Duration6

5.4 × 10–44 s	Planck time (shortest possible time)
0.3 ys	Lifetime of W and Z bosons
6 ys	Light travels diameter of atomic proton (1 chronon)
1 as (1 million ys)	Light travels length of 3 hydrogen atoms
12 as	Shortest laboratory laser pulse on record
320 as	Electron transfers from one atom to another in an electrical reaction
1.3 fs	One cycle of electromagnetic light between visible and ultraviolet light
200 fs	Fast chemical reactions (such as eye reacting to light)
1 ps (1 million as)	Half-life of a bottom quark
3.3 ps	Light travels 1 millimeter
1 ns	One machine cycle on 1 Ghz computer chip
2.5 ns	One million wavelengths of red light
5.4 µs	Light travels 1 mile in vacuum
22.7 µs	Length of a sound sample on an audio CD
5 ms	Bee wing beats once
8 ms	Camera shutter speed at 1/125 s
33.3 ms	One frame in digital movie
41.7 ms	One frame in a film movie
200 ms	Average human reflexes
30 cs	Blink of an eye
43 cs	Fastball travels from pitcher’s hand to home plate
1 second	Human heartbeat; light travels 300,000 km
9.58 s	World record 100 m dash
10.5 minutes	About the half-life of a neutron outside an atom
1,039 seconds (17 minutes, 19 seconds)	Record time holding breath underwater
28.8 ks (8 hours)	Average human daily sleep requirement
86.4 ks	One day
29.5306 days (2.55 Ms)	Lunar month
40 days	About the longest a person can survive without food
125 days	Life of red blood corpuscle
23 Ms (38 weeks)	Length of human pregnancy
356.2422 days	Average solar (“tropical”) year
27.7 years	Half-life of strontium 90
75 years (2.3 Gs)	Typical life span for a human being
90 years	Life span of anemone (longest-living invertebrate)
3.16 Gs	One century
122 years, 164 days	Oldest human: French woman Jeanne Calment (1875–1997); that’s 3.86 billion seconds!
150 years	Life span of tortoise
164.8 years	Neptune’s solar orbit
248.09 years	Orbit of Pluto around sun
550 years	Time since humans learned to roast coffee
31.55 Gs	One millennium
2,540 years	Time since Buddhism founded
6,000 years	Time since humans learned to brew beer
11,800 years	Time since last ice age (Holocene epoch)
25,784 years	Earth’s axis returns to same location (precession of the equinoxes)
1 Ts (1012 s)	31,689 years
100,000 years	Time since Homo sapiens appeared
65 million years	Cenozoic period (time since the dinosaurs died off)
225 million years	One rotation of the Milky Way
710 million years	Half-life of uranium 235 (relatively rare)
1.26 billion years	Half-life of potassium 40 (we have billions of these in our bodies)
2.4 billion years	Time since the Great Oxygen Catastrophe
4.5 billion years	Age of Earth
4.51 billion years	Half-life of uranium 238
4.63 billion years	Age of sun
13.75 billion years (about 434 Ps)	Age of universe
10 trillion years (312 × 1018 seconds)	Estimated life span of a red dwarf star
100 trillion years	Stelliferous era (time until all stars burn out or collapse into black holes)
311.04 trillion years (about 9.8 Zs)	Lifetime of Brahma in Hindu mythology
1034 years	Estimated half-life of proton
2 × 1067 years	Life span of a small black hole (mass of the sun)
10100 years	Time until stars, galaxies, black holes, and virtually all matter in the universe cease to exist