# Orders of magnitude (time) facts for kids

Kids Encyclopedia Facts

An order of magnitude describes the link between two amounts. The difference between each step is usually 10, with each order being either 10 times greater or 10 times smaller than the next amount. This makes the scale easy to manipulate using logarithms. For time, the difference between the smallest limit of time, the Planck time, and the next order of magnitude is larger than 10.

## Seconds

Orders of magnitude (time)
Factor (s) Multiple Symbol Definition Comparative examples & common units Orders of magnitude
10−44 tP Planck time is the unit of time of the natural units system known as Planck units. The shortest length of time that can be described by physics. ≈ 5.4×10−44 s. 10−44 s
10−24 1 yoctosecond ys Yoctosecond, (yocto + second), is one quadrillionth (in the long scale) or one septillionth (in the short scale) of a second. 0.3 ys: mean life of the W and Z bosons. 1 ys and less, 10 ys, 100 ys
10−21 1 zeptosecond zs Zeptosecond, (zepto + second), is one trillionth of one billionth 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
1 zs, 10 zs, 100 zs
10−18 1 attosecond as 100 attoseconds: shortest measured period of time. 1 as, 10 as, 100 as
10−15 1 femtosecond fs cycle time for 390 nanometre light, transition from visible light to ultraviolet 1 fs, 10 fs, 100 fs
10−12 1 picosecond ps 1 ps: half-life of a bottom quark
4 ps: Time to execute one machine cycle by an IBM Silicon-Germanium transistor (supercomputer)
1 ps, 10 ps, 100 ps
10−9 1 nanosecond ns 1 ns: Time to execute one machine cycle by an Intel Pentium 4 1 GHz microprocessor
1 ns: Light travels 12 inches (30 cm)
1,000,000,000 nanoseconds: 1 second
1 ns, 10 ns, 100 ns
10−6 1 microsecond µs sometimes also abbreviated µsec
1 µs: Time to execute one machine cycle by an Intel 80186 microprocessor
4-16 µs: Time to execute one machine cycle by an older minicomputer
1 µs, 10 µs, 100 µs
10−3 1 millisecond ms 50-80 ms: The time taken to blink an eye 1 ms, 10 ms, 100 ms
10−2 1 centisecond cs
100 1 second s 1 s: "One Mississippi" said aloud
60 s: 1 minute
1 s, 10 s, 100 s
103 1 kilosecond
(16.7 minutes)
ks 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 month = 2.6 x 106 s
year = 31.6 Ms = 107.50 s ≈ π x 107 s
106 s, 107 s, 108 s
109 1 gigasecond
(32 years)
Gs century = 3.16 Gs ≈ π×109 s
millennium = 31.6 Gs ≈ π×1010 s
109 s, 1010 s, 1011 s
1012 1 terasecond
(32 000 years)
Ts eon = 31.6 Ts ≈ π×1013 s 1012 s, 1013 s, 1014 s
1015 1 petasecond
(32 million years)
Ps aeon = 31.6 Ps ≈ π×1016 s
435 Ps = 4.35×1017 s ≈ 13.8 billion years, the approximate age of the Universe
1015 s, 1016 s, 1017 s
1018 1 exasecond
(32 billion years)
Es 0.43 Es ≈ the best estimate of the age of the Universe 1018 s, 1019 s, 1020 s
1021 1 zettasecond
(32 trillion years)
Zs 1021 s, 1022 s, 1023 s
1024 1 yottasecond
Ys 1024 s, 1025 s, 1026 s and more

## Years

Orders of magnitude (time)
Factor (a) Multiple common units orders of magnitude
10−50 Planck time, the shortest physically meaningful interval of time ≈ 1.71×10−50 a 10−50 a
10−24 1 yoctoannum -- 1 ya and less, 10 ya, 100 ya
10−21 1 zeptoannum -- 1 za, 10 za, 100 za
10−18 1 attoannum -- 1 aa, 10 aa, 100 aa
10−15 1 femtoannum -- 1 fa, 10 fa, 100 fa
10−12 1 picoannum -- 1 pa, 10 pa, 100 pa
10−9 1 nanoannum 1 second = 3.17 × 10−8 a ≈ 10-7.50 a 1 na, 10 na, 100 na
10−6 1 microannum 1 minute = 1.90 × 10−6 a
1 hour = 1.40 × 10−4 a
1 ua, 10 ua, 100 ua
10−3 1 milliannum 1 day = 2.73 × 10−3 a
1 week = 1.91 × 10−2 a
1 ma, 10 ma, 100 ma
100 1 annum year = 1 annum
century = 100 anna
1 a, 10 a, 100 a
103 1 kiloannum millennium = 1000 anna 103 a, 104 a, 105 a
106 1 megaannum epoch = 1,000,000 anna 106 a, 107 a, 108 a
109 1 gigaannum aeon = 1,000,000,000 anna
13.7 Ga = 1.37×1010 a ≈ 13.7 billion years, the approximate age of the Universe
109 a, 1010 a, 1011 a
1012 1 teraannum --- 1012 a, 1013 a, 1014 a
1015 1 petaannum --- 1015 a, 1016 a, 1017 a
1018 1 exaannum -- 1018 a, 1019 a, 1020 a
1021 1 zettaannum -- 1021 a, 1022 a, 1023 a
1024 1 yottaannum -- 1024 a, 1025 a, 1026 and more

Orders of magnitude (time) Facts for Kids. Kiddle Encyclopedia.