Life is one of those subjects that always makes me pause. Questions like “How did life start?” or “Why are we here?” can feel overwhelming, making it hard to know where to begin. That’s what led me to pick up The Science of Why We Exist: A History of the Universe from the Big Bang to Consciousness by Tim Coulson. From the very first page, I was captivated by the journey Coulson takes the reader on—starting with the birth of the universe and ending with the complexity of human life. He tackles grand questions with a level of simplicity that makes even the most complex scientific concepts feel accessible. By the end, I felt both excited and relieved to have gained a better understanding of these deep existential questions about the universe and our place in it.
Coulson begins with a detailed explanation of the four fundamental forces that govern the universe: gravity, electromagnetism, the strong nuclear force, and the weak nuclear force. Without these, neither we nor the universe as we know it would exist. He even touches on how competition between molecules may have sparked the earliest forms of life. This made me reflect on how simple everything once was, and how—through a combination of competition and challenges—life evolved into the complexity we know today. As someone who didn’t have much prior knowledge of these topics, I was impressed by how effortlessly Coulson explained them, making these forces feel central to our very existence. I began to see how everything, from the tiniest particles to the galaxies, is interconnected.
What really stood out to me in The Science of Why We Exist was how it celebrates the remarkable achievements of science. While the book only scratches the surface of what scientists know today, I came away feeling like I had learned so much about why we exist. Coulson has a talent for explaining the universe through amazing scientific discoveries, making the huge, complex ideas feel easier to understand.
On a personal note, what made this book particularly enjoyable for me was how Coulson broke down massive topics into manageable pieces, and how seamlessly he transitioned from grand scientific ideas to the history of humanity. I loved the witty questions sprinkled throughout the book, which added a playful element to the reading experience. One moment that especially made me smile was when he compared Earth to a “scotch egg”—a quirky yet perfect analogy that made a dense concept instantly relatable.
The book covers a wide array of scientific fields—chemistry, physics, biology, and earth sciences—without ever feeling overwhelming. It’s a comprehensive exploration of the question of our existence. And it doesn’t stop at explaining the science; Coulson also provides insight into how scientific research works and the importance of effectively communicating scientific findings.
One of the biggest takeaways for me was the thought-provoking question Coulson highlights: Were humans inevitable from the moment the universe began, or are we simply incredibly lucky? It’s a question that lingered with me long after I finished reading.
The Science of Why We Exist is more than just a book about facts; it’s a journey of discovery. It is a book that not only informs but inspires a deeper curiosity about the world around us.
Summary
The Beginning of Everything
The universe wasn’t always as we see it today. It’s expanding, which means that at some point, it must have had a beginning. Scientists believe it started as a tiny, intensely hot dot of energy. Since then, it has grown into the vast cosmos we know, filled with galaxies, stars, and planets.
At the heart of how the universe works are four fundamental forces. These forces shape everything, from the stars to the tiniest particles that make up our bodies:
- Gravity – It’s the force that keeps us grounded on Earth and controls the orbits of planets and stars.
- Electromagnetism – This force governs the chemistry of life, keeping electrons in place and making life possible.
- Strong Nuclear Force – It holds protons and neutrons together in the nucleus of atoms, making matter stable.
- Weak Nuclear Force – This is crucial for nuclear reactions like the ones that power the sun, giving life the energy it needs.
These forces didn’t just create the universe we see; they also made life possible. Understanding them is key to answering the question of why we exist.
The Origins of Life
Life, as we know it, emerged through a series of chemical reactions. While we don’t know all the details, scientists have made some impressive progress. They know that life emerged because, in the right conditions, it was the easiest, most natural outcome. Given the right mix of chemicals and energy, life became the most likely result.
Life probably started in small pools rich in amino acids and other building blocks, perhaps in freshwater environments or oceans. Early life began simply, but over time, competition among organisms led to greater complexity and, eventually, the incredible diversity of life we see today.
Key Ingredients for Life
For life to begin, a few essential ingredients were needed:
- Liquid – Life started once liquid water was available, which means early Earth was much hotter than today.
- Carbon-based molecules – Organic molecules like those found in meteorites were crucial for the building blocks of life.
- Phosphorus – An essential component of DNA and RNA, which could have come from meteorites or lightning strikes.
The Power of Evolution
Evolution is a process that can be difficult to grasp for a couple of reasons. First, some people find it hard to accept that humans evolved from simpler life forms like bacteria or, more recently, chimpanzees. Yet, comparisons of genomes between species as different as bacteria, bananas, and humans offer overwhelming evidence that all life on Earth is interconnected.
Second, evolution is complicated because it involves multiple factors happening at the same time. It’s not just about organisms changing; it’s about competition for survival, genetic mutations, and natural selection working together. These forces create species that are better adapted to their environments, allowing them to thrive where others might fail.
Every species alive today is a success story—surviving in a world where death or reproductive failure is always close at hand. Evolution is the process that drives this survival, shaping the incredible diversity of life we see around us, from the smallest microbes to complex creatures like humans.
The Mystery of Consciousness
One of the most intriguing parts of existence is consciousness. While we understand a lot about how the brain works, the question of why we experience life is still a mystery. Consciousness allows us to perceive the world, make decisions, and even pursue happiness. But it also raises deep questions: Are other animals conscious? Do they feel emotions like pain and pleasure?
Studies show that even simple animals like shrimp or octopuses may have some level of consciousness. The ability to experience pain is ancient and may have been the first emotion experienced by animals, leading to more complex thought and awareness over time.
Human Traits and Civilization
For humans to create complex societies, a few key traits had to evolve:
- Language – Our ability to communicate has been crucial for forming societies.
- Tolerance and cooperation – Living with others and forming hierarchies allowed us to create cities and nations.
- Future planning – Humans are unique in our ability to make decisions now that will pay off in the future.
These traits didn’t always lead to the same kinds of civilizations, showing just how flexible and diverse human societies can be.
Why We Exist
We exist because of a series of fortunate events. When the universe formed, the fundamental forces—gravity, electromagnetism, and the nuclear forces—were just right for creating atoms, stars, and planets. These forces allowed life to emerge and evolve over billions of years. Life’s building blocks are common in space, but it takes the right conditions, along with an energy source, to spark life.
While life on Earth took billions of years to evolve, from single-celled organisms to intelligent beings, this process could be common in the universe. Given enough time and the right conditions, complexity and intelligence might emerge elsewhere.
The science of why we exist is an ongoing journey. While we have learned so much about the universe, life, and consciousness, there’s still so much left to discover. Whether life is rare or common in the universe remains an open question, but one thing is clear: we are here because of a delicate balance of forces and processes that shaped our world.
As we continue to explore these questions, science brings us closer to understanding the greatest mystery of all—our existence.
My Favorite Bits
Intelligent life did arise in our universe, but our existence required a big dose of luck. Enjoy being conscious, for it doesn’t last for long.
Tim Coulson, The Science of Why We Exist: A History of the Universe from the Big Bang to Consciousness
Author: Tim Coulson
Publication date: 2 July 2024
Number of pages: 459 pages
