Millisecond to Century

Under 20 ms feels virtually instant; 20–50 ms is excellent for most games; 50–100 ms is fine for casual play; 100–150 ms causes noticeable delay in fast-paced shooters; above 150 ms is problematic. Fighting games are the most latency-sensitive — competitive Street Fighter players complain about 8 ms differences. Fiber internet typically delivers 5–15 ms within a country; satellite internet (except Starlink) delivers 600+ ms, making real-time gaming impractical.

A single spontaneous blink takes 100–150 ms for the lid to close and open. Voluntary blinks are slightly slower at 200–400 ms. Humans blink 15–20 times per minute, spending about 10% of waking hours with eyes closed — without noticing, because the brain suppresses visual processing during blinks (saccadic suppression). The brain also smoothly fills in the missing visual gap, which is why blinking does not feel like a strobe effect.

The Haas Effect (or precedence effect) means the brain fuses sounds arriving within 30–40 ms of each other into a single perceived sound — the first arrival dominates direction and character. Echoes only become perceptible above ~50 ms. Recording studios use this: adding a delayed copy at 15–20 ms creates a chorus/widening effect without audible echo. Room reflections below 20 ms contribute to the 'liveness' of a space without sounding reverberant.

An ECG (electrocardiogram) records the heart's electrical cycle in ms. A normal PR interval (atrium to ventricle conduction) is 120–200 ms; QRS complex (ventricular depolarisation) is 80–100 ms; QT interval (ventricular depolarisation + repolarisation) is 350–440 ms. Prolonged QT (>500 ms) indicates arrhythmia risk. Cardiologists rely on ms-precision measurement to diagnose conduction disorders, heart blocks, and pre-excitation syndromes.

A ruby-throated hummingbird beats its wings 50–80 times per second, meaning each complete up-down stroke takes 12–20 ms. During courtship dives, the frequency can reach 200 beats/s (5 ms/beat). By comparison, a honeybee beats at 200 Hz (5 ms), a dragonfly at 30 Hz (33 ms), and a large butterfly at 5–12 Hz (83–200 ms). Smaller flying insects generally have higher wing frequencies because smaller wings generate less lift per stroke.

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.

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.

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.

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.

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.