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The End of Everything

The Dark Ages, not a single star shines anywhere in the Universe.It can be said that humans have a bit of a short term view of things. We’re concerned about the end of summer, the next school year, and maybe even retirement. But these are just a blink of an eye in cosmic terms. Let’s really think big, stare forward in time, and think about what the future holds for the Universe. Look forward millions, trillions, and even 10100 years into the future. Let’s consider the end of everything.

End of Humanity – 10,000 years
Modern humans originated in Africa about 200,000 years ago. Since then, we’ve gone on to inhabit every single corner of the globe. But this is just temporary. The vast majority of every species that has ever lived on Earth is now extinct. To think that humans can avoid the fate of every other creature is arrogant. Like all life on Earth, our time is limited. How long will we last?

There are many natural and man made disasters that could wipe us out. From an asteroid strike to worldwide pandemic; global warming to a nearby supernova detonation – there are many ways we could go. Perhaps we’ll wrap it up in a mass extinction event, such as the one that killed the dinosaurs 65 million years ago, or “the Great Dying”, 251 million years ago that killed 70% of land species and 96% of all marine species.

Perhaps another species (intelligent cockroaches, rats) will evolve, and out compete with us in our niche. Or maybe we’ll engineer our robotic replacements.

But a species can last tens or even hundreds of millions of years. So how can we predict when our number will be up?

There’s no way to know, but there’s a calculation that can help. It’s called the Doomsday Argument, developed in 1983 by astrophysicist Brandon Carter. According to Carter, if you assume that half of the humans who will ever live have already been born, you get approximately 60 billion people. If you assume that another 60 billion are yet to be born, our high population levels only give us another 9,000 years or so. Or more precisely, there’s a 95% chance that humanity will have ended by the year 11,000.

There are other calculations, but they give similar amounts, ranging from a few thousand to a few million years.

That’s a long time, but not long enough to appreciate the future the Universe has in store for itself.

Gobi Desert. Image credit: NASA

End of Life – 500 million years – 5 billion years
We thank the Sun for giving us energy. Without it, there’d be no life on Earth. It’s ironic, then, that the Sun will eventually kill all life on Earth.

That’s because the Sun is slowly heating up.

One of the most fascinating books about this topic is The Life and Death of Planet Earth by Peter Ward and Donald Brownlee. In their book, they chronicle how Sun’s energy output is slowly increasing. In as soon as 500 million years, temperatures on Earth will rise to the point that most of the world will be a desert. The largest creatures won’t be able to survive anywhere but the relatively cooler poles.

Over the course of the next few billion years, evolution will seem to go reverse. The largest organisms and least heat tolerant animals will die out, leaving hardy insects and bacteria. Finally, it’ll be so hot on the surface of the Earth that the oceans will boil away. There’ll be no place to hide from the terrible temperatures. Only the organisms that live deep underground will survive, as they have already for billions of years.

Red giant Betelgeuse. Image credit: Hubble Space Telescope

End of the Earth – 7.5 billion years
As mentioned above, we exist because of the Sun’s good graces. But as our star nears the end of its lifetime, it’ll take our planet out as it goes; one way or another.

In approximately 5 billion years from now, the Sun will begin the final stage of its life, consuming the last of its hydrogen fuel supply. At that point, gravity will force the Sun to collapse, and only a small amount of hydrogen will remain in a shell wrapped around the star’s core. It will then expand into a red giant star, consuming each of the inner planets: first Mercury, then Venus, and finally encompassing even the orbit of Earth.

There is a controversy about whether or not a red giant Sun will actually burn up the Earth. In some scenarios, the change in the Sun’s density as it expands causes the Earth to spiral out away from the Sun, keeping out of reach. In another scenario, the Sun’s outer envelope will enclose the Earth. The additional friction will slow the Earth down, causing it to spiral down into the Sun.

Whatever the outcome, the Earth will be scorched to a cinder, and effectively destroyed, 5 billion years from now.

Ring Nebula. A vision of our Sun

End of the Sun – 7.5 billion – 1 trillion years
When the Sun becomes a red giant, that’s only the beginning of the end. With the end of its hydrogen, the Sun will have switched to fusing helium, then carbon, and finally oxygen. At that point, our Sun will lack the gravity to continue the fusion process. It will shut down, and shed its outside layers to form a planetary nebula, such as the ring nebula we can see in the night sky. It’ll then settle down to live out the rest of its days as a white dwarf.

