Global History

Here is an overview of our universal history starting from the big bang, as science could discover.
Most of this information was extracted from various Wikipedia articles (before noticing there is a short and a long summary of the history of life on Earth; something about cosmic inflation is from my understanding of general relativity).

The Universe is about 13.75 billion years old, starting with the "Big Bang" (a period of expansion starting by initially extreme and decreasing densities and temperatures). Current theories cannot account for any exact origin of time, but give a good description of what happened after a very short time (small fraction of a second) after it.

Cosmic Inflation: the first process of observable importance, that swept away all observable traces of what could happen before. In this period, most of the (very high) energy density (or mass density, which is the same by E=mc2) was of a form characterized by a high negative pressure. This negative pressure has a gravitational effect of accelerating the universal expansion in a roughly exponential manner, according to general relativity, multiplying the size of the universe by large numbers.
(The naive idea that, without gravitation, a positive pressure accelerates expansion like in an explosion, while a negative one would slow it down, only applies to a limited system surrounded by void, with its boundaries accelerating inwards or outwards by the difference between the internal pressure and the external void; such an effect cannot apply to the big bang because of the uniformity of the universe that has no such orientation of inwards and outwards; instead, only gravitation applies, as it is not a force but a determination of the space-time curvature).
This form of energy has the property of keeping its density during expansion, rather than diluting it (just as an elastic gathers potential energy during its extension, or a bubble keeps its surface density of capillar energy while expanding; this energy needs not come from anywhere because the conservation of energy only applies locally, while the universal expansion is a global process).
The precise field/particle responsible for the inflation has not been identified yet by particle physicists; still, predictions made out of known physical principles applied to the inflation hypothesis have already been verified by different observations. This explains the approximate uniformity of the universe at the largest scales (that became too far away for causally connecting and regularizing later), and the small inhomogeneities at the origin of the large scale structures of the cosmos (collapse of matter into galaxies and galaxy clusters).
Inflation ends when all that energy converts into "ordinary" particles and forms of energy, with positive pressure (photons and speedy particles), thus slowing down again the expansion and diluting the energy density faster than the density of ordinary particles (photons lose their energy by Doppler effect, while speedy particles reduce their speed by the relativity of speed between different regions).

Big Bang nucleosynthesis. Starting 3 minutes after the big bang (when the temperature was low enough to not immediately break away any composite nucleus), lasting 17 minutes (until the temperature was too low for fusion to occur - to be compared with the nearly 15 minutes of mean lifetime of free neutrons): Nuclei heavier than hydrogen formed, leaving about 1/4 th of the number of nucleons (or mass of ordinary matter if we forget other forms of energy : dark matter, photons, neutrinos, and kinetic energy) into Helium-4, while about 3/4 remained as Hydrogen-1.

Recombination (380,000 years after the big bang): The temperature of 3000 K is cool enough to let electrons and nuclei form atoms. The space becomes transparent to radiation, releasing what is now the Cosmic Microwave Background (whose temperature decreased to the current value of 2.725 K by Doppler effect during expansion). Ordinary matter at that time (hydrogen and helium) was about 4×10-22 times the mass density of water, that is about one atom per 5 mm3.

Reionization (400 million years after Big Bang). New sources of energy appear and break again atoms into nuclei and electrons, but the density is now low enough to leave the space rather transparent. These can be quasars (matter falling into galactic black holes) and/or Population III stars (very massive stars, thus with short lifetime, that were the only ones which could be formed first, in the absence of the heavy atoms).

Oldest known star of the Milky Way: 13.2 billion years ago (500 million years after the Big Bang).

Globular clusters formed about 12.7 billion years ago (1 billion years after the big bang).

Thin Disk of the Milky Way (8.8 ± 1.7 billion years ago)

Formation of the Solar System began 4.57 billion years ago, from a big molecular cloud, after one or more massive star(s), with thus short lifetime, first formed and exploded in supernovae, giving heavy elements and compressing the region of the cloud, making possible the creation of the solar system.

Moon's formation 4.527 ± 0.010 billion years ago, probably by a giant impact between the Earth and a Mars-size planet, that also inclined the rotation axis of the Earth and gave the Earth a very fast rotation (a day of 6 hours instead of 24). This rotation later slowed down by transmission to the Moon's orbit (initially close to the Earth) through tidal interaction.

Late Heavy Bombardment: period of intense meteorite impacts (began about 4.1 Ga, and concluded around 3.8 Ga). From Wikipedia: "no consensus yet exists as to its cause. One popular theory postulates that the gas giant planets migrated in orbit at this time, causing objects in the asteroid belt and/or Kuiper belt to be put onto eccentric orbits that reached the terrestrial planets.

