These inquisitive and clever researchers have revealed that there are many key events that were required for you and me to exist. They have made progress on identifying these events by asking carefully thought-through questions to explain why they occurred. We know that life exists in our universe by looking in the mirror, but could it have come about if gravity was just a little bit weaker, or if ice sank in water rather than floated? Volcanoes are thought to have played a key role in the birth of life, and Earth is unusually volcanic compared to other rocky planets we have studied. Tides may also have been necessary for life, and for those we have the moon to thank. Geologists think the moon was formed when a planet called Theia crashed into the young Earth. If Theia had passed by Earth, then we would have no moon and quite possibly no life. What if coal had not formed 300 million years ago in the carboniferous geological epoch? Would we have worked out how to use sunlight and wind to power our technological development and would we have avoided anthropogenic climate change? Our technological supremacy is almost certainly dependent on the 300-million-year-old dead plants from which coal is formed. Does this mean coal must form on all planets that harbour technologically advanced civilizations and, if it is a requirement, how often does it form? As we have made progress in answering some of these questions we have been able to tackle other important questions too, such as how common might life be in our universe: are civilizations like ours two a penny, or is ours unique?
The history of the scientific stories that have provided insight into the first 13.77 billion years of our universe is full of examples of perseverance and remarkable and sometimes surprising discoveries. There were many scientific dead ends, when good ideas proved to be wrong, but also many eureka moments when sense was made of bewildering observations. Many of these scientific breakthroughs led to technological developments that have defined the modern world. GPS, solar panels, nuclear power, high crop yields, modern medicine and smartphones are only possible because of the insights hard won by scientists. A few of these researchers achieved celebrity, and another few became rich from their discoveries, but the vast majority of advances were made by dedicated individuals who were driven by a desire to solve problems and to understand some aspect of the universe, rather than by a desire for fame and fortune. Humanity owes an enormous debt of gratitude to countless researchers who have spent careers trying to understand natural phenomena and the history of our universe. I largely avoid describing the stories of how scientists discovered the science I describe, not because they are uninteresting but rather because I want to focus on what we know. To also cover how we found out what we know would result in a much longer book.
The Universe Through Time
Describing 13.77 billion years of history in a single, short book required making many decisions regarding what to include and what to exclude. I focused on the key things that had to happen for you and me to exist. The universe had to form, and four fundamental forces (gravity, electromagnetism and the strong and weak nuclear forces) had to emerge and have the right strengths. Quarks and electrons needed to come into existence before the quarks combined to produce protons and neutrons that in turn joined with electrons to create atoms of hydrogen and helium. The first stars needed to form to create heavier elements such as carbon and oxygen, and the elements then had to interact to produce a vast array of molecules. The Milky Way, solar systems and in particular the sun and the Earth had to form, and conditions needed to be right to kickstart life. Conditions on our planet needed to stay within bounds for life as we know it to spread and evolve, eventually leading to complex, conscious animals like you and me. Various events then moulded our personalities. I describe the science of these key events before discussing whether they were inevitable, or if we were simply very lucky.
What is included could be described in much more detail, with the scientific research behind the insights described in each chapter filling entire libraries. My aim is to show what astonishing progress researchers have made in understanding so many aspects of our universe rather than to describe nuances and ongoing research on specific details. If you want to learn more, I provide a list of a few science books in an appendix that go into much more detail about physics, chemistry, earth science, evolution and human history.
You may wonder what background and expertise I have. Unless you are a researcher in the fields of ecology and evolution, there is very little chance you will have come across me. This is my first foray into popular science writing, so I have no catalogue of previous titles you could have read. I am a professor at the University of Oxford and am currently joint head of the Department of Biology. I have been working as a scientist in research institutes and universities for over thirty years, and my research focuses on understanding how the natural world works. When I teach, I strive hard to make complex ideas accessible, and I also get a kick out of giving public lectures.
When my wife, Sonya, told her close friends she was dating an Oxford don shortly after we got together in 2013, by their own admission they assumed I’d be aloof, pompous and arrogant. Not because they had met other Oxford professors but because scientists, particularly those employed by leading universities, don’t always have an endearing public image. I was pleased her friends liked me, and that I did not match their expectations. I have met aloof, pompous and arrogant Oxford dons, but I have also met lawyers, accountants and titans of industry with similar characteristics. Although science can be a daunting subject, scientists are just like everyone else. Some are humble, others not. They can be anxious, make mistakes, be serious or funny. I never chose to be an Oxford professor, and it instead happened through a series of fortunate and unplanned events, some of which I describe in this book as I interweave bits of my personal journey into the narrative. I do this for a number of different reasons. First, I not only want to make science accessible, I also want to reveal some of the human side of being a scientist. Second, towards the end of the book I explore how personalities arise. As a bit of this chapter focuses on how key events in my life may have shaped me, it is necessary for you to know a little bit about the sort of person I am. Finally, in the closing chapter, I touch upon what I have learned about what science has taught us and, once again, a little bit of my history helps the narrative.
Writing this book is part of a personal journey that started over thirty years ago when I was in my early twenties. As a teenager, I did not know what I wanted to do when I grew up, but I applied for and was offered a place to study maths at a university in the UK. I figured that being trained in mathematics to a high standard would keep my employment options open, and I was lucky in that I enjoyed the subject. Before starting university, I spent a year teaching in a rural school in Zimbabwe, and on one walk through the bush I stopped to watch a herd of antelope. I decided that being a biologist might be a better fit for me than being a maths graduate, and so I switched courses and ended up studying biology at the University of York in the north of England.
During my year of teaching, I fell in love with Zimbabwe and with the people I met there. I yearned to return to Africa, and the opportunity arose when it came to choosing an undergraduate research project that would be conducted at the end of my second year. It turned out it was possible to design your own project if you could persuade a faculty member to supervise it. I was lucky in that I managed to do just that.