Orders of magnitude (time)

In the context of time, an order of magnitude is a description of the quantity of a time in respect to comparison between differing magnitudes. In common usage, the scale is usually the base¹⁰ or base⁻¹⁰ exponent being applied to an amount, making the order of magnitude 10 times greater or smaller. As the differences are measured in factors of 10, a logarithmic scale is applied. In terms of time, the relationship between the smallest limit of time, the Planck time, and the next order of magnitude larger is 10.

Low order of magnitude - measures by the unit second (s)

Unit (s)	Multiple	Symbol	Definition	Comparative examples & common units	Orders of magnitude
10−44	1 Planck time	tP	The time required to travel one Planck length at the speed of light (c)	5.4×10−20 ys = 5.4×10−44 s: One Planck time tP = $\sqrt{\hbar G/c^5}$ ≈ 5.4×10−44 s is the briefest physically meaningful span of time. It is the unit of time in the natural units system known as Planck units.	10−20 ys, 10−19 ys (10−44 s, 10−43 s)
10−24	1 yoctosecond	ys	Yoctosecond, (yocto- + second), is one septillionth of a second	0.3 ys: mean life of the W and Z bosons. 0.5 ys: time for top quark decay, according to the Standard Model. 1 ys: time taken for a quark to emit a gluon. 23 ys: half-life of 7H.	1 ys and less, 10 ys, 100 ys
10−21	1 zeptosecond	zs	Zeptosecond, (zepto- + second), is one sextillionth of one second	7 zs: half-life of helium-9's outer neutron in the second nuclear halo. 17 zs: approximate period of electromagnetic radiation at the boundary between gamma rays and X-rays. 300 zs: approximate typical cycle time of X-rays, on the boundary between hard and soft X-rays. 500 zs: current resolution of tools used to measure speed of chemical bonding	1 zs, 10 zs, 100 zs
10−18	1 attosecond	as	One quintillionth of one second	12 attoseconds: shortest measured period of time.	1 as, 10 as, 100 as
10−15	1 femtosecond	fs	One quadrillionth of one second	1 fs: Cycle time for 390 nanometre light; transition from visible light to ultraviolet; light travels 0.3 micrometers (µm). 140 fs: Electrons have localized onto individual bromine atoms 6Å apart after laser dissociation of Br2.	1 fs, 10 fs, 100 fs
10−12	1 picosecond	ps	One trillionth of one second	1 ps: half-life of a bottom quark; light travels 0.3 millimeters (mm) 1 ps: lifetime of a transition state 4 ps: Time to execute one machine cycle by an IBM Silicon-Germanium transistor	1 ps, 10 ps, 100 ps
10−9	1 nanosecond	ns	One billionth of one second	1 ns: Time to execute one machine cycle by a 1 GHz microprocessor 1 ns: Light travels 30 centimetres (12 in)	1 ns, 10 ns, 100 ns
10−6	1 microsecond	µs	One millionth of one second	1 µs: Time to execute one machine cycle by an Intel 80186 microprocessor 4–16 µs: Time to execute one machine cycle by a 1960s minicomputer	1 µs, 10 µs, 100 µs
10−3	1 millisecond	ms	One thousandth of one second	1 ms: time for a neuron in human brain to fire one impulse and return to rest 4–8 ms: typical seek time for a computer hard disk 100–400 ms (=0.1–0.4 s): Blink of an eye 18–300 ms (=0.02–0.3 s): Human reflex response to visual stimuli	1 ms, 10 ms, 100 ms
100	1 second	s	The duration of 9,192,631,770 periods of the radiation corresponding to the transition between the two hyperfine levels of the ground state of the caesium 133 atom.	1 s: 9,192,631,770 periods of the radiation corresponding to the transition between the two hyperfine levels of the ground state of the cesium-133 atom. 60 s: 1 minute	1 s, 10 s, 100 s
103	1 kilosecond (16.7 minutes)	ks	One thousand seconds	3.6 ks: 3600 s or 1 hour 86.4 ks: 86 400 s or 1 day 604.8 ks: 1 week	103 s, 104 s, 105 s
106	1 megasecond (11.6 days)	Ms	One million seconds	2.6 Ms: approximately 1 month 31.6 Ms: approximately 1 year ≈ 107.50 s	106 s, 107 s, 108 s
109	1 gigasecond (32 years)	Gs	One billion seconds	2.1 Gs: average human life expectancy at birth (2011 estimate) 3.16 Gs: approximately 1 century 31.6 Gs: approximately 1 millennium	109 s, 1010 s, 1011 s
1012	1 terasecond (32 000 years)	Ts	One trillion seconds	6 Ts: Time since the appearance of Homo sapiens (approximately) 80 Ts: Time it takes for light to travel from the Andromeda Galaxy to the Milky Way. 160–220 Ts: Time since the divergence of the human and chimpanzee lineages.	1012 s, 1013 s, 1014 s
1015	1 petasecond (32 million years)	Ps	One quadrillion seconds	2.1 Ps: (66 million years) Time elapsed since the Cretaceous–Paleogene extinction event, during which all non-avian dinosaurs became extinct. 7.1–7.9 Ps: 1 galactic year (225-250 million years) 143 Ps: the age of the Earth 144 Ps: the approximate age of the Solar system and the Sun. 430 Ps: the approximate age of the Universe 440 Ps: the half-life of thorium 232	1015 s, 1016 s, 1017 s
1018	1 exasecond (32 billion years)	Es	One quintillion seconds	312 Es: Estimated lifespan of a 0.1 solar mass red dwarf star.	1018 s, 1019 s, 1020 s
1021	1 zettasecond (32 trillion years)	Zs	One sextillion seconds	3 Zs: Estimated duration of Stelliferous Era.	1021 s, 1022 s, 1023 s
1024	1 yottasecond (32 quadrillion years)	Ys	One septillion seconds	1.6416 Ys: Estimated half-life of the meta-stable 20983Bi radioactive isotope. 6.616×1050 Ys: Time required for a 1 solar mass black hole to evaporate completely due to Hawking radiation, if nothing more falls in.	1024 s, 1025 s, 1026 s and more

See also

2

Footnotes

Notes

References

External links

• Exploring Time from Planck time to the lifespan of the universe