TIMELINE

BIG Bang Expansion-13.8 billion years.

• One 10-million-billion-billion-billion-billion-billion-billionth of a second:[PLANK Era]

 The temperature is 100,000 billion billion billion degrees.

• One hundred – thousand- billion-billion-billionth of a second:[INFLATION]

The universe undergoes a rapid cosmic growth spurt, increasing in size exponentially fast, solving various cosmological problems and creating the seeds from which large scale structures in the universe such as galaxies and clusters later grow.

• One-millionth of a second :[QUARK Era]

The universe is a sea quark, the tiny particles that makeup protons and neutrons.

• 1 second : [HADRON Era]

As the temperature drops below around 1000 billion degrees, quarks condense into protons and neutrons (known as collectively as Hadrons), the basic building blocks of the atom.

• 10-1000 seconds:[The synthesis of light atomic nuclei.]

The temperature falls to a billion degrees, allowing proton sand neutrons to stick together and begin forming the light chemical elements – Hydrogen, Helium and a small quantity of Lithium.

• Less than 380,000 years  :[RADIATION Era ]

Although atomic nuclei exist at this time, the universe is still awash with fiercely hot radiation that rips apart any atoms attempting to form.

• 380,000 years : [RECOMBINATION]

The temperature drops down to around 3,700C, allowing electrons to finally combine with a proton to create the first atoms. The universe is now dominated by matter rather than radiation.

• 380,000-180 million years:[Dark Ages]

The universe is dominated by matter, but none of it has formed stars or galaxies or anything else luminous.

• 180 million-1 billion years:[Structure formation]

Galaxies, clusters and superclusters all begin to take shape from around 1 billion years after the Big Bang. Galaxies gather into clusters and clusters gather into superclusters.

• 9.2 billion years :[Birth of our solar system]

A cloud of hydrogen, helium and few heavier elements circling around the Milky Way galaxy

Begin to collapse under its gravity. The core of cloud becomes a hot, young star while around it a disc of material condenses and fragments into a mix rocky, gaseous and icy bodies. This is the birth of our solar system.

• 13.8 billion years :[PRESENT DAY]

Today the universe is in the stelliferous era (the age of stars). Astronomers expect the stelliferous era to last until the universe is 100,000 billion years old, after which the formation of new stars will cease. By this time the sun will be long dead.

• Longer than 100,000 billion years [FAR FURTHER]

Beyond 100,000 billion years, the behaviour of the universe is a largely unknown quantity.