Deep Time: Welcome to Earth

6 minute read
A shot of Earth from space. Photography @actionvance.

The date is unknown and the time is now. The scene is set here, narrated by a collection of stardust. 

These words humbly appear to you from a rock rotating around a ball of gas. This rock and ball of gas are part of a larger entity that exploded into existence roughly 13,800,000,000 years ago. The entity stringing these words together is the result of 3,700,000,000 years of transformation.

In other words, these entities and you are the result of a very old cosmic boom. 

Let’s reframe this further. 

Approximately 13.8 billion years ago, a volume less than 0.0000000000001 of a pinpoint, containing all the matter, energy, and space of the known universe, started to expand. Rapidly. This expansion marks the beginning of existence and is commonly referred to as the Big Bang. 

After a prolonged period of forceful collision and cooling, our solar system coalesced into its current form ~4.5 billion years ago. The Earth, like many other planets, resulted from a rapid gravitational collapse of gas and dust, producing a dense orb. Bombarded by meteorites, our young planet was not yet habitable. Comets containing ice struck as well, evaporating and cooling the hellish molten exterior to form an atmosphere. Even so, the Earth’s core was still very hot at 2,900 °F. The Earth’s plates shifted frequently as the skies flooded the surface. From this primordial soup, life first appeared on Earth ~3.7 billion years ago. ~7.5 billion years from now, the sun will expand and engulf the planet’s orbit, effectively ending planetary life. 

The human mind is not made for understanding numbers, let alone large numbers. When we hear words such as thousands, millions, or billions, it all starts to mush together into an eye-glazing, emotionless narrative with no intuitive relevance. To put all these large numbers into perspective using deep time, we can compare the 12 billion years constituting Earth’s existence to the clock below:  

Clock representing the 12 billion years of Earth’s projected existence.

Examining the Earth Clock, it is immediately clear that plants and animals are “only” going to be here for 1 billion years. Furthermore, homo sapiens’ (that’s us) scant ~200,000 years presence thus far is a mere sliver of history. We are halfway through the period where Earth is habitable by organisms other than microbes. Before descending into despair, it is worth noting that these big numbers are in fact, quite large. Given the average human generation is ~30 years, and that mammalian species have lifespans (from origination to extinction) ranging from 1-10 million years, one can imagine just how many generations (and lives within those generations!) are left to live when dividing 10 million years by 30. A lot.

Language is critical in comprehending numbers. Without it, anything beyond one and two starts to lose meaning. Lacking this innate sense of scale, it is difficult to cultivate an appreciation for deep time. Deep time is a geological concept for putting time and existence into context. Using fossils and radioactive dating in rocks, geologists are able to represent how “old” something is relative to another thing by turning large numbers into timelines and scales. When confronted with geological evidence, time thus becomes tangible. For some, it is a humbling exercise; for others, it may bring about great alarm. Regardless, the important thing to recognize is:

the Earth was not always this way, and will not stay this way forever

Rarely do humans possess the desire to peer deep into the past or deep into the future. When trying to plan ahead, we can only imagine a future in abstract terms. Yet it is real. Incredibly real. There are likely trillions of human and non-human lives left to be had in the 500 millions years ahead on our habitable planet. To understand our finite existence is to accept the natural rhythm of all life cycles, rather than a descent into nihilism.

Our existence today with complex, conscious minds was contingent upon a myriad of events going a certain way. Evolution, contrary to popular belief, is not a march of progress, but rather a byproduct of forces acting in a chaotic environment. Rocks falling out of the sky and balls of gas exploding in space do not lend themselves to order, yet this is what the past was like — the foundations of now are built upon serendipity.

Evolution, contrary to popular belief, is not a march of progress, but rather a byproduct of forces acting in a chaotic environment.

Fermi’s Paradox postulates that the likelihood of life forms on other planets is quite high, given the size of the universe. However, none have revealed themselves. While it is dangerous to assume we are exceptional, Earth’s uniqueness in the known universe cannot be denied. Our planet, a pale blue dot in the cosmos’s canvas, houses ~8.7 million species with an estimated 86% of terrestrial and 91% of marine species still awaiting discovery. The abundance of life here, once recognized, requires conscious efforts to sustain and protect.

To sustain the present and ensure the future of life, the power of language must be harnessed. Narratives create emotional attachments, illuminating the value of our relation to one another and to the living world. Headlines flash the narratives of today: “Hundreds of Species Lost Every Year…,” “Thousands of New COVID-19 Cases Worldwide…,” “Global Hunger Reaches 820 Million…” — perhaps you recognize the familiar numbness of desensitization. These struggles seem to stretch far into the future, endless cycles of injustices beyond our control. Meanwhile, existential thoughts cloud the present, extending apathy and nihilism toward the future. But when viewed through a deep time lens, it is easy to recognize the impossibility of these cycles’ perpetuity.

No system, including this planet, is built to function a certain way forever. Our contemporary struggles, albeit unprecedented and daunting, are no different. Biophysical parameters and social forces propelled by individuals acting collectively have co-written the past, creating present paradigms. These same dynamics will play out to shape the path ahead.

Knowing this, new narratives have potential to puncture the mainstream. As the clock ticks on, there is overwhelming pressure to “save the planet,” “reform the system,” or some other variant — this urgency is crucial but should not be crippling. Grounded in deep time, we can reframe present efforts and narratives to account for the future, while avoiding nihilistic burnout in recognizing the ephemerality of good and bad things. Ensuring planetary health flourishes well into the future (at least for the period it is able to — remember, there are still 500 million years ahead), requires the sapience to grasp deep time implications and act accordingly

Works Cited
Casasanto, Daniel, and Max Planck Institute for Psycholinguistics. “Without Language, Large Numbers Don’t Add Up.”, February 9, 2011.

Catling, David. “How Long Will Earth Remain Habitable? .” University of Washington, n.d.

Devine, Donn. “How Long Is a Generation?” ancestry. Accessed June 24, 2020.

Earth How. “Human Timeline: How Long Have Humans Existed?,” May 17, 2020. “Evolution: Library: The Current Mass Extinction,” 2001.,mammalian%20species%20alive%20at%20present.CloseDeleteEdit

“Fermi Paradox | SETI Institute,” April 19, 2018.

Greshko, Michael. “The Origins of the Universe, Explained.” Science, January 18, 2017.

“History of Life on Earth | Smithsonian National Museum of Natural History.” Accessed June 15, 2020.

“How Old Are Galaxies? | NASA Space Place – NASA Science for Kids.” Accessed June 15, 2020.

Mora, Camilo, Derek P. Tittensor, Sina Adl, Alastair G. B. Simpson, and Boris Worm. “How Many Species Are There on Earth and in the Ocean?” PLOS Biology 9, no. 8 (August 23, 2011): e1001127.

Wenner, Jennifer. “Deep Time.” Teaching Quantitative Literacy. Carleton College. Accessed June 15, 2020.

Williams, Matt. “How Was the Earth Formed?”, December 10, 2014.