From the Big Bang to the Heat Death of the Universe, explore the history - and possible future - of our Universe with this interactive timeline.

To navigate the timeline, move your mouse to the left of the timeline to go back through time, and to the right to go forwards. Key events in the history of the Universe are marked with a star; to find out more, simply click on the star image.

  1. Big Bang

    0 sec

  2. Planck Time

    10-44 sec

  3. Inflation Era Begins

    10-37 sec

  4. Radiation Dominated Era Begins

    10-34 sec

  5. Electroweak Phase Transition

    10-10 sec

  6. Quarks Get Confined


  7. Synthesis Of Light Elements

    102 sec

  8. Radiation Dominated Era Ends

    105 years

  9. Stelliferous Era Begins

    106 years

  10. Galaxies Begin To Form

    108 years

  11. Now

    1010 years

  12. Last Red Dwarfs Die

    1014 years

  13. Start Of Degenerate Era

    1018 years

  14. Galaxies Dissolve

    1020 years

  15. White Dwarfs Absorb Wimps

    1024 years

  16. Wimps Die Out

    1028 years

  17. End Of Degenerate Era

    1030 years

  18. The Black Hole Era


  19. Dark Era

    10100 years


This history of the Universe assumes that the Universe will expand forever and has access to infinite amounts of time. This is the most likely scenario for the Universe's future, based on what astronomers can measure. To find out more about this incredible story, move the cursor over the timeline above and click on each event to find out more

Big Bang

The universal starting point. Everything starts from here, including time itself. All space, matter and energy - everything the Universe will ever know - is contained in a single point, and the Universe is infinitely dense. Pretty mind-blowing stuff.

Planck Time

This is the Planck Time, named after the physicist Max Planck, who was big in quantum physics circles. Physics as we know it only really makes sense from here. Time isn't really divisible into chunks smaller than 10-44 seconds, just as fundamental particles like electrons can't be broken up into smaller pieces.

Inflation Begins

The new-born Universe is immensely hot and dense and the so-called Inflation Era begins. High energy quantum fields drive an incredibly fast expansion of everything, and there are tiny fluctuations in these energy fields which eventually become the galaxies and other large-scale structures we can see today.

Radiation Dominated Era Begins

This marks the end of the inflation era. The Universe begins to calm down a bit, expanding at a more moderate rate. For the next hundredth of a billionth of a second (10-11 seconds), it contains almost nothing but a vast sea of radiation. Complicated particle processes set up an imbalance of matter and antimatter, which is why there's more matter than anti-matter around today.

Electroweak Phase Transition

Around about here, two of the four fundamental forces in the Universe separate from each other. This is known as 'the electroweak phase transition'. At this point, the electromagnetic force (related to electricity and magnetism) and the weak force (related to radioactive decay) become distinct for the first time.

Quarks Get Confined

Quarks, the fundamental building blocks of matter, get together to form protons and neutrons. When the Universe is about 10s old, electrons and positrons mutually annihilate each other, leaving an imbalance of just one particle of matter for every billion photons of radiation.

Synthesis Of Light Elements

When the Universe is a few minutes old, the cooling cosmic soup begins to fuse and synthesise the nuclei of light elements, including hydrogen, helium and lithium. The ordinary laws of nuclear physics can be used to describe this - the results match what we actually see if we look at the oldest matter in the Universe.

Radiation Dominated Era Ends

Around this time something else happened which was very significant: the Universe was cool enough for atoms to begin to form. Before this time, the universe was 'opaque' - radiation was constantly interacting with matter. But from this point onwards, radiation was able to fly free, You can see the radiation which broke free today, in the cosmic microwave background radiation.

Stelliferous Era Begins

The first stars form, which generate most of the energy in the Universe through the nuclear reactions going on inside them. This marks the start of the 'The Stellar Era', and we're living in the midst of it. In this era, stars are forming, living and dying. The first generation of stars probably formed when the Universe was a few million years old.

Galaxies Begin To Form

Galaxies begin to form, and organise themselves into clusters and superclusters. This happens because gravity causes clumps of matter in the Universe to collapse together and ignite to form bright and hot stars and galaxies. The Hubble telescope has seen many of the Universe's oldest galaxies, which appear as blue dots in pictures like this.


