Chapter 1: The Evolution of Life

The universe is filled with headlines about "potentially habitable planets," often leading us to envision thriving civilizations. When we think of life, we frequently picture complex multicellular organisms with a variety of unique adaptations. While the fundamental components of life are prevalent throughout our solar system and beyond, multicellular life is particularly noteworthy. On Earth, it took around four billion years for multicellular organisms to emerge, whereas single-celled organisms appeared much earlier, approximately 300 million years after the planet cooled.

Despite having only one example to study, the development of life on Earth provides valuable insights into what might occur elsewhere in the cosmos. All multicellular organisms, with one exception, consist of eukaryotic cells. It is widely accepted that plants, animals, and all other complex forms of life evolved from a primitive eukaryotic cell. Researchers concur that this ancestor originated when a prokaryotic cell, possibly an Archean, attempted to consume an aerobic bacterium, leading to a symbiotic relationship instead of destruction. This partnership allowed the bacterium to generate ATP, the cell's energy currency, while the prokaryote offered a protective environment.

The smaller organism eventually became the mitochondrion, the powerhouse of the cell. Every multicellular organism possesses mitochondria, with varying quantities based on their energy needs—ranging from a few dozen to hundreds of thousands.

Estimating the number of single-celled organisms in Earth's oceans during that time is challenging. However, a projection from the University of Potsdam suggests there might have been around 300 octillion. Given the lack of selective pressure that would facilitate interactions between these two organisms among the countless others, it raises the question of whether the first eukaryote's emergence was merely a random event, explaining the 2.5 billion years it took to develop.

The Sun's Role in Supporting Life

Image by Erasmo Acosta. Credit for Earth's icon and City Skyline: freesvg.org.

Two and a half billion years is a significant span of time, not to mention the additional 900 million years required for multicellular life to evolve and another 600 for intelligence to develop. The Sun is expected to remain conducive to life for only a few more hundred million years; a mere 10 percent increase in its brightness could severely disrupt our biosphere, rendering agriculture nearly impossible. While we barely survived this long, planets orbiting other yellow dwarfs may not be as fortunate.

On Earth, we've utilized biomass as an energy source for approximately one to two million years. Though fossil fuels pose environmental challenges, they seem essential for the development of our sophisticated technology. It's easy to envision an alien civilization trapped in a pre-industrial state due to an insufficient energy source.

Image Credit: NASA ESA, Z. Levy (STScI)

The Sun generates an astounding 500,000 times the total energy consumption of humanity in just one second. Yet, among the 200 billion stars in the Milky Way, sun-like stars constitute less than 5 percent. The majority are red dwarfs, significantly smaller and more volatile than the Sun. Their size necessitates that planets orbit much closer to maintain liquid water, often resulting in tidal locking and reduced magnetic field protection against radiation.

Despite this, billions of yellow dwarfs in our galaxy could still host planets capable of supporting civilization. However, time is of the essence; larger stars have shorter lifespans. For instance, Vega, which is 2.1 times more massive than the Sun, will only last one-tenth as long.

It remains plausible that multicellular life could arise on planets orbiting low-mass yellow dwarfs, benefiting from the fortunate accidents that occurred on Earth, leading to technologically advanced societies. Civilizations require energy similarly to eukaryotes needing ATP. The Sun, as nature's fusion reactor, generates an abundance of energy.

Artist’s conception of an island-sized rotating colony built with 21st-century technology. Image Credit: Katie Lane (Full distribution rights reserved by Erasmo Acosta)

Chapter 2: The Future of Civilization

A civilization that exhausts its planetary resources and requires more space will inevitably construct rotating habitats around their star to avoid collapse! Once they harness their stellar energy, expanding throughout the galaxy becomes a matter of time and persistence.

At present, each organ and system in our bodies is adapted to Earth’s conditions, making it unlikely we could terraformer (eliminate indigenous life) on many other planets. Replicating Earth’s environment within space colonies—known as O’Neill cylinders—would be simpler with our current technology. By leveraging the Sun's resources, we could potentially reach neighboring stars within decades and colonize the galaxy in under a million years, even without faster-than-light travel. Given the age of the Milky Way, there has been ample opportunity for another civilization to have accomplished this already.

Regardless of how many times life may have originated elsewhere in the universe, complex organisms capable of forming civilizations might be exceedingly rare. The visible stars in the night sky suggest we might be the first civilization in the Milky Way, or even in the entire Laniakea supercluster.

The first video, "LIFE FAR AWAY FROM CIVILIZATION," explores the challenges and possibilities of life existing in isolation from advanced societies. This fascinating examination delves into how life might develop in such environments.

The second video, "Uncovering the Lost Wisdom of Our Ancient Past | Billy Carson," investigates the ancient knowledge that may hold keys to our understanding of civilization's evolution and potential future.

As we ponder the rocky journey of life on planets orbiting red dwarfs, the fleeting nature of yellow dwarfs, and our ability to construct Dyson swarms around viable stars, Fermi's question from seventy-four years ago—"Where is everyone?"—remains one of the most profound mysteries of our time.