Timeline of the Far Future

This article features the first new content for this project after its fourth birthday. Anniversaries inherently elicit exercises in tense: Where have we been? Where are we now? Where are we going? I tried to envision what an episode of The Mountains Are Calling might look like in a year or five. What will my life be? In what state will Earth find herself? Since I’m no Alfred Wegener, a Nostradamus of the natural world, who predicted continental drift and hair ice, nor am I a groundhog, I have no answers to these questions. Forecasting the future is, alas, rather difficult.

The thought exercise did lead to another query, however.

Are there natural events we can predict? With certainty?

A few examples of low-hanging produce come to mind. The sun will rise tomorrow (yes, better stated, the Earth will continue to spin, creating the illusion of a rising and setting sun; it’s always sunny somewhere). Any objects I drop will fall to the ground thanks to gravity. My infant daughter will wake up every three hours overnight.

These examples immediately raise an important attribute, the difference between current predictability and permanence. Will the sun always rise tomorrow? Will gravity ever cease? Will my daughter ever decide to sleep through the night?

The nature of this question gets to the heart of the attempts by scientists and philosophers to craft a timeline of the far future. The sum of human knowledge to date is rather impressive. We have deduced and induced many universal laws that enable us to explain and, yes, predict the future. Because we understand the mechanics of cosmic bodies, we know the sun will rise approximately every 24 hours, barring some unseen catastrophe. Gravity is a little trickier. Though we largely understand the mathematics of the force, we don’t truly know why it occurs. Could it suddenly stop occurring at some point? Sure, but it’s rather unlikely. And, as for my daughter, I’m convinced I’m stuck in a Dantean ring where time passes but the progression of time is forbidden.

Even some scientific aspects with which we are well acquainted are difficult to predict due to scale. Contrary to one’s anecdotal experiences, we know quite a bit about the weather, and we can predict it with relative ease. The problem is the size of the system. Theoretically, if we had monitors at nearly every spot on the planet, we could predict the weather with surprising accuracy. Unfortunately, the oceans are big and we have nowhere near the proper info to model. Another example is something like a volcano. We understand a great deal about how they form, how they erupt, and what happens after they go boom. Yet, we have almost no way to truly predict their behavior because we do not have information from below the surface. So, knowledge about how things work isn’t necessarily the key to predicting the future.

A nexus of wisdom and data, however, can provide soothsaying powers.

Last fall, we provided you the ability to become a magician by making Saturn’s rings disappear. Thanks to our understanding of axial tilt and our knowledge about the state of play in the solar system, we can predict that the rings will disappear from the perspective of an Earthling in 2025. We know that Halley’s Comet is currently just past its aphelion (farthest point on its orbit around the sun) and will return to our neck of the system in 2061. These examples are, especially on cosmic scales, short-term prophecies, which makes them a bit unexciting.

Other events much farther ahead in time can be chiseled into the future history books, according to scientists. Some of them include rather large changes that we tend to view as bedrock features, too.

For example, Polaris, the north star, has been used to navigate our planet for as long as humans have explored. Right? Ur sa wrong, if you believe that! As recently as classical antiquity – approximately 8th century BCE to 5th century BCE – Polaris did not sit above the north pole. Instead, its Ursa Minor compatriot, Kochab, was closer to being the pole star, though north actually sat between the two. Phoenicians, the greatest wayfaring peoples of the era, used the entirety of Ursa Minor to orient (if you’ll excuse the word nerd’s mixed metaphor) themselves. On an interstellar scale, this change in the firmaments is a blink. And, in just 1,100 years, Polaris will no longer be the pole star. Instead, Gamma Cephei will inherit the mantle. Your 36th-great-grandchildren, if they still inhabit Earth, will navigate with a different star. It will require apocalyptic events on a universal scale to preclude this takeover.

The changing of pole stars occurs due to precession, a change in the orientation of a body’s rotational axis thanks to gravity. In Earth’s case, the sun and the moon provide the tugs for precession. Between 11,000 and 15,000 years in the future, summer and winter will happen at different points during our orbit than they do currently. Right now, when the Earth is closest to the sun, the Southern Hemisphere tilts toward the sun, causing summer. At the farthest point, the Northern Hemisphere points toward our star. Because of precession, these tilts will mirror the current setup.

Closer to home, we can mark down a few geological events. Spoiling a future newsletter topic, in 50,000 years, Niagara Falls will disappear. More technically, it will have eroded into Lake Erie. The mighty waterfall slowly eats itself. Today, about 20 miles of rock separate it and the great lake. One day, it will merge with Erie! In 250,000 years, the Big Island will no longer be the youngest Hawaiian Isle. Instead, Kamaʻehuakanaloa, already building below the ocean, will surface to become the baby. In 500,000 years, the Badlands of South Dakota will no longer exist. And zoom way into the future – 250 to 350 million years – and Earth will witness Pangea, Jr., as all the puzzle pieces of land will form another supercontinent.

Where the changing of the pole stars seems rapid on cosmic scales, another future happening seems rather slow. In addition to ocean tides, the moon’s gravitational pull has another effect on Earth: slowing its rotation. The moon is slowing our spin, which will change the length of our day. This outcome doesn’t sound great, though the consequence will be rather minor. It will take 3 million years for the length of the day to increase by one minute. The pole star will cycle about 300 times in that period!

In sad news, 600 million years in the future, tidal acceleration will have moved the moon far enough away from Earth that we will no longer experience solar eclipses.

Based on our current understanding of the life cycle of stars, one day, even the sun will no longer rise. That’s because, somewhere between 7 and 8 billion years in the future, the sun will become a red giant, gradually growing to engulf the inner planets. If Earth is subsumed, it’s hard for the sun to “rise” on it.

Scientists across various disciplines have contributed to a grand timescale of the future. Many of the things included on the list are not given, as most experts would agree the preceding examples are. After all, it’s hard to know with certainty that the heat death of the universe will occur 10¹⁰⁶ – 2.1 × 10¹⁰⁹years in the future when we don’t even know if supermassive black holes decay, protons decay, or if all matter will break into subatomic particles. Closer to now, we don’t know for certain if a major volcanic eruption will threaten life on Earth or if the planet will collide with a kilometer-wide asteroid. These events are simply statistically likely. It’s like the weather: we don’t have enough info.

That these events are not guaranteed to occur does not detract from the fun of thinking about the timeline. This visualization represents an impressive accumulation of information in astronomy, geology, biology, physics, mathematics, and technology.

Depending on when you read these words, everything contained here could already be old news. The newsletter could be long-dead or have evolved into a completely different type of undertaking. If a new pole star sits above your north, we’ll have figured out a way to keep digital information from degrading, though I’ll likely be long gone. Perhaps you’ll read this from a new planet or an interstellar craft. Perhaps you’re even a Boltzmann brain, a theorized entity that could emerge from a vacuum thanks to a spontaneous entropy decrease. If you are a Boltzmann brain, you’re likely reading about 10^10^50 years after this sentence was typed, the time it’s thought for such a brain to appear. Yes, that number contains two superscripts (and the visualization broke the newsletter’s emailing capabilities, so we’ll have to go old school with two carets)! Of course, explaining what a Boltzmann brain is and pointing out exponents to an actual Boltzmann brain is the definition of redundant.

I’ll toss my only remaining question about the future to the Boltzmann brain: did my daughter ever sleep through the night?