This website has earned its dozens of readers from writing about either the past, through its historical posts, or the present, through political analyses. Aside from an upcoming primary or election, however, PPFA has never taken a look too far in the future.
I recently found myself drawn into a disturbing internet spiral wherein I learned the possible fates of the universe. Most of us already knew that Earth’s days are numbered. Our sun is slated to bloat into a red giant in the next eight billion years or so, perhaps consuming our planet in the process. Many other doomsdays could end us before that point, of course, but we can assume that if humanity survives various apocalyptic scenarios — climate change, a meteor strike, a nuclear holocaust, self-aware artificial intelligence, a third Trump term, et cetera — to the point that we still exist in eight billion years, that likely means we found a way to move off this rock and into other solar systems. If this assumption were correct — if we successfully scattered humanity’s eggs into many baskets — you might think our species would be safe forever.
You would be wrong. Not only is humanity doomed, all life in the universe is doomed. So are the building blocks of life — every molecule, every atom, and even time and space itself. Some time in the very far future, it will be like this universe never existed.
What follows is a rough timeline of the future of everything.
2061 CE: Halley’s Comet makes another appearance. My parents tell me I saw it back in 1986 when I was three years old, but I was probably too distracted by the 1986 midterm elections to notice.
2113 CE: Pluto reaches the farthest point of its enormous orbit for the first time since its discovery in 1930. It still won’t be a planet.
2134 CE: Halley’s Comet shows up again.
2186 CE: We’ll experience the longest solar eclipse in thousands of years and for thousands of years. If you buy some property in northern Guyana, where the eclipse will last over seven minutes, your great-great-great-great-great-grandchildren will thank you.
2209 CE: Halley’s Comet shows up again. (Okay, I’ll stop.)
2492 CE: The eight planets and Pluto will be in the same 90 degree sector of the solar system for the first time since 949, which, it goes without saying, is the year the Byzantine eunuch Constantine Gongyles tried to retake the Emirate of Crete from Saracen occupiers. Infer significance at your leisure.
2640 CE: The scheduled end year for the St. Burchardi church organ’s rendition of John Cage’s “As Slow As Possible” in Halberstadt, Germany, which began back in 2001. Germans take song titles, like everything else, verrrry seriously.
2880 CE: The predicted impact date for (29075) 1950 DA, the asteroid that currently ranks highest on the Palermo Scale, which combines the likelihood of impacts with their potential force. With an average diameter of 1.1 kilometers, it would have a devastating effect on Earth. The scale suggests a 1 in 8,300 chance it’ll strike. I can’t decide if that makes me feel better or worse.
6939 CE: The scheduled opening of the first Westinghouse Time Capsule, 5000 years after its burial.
7200 CE: Without fine tuning, the Gregorian Calendar will have grown one day off of the vernal equinox. Way to go, Church.
10,000 CE: We’d wrestle with the Y10K Problem. It’s like Y2K, but five times worse.
22,000 CE: It again becomes safe to live in the one-thousand square mile Chernobyl Exclusion Zone.
36,000 CE: Around this year, the red dwarf Ross 248 will become the nearest star to our sun at an approximate distance of 3.024 light years. After another 8,000 years, Alpha Centauri will regain the crown.
(Since all times that follow are estimated, and since it feels unlikely that humanity will be both alive and using our current calendar, what follows are just “years from now” numbers.)
50,000 years from now: Niagara Falls will have finished eroding the 20 miles of land underneath it all the way to Lake Erie. So book your honeymoon soon.
100,000 years: The motion of the stars and galaxies will have outdated many of our constellations. Astrologers will find new ways to convince gullible people that they matter.
1.3 million years: The new closest star to our own, Gliese 710, will reach its closest point — just 0.221 light years, or only about 270 times the farthest distance of Pluto. From Earth’s vantage point, it would be brighter in our night sky than Mars. It would also shake up the many outer orbiting Small Solar System Bodies (like Andrew Messam), likely sending many into the inner solar system, increasing the likelihood of an impact on our planet that we wouldn’t be able to predict until Gliese’s arrival acts as the catalyst. We could really use a giant space laser by then.
50 million years: The maximum estimated time it will take for Mars’s moon Phobos to crash into its host planet. If we’ve colonized Mars, that’ll be a big problem for the colonists. Space lasers could really solve some issues.
110 million years: The sun’s luminosity will have climbed 1% from today’s output. This rate — one percent every 110 million years — will continue for a few billion years.
180 million years: Due to the moon’s ongoing effect of gradually slowing the Earth’s rotation, by this point an Earth day will be 25 hours long. Finally that extra hour we need to get everything done!
