Scientists, from Thales of Miletus to the modern day, strive to discover facts about the world. They do this using something called the scientific method. It is not complicated, but it is incredibly powerful, and it is the way that all the facts described in this book have been identified.
Science is about explaining why a particular observation happens and then predicting future occurrences. The simplest observations are of things that always happen, such as jumping into the air and falling back to Earth. When we jump up from the ground, we never float off into outer space, and we have gravity to thank for this. Gravity always pulls us down, but other observations are more fickle, sometimes occurring and other times not. Ice, when left alone, will sometimes become liquid water, and other times will remain as ice. When the temperature is below freezing (when you’re at sea level on Earth, at least), ice remains ice, but when it is above freezing, ice will become liquid water. Science aims to make sense of observations, and to identify the circumstances when particular ones occur. Jumping into the air, and ice melting or not, are relatively simple observations that we can endlessly repeat.
Rarer events are harder to study. Observing that we exist and working out whether you and I were inevitable at the universe’s birth is a much harder observation to understand and predict because it has only happened once, Nonetheless, scientists have been chipping away at the problem. Events that happened long ago are also difficult to study. The further back we look in time, the less information is typically available. We know much more about the life of modern celebrities, and often way more than we might like, than we know about eminent people in ancient Greece. Yet we know more about the inhabitants of ancient Miletus than we do about those of Çatalhoyuk, the world’s first city, which reached its zenith about 9,000 years ago. Knowledge gets even scarcer when we go even further back in time. The fossil record that contributes to our understanding of the history of life is sparse, and usually patchy. Very few ancient individuals of any species became fossils after death. To date, palaeontologists have unearthed thirty-two adult Tyrannosaurus rex fossils. T. rex were large animals with massive bones and teeth, the parts of animals that are most likely to become fossils. You might think that thirty-two sounds like quite a lot, and compared to some species it is, but this fearsome and massive dinosaur species roamed the Earth for 2.5 million years, and palaeontologists have estimated that a total of 2.5 billion T. rex individuals may have lived. If these rates of fossilization translated to humans alive today, the remains of only about 100 of us will survive as fossils 66 million years hence. That translates to 0.00000128 per cent of people becoming a fossil.
For an animal (or plant) to become a fossil, it must die under the right circumstances in the right environment. If you want to maximize the chance of becoming fossilized, your best bet is to be rapidly buried in sediment from a flash flood or ash from a volcanic eruption, and for your corpse to lie undisturbed for at least 10,000 years, yet this is still no guarantee. I would like to become a fossil – my children argue I already have – although I’d rather have a more peaceful end than being buried alive by flood or eruption. I’d like to become a fossil because it would help future scientists interpret the history we are creating today. If future palaeontologists were to discover my fossil, I may prove more useful to humanity after death than during my life.
The history of organisms alive in the past is partially written in impressions in rocks, but these etchings are rare and are often little help when working out part of the story of how you and I came to be. Despite this, palaeontologists studying fossils have uncovered remarkable insights about the history of life.
In this chapter I want to explore how science works. The scientific method consists of several techniques that allow us to find out things about the universe in which we live. Contrary to the belief of some populist politicians and social media gurus, repeatedly saying fictitious stuff over and over again is not how knowledge is created. It is a very outdated way of trying to make sense of the world. Prior to knowledge gained via the scientific method, people would explain observations of the world around them with stories. Many of these are great yarns, but they are often nothing more than myths.
Given how much knowledge the scientific endeavour has created, I am surprised and disappointed at the high-profile role that myths and myth-creation continue to play in today’s society. I have met conspiracy theorists who believe that the royal family is a race of alien lizards, that Elvis is still alive and in hiding, that Donald Trump won the 2020 US election, that the moon landing was faked, and that Keanu Reeves is immortal and may in fact be a vampire. Some of the more nonsensical theories may be laughable, but when people embark upon a path of rejecting facts for unsupported nonsense, they can do harm. Science has convincingly shown that neither homeopathy nor distance healing works, and that ginger cannot cure cancer. Yet many people cling to these misguided beliefs. Science and medicine cannot cure all diseases, but they have made astonishing progress in treating many. Turning one’s back on modern medical treatments because a mystic you have never met claims to be praying for you in Timbuktu risks shortening your life. Trust in science. It produces evidence to support or refute hypotheses and to explain the unexplained. Myths and conspiracies are not based on evidence. Our civilization is advanced because of science, not because illuminati are acting as master puppeteers, pulling strings from behind the scenes. The facts of why you came to exist are more inspiring than any myth or conspiracy theory can ever be, and they can also be verified.
The scientific method starts with an observation, often posed as a question. The observation could be about any aspect of the natural, or human-built, world. It might be as simple as ‘why is that tree there?’ or ‘why is it that sort of tree and not another type?’; or ‘why do I get ill?’ and ‘why do I get better?’; or ‘why do I always return to the ground when I jump in the air?’; or ‘why does it not snow as much in England now as it did when my parents were young?’ The observation I address in this book is ‘you and I exist’, and the question I ask is ‘why are we alive?’ Science has taken us a long way towards answering this question.
The Scientific Method
I have asked questions like this from a young age and suspect they sometimes maddened my parents. The first time they took me to see the sea at the age of three or four, I apparently stared at the waves for several minutes before asking why they went up and down. My parents are well educated, and although they both have a grasp of science I was soon asking questions they could not answer, so we borrowed science books from the library. By the time I was a teenager they had bought me a subscription to a weekly science magazine for young adults. I looked forward to its arrival and would read it from cover to cover, sometimes drawing graphs or trying to write equations to help me understand some of the concepts I had read about.