It will still retain most of its mass, but have a size no larger than the Earth’s diameter. Once yellow-hot with the heat of fusion, the Sun will slowly cool down over time. Eventually, its temperature will match the background temperature of the Universe and it will become a cold black dwarf star – an inert chunk of matter floating in the darkness of space.

Even the oldest white dwarfs still radiate at several thousand degrees Kelvin, so the Universe hasn’t been around long enough for black dwarfs to exist.. yet. But give the Sun another 1 trillion years or so, and it should finally become a cold black dwarf.

Artist impression of a disk of material around a white dwarf star. Image credit: Gemini Observatory

End of the Solar System
Even though the Sun will have burned out billions of years from now, the planets that weren’t consumed will remain. Perhaps even Earth will join that group. Certainly Jupiter, Saturn, the rest of the outer planets and the Kuiper belt objects will remain orbiting for eons.

A recent discovery published in the journal Science, reported that astronomers had discovered a disk of rapidly rotating metallic material orbiting a white dwarf. Researchers built a simulation where they put hypothetical planets in orbit around a dying star, and found that the star’s death wreaked havoc on the stability of a star system. Changes in the mass of a star causes planets to collide, and rearrange their orbits. Some spiral into their star, while others are ejected into interstellar space.

Once all these new gravitational interactions are worked out, all that might remain of our solar system is the white dwarf remnant of our Sun and the rapidly rotating disk of planetary wreckage surrounding it. Everything else will be lost to interstellar space.

Hubble Deep Field survey shows many many galaxies. Image credit: Hubble

End of Cosmology – 3 Trillion Years from Now
The Universe acts as a natural time machine. Since light moves at the speed of, well, light, we can look at distant objects and see them how they looked in the past. Look to the very ends of the visible Universe, and you see light that was emitted billions of years ago, shortly after the Big Bang.

It’s handy, but there’s a problem. That mysterious dark energy force, which is accelerating the expansion of the Universe is making the most distant galaxies move faster and faster away from us. Eventually, they will cross an event horizon and appear to be moving away from us faster than the speed of light. At this point, any light emitted by the galaxy will cease to reach us. Any galaxy that crosses this horizon will fade away from view, until its last photon reaches us. All galaxies will disappear from view forever.

According to a new research paper by Lawrence M. Krauss and Robert J. Scherrer, future astronomers living 3 trillion years from now will only see our own galaxy when they look into the night sky.

This accelerating expansion has another consequence as well. The cosmic microwave background radiation, which astronomers used to discover evidence of the Big Bang will have faded away too. Not only that, but the abundance of chemicals, which precisely match the amounts theorized for the Big Bang will be hidden by subsequent generations of stars.

And so, 3 trillion years from now, there won’t be any trace of the Big Bang. No clues for future cosmologists to recognize that the Universe we live in started from a single point, and has been expanding ever since. The Universe will seem static and unchanging.

The core of the Milky Way seen in Infrared. Image credit: Spitzer

End of the Milky Way
Galaxies collide. All you have to do is look out into space with a telescope and see the fate that awaits our galaxy. In all directions we can see the interactions between the gravity of various galaxies. At first the encounters are violent; galaxies tear at each other, stripping off material, and generating huge swaths of star formation. The dormant supermassive black holes at their centres spring to live and become active galactic nuclei, gobbling up the newly delivered material.

Our future merger partner is barreling towards us right now: Andromeda. In approximately 2 billion years from now, our two galaxies will collide, and then pull apart. Then they’ll collide again and again until they settle down into a new, larger galaxy: Milkomedia. The twin supermassive black holes will orbit one another, and eventually merge together into an even more massive black hole.

Our position in the galaxy will change; we’ll probably be pushed out to the outer reaches of the galaxy’s halo – at least 100,000 light years from the centre. Since the Sun will still have billions of years left, some future form of life on Earth might be around to watch these events unfold.

The merger process will be complete approximately 7 billion years from now.

That’s not the end of the galaxy, though. It will still be an island in space, with stars orbiting a central core. Over a long period of time, though, estimated to be between 1019 1020 years. The galaxy will erode, with all the stars escaping into intergalactic space.

Artist impression of a white dwarf, surrounded by shed material. Image credit: STSCI

End of Stars – 100 trillion years from now
We can look out into the Milky Way and see stars forming all around us. There is still enough remaining gas and dust in the Milky Way to create whole new generations of stars. But when we look at other galaxies, we can see older, elliptical galaxies which have already used up their free gas and dust. Instead of the bright, hot stars we see in star forming regions, these aging red galaxies are cooling down.