350 million years: Continental drift has rejoined the continents in a Pangaea Ultima, which, if I ever have a third child, is now the leading contender for its first and middle name. Boy or girl, I don’t care. “Pangaea Ultima for America.” Mm, yeah, that’s nice.
500 million years: It is likely that by this time there would have been a dangerous supernova within 6,500 light years of Earth. Such an explosion would emit Gamma-rays that, if pointed at us, could destroy our ozone and be catastrophic for life on Earth or any other colonized planets.
600 million years: The moon, which is slowly receding, will be too far to create a total solar eclipse. I’m starting to think your real estate investment in Guyana was a bit shortsighted.
Also 600 million years: The sun’s luminosity, now nearly 5% more than today’s, climbs to the point where it disrupts the critical carbonate–silicate cycle, the effects of which are water evaporation and rock hardening, which will stop tectonic shifts and shut down volcanoes, which then cannot recycle carbon, which then lowers carbon dioxide levels to the point where photosynthesis can no longer occur. Almost all plant species will start to die, and consequently so will most species that rely on plants to survive. (Barring a man-made or unforeseen cosmic catastrophe, it is this point — not the sun swallowing us up in billions of years — that feels like the hardest deadline for us to be off this planet.)
700 million years: The loss of plant life deprives the planet of oxygen. The lack of the planet’s typical atmospheric gases exposes Earth to DNA-damaging UV rays, farther increasing global temperatures. Nearly all land will become desert. All remaining species will likely be nocturnal and eke out a living at the poles, underground, or deep in the slowly evaporating ocean.
800 million years: All multi-cellular life is likely dead. (The reign of the amoeba begins?)
1.1 billion years: The sun’s luminosity is 10% stronger than it is today. The average surface temperature of the planet will be 116 degrees. Our atmosphere will turn into a sort of greenhouse, resulting in runaway evaporation of oceans. Water will only exist at the poles, with simple life restricted to those two regions. See? Global warming. Al Gore was right all along.
1.2 billion years: The highest estimate of when all plant life is dead. Good run for plant life there, though.
1.6 billion years: Prokaryotes are dead.
1.6 billion years: The sun’s increased luminosity makes Mars about the temperature Earth is now, which would be pretty nice for any human colonies that survived the Phobos Catastrophe of Fifty Million CE.
2 billion years: Our oceans have likely evaporated.
2.3 billion years: Core problems shut down Earth’s magnetic field. Solar radiation depletes the atmosphere.
2.8 billion years: The planet’s average temperature reaches 147 degrees Celsius (296 F). It’s the highest estimate of any remaining single-celled going extinct.
3 billion years: The moon is so distant it barely provides a ballast to Earth’s axial tilt, which then spins wildly.
3.5 billion years: The sun’s luminosity is up 40 percent, turning Earth’s average temperature to over a thousand degrees Celsius, or twice the current temperature of Venus. Surface rock turns molten.
4 billion years: The Milky Way and the nearby Andromeda Galaxy, which are on a collision course, finally start to collide and merge into a super-galaxy, not at all jokingly called Milkomeda. This merging, surprisingly, is unlikely to cause much disturbance to individual solar systems.
5.4 billion years: The sun runs of out hydrogen to fuse and begins feasting on helium, which begins its transition into a red giant.
7.5 billion years: Our red giant sun “tidally locks” Earth and Mars, meaning one side of the planet will always face it, like the Moon does us.
7.6 billion years: The probable death of the Earth at the hands of a swollen sun, which has grown to about 250 times its current size, swallowing up our former home.
8 billion years: The sun begins cooling and collapsing into a white dwarf, which it will remain for billions of years.
13.8 billion years: The universe reaches twice the age it is now.
With the Earth consumed, the solar system transformed, and our galaxy unrecognizable, we’ll now zoom out a little bit and look at things on the universal scale to see how it becomes the next casualty of unrelenting time. According to most scientists, our universe will suffer one of three realistic fates — the Big Rip, the Big Crunch, and the Big Freeze (or Big Chill). All three theories consider our expanding universe, but only one adequately acknowledges our latest, if scant, understanding of dark energy, which is driving the universe apart faster than gravity can keep it together. Dark energy and dark matter, which make up most of the universe, are mysterious to us, hence their names and uncertain effects they’ll have on the universe’s fate.
