Terasecond and longer

A terasecond (symbol: Ts) is one trillion seconds. That is about 31,700 years. It can be written as 10¹² seconds.

Here is a list of time spans longer than 1 terasecond:

• 10¹⁵ seconds = 1 petasecond = 31.7 million years
• 10¹⁸ seconds = 1 exasecond = 31.7 billion years
• 10²¹ seconds = 1 zettasecond = 31.7 trillion years
• 10²⁴ seconds = 1 yottasecond = 31.7 quadrillion years

Teraseconds

Here are some examples of events that take this long:

• 75,000 years — time since the ancestors of the Indigenous Australians reached Australia
• 76,000 years — half-life of nickel-59
• 154,000 years — half-life of neptunium-236
• 159,200 years — half-life of uranium-233
• 200,000 years — age of Homo sapiens
• 211,100 years — half-life of technetium-99
• 250,000 years — age of Homo neanderthalensis
• 301,000 years — half-life of chlorine-36
• 340,000 years -- half-life of curium-248
• 379 000 years -- time after the Big Bang until cosmic microwave background radiation began
• ~700,000 years -- time since the earth's magnetic field last changed
• 1,000,000 years -- the lifespan of a blue supergiant star
• 1,530,000 years -- half-life of zirconium-93
• 2,600,000 years -- amount of time the Paleolithic era lasted
• 2,600,000 years -- half-life of technetium-97
• 3.74 million years -- half-life of manganese-53
• 4 million years -- time since the last ice age
• 4.2 million years -- half-life of technetium-98
• 6.5 million years -- half-life of palladium-107
• 15.6 million years -- half-life of curium-247
• 20 million years -- time since the first forms of grass appeared
• 23.42 million years -- half-life of uranium-236
• 26 million years -- time since the first elephants were born

Petaseconds

• 34 million years -- time since the evolution of the cat
• 34.7 million years -- half-life of niobium-92
• 49 million years -- time since the whales returned to the water
• 60 million years -- time since the evolution of the first primates.
• 135 million years -- time since end of Jurassic and beginning of Cretaceous period
• 250 million years -- Galactic year - an orbit around the center of the Milky way of our Sun and the Solar system
• 251.4 million years -- time since the Permian mass extinction
• 280 million years -- time since end of Carboniferous and beginning of Permian Period.
• 390 million years - first fishapods
• 575 million years - age of the oldest animal fossils
• 580 million years - time since the end of a possible Snowball Earth ice age
• 703.8 million years - half-life of uranium-235
• 750 million years - time since the beginning of a possible ice age
• 1277 million years - half-life of potassium-40
• 1.8-2.1 billion years - age of the earliest eukaryotes
• 2.3 billion years - time since the first known ice age
• 3.5 to 3.8 billion years - age of oldest records of life: stromatolites and cyanobacteria
• 4.468 billion years - half-life of uranium-238
• 4.5 billion years - age of the Earth
• 13.7 ± 0.2 billion years (4e17 seconds) - age of the universe according to the Big Bang theory
• 20 billion years - time until the end of the universe in the Big Rip scenario

Exaseconds

• 100 billion (10¹¹) years -- If the universe is closed, the lifetime of the universe
• Some radioisotopes have very long half-lives:

• (1.4 ± 0.4) × 10¹⁷ years – vanadium-50
• (1.9 ± 0.2) × 10¹⁹ years – bismuth-209
• (3.1 ± 0.4) × 10¹⁹ years – cadmium-116
• (2.2 ± 0.3) × 10²⁴ years – tellurium-128