“Parallel Worlds” By Michio Kaku

Science - 10 Minute Read

Michio Kaku’s “Parallel Worlds: The Science of Alternate Universes and Our Future in the Cosmos'' is, as its lengthy title suggests, a densely informative and riveting piece of nonfiction writing that explores several intriguing concepts, from the origins of the universe, to the our current capabilities as a civilisation, to ultimately outlining our place in the cosmos. Through his sustained poetic fluidity throughout the book, Kaku conveys some of the most complex, and increasingly significant, ideas in a way that leaves the reader stunned at how the science fiction of old may well be humanity’s future. 

Personally, when reading pieces of nonfiction that can grow increasingly complex as the book progresses, I tend to appreciate authors who maintain a sense of continuity and logical progression throughout their work. This may well be why I enjoyed Stephen Hawking’s “A Brief History of Time” more than the collection of Richard Feynman’s lectures in his book, “Six Easy Pieces.” In this case, I believe that the progression in Michio Kaku’s writing is more than just logical, it is exceptionally well thought-out, to the extent where his ideas link together poetically. To elaborate, this is not due to brief linkages at the ends of each chapter, which Kaku does implement, but rather a sustained theme that progresses the book forward through the history of the universe and well into its future. The aforementioned sustained theme is the findings from the Wilkinson Microwave Anisotropy Probe, or the WMAP satellite. 

Kaku introduces the WMAP satellite on the 7th page of  “Parallel Worlds,” right after establishing humanity’s previous impressions of the creation and future of the cosmos, and WMAP’s significance quickly becomes clear. After being launched in 2001, the data collected by the WMAP satellite was harvested in 2003, where they learned that the satellite had detected radiation “from the original fireball that created the universe.” The data gathered from the WMAP painted a picture of the universe when it was 380,000 years old, while also unbelievably accurately confirming its age to 13.7 billion years. As Kaku puts it, “if the universe today is an eighty-year-old man, the WMAP pictures show him as a newborn, less than a day old.” Kaku employs an even more astounding analogy when he writes, “if the base of the Empire State Building represents the big bang, then, looking down from the top, distant galaxies would be on the tenth floor, the distant quasars seen by Earth telescopes would be on the seventh floor. The cosmic background measured by the WMAP satellite would be just half an inch above the street, giving us the measurement of the age of the universe to an astonishing 1 percent accuracy.”  

Despite the significance of the WMAP satellite, in all honesty, I only took its findings and implications as another great, modern scientific feat, one of many that the book would likely go on to explore. Although it did, Kaku consistently mentioned the WMAP satellite throughout this book, from dark matter, the expanding universe, the temperature and background radiation of space, the WMAP clearly had a significant impact. In fact, as per the book’s index, the WMAP satellite was mentioned in 15 different contexts, 2 more than Albert Einstein. As a result, it soon became clear how the findings from the WMAP had had massive implications to many of the elements that were critical to the topics of this book. Also, the fact that the findings of the WMAP were harvested in 2003, just a year before this book was published, gives Kaku the role of a storyteller at the scene of the story. This enables the book to also have a very comfortable frame of reference as it is built around the findings of the WMAP and how they answer questions of the past but also give birth to more questions about the uncertain future. 

To expand upon the future’s uncertainty, one of my favourite parts of this book was the transition between Part II and Part III. I think that after establishing the history and the path that science has taken to arrive at its present state in Part I, and then conveying the possibilities and limitations with our current resources in Part II, Kaku’s transition into a series of chapters that focus more on entirely theoretical, and in the end philosophical, concepts in Part III was very timely. From covering what we have achieved, then transitioning to where we are now, a shift into humanity’s uncertain future was one that I found extremely compelling. 

In the third part of his book, Michio Kaku explores a range of concepts that have not been fully constructed and backed up by scientific evidence, yet nonetheless remain to be intriguing insights into the future of the cosmos. For instance, in the tenth chapter, Kaku explores the five stages of the universe, starting with the primordial era, then to the stelliferous era, which we live in today, before degenerating into the stage of black holes and ultimately resulting in the era of darkness. This puts into perspective how the universe may continue to expand before, as a civilisation, humanity must try to survive against a natural disaster of the greatest magnitude: the collapse of our solar system. However, Kaku makes it very clear that in its current state, humanity is in no condition to fully explore our solar system, let alone escape from it. 

When nearing the latter stages of the book, Kaku presents the Kardashev scale and introduces the reader to one of, in my opinion, the most interesting depictions of our role in the universe. The Kardashev scale, as Kaku writes, “was introduced by Nikolai Kardashev in the 1960s for classifying the radio signals from possible civilisations in outer space. Each civilisation type emits a characteristic form of radiation that can be measured and catalogued.” The scale identifies the characteristics of three different types of civilisations. The first type is a civilisation that is able to harness all planetary forms of energy, or all of the energy that it receives from its host star. A type 2 civilisation is one that exhausts its planetary energy and is able to consume the entire energy output of their star. The third type of civilisation is one that has exhausted the energy of its entire solar system and has colonised large portions of its home galaxy. Although a fourth type was not included on Kardashev’s scale, Kaku explores the possibility of a civilisation that is able to tap into the energy of dark matter, which makes up 73% of all matter in the universe. Finally, Kaku highlights that in our present state, we do not even reach the standards of a type 1 civilisation, instead we are classified as a 0.7, but he also identifies how the prospect of transitioning into an advanced civilisation is becoming increasingly possible. 

Kaku ends off by identifying a range of steps that we could hypothetically take to advancing ourselves forward on the Kardashev scale, such as find naturally occurring wormholes, construct and send probes through black holes, but above all, Kaku identifies, much as Stephen Hawking did, the necessity for a theory of everything. Perhaps after achieving some of these steps, humanity may finally be able to colonise other planets, explore the extents of our galaxy and gauge a better understanding of the cosmos. “Perhaps,” Kaku finishes, “the purpose and meaning for the current generation are to make sure that the transition to a type 1 civilisation is a smooth one. Perhaps this is our destiny.”