The Big Rip is the earliest possible fate — just 22 billion years away, by one major calculation — but fortunately it’s one of the two outdated scenarios. It assumes that dark energy is not just winning the war with gravity and other forces that keep things together, but dominating those forces. True enough, our universe is not only expanding, but observations from the last few decades determined that it is doing so faster and faster. The Big Rip suggests dark energy will gradually just stretch everything apart — not just the universe, but eventually all smaller things as well — galaxies, solar systems, planets… everything down to the atomic level. According to Wikipedia:
“About 60 million years before the Big Rip, gravity would be too weak to hold the Milky Way and other individual galaxies together. Galaxies would be destroyed as stars separate from the main black hole. Approximately three months before the Big Rip, the Solar System (or systems similar to our own at this time, as the fate of the Solar System 22 billion years in the future is questionable) would be gravitationally unbound. Planets would be detached from the star’s orbit. In the last minutes, stars and planets would be torn apart, and an extremely short amount of time before the Big Rip, atoms would be destroyed. At the time the Big Rip occurs, even spacetime itself will be ripped apart and the scale factor will be infinity.”
Not fun. (For a short story about two modern-day women handling news of the Big Rip when it’s announced that it’s not 22 billion years in the future, but just six months away, find ten minutes to read Stephen Baxter’s “Last Contact.”) Fortunately, recent observations suggest dark energy won’t condemn us to our atoms ripping apart.
Farther away but even more unlikely than the Big Rip is the Big Crunch, which would be a long process slated to take place from 100 billion to 1 trillion years from now. Whereas the Big Rip results from dark energy overwhelming the forces that hold the universe, galaxies, solar systems, and atoms together, the Big Crunch theory says that the density of the universe overcomes dark energy, meaning that gravity would ultimately prevail. Then, like hitting rewind, the universe would contract in on itself into an infinitely powerful black hole. Everything would get closer and closer together until the universe returns to the kind of singularity it was before the Big Bang. Says Wikipedia:
“Galaxy superclusters would first merge, followed by galaxy clusters and then later galaxies. Eventually, stars have become so close together that they will begin to collide with each other. As the Universe continues to contract, the cosmic microwave background temperature will rise above the surface temperature of certain stars, which means that these stars will no longer be able to expel their internal heat, slowly cooking themselves until they explode. . . . Minutes before the Big Crunch, the temperature will be so great that atomic nuclei will disband and the particles will be sucked up by already coalescing black holes. Finally, all the black holes in the Universe will merge into one singular black hole containing all the matter in the universe, which would then devour the Universe, including itself.”
Also not fun. Interestingly, some scientists suggest that after that point there would be a Big Bounce and the universe would start all over again with another Big Bang, another expansion, and then another Big Crunch 100 billion years later, and then we’d repeat that an infinite amount of times. In fact, if this were the cycle, there’s a strong probability that we’re already in some version of this process well after the “first” universe, with all life, matter, and knowledge from past universes having already been eradicated, like our’s one day will be. That’s creepy to think about, so take solace in the fact that the Big Crunch theory is generally considered disproven. Hypothesized before we understood the universe’s accelerating expansion, its initial data is outdated.
That brings us to the leading scientific theory of the universe’s fate, and it’s thankfully farthest away — the Big Freeze. For the proper context, consider that if the universe keeps expanding faster and faster, there will come a time where it’s expanding at an incomprehensible rate. For example, around 1.25 trillion years from now, galaxies that are now one megaparsec apart (a megaparsec is a million parsecs, or 3.26 million light years, which is a bit greater than the distance from the Milky Way to our galactic neighbor, the Andromeda Galaxy) would be receding from each other at a speed of a hundred million times the distance of the current observable universe, or 93 billion light years, every second. It’ll be quite the eye-opener when the distance between our galaxy and others grows at a rate faster than the speed of light, because it is then that we will cease seeing these galaxies altogether. One by one, galaxies, which make up many of the points of light in a night’s sky, will blink out of observable existence, like they never existed to us, nor we to them.
An important side-effect of this rampant inflation is that the universe will gradually cool as it expands. As all stars use up their energy, they’ll collapse into tiny neutron stars, dwarf stars, or black holes. The universe will consist of fewer and fewer stars. The key tipping point will be about 100 trillion years from now, when the universe’s hydrogen supply runs out and new stars cannot be born. The universe will then enter its Degenerate Era. Any stars created before the deadline will live out the rest of their respective evolutions, but the number of total stars will only fall. By 120 trillion years from now, our galaxy, for example, will likely only have a hundred or so stars still barely shining, like the last of a species taking its final, whimpering breaths.
Gradually, all stars will rot away, outlived only by black holes and random stellar remnants. The “Black Hole Era” will begin in 1040 years, but even black holes will gradually decay through Hawking Radiation. By 10100 years, when the universe arrives in its Dark Era, it will be essentially empty.
Nah, I can’t leave you like that — especially on a Monday of all days. Interestingly, some physicists suggest sufficiently advanced life might be able to create a sort of escape pod — a life raft to save us from drowning in the cosmic abyss. Theoretically, future beings could either create their own universe and inject themselves into it, or if the multiverse theory is correct, they might also find a way to access other already existing universes. Fingers crossed, amiright?