Life Story of the Universe

The Life Story of the Universe is the history of the cosmos, and the many phases, dynamics, and stages that it went through from its inception to its present state. At present we can trace the life story of the universe backwards to the singularity it began as, and can see a number of relevant stages in the history of the universe based on a number of pieces of evidence, such as the generations of stars that we observe.

The Birth of the Universe

According to the most commonly accepted theory — the Big Bang Theory — all matter, energy, and space was created about 13.7 billion years ago in a cosmic explosion. The so-called Big Bang.

The universe began as a tiny, hot ball compressed under extreme gravitational forces, like the singularity of a black hole. For some reason, this state of the universe became unstable and erupted in a cosmic explosion of matter.

Nuclear particles coalesced together to form hydrogen and a smaller amount of helium (the first atomic elements to be created) and expanded in a giant cloud of hot gas. The hot gas gradually cooled as the universe expanded, and since this event 13.7 billion years ago, throughout the expanding universe this cloud of gas collapsed to form galaxies, stars, planets, and asteroids resulting in the complex environment of space that we see today.

Scientists can trace the Birth of the Universe back to Planck time, of the order of 10^-43 seconds — literally trillionths of trillionths of trillionths of a second — beyond which the laws of physics as we presently understand them break down. We literally of no clue what came before, and at the moment, no way to find out.

No theories of before have any real value, all being based entirely on no facts and rampant speculation.

In the image above, you can see gradations in temperature of the universe, which arose from the Big Bang itself.

Expansion and Growth

The initial temperature of the universe was about 10 trillion degrees Celsius. As the universe cooled during the early years of its expansion, matter began to clump together. The first atoms created were hydrogen and helium, at a ratio of about 75% hydrogen to 25% helium.

As the universe cooled, matter began to clump together. The giant cloud that was the universe in those days, also collapsed in on itself due to gravitational forces, creating the first galaxies and the oldest generation of stars.

The Milky Way, our home galaxy, formed about 13.6 billion years ago, according to the best estimates by modern astronomers and astrophysicists, within a 100,000,000 years of the Big Bang. As such, the Milky Way is relatively old in the Universe. The youngest galaxy we know of formed closer to 500,000,000 years ago.

The Sun formed about 5 billion years ago, during which time the planets also begin their formation, about 8 billion years after the Big Bang. However, our star is of the younger generations of stars. Life emerged on Earth shortly after its formation, close to 10 billion years after the Big Bang.

Cooling Data of the Universe

(This might be out of date.)

The Death of the Universe

At present the universe is still expanding, although its rate of expansion is not behaving in a way that we completely understand.

Two main theories of the end of the universe exist. Either it will expand eternally, gradually becoming a diffuse remnants of matter as it expands for the rest of time into the infinite vacuum of space.

Or its rate of expansion will slow down, eventually ceasing. If this occurs, it is believed that the universe will begin to collapse again under its own mass, moving back towards the infinitely dense state in which it began in a process called the Big Crunch.