Note that the Sun's luminosity progressively increases in time. It is now 30% brighter than it previously was. This needs to be balanced by other processes, mainly a decrease of atmospheric concentrations of CO2 and other greenhouse gases (which were initially abundant), to make it possible for water to keep existing in liquid form meanwhile. This will mainly take place in 2 ways: deposit of calcium carbonate (CaCO3) in the oceans, and photosynthesis.

Last universal common ancestor between all current living forms on Earth (Bacteria, Archaeas, animals and plants; except viruses): some 3.5 to 3.8 billion years ago

Photosynthesis started about 3.5 billion years ago

Cyanobacteria making oxygenic photosynthesis (producing O2), may have appeared 3 billion years ago (or between 2.8 and 3.7 billion years ago).

Great Oxygenation Event (2.4 billion years ago): The oxygen produced by cyanobacteria, could finally remain in the atmosphere, after organic matter and dissolved iron were saturated and could no more capture it. This resulted in a massive extinction of anaerobic organisms for which oxygen was toxic; but also in the appearance of an ozone layer that would open the possibility for life outside the ocean; and the possibility to get more energy for organisms able to use O2 in their metabolism.

Huronian glaciation (2.4 to 2.1 billion years ago): the Earth was covered with ice, which may be due to the disappearing of methane (consumed with oxygen).

Eukariotic cells appeared 1.7-2 billion years ago by integrating bacteria that could use O2 for metabolism, in the role of mitochondria.

First multicellular organisms (1 billion years ago) while the lineages of animals, fungi and plants were separated; molecular evidence suggests that fungi colonized land at that time (while procariotes had done it already around 2.6 billion years ago). Plants started photosynthesis by integrating cyanobacteria in the role of chloroplasts.

(Ma = million years ago)

More Snowball Earth periods (intense glaciations) would have occured around the times of 750, 710 and 640 M y

Cambrian explosion : life seemed to complexify a lot around 530 Ma. This would include the development of complex eyes, shells, skeletons (with the emergence of vertebrates) and exoskeletons - unless these were what made possible a better preservation of fossils, that our ability to detect the presence of life diversity depends on. The earliest fossil crustaceans date from about 513 million years ago

Oldest fossils of land fungi and plants date to 480–460 M y

Arthropods on land around 530-450 M y. (Arthropods were well pre-adapted to colonize land, because their existing jointed exoskeletons provided protection against desiccation, support against gravity and a means of locomotion that was not dependent on water).

Ordovician–Silurian extinction event (End Ordovician or O-S) (450-440 M y, at the Ordovician-Silurian transition). Two events occurred that killed off 27% of all families and 57% of all genera. Together they are ranked by many scientists as the second largest of the five major extinctions in Earth's history in terms of percentage of genera that went extinct.

The first tetrapods evolved from fish (380 to 375 M y)

Late Devonian extinction (360-375 M y) near the Devonian-Carboniferous transition. A prolonged series of extinctions eliminated about 19% of all families, 50% of all genera and 70% of all species.

Plants evolved seeds (360 M y) which dramatically accelerated their spread on land.

The Karoo Ice Age (360 to 260 M y, named after the glacial tills found in the Karoo region of South Africa where evidence for this ice age was first clearly identified). The Earth during this time was covered with an immense degree of vegetation compared to earlier times, causing a long term increase in planetary oxygen levels and reduction of CO2 levels that resulted in this ice age.

The amniotic egg evolved (340 M y), which could be laid on land, giving a survival advantage to tetrapod embryos. This resulted in the divergence of amniotes (most terrestrial vertebrates) from amphibians.

Divergence of amniotes, between the Synapsids (ancestors of mammals, also called "mammal-like repliles"), which started to dominate, and the Sauropsids (other reptiles) 310 M y.

Supercontinent Pangea formed 300 Ma (?) (after a long story of continental drifts alternating supercontinents and separations of continents).

Sauropsids split: as for those still existing today, the ancestors of turtoises diverged first, then quite later (at the end of the Permian period) came a split between Lepidosauromorpha (ancestors of lizards and snakes) and archosaurs.

Marine reptiles from different origins started developing and will take an important place until the Cretaceous extinction (65 M y).

Permian–Triassic extinction event (End Permian - 250 M y at the Permian-Triassic transition). Earth's largest extinction killed 57% of all families and 83% of all genera (53% of marine families, 84% of marine genera, about 96% of all marine species and an estimated 70% of land species). On land, it ended the primacy of Synapsids. The cause of this extinction remains unclear.

Archosaurs split soon after, between  Avemetatarsalia (ancestors of pterosaurs and dinosaurs, and thus of birds) and Crurotarsi (ancestors of crocodiles).

Dinosaurs (230 M y) appeared by diverging from other Archosaurs.

