Celestium presents
From the first instant
to the last light.
A continuous passage through the history we can observe and the futures physics allows us to imagine.
Guided journey - pause or move at your own pace
Act I - Origin
10^-43 seconds
At the Planck scale, general relativity and quantum theory no longer give us a complete description of the universe.
The Timeline
A readable journey through the observed history and modelled future of the universe.
About 10^-43 seconds. At the Planck scale, known theories are incomplete; a tested theory of quantum gravity does not yet exist.
Roughly 10^-36 to 10^-32 seconds. A brief accelerated expansion explains several large-scale properties of the cosmos, but its physical mechanism remains unconfirmed.
About one microsecond. Cooling quark-gluon plasma allows protons and neutrons to form; the origin of matter's slight excess over antimatter remains an open question.
Three to twenty minutes. Big Bang nucleosynthesis produces mostly hydrogen and helium nuclei, with traces of lithium.
About 50,000 to 380,000 years. Matter and radiation fill an opaque plasma while gravity amplifies small density differences.
About 380,000 years. Electrons bind to nuclei, photons travel freely, and the light now observed as the cosmic microwave background is released.
From 380,000 years to roughly 100 million years. Neutral gas gathers inside dark-matter structures before the first stars ignite.
Roughly 100 to 200 million years. The first generations of stars begin transforming a dark universe.
Within the first billion years. Radiation from early stars and galaxies ionizes much of the hydrogen between galaxies.
One to three billion years. Galaxies grow by forming stars, accreting gas and merging with smaller systems.
About 3.5 billion years. The observable universe reaches its peak rate of star formation.
Across billions of years. Our galaxy assembles through repeated star formation, accretion and mergers.
About 9.2 billion years after the Big Bang. A molecular cloud collapses into the Sun and a protoplanetary disk; Earth forms from the same enriched material.
About 9.8 billion years. Dark energy becomes dynamically dominant and cosmic expansion accelerates.
13.8 billion years. On one small world, matter has become capable of reconstructing its own cosmic history.
Roughly 4.5 billion years from now. Andromeda and the Milky Way are expected to interact and eventually merge.
Roughly 5 to 7 billion years from now. The Sun becomes a red giant, sheds its outer layers and ends as a white dwarf.
Beyond 100 billion years. Accelerated expansion carries unbound galaxies beyond our future horizon.
Across trillions of years. Usable gas becomes scarce and new stars become increasingly rare.
Up to about 100 trillion years. The longest-lived red dwarfs exhaust their fuel, ending the stelliferous era.
Far beyond 10^14 years. White dwarfs, neutron stars, brown dwarfs and black holes dominate an increasingly cold universe.
Not yet observed. Some theories allow protons to decay over immense timescales; others do not.
Up to roughly 10^100 years. If Hawking radiation behaves as predicted, black holes eventually evaporate.
An asymptotic future. Under the standard cosmological model, usable energy differences continue to disappear as the universe expands and cools.
