A familiar trope in the Looney Tunes cartoons of my boyhood had Elmer Fudd or some other zany character digging a hole with such vigor and determination that
There were healthy doses of both hilarious comedy and uncomfortable caricature here, but what really stuck in a kid’s mind was the notion that you could somehow burrow through the earth with a shovel or some explosive force, which it turns out is just as impossible in 2022 as it was in 1964. But if you hypothetically wanted to give it a go, you would have to start at China’s actual antipode in this hemisphere, which lies in Chile or Argentina, and then tunnel some 7,918 miles: twice the distance to the center of the earth you would pass through, which lies at around 3,959 miles (6,371 km) from the surface.
So what about the center of the earth? Could we go there? After all, we did visit the moon, and the average distance there—238,855 miles away—is far more distant. But of course what lies between the earth and its single satellite is mostly empty space, not the crust, mantle, outer core, and inner core of a rocky earth that is a blend of the solid and the molten. Okay, it’s a challenge, you grant, but how far have we actually made it in our effort to explore our inner planet? We must have made some headway, right? Well, it turns out that the answer is: not very much. A long, concerted effort at drilling that began in 1970 by the then Soviet Union resulted in a measly milestone of a mere 7.6 miles (12.3 km) at the Kola Superdeep Borehole near the Russian border with Norway; efforts were abandoned in 1994 because of higher-than-expected temperatures of 356 °F (180 °C). Will new technologies take us deeper one day at this site or another? Undoubtedly. But it likely will not be in the near future. After all, there’s another 3,951.4 miles to go and conditions will only grow more perilous at greater depths.
But we can dream, can’t we? Indeed. And it was Jules Verne who did so most famously when he imagined just such a trip in his classic 1864 science fiction novel, Journey to the Center of the Earth. Astrophysicist and journalist David Whitehouse cleverly models his grand exploration of earth’s interior, Into the Heart of the World: A Journey to the Center of the Earth, on Verne’s tale, a well-written, highly accessible, and occasionally exciting work of popular science that relies on geology rather than fiction to transport the reader beneath the earth’s crust through the layers below and eventually to what we can theoretically conceive based upon the latest research as the inner core that comprises the planet’s center.
It is surprising just how few people today possess a basic understanding of the mechanics that power the forces of the earth. But perhaps even more astonishing is how new—relatively—this science is. When I was a child watching Looney Tunes on our black-and-white television, my school textbooks admitted that although certain hypotheses had been suggested, the causes of sometimes catastrophic events such as earthquakes and volcanoes remained essentially unknown. All that changed effectively overnight—around the time my family got our first color TV—with the widespread acceptance by geologists of the theory of plate tectonics, constructed on the foundation of the much earlier hypothesis of German meteorologist and geophysicist Alfred Wegener, who in 1912 advanced the view of continents in motion known as “continental drift,” which was ridiculed in his time. By 1966, the long-dead Wegener was vindicated, and continental drift was upgraded to the more elegant model of plate tectonics that fully explained not only earthquakes and volcanoes, but mountain-building, seafloor spreading, and the whole host of other processes that power a dynamic earth.
Unlike some disciplines such as astrophysics, the basic concepts that make up earth science are hardly insurmountable to any individual with an average intelligence, so for those who have no idea how plate tectonics work and are curious enough to want to learn, Into the Heart of the World is a wonderful starting point. Whitehouse can be credited with articulating complicated processes in an easy to follow narrative that consistently holds the reader’s interest and remains fully comprehensible to the non-scientist. I came to this book with more than a passing familiarity with plate tectonics, but I nevertheless added to my knowledge base and enjoyed the way the author united disparate topics into this single theme of a journey to the earth’s inner core.
If I have a complaint, and as such it is only a quibble tied to my own preferences, Into the Heart of the World often devotes far more paragraphs to a history of “how we know what we know” rather than a more detailed explanation of the science itself. The author is not to be faulted for what is integral to the structure of the work—after all the cover does boast “A Remarkable Voyage of Scientific Discovery,” but it left me longing for more. Also, some readers may stumble over these backstories of people and events, eager instead to get to the fascinating essence of what drives the forces that shape our planet.
A running gag in more than one Bugs Bunny episode has the whacky rabbit inadvertently tunneling to the other side of the world, then admonishing himself that “I knew I shoulda taken that left turn at Albuquerque!” He doesn’t comment on what turn he took at his juncture with the center of the earth, but many kids who sat cross-legged in front their TVs wondered what that trip might look like. For grownups who still wonder, I recommend Into the Heart of the World as your first stop.
[Note: this book has also been published under the alternate title, Journey to the Centre of the Earth: The Remarkable Voyage of Scientific Discovery into the Heart of Our World.]
[A link to the referenced 1964 Road Runner episode is here: War and Pieces]