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The Big Bang
The Big Bang theory is a cosmological model of the observable universe from the earliest known periods through its subsequent large-scale evolution.
The Big Bang theory is a cosmological model of the observable universe from the earliest known periods through its subsequent large-scale evolution.
The Planck scale is the physical scale beyond which current physical theories may not apply, and cannot be used to calculate what happened.
The three forces of the Standard Model are unified (assuming that nature is described by a Grand Unified Theory).
The electroweak epoch began when the temperature of the universe was low enough (1028 K) for the electronuclear force to begin to manifest as two separate interactions, called the strong and the electroweak interactions.
The universe suddenly expanded, and its volume increased by a factor of at least 1078 (an expansion of distance by a factor of at least 1026 in each of the three dimensions), equivalent to expanding an object 1 nanometer (10−9 m, about half the width of a molecule of DNA) in length to one approximately 10.6 light years (about 1017 m or 62 trillion miles) long.
The forces of the Standard Model have separated, but energies are too high for quarks to coalesce into hadrons, instead forming a quark–gluon plasma.
Quarks are bound into hadrons. A slight matter-antimatter-asymmetry from the earlier phases (baryon asymmetry) results in an elimination of anti-hadrons.
Neutrinos cease interacting with baryonic matter. The sphere of space that will become the observable universe is approximately 10 light-years in radius at this time.
Protons and neutrons are bound into primordial atomic nuclei, hydrogen and helium-4. Small amounts of deuterium, helium-3, and lithium-7 are also synthesized.
The universe consists of a plasma of nuclei, electrons and photons; temperatures remain too high for the binding of electrons to nuclei.
Helium hydride is the first molecule
The time between recombination and the formation of the first stars.
The earliest known galaxies existed by about 380 Ma. Galaxies coalesce into "proto-clusters" from about 1 Ga and into galaxy clusters beginning at 3 Ga, and into superclusters from about 5 Ga
As the first stars, dwarf galaxies and quasars gradually form, the intense radiation they emit reionizes much of the surrounding universe; splitting the neutral hydrogen atoms back into a plasma of free electrons and protons for the first time since recombination and decoupling.
Up to this time we think that we can predict its large-scale development.
As expansion continues, the universe becomes larger, colder, and more dilute; in time, all structures eventually decompose to subatomic particles and photons.
Expansion of space accelerates and at some point becomes so extreme that even subatomic particles and the fabric of spacetime are pulled apart and unable to exist.
Expansion eventually slows and halts, then reverses as all matter accelerates towards its common centre.
Collapse of the quantum fields that underpin all forces, particles and structures, to a different form.