Decade to Century
dec
c
Conversion History
| Conversion | Reuse | Delete |
|---|---|---|
1 dec (Decade) → 0.1 c (Century) Just now |
Quick Reference Table (Decade to Century)
| Decade (dec) | Century (c) |
|---|---|
| 0.5 | 0.05 |
| 1 | 0.1 |
| 2 | 0.2 |
| 3 | 0.3 |
| 5 | 0.5 |
| 7 | 0.7 |
| 10 | 1 |
About Decade (dec)
A decade is exactly ten years (315,360,000 seconds using the 365-day year convention), used in history, economics, and demography to describe medium-term trends. Decades are culturally significant — the 1920s, 1960s, and 1980s each carry distinct cultural associations. Economic cycles, policy changes, and technology generations are often framed in decade terms. Central bank inflation targets and pension projections span decades. In astronomy, the secular acceleration of the Moon and polar wander are measured in arcseconds per decade.
The smartphone era began roughly two decades ago. A 30-year mortgage spans three decades. Climate projections are typically made in decade increments.
About Century (c)
A century is exactly one hundred years (3,153,600,000 seconds), the unit of historical timescales. Constitutions, legal codes, and architectural landmarks are described in centuries. The Gregorian calendar century correction rule (century years are only leap years if divisible by 400) reflects the 0.0078-day error that accumulates per century. Sea level rise projections, radioactive decay of long-lived isotopes, and geological processes are measured in centuries or millennia. The Julian calendar drifted roughly 3 days per 400 years, corrected by the century leap-year rule introduced in 1582.
The Eiffel Tower has stood for over a century. Carbon-14 dating is precise to within centuries for samples up to 50,000 years old.
Decade – Frequently Asked Questions
Does a decade start in the year ending 0 or 1?
Technically, the first decade CE ran from 1 CE to 10 CE (since there was no year 0), so the 'correct' start of each decade is the year ending in 1 (2021, 2031). However, culturally, decades are named for the tens digit — 'the 1980s' means 1980–1989. Pedants reliably emerge at each decade boundary; the BBC noted in 2000 and 2010 that the millennium/decade technically started one year later. Most people (correctly) ignore this.
What major technology changed every decade in the 20th century?
Each decade introduced a defining technology: 1900s — powered flight; 1910s — mass automobile production; 1920s — radio broadcasting; 1930s — radar; 1940s — nuclear power/weapons; 1950s — television; 1960s — satellite communication; 1970s — microprocessors; 1980s — personal computers; 1990s — the World Wide Web; 2000s — smartphones; 2010s — social media. Each took roughly a decade to reach mass adoption — a pattern noted by technology historians as the 'decade diffusion' cycle.
Why do economists talk about "lost decades"?
A 'lost decade' describes a 10-year period of economic stagnation or decline. Japan's 1990s is the canonical example — following a 1989 asset bubble collapse, GDP growth was near zero for 10+ years. The US 2000s was described as a 'lost decade' for stock market returns (the S&P 500 ended 2009 below its 2000 start). Decades are a natural framing for these assessments because they align with business cycles, political cycles, and generational economic memory.
What is the Saros cycle and how does it relate to decades?
The Saros cycle is 18 years, 11 days, and 8 hours (approximately 1.8 decades) — the period after which the Sun, Earth, and Moon return to almost identical relative geometry, causing near-identical eclipses. Ancient Babylonians discovered this cycle around 600 BCE and used it to predict lunar eclipses. NASA uses the Saros series to catalog eclipses: each eclipse is numbered within its Saros series, which lasts about 1,300 years (roughly 130 decades).
How long does it take for fashions to "come back" — is it really a decade?
Fashion cycles have been studied empirically and do show roughly 20-30 year revival patterns — not exactly one decade. Styles become unfashionable, then nostalgia peaks when the generation that wore them reaches their 30s–40s and has disposable income. 1990s fashion revived in the 2010s; 1970s styles returned in the 1990s and 2010s. The "20-year rule" is a reasonable approximation, though fast fashion and social media are compressing cycles significantly.
Century – Frequently Asked Questions
What technologies from a century ago were predicted to change the world but failed?
The 1920s confidently predicted personal autogyros (helicopter-planes) would replace cars within decades — they never became practical for commuters. Pneumatic tube mail was expected to connect every home; it peaked in the 1930s and vanished. Radium-infused products (water, toothpaste, suppositories) were marketed as health miracles until people started dying. Moving sidewalks, demonstrated at the 1900 Paris Exposition, were expected to replace urban walking. Airships were the "future of travel" until the Hindenburg (1937). Meanwhile, technologies nobody hyped — antibiotics, containerised shipping, transistors — quietly reshaped civilisation without fanfare.
How accurate is carbon-14 dating in terms of centuries?
Carbon-14 dating (radiocarbon dating) is reliable for organic material up to ~50,000 years (roughly 500 centuries). Precision is typically ±40–200 years for samples from the last 2,000 years, improving to ±centuries for older samples. Calibration against dendrochronology (tree rings) sharpens accuracy significantly. The method measures the decay of ¹⁴C (half-life 5,730 years) — after ~8 half-lives (46,240 years), too little ¹⁴C remains to measure reliably.
What has lasted more than a century that still works today?
The Westinghouse generators installed at Niagara Falls in 1895 ran until 2006 — 111 years. Many Victorian-era water mains and sewer systems in London (built 1858–1875) are still in service. Stradivarius violins from 1700 are still played. The Antikythera mechanism (ancient Greek astronomical computer, ~87 BCE) still demonstrates correct gear ratios. Some Japanese Buddhist temples have been maintained continuously for 14 centuries.
How much sea level rise is projected per century?
IPCC projections (2021) estimate 0.3–1.0 m of sea level rise by 2100 (0–1 century from now) under moderate to high emissions scenarios. Under worst-case scenarios involving ice sheet instability, multi-meter rise within 1–2 centuries is possible. The last time CO₂ was at current levels (around 3 million years ago), sea levels were 15–25 m higher — though the adjustment to that equilibrium takes centuries to millennia.
What institution has existed for more than 10 centuries?
The University of Bologna (founded 1088) is the oldest continuously operating university — now over 9 centuries old. The Papacy has continued as an institution for approximately 20 centuries. The oldest continuously operating business is Kongo Gumi, a Japanese temple builder founded in 578 CE — 14+ centuries, though it was absorbed into a larger company in 2006. The British Crown Jewels include items spanning 10 centuries of continuous use.