. (2010). The Control Handbook: Control System Fundamentals, p. 9-29. ISBN9781420073621.
3. ^ ^abPerdikaris, G. (1991). Computer Controlled Systems: Theory and Applications, p.117. ISBN9780792314226.
4. ^Davis, Don and Patronis, Eugene (2012). Sound System Engineering, p.13. ISBN9780240808307.

A decade is a period of 10 years. The word is derived (via French and Latin) from the Ancient Greek: δεκάς, romanized: dekas, which means a group of ten. Decades may describe any ten year period, such as those of a person's life, or refer to specific groupings of calendar years.

Usage[edit]

Any period of ten years is a 'decade'.^[1] For example, the statement that 'during his last decade, Mozart explored chromatic harmony to a degree rare at the time' merely refers to the last ten years of Wolfgang Amadeus Mozart's life without regard to which calendar years are encompassed. Also, 'the first decade' of a person's life begins on the day of their birth and ends at the end of their 10th year of life when they have their 10th birthday; the second decade of life starts with their 11th year of life (during which one is usually referred to as being 10) and ends at the end of their 20th year of life on their 20th birthday; the third decade, referred to as being in one's twenties (20s), starts with the 21st year of life (during which one is referred to as being 20) and ends at the end of the 30th year of life on their 30th birthday; subsequent decades of life are described in a similar way by reference to the tens digit of their age.

There are two methods of demarcating Gregorian calendar decades:

0-to-9 decade[edit]

The most widely used method for denominating decades is to group years based on their shared tens digit, from a year ending in a 0 to a year ending in a 9 – for example, the period from 1960 to 1969, the nineteen-sixties or 1960s, is one such grouping.^[2] Sometimes, only the tens part is mentioned (60s or sixties), although this may leave it ambiguous as to which century is meant.Particularly in the 20th century, 0-to-9 decades came to be referred to with associated nicknames, such as the 'Swinging Sixties' (1960s), the 'Warring Forties' (1940s) and the 'Roaring Twenties' (1920s). This practice is occasionally also applied to decades of earlier centuries; for example, referencing the 1890s as the 'Gay Nineties' or 'Naughty Nineties'.

1-to-0 decade[edit]

A rarer approach groups years from the beginning of the AD calendar era to produce successive decades from a year ending in a 1 to a year ending in a 0, with the years 1–10 described as 'the 1st decade', years 11–20 'the 2nd decade', and so on; later decades are more usually described as 'the Nth decade of the Mth century' (using the strict interpretation of 'century')^[a]. For example, 'the second decad of the 12th. Cent.' [sic];^[3] “The last decade of that century”;^[4] '1st decade of the 16th century';^[5] 'third decade of the 16th century';^[6] 'the first decade of the 18th century'.^[7] This decade grouping may also be identified explicitly; for example, '1961-1970';^[8] '2001-2010';^[9] “2021-2030”.^[10]

Public usage of the two methods[edit]

A YouGov poll was conducted on December 2, 2019, asking 13,582 US adults 'When do you think the next decade will begin and end?' Results showed that 64% answered that the next decade would begin on January 1, 2020, and will end on December 31, 2029 (0-to-9 method); 17% answered that the next decade will begin on January 1, 2021, and will end on December 31, 2030 (1-to-0 method); 19% replied that they did not know.^[11]

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See also[edit]

References[edit]

1. ^'Decade'. Lexico. 2020. Retrieved 2020-02-26.
2. ^'1960s'. Memidex/Wordnet Dictionary/Thesaurus. Retrieved 2011-08-18.
3. ^1837 HALLAM Hist. Lit. I. i. 19. The Compact Edition of the Oxford English Dictionary.
4. ^1878 DOWDEN Stud. Lit. I. The Compact Edition of the Oxford English Dictionary.
5. ^'Catalogue of Illuminated Manuscripts'. British Library. Retrieved 24 February 2020.
6. ^'Illuminated Manuscripts from the Collection of Maurice Burrus (1882-1959)'. CHRISTIE'S. Retrieved 24 February 2020.
7. ^'French harpsichord music in the first decade of the 18th century'. Oxford Academic. Retrieved 24 February 2020.
8. ^'Past Poets Laureate: 1961-1970'. The Library of Congress. Retrieved 24 February 2020.
9. ^'Milestones 2001-2010'. United Nations. Retrieved 24 February 2020.
10. ^'Solar Eclipses: 2021–2030'. NASA. Retrieved 24 February 2020.
11. ^'In recent years, there has been debate around when a decade begins and ends. When do you think the next decade will begin and end?'. YouGov. Retrieved 21 December 2019.

Notes[edit]

1. ^ There are two ways of thinking about when a century begins and ends. The 'strict' viewpoint counts centuries from -01 to -00, while the 'general' viewpoint counts centuries from -00 to -99. For example, the '1st decade of the 19th century' may mean either 1801–1810 (if used in 'strict' terms) or 1800–1809 (if used in 'general' terms). See century for more information.

External links[edit]

• Definition from Etymology Online

What Is A Decade Volcano