This is our very special bit of the entire history of the universe. The Sun and Solar System formed about four and a half billion years ago. This was about nine billion years into the Universe's lifespan, after the Milky Way had existed for quite a long time. The conditions in the Solar System are just right for life on Earth. In a few billion years though, the Sun will start to expand and get hotter as it completes its evolution. When it exhausts its hydrogen fuel, it will readjust its structure to become a red giant. Its radius will swell and come dangerously close to the Earth, which by this time will have been reduced to a sorry state of lifelessness, owing to the Sun becoming scorchingly hot over millions of years. On a larger scale, galaxies will begin to merge, and the Milky Way will hit Andromeda galaxy in about 6 billion years from now.

Last Red Dwarfs Die

Throughout the Stella Era, stars have been gradually burning out, at a rate depending on their size. The ones to burn out last will be red dwarfs, and at this point the Universe will be about 100 trillion (100 million million) years old.

Start Of Degenerate Era

This marks the start of the so-called degenerate era. By this time, there aren't any ordinary stars left, and the universe is cold and black because there aren't any glowing bodies to warm and light up the sky. The background temperature is only a tiny fraction of a degree above absolute zero. Brown dwarfs, white dwarfs, neutron stars and black holes are the only things around.

Galaxies dissolve

Most stars and planets have left galaxies by this time. Anything that's around will just float through intergalactic space, which is now a very large realm indeed. Black holes will get bigger during this time, as they swallow up mass which innocently passes in their vicinity. Although the Universe is very cold and dark during this time, there'll be rare and exciting events which cause energy generation. Every thousand million years or so, two white dwarfs will collide to cause a massive supernova explosion, which will be incredibly spectacular against the dark and featureless sky.

White Dwarfs Absorb Wimps

Dark matter which surrounds what's left of galaxies becomes swept up by white dwarfs. This type of dark matter is made up of WIMPS (weakly interacting massive particles), and once the WIMPS are trapped inside white dwarfs they annihilate and give out energy. This process will replace the nuclear burning in stars as the Universe's dominant method of energy generation.

Wimps Die Out

The supply of WIMPS has more or less come to an end, so their annihilation within white dwarfs has ceased to create energy. The Universe is a sparse sea of cold and dark white and brown dwarfs, neutron stars and dead planets and rock.

End Of Degenerate Era

Now things get a lot more speculative! Although protons were once thought to go on existing forever, a number of theories now indicate that protons may have a long but finite lifetime, perhaps in the range 1030 to 1040 years.

Proton decay would allow the degenerate era to end, and eradicate all the familiar forms of matter. But things wouldn't end there...

The Black Hole Era

This is the Black Hole Era, because the only remaining objects in the Universe are black holes. The universe is extremely dark, cold and unwelcoming. These black holes live for an extremely long time, but even they don't last forever. The black holes eventually evaporate through a very slow, quantum mechanical process known as Hawking radiation. The size of the black hole depends on how big it is: black holes with masses similar to the Sun will last for about 1035 years, whereas a huge black hole with a galaxy type mass will take about 10100 years to evaporate. When a black hole is near the end of its lifetime, it produces a minuscule haven of warmth, providing a room temperature environment less than a millimetre wide for about 1035 years. When even the biggest black holes have evaporated, the Black Hole Era will come to an end.

Dark Era

This is the Dark Era. The Universe is now empty of almost everything, and all that remains are the waste products from previous eras. There are a few photons floating around, but with immensely long wavelengths, and there are also some neutrinos, electrons and positrons. These particles are separated by inconceivably long distances, but there is the possibility of chance encounters. Electrons and positrons can experience a mutual attraction and form an 'atom' which is larger in size than the entire observable Universe of today. But these immense 'atoms' are unstable, and the positron and electron eventually spiral towards each other and annihilate. Energy and matter as we know it has withered away and dissipated. So is this the end of the Universe? Or is it just that humankind can't get its head around what all this really means? Scientists and philosophers can't decide on this one, so your guess is as good as anyone's...

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