Chronology of the Universe

Our universe is 13.7 billion years ago. It turns out that it is actually comparatively young in terms of the whole lifetime of the universe.

We can review this below by looking at what physics says about the lifetime of the universe and its various eras:

(1) Primordial Era (beginning to 1 million years after the Big Bang)
The Big Bang is thought of as the beginning of the universe, and time and space had a beginning that is conventionally understood to be the origin of matter and energy inside of the singularity that was the Big Bang. Before the Big Bang, no space, time, matter, or energy existed.

One hour after the Big Bang and the cosmic inflation, there was the emergence of quarks, hadrons, hydrogen nuclei, and the origin of gravity, the strong force, weak force, and electromagnetic forces.

For the next million years, continuing inflation occurred and stable atoms formed.

(2) Stelliferous Era (1 million to 100 trillion years after the Big Bang)
The present era we live in is called the “Stelliferous Era.” By 100 million years after the Big Bang, the first stars developed.

This Stelliferous Era is a time in which new stars are still forming and most energy comes from nuclear fusion in stars. This is the era in which organic life can evolve and live, and in which civilizations with organic sentient beings can exist. This era will end by about 100 trillion years from now.

Since it was been 13.7 billion years from the big bang, we are at 0.0137% of the total age of the Stelliferous Era. In other words, only 0.0137% of the total age of the Stelliferous era has passed. The universe is remarkably young.

(3) Degenerate Era (100 trillion to 10 trillion trillion trillion years)
In 100 trillion years, the “Degenerate Era” will begin. Stars will no longer form and all the stars will die. Civilizations at that time will need to find new ways of existing in the absence of stars. By 10 trillion trillion trillion years from now, all the stars will have collapsed into black holes, neutron stars, or white dwarfs.

(4) Black Hole Era (10³⁸ to 10¹⁰⁰ years)
During this era, black holes are the only star-like objects. In this era, they all evaporate.

(5) The Dark Era (10¹⁰⁰ years to infinity)
In the Dark era, all the black holes have evaporated. Only photons, neutrinos, electrons, and positrons remain. The universe is dark and empty. This state of affairs will then continue to infinity. This era will begin in 10 000 trillion trillion trillion trillion trillion trillion trillion trillion years from now.

Finally, some examples of the types of numbers used above, so one can grasp the time scales:

10¹⁰⁰ = 10 000 trillion trillion trillion trillion trillion trillion trillion trillion years

10 trillion trillion trillion = 10 000 000 000 000 000 000 000 000 000 000 000 000

10³⁷ = 10 trillion trillion trillion years = 10 000000 000000 000000 000000 000000 000000