One day there won’t be newly forming stars at all. And then one day, the last star will use up the last of its hydrogen fuel, become a red giant and then fade away to a white dwarf. Even the dimmest stars, the cool red dwarfs will use up their fuel – although, it might taken another 10 trillion years or so. They too will turn into black dwarfs.

And so, in about 100 trillion years from now, every star in the Universe, large and small, will be a black dwarf. An inert chunk of matter with the mass of a star, but at the background temperature of the Universe.

Artist illustration of a black hole. Image credit: NASA

The End of Regular Matter – 1030 years
So now we have a Universe with no stars, only cold black dwarfs. There will also be neutron stars and black holes left over from the time where there were stars in the Universe. The Universe will be completely dark.

A future observer might notice the occasional flash, when some object interacts with a black hole. Its matter will spread out into an accretion disk around the black hole. And for a brief period, it will flare up, emitting radiation. But then it too will be added to the mass of the black hole. And everything will go dark again.

Chunks of matter and binary black dwarfs will merge together creating new black holes, and these black holes will be consumed by even larger black holes. It might be that in the far future, all matter will exist in a few, truly massive black holes.

But even if matter escapes this fate, it’s doomed eventually. Some theories of physics predict that protons are unstable over long periods of time. They just can’t last. Any matter that wasn’t consumed by a black hole will start to decay. The protons will turn into radiation, leaving a fine mist of electrons, positrons, neutrinos and radiation to spread out into space.

Theorists anticipate that all protons in the Universe will decay over the course of 1030 years.

Artist impression of a black hole consuming a star.

End of Black Holes – 10100 Years
Black holes were thought to be one-way streets. Matter goes in, but it doesn’t come out. But famed astrophysicist Stephen Hawking turned that concept on its head with his theory that black holes can evaporate. It’s not much, and it’s not fast, but black holes release a tiny amount of radiation back into space.

As it releases this radiation, the black hole actually loses mass, finally evaporating away entirely. The amount of radiation increases as the black hole loses mass. It’s actually possible that it could generate a final burst of X-rays and gamma rays as it disappears completely. Future observers (who survived their protons decaying) might see the occasional flash in an otherwise dark universe.

And then in about 10100 years, the last black hole will be gone. All that remains is the radiation emitted.

The Dark Ages, not a single star shines anywhere in the Universe.

The End of Everything – 10100 years and beyond
When the last black hole evaporates, all that will remain in the Universe are photons of radiation, and elementary particles that escaped capture by black holes. The temperature of the entire Universe will reach a final temperature just above absolute zero.

Dark energy may play some future role, continuing the expansion of the Universe, accelerating each of these elementary particles and photons away from each other until they’re effectively cut off from one another. No future gravity will bring them together again.

Perhaps there will be another Big Bang someday. Perhaps the Universe is cyclical and the whole process will start up again.

Perhaps it won’t, and this bleak future of a cold, dead Universe is all that awaits us. It’s not happy, but it’s awe inspiring to consider the long future ahead, and helps us appreciate the vibrant age we live in today.


Fraser Cain is the publisher of Universe Today. He's also the co-host of Astronomy Cast with Dr. Pamela Gay.

Comments on this entry are closed.

  • jeepin May 1, 2008, 4:54 PM

    Great read. We’ve all heard the story before, in one way or another….but it’s good to be reminded that the odds are stacked against us, and we’re all in this together. It’s easy to sit back and take the approach of “Well, I’ll be gone before it’s a real issue,” but we must remind ourselves that some day people won’t be gone when the “real issue” finds them. We must never cease asking the hard questions, taking on the most difficult challenges, and being innovative enough to solve them.

  • Daniel Blundell May 2, 2008, 1:26 AM

    Our great arbiters of truth have spoken. Kneel before them and digest if you can you plebs their inane ramblings on universal discourse.

    I wonder what the great bard Terrence Mckenna would have thought of this? Novelty is a process of accretion and spirituality is a process of unfoldment. Listen up all ye MATERIALISTS, your days are numbered.

  • biblio basherio May 2, 2008, 4:38 AM

    Of course God will come into play. He will scoop the dead universe up into his giant hand and give it the David Blaine kiss of life. Satan will be fuming bevause that was never mentioned in their $1 dollar bet for mans souls.

