The Edge of Physics: Dispatches from the Frontiers of Cosmology by Anil Ananthaswamy (Duckworth Overlook)
Four hundred years ago Galileo took a telescope the size of a rolling pin and turned it to the heavens. With that singular act, our view of the cosmos was dismantled and rewritten.
We learned that the moon is not smooth, but craggy and cratered, and that Jupiter has moons of its own. Observations of Venus revealed the planet moving through phases, overturning in spectacular, not to say heretical, fashion the flawed belief that celestial bodies circle the Earth.
Astronomy has progressed in giant leaps ever since, but our ignorance remains profound. In the past few decades we have discerned enough to be confident that the ordinary matter of stars and planets makes up a mere 4% of the cosmos. The rest is invisible to us — a mystery of epic proportions. In the absence of a more enlightened description, the missing 96% of the universe is known as “dark matter” or “dark energy”.
Roughly a quarter of the universe is dark matter, a kind of gravitational glue that lurks around galaxies. A further 70% is dark energy that apparently drives the expansion of the universe, pushing galaxies away from one another at ever-increasing speeds. The word “dark” is shorthand. It means none of this stuff can be seen directly — it neither shines nor refl ects the light shining on it. We know it only by its actions.
Our ignorance of the cosmos is not because of a lack of eff ort. Giant telescopes perched on mountaintops stare into the darkest skies to watch galaxies recede and so capture dark energy in action. In a defunct iron mine half a mile beneath Minnesota, equipment of exquisite sensitivity waits for the tell-tale “ping” of dark matter particles.
In Antarctica, physicists release vast balloons that loft sensors 36km into the sky to collect remnants of antimatter left over from the Big Bang. At the South Pole, others are drilling holes so deep they could hide the Eiffel Tower eight times over.
By doing so, they will turn a cubic kilometre of ice into a detector capable of spotting particles passing right through the planet. Anil Ananthaswamy, a consultant for New Scientist magazine, has travelled to these and other facilities in some of the most extreme regions on Earth to report back on the human endeavour to understand the universe.
At heart The Edge of Physics: Dispatches from the Frontiers of Cosmology is a travelogue, with a cast of scientists and engineers on hand at every turn to explain the physics, and occasionally the sociopolitical backdrop. There is a pilgrimage in here too.
Monks and monasteries vie for attention among the tools of hard science, the inference being that both science and spiritualism involve sitting about in quiet isolation waiting for revelation to strike.
The journey begins at the Mount Wilson Observatory in California. It was here in the Twenties that Edwin Hubble noticed galaxies tearing away from us, demolishing our preconceptions of a static universe and setting the stage for the big bang.
The author flies to Mount Paranal Observatory in Chile’s Atacama desert, a place so barren that workers pondering dark energy come to crave the greens and blues of the living world. Things are no cushier in Antarctica, where Ananthaswamy joins hardy researchers in their daily battle against the elements to run experiments to reveal the goings-on at the galactic centre or the texture of space-time.
Ananthaswamy’s book is a potent antidote to stereotypes. His characters — more technicians and engineers than scientists — are as tough as old boots and endure the bleakest of conditions in pursuit of their calling. Nowhere is this more apparent than in southern Siberia, where he joins workers who drive dilapidated jeeps over the frozen surface of Lake Baikal.
Under the ice is nearly 2km of crystal-clear water, but that is not all. Halfway down is a deep-water telescope, which stares at the lake bed for signs of ghostly particles called neutrinos arriving from the heart of the Milky Way. This is a hard-working and hard-drinking place.
The staffers bore holes in the ice and drag equipment up for maintenance at all hours of the day and night. As an offering to Burkhan, the great spirit of the lake, they flick vodka on the ice before downing the rest. When they do retire, it is to bunk beds in cluttered and ramshackle cabins along the shore, where pictures pinned to the walls are of particles rather than party girls.
For some readers, there may be a few too many cameo roles and lines that feel extraneous. Occasionally, the technical explanations are lengthy, if not hard going. But for the larger part, this is a striking tour of modern cosmology, and the lasting impression is a heartening one.
Galileo once commented: “All truths are easy to understand once they are discovered. The point is to discover them.” More than anything, this book shows that humans have never lost the appetite for discovery and for learning the truth of our place in the universe. —