The Universe: What is it, how it began, and its future
By : John Whitworth / Updated : May 10th, 2026 21:56
Contents
The Universe contains everything that exists — all space, matter, energy, planets, stars, galaxies, and even the vast emptiness between them. The Universe is everything that exists, and it has been expanding ever since the Big Bang, which occurred around 13.8 billion years ago.
Our The Solar System is just one tiny part of the Milky Way, itself one of trillions of galaxies. The most distant known galaxies, such as UDFj-39546284, formed only a few hundred million years after the Universe began.
Cosmologists divide the Universe’s lifetime into five eras — from the Primordial Era to the Stelliferous Era (our current age of stars), followed by the Degenerate, Black Hole, and Dark Eras.
The Universe will continue expanding for unimaginable lengths of time, likely ending in a slow "Big Freeze". However, theories such as the multiverse suggest our cosmos may be just one of many.
The Universe is everything that there is. The Universe includes space, planets, galaxies, stars and every other object outside the Earth's atmosphere that we know and don't know. The difference between space and the Universe is that space is the gaps between objects and not any physical objects, such as an asteroid. The Universe is everything, as mentioned at the start of the sentence. The size of the Universe is unimaginably large; it stretches further than we could ever imagine, and we would never be able to travel to the outskirts of the known Universe. If the Universe expands out, there is probably a location where there are no stars when you look out in one direction.
Our Earth is just one of eight planets orbiting a star called the Sun, which in turn orbits a supermassive black hole in the centre of our galaxy known as the the Milky Way. The galaxy is just one of many, many trillions of galaxies.
Currently, the farthest galaxy that we can see from the Earth is called UDFj-39546284. It can be found in the constellation of Fornax in the southern hemisphere. You won't be able to see it in the night sky, and it was spotted by N.A.S.A. using the Hubble Space Telescope. The galaxy is currently 13.2 billion light-years away from Earth. The galaxy of blue stars formed a mere 400 million years after the Big Bang. 1 There could be a galaxy further away, but its light has not reached us, or we've not discovered it. If a galaxy were further than 13.8 billion light-years away, we would have to rethink the age of the Universe. Reports say the Methuselah Star is older than the Universe itself.
Since it was born, the Universe has been expanding from the singularity from which it was born. It is believed that the Universe was tinier than a garden pea, with all its matter inside, and that it began to expand over time. The term Big Bang was given to the theory by opponents of the theory, but was later adopted by supporters who liked it. The Universe is still expanding in all directions. Galaxies are moving closer to one another, and the Andromeda Galaxy is a galaxy that is moving towards us. Some galaxies are moving away from us faster than the speed of light, and some galaxies are so far away that their light is so faint we can't measure it. 3 . One of the causes of why the Universe is expanding is believed to be dark energy and matter, something scientists don't yet understand.
There is a theory known as the multiverse theory, which says our Universe is just one of many universes that live in the Multiverse. These universes could be similar but for subtle changes, a change in decision, a change in the fundamentals of science, one that could allow faster than light travel.
The vast lifespan of our universe
The lifespan of the Universe is unimaginably huge. The Universe is widely recognised to be about 13.7/8 billion years old, having been created in the Big Bang. Some places say 13.7. Others will say 13.8 billion years ago. One theory says that there are not enough atoms in the Universe to represent the number of years left of the Universe's life. We don't know how long the Universe has left. It won't end in the next hundred years, so don't worry.
The Universe is like everything else. It has a beginning, a middle and an end. It is theorised that the Universe would one day end like most things, and there are several competing end of the Universe theories. Don't have nightmares. These events that will end the Universe will not occur for an unimaginable length of time. In the "Wonders of the Universe" television programme starring Professor Brian Cox of Manchester University, Brian said that there are not enough particles in the Universe to represent a year's worth of time until the end of the Universe. We are currently in the Stelliferous Era of the life of the Universe. It is also detailed in the book "The Five Ages of the Universe"2. There are five eras of the Universe, and they are:-
The five distinct stages of the universe
Primordial Era
This is the earliest of the five eras when the Universe was very young and had not yet formed into the molecules we know today.
Stelliferous Era
This is the era in which the Universe is currently. It is the age of Stars. By the end of this era, the stars will all have burnt themselves out, and all that remains are Black Holes, neutron stars and brown and white stars. This era is a very long time. During this time, stars will be born, die and be born again.
Degenerate Era
All that exists now will be neutron stars, black holes and brown and white dwarfs. The stars will have burnt themselves out and no longer be created. At this point, protons, the smallest matter particles, will start to break down and decay.
Black Hole Era
By this time, black holes will be the sole survivors, but these will start to break up and die over time. All that will be left are the protons and particles that have not decayed yet
Dark Era
It is just particles, protons, and light protons that inhabit the Universe. It will be as it was near enough a second before the Big Bang happened.
It assumes that the Universe will end in the Big Freeze when the Universe just slowly dies over time. Like stars reborn from the ashes of old stars, a new Universe could be born from the old.
Key facts about the universe
- No one knows how big the Universe is because it stretches further than we can see.
- The Universe contains all that there is, all the planets and stars, galaxies etc.
- There is a theory that our Universe might not be the only Universe but one of many in the Multiverse.
- The Universe was believed to have started 13.8 billion years ago in an event called The Big Bang.
- Although only 13.8 billion years old, we can see roughly 46.5 billion light-years in every direction. We can say that the observable universe is around 93 light-years. Metro
- The End of the Universe is an unimaginable length of time in the future.
- There are five stages to the life of the Universe.
- Primordial Era
- Stelliferous Era (Current Era)
- Degenerate Era
- Black Hole Era
- Dark Era
- Ever since the Big Bang, space has been expanding. Although some galaxies are moving away, the Andromeda Galaxy is moving towards us at about 75 miles per second, so there is no need to worry. The collision won't occur for five billion years.