  • Ian M May 5, 2008, 5:10 PM

    Gribben (great reference Archon) – provides the theory to build upon here: Edges imply a center. Expansion begets weakening. If something (or in this case, everything) is stretched too far, it tears. If you are reading this, you know what happens when spacetime is torn.
    It could well be that the universe is receding already. If not, it will be – and all the matter of the universe will be condensed into a very small place. If you are reading this, you know what happens when all the matter of the universe is condensed into a very small place. And so it goes…a sort of universal tide.

  • Everton May 8, 2008, 4:09 AM

    Oh well. Will the last person (or thing) to leave switch the lights out. Thank you.

  • meagan May 9, 2008, 11:15 AM

    Hi there im very worried about gobal warming and the earth ~! i would like my kids and my family live to see there lifes ! from 2008 how much longer do we have on earth to live ?
    whate happens when the earth cools in the next 10 years? please get back to me

  • Stuart May 10, 2008, 6:59 AM

    Interesting, veryyyy interesting…just too many zeros in those numbers for my little brain to take in. Now if all this happens ‘naturally’ I guess humanity has nothing to complain about. It’s the (sometimes) foolish pilocs that lead us into destroying each other that we need to be aware of. My bet would be they get to us all long before the ‘natural’ stuff comes along. Live, love and enjoy, and if you can, offer a little prayer…:-)

  • M.Jones May 10, 2008, 11:01 AM

    Do we all knoiw what happens AFTER the dark matter phase of the universe? I do. its a technical knockout screen. Fading into static, and then starting over again.

  • Alex May 13, 2008, 11:22 AM

    This is of course assuming the universe doesnt re collapse back into itself in the big crunch. If indeed the big crunch does occur, it may occur before even a starless universe does. I too have wondered how long it would take for all the stars in the universe to die out, but from my understanding of the big crunch, the universe will have collapsed in upon itself long before 100 trillion years.

  • Fuzzie May 21, 2008, 4:41 PM

    I think angryrat is correct. Recent scientific discoveries related to the human mind and its consciousness point to the idea that consciousness exists solely as a product of neural synapse translations. If this science turns out to be true, then it follows that each person’s own subjective “awareness” is a consequence of human nature itself. Therefore, on bodily death, consciousness must evaporate too as neurons stop firing. So, how then can mankind really know anything for certain about natural law given these limitations? Our technologies may advance, but human nature won’t – otherwise we become something other than human. Like angryrat says, this is all we have.

    Yet, with respect to Fraser Cains superb article, I think it’s still amusing to speculate what “the end” might be like. Given the uncertainties posed by 2012, I have, unlike Cain, some trouble grasping a solid understanding of how the universe might die. There are too many variables to consider, IMO.

    The most important question to me is, what would happen AFTER everything ends? (Conversely, what happened BEFORE everything began?) If the space/time continuum is involved in such a development (the end of the physical universe as we know it and as Cain proposes it), it wouldn’t matter whether it’s Quantum Theory or General Relativity Theory which would dominate any such discussion.

    Cain says the photons at the very end fly off into infinity, but then if they should do so, space would prove to be infinite, would continue on, and ultimately would make itself the substance of the universe. And time factors in too. It’ll take time in Cain’s scenario for the photons to keep flying away. Hence, would ongoing time mean that time itself, like space, also would be eternal? If time space is infinite, then the universe would also continue existence with ongoing time and the continued spatial expansion of some future emptiness. Both GRT and QM have not yet adequately addressed time space in QM probabilities nor in a GRT universe for me to see clearly that there would be any end whatsoever to the universe.

    The question then remains: what happens after the end of everything? The question is not yet answered for me.

    And then there are the questions of superposition and coherence values. Can a photon be here and there at the same time? It would seem that if time and space are eternal, then a photon at the end of everything would move from here to there. A thing cannot exist in two points at the same time. This idea also then logically implies an eternally existing universe.

    But what if time space are not infinite? What happens if time space breaks down for some unimagined reason at some unknown point in time in the developing cosmos? Could a new set of laws of physics arise – vastly different laws than those we now know – to determine any (cold, heat, other) death of the universe? Would we as people at such future time become subject to some fourth, fifth, or, say, 265th dimension?

    Would different physics and alternative dimensions perhaps rule some sort of “multiverse”, with subset universes themselves operating under even other alternative laws of dynamics, laws relevant only to each little bubble universe? Would some smaller multiversal universes indeed die and others live on forever? Could there be multiverses of multiverses? How could we ever really understand any of these possibilities, since we are products of our own current physical and chemical laws?

