Once upon a time.....is how some of our favorite stories start. A magical kingdom, a beautiful princess and a very poor yet brave lad, all come together to gives us the blissful experience of a heartwarming tale. These are stories of the times past.
The story you are about to read is about the future and can only be told from its past, as you are about to see. Although fascinating there shall be no remembrance of these events and no stories told of it from memory, around a campfire.

source

The mysterious forces of our universe.

source

Our current understanding of the origin of our Universe is pretty good upto a small fraction of the time right after the Big Bang. It all seems to have started from a singularity about 13.8 billion years ago. Observations from Edwin Hubble in 1929 suggested that the universe was expanding. In general things are moving away from each other. source. It was the Hubble telescope that surprised us later showing that the universe is expanding faster than we expected. source The Big Bang left in its wake the Cosmic microwave background radiation. It is spread quite evenly throughout out the universe and was once warmer. Today it is only 2.725 degrees above absolute zero.source. There are sprinklings of warmer areas and colder areas.
Well by common sense notions with all the matter and heavy bodies in the universe, gravity surely would slow down the expansion of the universe or even reverse it. The Hubble telescope of NASA has proven this wrong. Surprisingly the universe is expanding faster than expected. How is this happening? Is there a mysterious force counteracting gravity? Not a whole lot is known about this mysterious force. Physicists call it the Dark energy. Dark energy is present everywhere and as Universe and space expand, there is newly formed space. This newly formed space will contain dark energy. As space expands dark energy grows in its effects. So we can calculate the magnitude of its effects and feel its presence in equations and observations but the rest ..... well it’s still in the dark. Dark energy seems to be stronger than opposing forces such as gravity and thus the universe is expanding. As galaxies and celestial bodies fly away from each other the density of matter and thus gravitational forces decrease. As space expands more dark energy comes into being. It’s easy to see who is winning the battle here. Another force that comes into play is Dark matter. Calculations suggest that this is matter that holds the elements of the universe together. Think of it as the glue of the universe. What is it is not known either. Particles making up dark matter have not been observed yet. The particles in theory has to be large heavy particles that have very weak interactions. Hence they are called WIMPS ( weakly interacting massive particles).source.
The above is a very basic understanding of Cosmic background radiation leading back to the Big Bang and giving us a better sense of the evolution and age of the universe as well as some basic forces of nature at work with the dark ones and even gravity yet escaping a comprehensive understanding.

The future timeline of the Universe.

Although I reviewed a large body of literature on the subject, the most fascinating read was the following book:

[source:Amazon]

This book is the primary source for the rest of this discussion.

The Sun and the Earth.

source
The sun is a fusion furnace with hydrogen fusing to form helium. The energy derived from this pushes the sun’s surface outwards and radiation is given off as light, mostly. The hydrogen eventually gets depleted and helium starts to fuse to form carbon. This reaction produces more energy and the sun starts to grow. The outer layers of the sun cool a bit but it is still very very hot and much closer. The sun may engulf the earth. It will surely eat Mercury. The sun is now large and red. A red giant. Whether it eats earth or not, it will evaporate oceans, melt the continents and make earth inhabitable. The earth becomes too hot to support life at 1,000,000,00 AD. Human race is long gone. Extinct. Maybe we survived by moving out into the Universe.Even long before that many catastrophic events would have happened and the future of humanity on earth may be far shorter. The sun eventually depletes it’s energy resources. The outer layers will fly away and it will turn into a white dwarf.

The Stelliferous Age.

source
Stars are all around us. Some new some old. There are low mass stars and high mass stars. Low mass stars burn through their fuel slower than higher mass stars. They all run out of fuel eventually. As they do they turn into red dwarfs, smoldering slowly and then become chunks of lifeless carbon and other ekements. Now they are called black dwarfs. In a 100 trillion years the stars are all dead. Except perhaps Elvis. 100,000,000,000,000 AD marks the end of this era.

The Degenerate Age.

10,000,000,000,000,000,000,000,000,000,000,000,000 AD.
What remains now are Black holes and a lot of dead stars. The are white dwarfs and brown dwarfs and neutron stars etc.
Here and there due to collisions and merging there may be a bit of light. Andromeda would have merged with our galaxy. Local dwarfs in galaxies come close to each other tending to coalesce. All gets eaten by the black holes. Black holes is all that remains.

The Black Hole Age.

source

10,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000 AD.
Black holes emit radiation and slowly evaporate. The lesser the mass gets the faster they evaporate. Near the end a black hole emits a large burst of radiation and is then no more. All black holes will disappear.

The Dark Age.

10¹⁰⁰ AD plus years.
All is dead and gone. Protons have decayed. Some stray photons, electrons, neutrons may be found here and there in the empty cold vastness of space.

The Big freeze, Big Crunch and the Big Rip.

Currently these 3 scenarios are described as the possible fates of the universe. Alternate endings, you might say. What Fred Adams and Greg Laughlin described is closest to what is now considered the Big Freeze, considered by most the likeliest fate of the universe. For those interested in the other 2 theories, click here.

Comments.

No story ever told is as beautiful, as poignant, as heart rending and as life affirming. In a small lonely corner of this vastness of the Universe, against all odds, we came to be. Our struggle and passion to understand life, ourselves and this Universe is astounding in the mere fact that we experience the desire for that knowledge. We are here for less than a blink on the cosmic scale. Our only chance of survival as a race will be to leave the universe. And go where??? The state of being for a human is so unfathomable that we with all our might shall seek happiness and joy in this world for ourselves and for others.

source