The unique feature of this book lies in its approach to geological eras through various stages of Earth’s development: the era of “atmosphere” when Earth was first formed, the era of “water” when water eventually formed and there were periods of global freezing, the era of “green” when plants emerged on land and flourished, the era of “fire” characterized by vigorous volcanic activity, and finally, the era referred to as “human,” representing mammals, with humans being the most emblematic of them. For example, while many books on Earth’s history focus on popular dinosaurs, this book dedicates considerable pages to plants, which are often overlooked in other works. It balances detailed sections with concise ones, reflecting the author’s unique perspective and passion for Earth’s history. Moreover, the book features stunning photographs provided by National Geographic, including meticulously captured images such as microscope photos processed to clearly show specific bacteria, and drone photos of islands I personally visited. These photographs were taken with great care and attention to detail.

My specialty in carbonate sedimentology involves analyzing the shells of organisms and naturally deposited calcium carbonate in the ocean to decipher Earth’s history. A significant portion of the Earth’s history presented in this book was elucidated through the analysis of carbonate sediments. Through my role as a supervisor, I rekindled my appreciation for the importance of my research field and felt proud.
There are numerous theories for every event in Earth’s history. Simply listing these theories does not create a story, which is essential for a book on Earth’s history. Therefore, the author must select theories carefully. The danger lies in authors pretending to understand theories they don’t fully comprehend and selecting theories based on personal preference to construct a plausible narrative. This poses a risk of spreading misinformation due to the vulnerability inherent in freely written science books, rather than peer-reviewed papers that undergo content checks. As a supervisor, my foremost responsibility was to meticulously check for any scientific inaccuracies in the content of this book. While there were moments where I disagreed or found certain passages questionable, I respected the authors’ perspectives. Additionally, I ensured that the Japanese language used throughout the book was both accurate and natural-sounding.

My favorite photo in this book is one where a researcher is pictured in front of a rather unremarkable, dark cliff (on the “line of death” page). It’s not Instagram-worthy, not panoramic, nor does it feature any striking or peculiar landscapes. However, this area’s rock layers hold records of significant events in Earth’s history. Earth’s history is woven together from meticulous analysis by numerous researchers of samples collected from various locations worldwide. While picturesque settings are ideal, more often than not, these significant locations are just mundane cliffs or valleys. Just like this photo. From my own experience, I also have had important discoveries on plain cliffs or coastlines rather than panoramic vistas. Strangely, new discoveries often come on days when you least expect them, rather than on days filled with enthusiasm. It’s important not to be too eager.