“The First Three Minutes” by Steven Weinberg
Science - 10 Minute Read
Steven Weinberg’s “The First Three Minutes: A Modern View of the Origin of the Universe” is a piece of science writing that focuses on exploring the initial state of the universe by analysing our present knowledge of the forces and laws that govern the cosmos. Weinberg is a Nobel Laureate in Physics for his work into devising the Standard Model, a well-accepted and much-utilised system that unifies three of the four forces in our universe. With his expertise, Weinberg creates a wholly intriguing nonfiction piece and neatly justifies his intricate and almost intimate description of the baby universe.
In the initial chapters, Weinberg establishes the fundamentals when it comes to the crucial forces present in the cosmos in order to back up and reinforce the claims that he later makes. The first chapter of “The First Three Minutes” serves as an introduction and is titled “The Giant and The Cow.” In this preliminary chapter, Weinberg references Norse mythology and discusses Niflheim and Muspelheim, the supposed northern and southern regions of the universe. Niflheim is said to be a region of fire while Muspelheim is a region of frost. According to Norse mythology, the heat from Niflheim melted the frost of Muspelheim and the liquid drops gave birth to a giant Ymer. Ymer the giant ate a cow Audhumla. Audhumla the cow ate conveniently present salt. Whilst still being careful not to offend any religious sentiments, Weinberg asserts that this is not a satisfying model of the universe but is an indicator of how the seemingly innate nature to answer the question of “origin” has been part of humanity for millenia.
Following this, Weinberg goes on to discuss how despite the immense difficulty to make any validated conclusions, astronomers and stargazers of old did manage to find evidence that pointed towards one particular property of the cosmos: expansion. Weinberg elaborates on this by describing a scenario where a stationary person is observing sound or light. He states that the time between the arrival of wave crests for our instruments will be the same as the time between the wave crests when they leave the source. However, if we start to move away from the source, or the source moves away from us, then every proceeding wave crest will have a larger distance to travel before it reaches us, progressively increasing the time between wave crests. This increase in time causes an overall shift in the wavelength of the signal that we are receiving. This shift is known as the Doppler Effect and, as Weinberg emphasises, it can be used as an indicator to determine whether an object is moving towards or away from us. With the Doppler Effect, astronomers were able to conclude that the galaxies were in fact moving away from us as their light wavelengths had shifted to a redder hue.
Weinberg establishes a few more core principles in the following chapters, including the presence of antiparticles as well as the density of the universe. Antiparticles are the counterparts to conventional particles, having the same mass and spin but the opposite electrical charge. For instance, the antiparticles to electrons are positrons, which have the exact same properties except they are positively charged. An important property of antiparticles is that upon interacting with their respective particles, they collide into a violent explosion. This is because although their charges neutralise and they disintegrate, due to the conservation of energy, the energy and momentum they possess has to be released. Hence, this energy is emitted in the purest form: radiation. Weinberg states that at the early stages of the universe, when all the particles were tightly condensed into a small region, one must be careful to not assume that the number of electrons and positrons were equal. In fact, Weinberg states that our very presence is proof that the numbers were not balanced and there must have been an excess of electrons. This is because equality in numbers would have resulted in perpetual explosions of radiation as particles met their respective antiparticles, restricting the universe to even develop protons, let alone planets, galaxies and us.
Continuing on, Weinberg emphasises the importance of the density of space in our understanding of an early universe. He states that the critical density of the universe plays a key role in determining whether the cosmos experiences continuous expansion or not. Intriguingly, Weinberg not only focuses on the Big Bang theory, where the density caused a rapid expansion, but also explores the direct opposite, the Big Crunch. The Big Crunch theory identifies a time where the universe expands to such a degree where space is hugely larger than the mass that occupies it, resulting in a very low density. This low density, identified as Omega, could, in theory, cause the expansion to reverse into contraction, resulting in the universe to revert back into its initial state of high density. This would force all matter to be compressed and ultimately “crunched” until the Big Bang is triggered once more. Weinberg returns to this concept later on in the book and offers intriguing insights into what the Big Crunch theory may propose in the grand scheme of our understanding.
Having laid the foundation for his description of the baby universe, Weinberg delves into asserting his view of the origin of our cosmos in the form of a riveting film. The first frame, Weinberg writes, begins with the universe at 100,000 million degrees Kelvin(he identifies that he cannot begin at time zero and a point of infinite density, obviously) and that “the universe is simpler and easier to describe than it will ever be again.” As he continues with the next frames of his dramatic astrophysical film, Weinberg elaborates on the rapid cooling of the universe, the introduction of protons and neutrons, and soon, the annihilation of all electrons and positrons save a small, yet immensely critical, portion of electrons. This entertaining depiction of the early stages of the universe is definitely a satisfying climax to the extensive build up and foundational explanation from earlier on.
Despite this, to my surprise, the most enjoyable part of this book was not the remarkable and dramatic chapter titled “The First Three Minutes” but instead the final chapter and epilogue of the book: “The Prospect Ahead.” Weinberg returns to the idea of the Big Crunch and suggests that perhaps then the expansion and contraction of the universe is a continuous cycle that has, quite literally, been present before time. However, Weinberg identifies that with each cycle of the universe’s expansion and contraction, certain ratios between photons and nuclear particles are increased through friction known as “bulk viscosity,” possibly meaning that the universe will never be in the state that it is in now ever again(or perhaps it will, considering the concept of “again” is derived from the concept of time, which is also continually rebirthed with each cycle!). Nevertheless, Weinberg states “if this is our future, it is also presumably our past.” Though this may seem intriguing, it also leaves the reader questioning therefore what the point to our existence is. In my opinion, Weinberg follows this by delivering one of the most profound takes on our place in the universe. He identifies that as we become increasingly aware of our presence in the cosmos, the less our significance seems to become. We have found ourselves with stability and civilisation but only in a violent and unforgiving universe that faces a future of endless cold or intolerable heat, a cycle that it may repeat infinite times over. However, although the fruits of our search seem pointless, we can still find consolation within the search itself. After all, is there a greater pursuit, a greater quest, than the search to understand the cosmos, to understand where we stand and how we got here? Weinberg finishes by writing, “the effort to understand the universe is one of the very few things that lifts human life a little above the level of farce, and gives it some of the grace of tragedy.”
