“A Brief History of Time” by Stephen Hawking
Science - 8 Minute Read
“A Brief History of Time” is considered to be one the greatest works of science writing and is widely regarded to be an insightful opening into the countless complexities of traditional and theoretical physics. Given that the book itself is a very dense evaluation of humankind’s journey towards our current understanding of the universe, summarising this book for you seems to not only be difficult but also may not do justice to the intricate nature of the ideas that Hawking covers. Hence, I will instead be providing a few sentences about each of the eleven chapters in this book as well as comment on some of the aspects that I personally found to be intriguing.
To begin with, Hawking introduces the reader to the current picture of the universe, or its picture as we currently know it. The first chapter felt very introductory and glazed over certain topics that Hawking later delves deeper into. However, one point from the first chapter that I found to be interesting as well as clearly significant moving forward was Hawking’s explanation of what a scientific theory is. He states that a scientific theory is a model of the universe, or a small part of it, that contains a set of rules that relate quantities to the observations that we make. Hawking also writes that a scientific theory should accurately describe a large class of observations with only a few arbitrary elements and it should make definite predictions about the results of future observations. When really thought about and compared to theories such as Empedocles or Newton’s, these criteria for scientific theories make perfect sense and seem to be a very effective way of determining the success of a theory. That being said, Hawking also states that a theory is always a hypothesis, it can never be proved because no matter how many observations agree, we can never be certain that the next result will not contradict the theory.
Continuing on, in the next few chapters, Hawking covers the significant relationship between space and time, the nature of the expanding universe and his personal work on the universe’s origin but perhaps one of the chapters that I found the most interesting, is his explanation of the uncertainty principle. Touched on in the first chapter when explaining why we can never be sure that observations will be the same when repeated, the uncertainty principle, did and still has monumental impacts on our exploration of science as it quite literally limits what we can know. Granted, this may seem discouraging to some, to others it may seem an indication of God’s eternal dominance of knowing, but regardless, the principle, formulated by Werner Heisenberg is quite remarkable due to its sheer simplicity. The principle states that if we want to know the current position and velocity of a certain particle, then we simply need to shine light on it and observe. If we want to get really up close and personal, the wavelengths of the light need to be really small so we can measure to a higher degree of accuracy. But when we shine light waves that are so small, they are concentrated with higher energy. This energy causes the particle to move in ways that we cannot predict and hence, the velocity of the particle will be disturbed. In other words, the more accurately you try to measure the position of a particle, the less accurately you can measure its speed. Therefore, as aforementioned, the uncertainty principle places a boundary on how close we can get to determining the nature of the universe.
After this bombshell, Hawking casually moves into describing the elementary particles and forces of our universe, two much-anticipated chapters on black holes and a section on the origins and fate of the universe. It was here where I found a truly impactful paragraph where Hawking is in the midst of discussing imaginary numbers. In this part of the book, Hawking has delved so far into these theoretical concepts that it is very easy for the reader to be drowned in mounds of “what-ifs” and “if-thens” but he then breaks away and connects this topic back to the first chapter. He states that fundamentally speaking, there is no point in wondering what is imaginary and what is real because as he previously outlined, a scientific theory is just something that exists in our own minds to make sense of observations. “It is simply a matter of which is the more useful description.”
In the last three chapters, Hawking explores the arrow or rather arrows of time, the possibility of wormholes and time travel which seems dreamy to science-fiction fanatics but more plausible than one might think and finally comments on the unification of physics. Since the initial stages of the book, Hawking sporadically mentions the existence of God and the possibility of his role as creator. When discussing whether or not humans will ever arrive at a unified theory to determine the state of the universe, Hawking states that there are those who argue that this will never happen as it would infringe on God’s ability to change and intervene with the occurrences of the universe. However, this in itself is a paradox because it describes God at different points in time but time is a concept that is said to be created by God.
It’s not the easiest thing to wrap your head around but Hawking concludes the book with an intriguing and perhaps a little more manageable thought. As we humans begin to answer the “what” questions regarding our universe, fewer and fewer of us are asking the “why” questions. Originally, these questions were one and the same and were pondered upon by philosophers of old. But now as humanity continues its exponential discovery of the universe, those who ask the “why” questions are finding it difficult to keep up with the answers to new “what” questions. And so, it is very possible that the universe may always, to some degree, remain unknown to us humans, or perhaps we will reach a satisfactory conclusion, describing the universe as we know it. Unfortunately, we will never know for certain.