    And, to make matters even worse, let’s suppose that Kardashev’s scales of civilizations are in fact true? How does an advanced civilization extract needed energy from an almost absolute zero energy state, which Cain supposes would be the status of our universe at its demise? Might any advanced civilization impose its own causalities into low entropy or high entropy states? How would this impact “the end”? Would there even be an end if humans become the masters of their own fate? Or would mankind always be a “step behind” as I mentioned previously, keeping current physics intact, where Nature is the master of its own product – us?

    Just too many questions for me. Maybe someone else reading Cain’s article could further hypothesize on some of these matters for me? With all these uncertainties in my mind, I’m perplexed.

  • Fuzzie May 24, 2008, 8:18 AM

    I need a theory of everything bad. Too much of a lay cosmo-buff for my own good.

  • Hanchai Sawangned May 27, 2008, 2:34 PM

    Thanks for 63 comments, please don’t miss “Universe(s, infinity or not please verify?) Consistant” Human Mind & Body Concern to Hydrogen Atom & Electron Levels With Space Between Its[when electron speed is limtied to be zero or and it’s light speed]. Space-Time-Mind Suituation @ It’s Balance State & U(s) Came From 8[infinity state balance], Pi is 22/7 0r and 3.1415926…[usa used it]…8[infinity],it is basic of The Periodic Table of Elements and The-o-ry of Everything [good & bad]. Because of Circle & Globe Made from 2-Legs (Divider[s]) staring point to the end is reached the starting point again & again [8(infinity) state untill U(s)-Legs Weak it will change it’s Level]. Is it or not? please verify?

  • Gralgrathor June 4, 2008, 2:48 AM

    @ Andrew, 2008-04-30 09:38

    “If we manage to overcome a few technological hurdles in the here and now then there’s really no limit to what humanity could achieve in the next five hundred, thousand, or six-thousand years.”

    I bring in to play the next bit of interesting philosophy: the Fermi Paradox.

  • Graham Richard June 24, 2008, 12:19 PM

    Jeff Lloyde;

    Your ignorant drivel is exemplary of the wanton grammatical depravity that runs rampant in the English language. Your speech is as a hideous plague, a desecration of our beautiful language. Your comment is a disgrace to the satire of this article and to the legacy of our tongue! Flee from your dereliction, away from any implements of the written word, never again to obscure the corners of the internet with your incomprehensible cyber-babble!

    Go wallow in self-despise and bask in the vehement isolation of my scorn!

    A curse upon the linguistically irreverent! May you forever wear not but the most tasteless of neck-ties and may you stutter your way through every one-liner!

    Graham Richard.

  • Graham Richard June 24, 2008, 12:24 PM

    Hi-five, Pommy. That’s nerd-core.

  • Tom W June 24, 2008, 4:26 PM

    Dear Mister Richard,
    That was harsh.

    Fraiser Cain,
    it is almost incomprehensible that one day there will be nothing while now we have so much, your article however is very informative and has helped me greatly with my school work.

    To the haters,
    If you dont want to read about this kind of stuff, what are you doing sucking the bandwidth from others that do want to read it, there is no law against free speech, and even less laws against posting it on the internet, unfortunately there are also no laws against being wankers, seriously just go sit in the corner and wait for your judgment day.

  • chaz metty June 30, 2008, 4:11 PM


  • darrin kenneally July 4, 2008, 10:42 AM

    i agree with tom w.if you read the whole article then it must have been interesting.Cain did his job.haters go away

  • Nohemi July 15, 2008, 7:34 PM

    This article was really nice to read it really gave me a strong perspective of the world and how we live it and stuff, I think this is nice for me since im just 13.

  • Matthew August 28, 2008, 10:46 PM

    Infinity must be rethought. The common idea of infinity is that it is endless. No thing is endless, only nothingness is endless. Also, nothingness is an eventuality like death is an eventuality. Whole universes die, every thing that is, dies; structures die. However, reality will never die, because it is both nothing and something at the same time. There are some things in it, but waiting behind the notes of the song is a silence, it is an eventuality. I tend to believe that reality is cyclic, like seasons of eventfullness vs timeless emptiness. Those times of evenfulness are like flowers, like life itself, and thus is supremely sacred because it is unique in all of reality!