Pterosaurs (220 M y), earliest vertebrates known to have evolved powered flight, appeared. Pterosaur fossils have been found on every continent. At least 60 genera of pterosaurs have been found to date, ranging from the size of a small bird to wingspans in excess of 10 metres (33 ft).

Triassic–Jurassic extinction event (End Triassic) - 205 M y at the Triassic-Jurassic transition. About 23% of all families and 48% of all genera (20% of marine families and 55% of marine genera) went extinct. Many of the dinosaurs were spared and soon became dominant among the vertebrates, as most of the other groups of early archosaurs (like aetosaurs, ornithosuchids, phytosaurs, and rauisuchians) were killed. These losses left behind a land fauna mainly made of crocodylomorphs, dinosaurs, mammals, pterosaurians, and turtles. Mammalian were small, but their lines began to separate.

Pangaea broke up (180 - 200 M y) into Laurasia on the north, and Gondwana on the south. 

Gondwana broke up (167 M y) into East Gondwana and West Gondwana.

Archaeopteryx, a dinosaur traditionally considered one of the first birds (probably close to their ancestors but not among them), lived around 150 M y

Flowering plants : first evidence to 132 M y

Eutherians (ancestors of placental mammals, which is the main branch of mammals) diverged from metatherians (ancestors of marsupials), while prototherians (ancestors of monotremes) had already diverged before. The earliest known fossil eutherian, was found in Asia, and is dated to about 125 M y.

Confuciusornis (125 to 120 M y) is a genus of primitive crow-sized birds, more advanced than Archaeopteryx (same remark).

West Gondwana split (130 - 110 M y) into South America and Africa, opening the South Atlantic Ocean
East Gondwana split between (India-Madagascar-Seychelles) that began to move northward, and (Australia-Antarctica-New Zealand), but some connections with Africa will still exist later.

Later, competition with birds drove many pterosaurs to extinction and the dinosaurs were probably already in decline, when came:

Cretaceous–Tertiary extinction event (End Cretaceous or K-T extinction, 65 M y), which may have been caused by the impactor that created Chicxulub Crater on the Yucatán Peninsula. About 17% of all families, 50% of all genera and 75% of species went extinct, including Pterosaurs, all non-avian dinosaurs, most avian dinosaurs, and many other animals.
This left the space for mammals to diversify and grow larger.

Last common ancestor of primates: 63 M y, as Strepsirrhini (which are the only primates of Madagascar, also present in South-East Asia and Africa) split from the main branch.

Laurasia split (about 60 M y), separating Eurasia from (Greenland + North America).

Indian plate collided with Asia (45 M y) while Australia separated from Antarctica

Split between humans and chimpanzees at 5 or 7 M y

The Quaternary glaciation, or current ice age, marked the start of the Quaternary period, about 2.58 million years ago when the spread of ice sheets in the Northern Hemisphere began. Since then, the world has seen cycles of glaciation with ice sheets advancing and retreating on 40,000- and 100,000-year time scales.

Homo genus appeared then (while the ancestors of the common chimpanzee and the bonobo split from each other).

Quaternary extinction and Holocene extinction: the Quaternary period saw the extinctions of numerous predominantly larger species (megafauna), many of which occurred during the transition from the Pleistocene to the Holocene epoch (around 12,000 years ago). Among the main causes hypothesized by paleontologists are natural climate change and overkill by humans.

Homo erectus migrated from Africa around 2.0 million years ago, and dispersed throughout much of the Old World, especially in Asia, until they probably went extinct about 70,000 years ago.

Homo neanderthalensis lived in Europe from about 400,000 to 30,000 years ago. They were strong hunters, mainly (but not completely) carnivorous, thus more depending on fauna for their subsistence than homo sapiens.

The last glacial period (most recent glacial period within the current ice age) started approximately 110,000 years ago.

The Toba supereruption occurred between 69,000 and 77,000 years ago at Lake Toba (Sumatra, Indonesia), and it is recognized as one of the earth's largest known eruptions. This supervolcanic event may have plunged the planet into a 6-to-10-year volcanic winter

A bottleneck in human evolution probably resulted from this eruption. The homo sapiens population was reduced to a group of 10,000 or even a mere 1,000 breeding pairs in East Africa. An important final step of the cultural development of homo sapiens, as seen in the more sophisticated technology and artwork, happened in that period (between 100,000 and 50,000 years ago).

Homo sapiens conquered the world in several waves quickly after this bottleneck, causing an extinction of Neanderthals on their way (except for a little interbreeding between roughly 80,000 and 50,000 years ago in the Middle East, resulting in 1–4% of the genome of people from Eurasia having been contributed by Neanderthals).

End of the last glacial period 10,000 years ago.
Other works : foundations of mathematics and physics, other topics - metaphysics