Terasecond and longer

For past times above one terasecond, see Timeline of prehistory. For future times above one terasecond, see Timeline of the far future. For a list of half-lives above one terasecond, see List of isotopes by half-life.

A terasecond (symbol: Ts) is 1 trillion (1 × 10¹²) seconds, or roughly 31,558 years. This page lists time spans above 1 terasecond.

• Shorter times

Teraseconds

• 12 Ts (379,000 years) – the time that elapsed after the Big Bang before the cosmic microwave background radiation (CMBR) was emitted
• 31.6 Ts (1 million years) – about the average lifespan of a blue supergiant star
• 80 Ts (2.54 million years) – approximate time needed for light to travel from the Andromeda Galaxy to the Milky Way
• 82 Ts (2.6 million years) – estimated duration of the Paleolithic Period
• 130 Ts (4 million years) – estimated average lifetime of biological species
• 137 Ts (4.32 million years) – one mahayuga, or 12,000 divine years, in Hindu mythology
• 850 Ts (27 million years) – estimated duration of the Silurian Period

Petaseconds

1 thousand teraseconds (or 1 quadrillion seconds) is called a petasecond, and is equal to about 32 million years.

• 1.4 Ps (45 million years) – estimated duration of the Ordovician Period
• 1.6 Ps (50 million years) – estimated duration of the Triassic and the Permian Periods
• 1.7 Ps (54 million years) – estimated duration of the Cambrian Period
• 1.8 Ps (56.8 million years) – estimated duration of the Devonian Period
• 1.9 Ps (60 million years) – estimated duration of the Carboniferous Period
• 2.0 Ps (62.4 million years) – estimated duration of the Tertiary Period
• 2.1 Ps (65 million years) – estimated duration of the Jurassic Period
• 2.5 Ps (80 million years) – estimated duration of the Cretaceous Period
• 5.85 Ps (185 million years) – estimated duration of the Mesozoic Era
• 7.9 Ps (250 million years) – approximate length of one galactic year (one revolution of the Solar System around the galactic center)
• 9.22 Ps (291 million years) – estimated duration of the Paleozoic Era
• 25 Ps (800 million years) – duration of the Hadean Eon
• 31.688 Ps (1 billion years) – 1 eon
• 41 Ps (1.3 billion years) – estimated duration of the Archaean Eon
• 63 Ps (2 billion years) – estimated duration of the Proterozoic Eon
• 125 Ps (4 billion years) – estimated duration of the Precambrian Supereon
• 137 Ps (4.32 billion years) – one kalpa, or half a day in the lifetime of Brahma, in Hindu mythology
• 315 Ps (10 billion years) – expected main sequence lifetime of a G2 dwarf star (like our Sun) – also, the estimated lifespan of a globular cluster before its stars are ejected by gravitational interactions

Exaseconds

1 million teraseconds (or 1 quintillion seconds) is called an exasecond, and is equal to 32 billion years, or roughly twice the age of the universe at current estimates (the universe is currently thought to be a bit less than 14 billion years old).

• 1.08 Es (34 billion years) – estimated lifetime of the universe, assuming the Big Rip scenario is correct; experimental evidence currently suggests that it is not
• 300 to 600 Es (10 to 20 trillion years) – approximate lifetime of the longest-lived stars, the low-mass red dwarfs

Zettaseconds

1 billion teraseconds (or 1 sextillion seconds) is called a zettasecond and is equal to roughly 32 trillion years.

• 3 Zs (100 trillion years) – estimated duration of the Stelliferous Era (the time during which the stars shine)
• 9.85 Zs (311 trillion years) – the lifetime of Brahma in Hindu mythology

Yottaseconds and beyond

1 trillion teraseconds (or 1 septillion seconds) is called a yottasecond and is equal to roughly 32 quadrillion (or 3.2×10¹⁶) years

• 1 Ys - The average half life of Bismuth.
• 1.310019×10¹² Ys (4.134105×10²⁸ years) – The time period equivalent to the value of 13.13.13.13.13.13.13.13.13.13.13.13.13.13.13.13.13.13.13.13.0.0.0.0 in the Mesoamerican Long Count, a date discovered on a stela at the Coba Maya site, believed by archaeologist Linda Schele to be the absolute value for the length of one cycle of the universe
• 2.6×10¹⁷ Ys (8.2×10³³ years) – the smallest possible value for proton half-life consistent with experiment
• 10²⁹ Ys (3.2×10⁴⁵ years) – the largest possible value for the proton half-life, assuming that the Big Bang was inflationary and that the same process that made baryons predominate over anti-baryons in the early Universe also makes protons decay
• 6×10⁵³ Ys (2×10⁶⁶ years) – approximate lifespan of a black hole with the mass of the Sun
• 5.4×10⁹³ Ys (1.7×10¹⁰⁶ years) – approximate lifespan of a supermassive black hole with a mass of 20 trillion solar masses
• $10^{10^{10^{76.66}}}$ Ys ($10^{10^{10^{76.66}}}$ years) – Scale of an estimated Poincaré recurrence time for the quantum state of a hypothetical box containing an isolated black hole of stellar mass This time assumes a statistical model subject to Poincaré recurrence. A much simplified way of thinking about this time is that in a model in which history repeats itself arbitrarily many times due to properties of statistical mechanics, this is the time scale when it will first be somewhat similar (for a reasonable choice of "similar") to its current state again.
• $10^{10^{10^{120}}}$ Ys ($10^{10^{10^{120}}}$ years) – Scale of an estimated Poincaré recurrence time for the quantum state of a hypothetical box containing a black hole with the mass within the presently visible region of the Universe.
• $10^{10^{10^{10^{13}}}}$ Ys ($10^{10^{10^{10^{13}}}}$ years) – Scale of an estimated Poincaré recurrence time for the quantum state of a hypothetical box containing a black hole with the estimated mass of the entire Universe, observable or not, assuming Linde's chaotic inflationary model with an inflaton whose mass is 10⁻⁶ Planck masses.

See also

• Chronology of the universe
• Orders of magnitude (time)