What to read this week: Ripples on the Cosmic Ocean by Dagomar Degroot

Ripples on the Cosmic Ocean
Dagomar Degroot
Viking, UK; Belknap Press, US

If you pay attention to news from beyond Earth – and, as a New Scientist reader, the chances are you do – then you may have heard about hints of life on a faraway planet, or perhaps the news that a Mars Rover found possible signs of ancient life in distinctive spotted rocks. You might also remember the brief period, around a year ago, when it seemed as if a deadly asteroid might strike Earth.

As exciting as these events were, they also quickly faded into a background hum, all too easily usurped by more pressing and all too real events on Earth, like new wars or imminent climate catastrophe. The tantalising possibility of microbes belching out gas on a planet more than a trillion kilometres away might spark the imagination for a few minutes, perhaps even trigger a restless night, but what relevance do these cosmic discoveries really have for our lives on Earth?

In fact, turning our eyes outwards beyond our cosmic shores has had a profound effect on human history, argues climate historian Dagomar Degroot in his new book Ripples on the Cosmic Ocean: How the solar system shaped human history – and may help save our planet.

Although Degroot isn’t a scientist, he is a relatively new breed of interdisciplinary historian, and currently an environmental historian at Georgetown University in Washington DC.

His new book underscores his interest in how changes in cosmic environments influenced human history, and he takes a sweeping view of scientific progress, drawing on the archives of scientists both prominent and obscure, to make a convincing argument for looking out to the cosmic ocean from our isolated vantage point on Earth. “We cannot pretend the ocean does not exist,” writes Degroot. “It is not only because its waves will come whether we look for them or not; it is also because we can only understand our island by looking out toward the ocean.”

Without our planetary neighbours lighting up the night sky throughout human history, we would be impoverished. We would have less understanding of Earth’s climate, its past ice ages and future global warming; we would be at far greater risk from existential threats, such as nuclear weapons and cataclysmic asteroid strikes; and we would, in all likelihood, be stuck in the religious conflict surrounding the heliocentric world view. That is quite a list.

Degroot shows how much influence a single planet can have. Take Venus, for example, an inhospitable hellscape of blazingly hot volcanoes belching out sulphur dioxide on a scorched surface, where temperatures exceed 460°C.

This view wasn’t always so. When astronomers first turned their telescopes towards Venus, it proved difficult to observe, which we now know is due to the planet’s thick atmosphere. But by the 19th century, most observers agreed it had clouds.

This led to fantastical imaginings of Venusian beings underneath this cloud cover, which was pivotal in the emerging idea of cosmic pluralism that argued that Earth wasn’t the only place where life existed.

As our observational tools improved, and we began to learn more about the true, inhospitable nature of Venus, a more pressing concern emerged – is this a vision of Earth’s future?

Understanding that Venus became so hot because of a runaway greenhouse effect raised the question of whether the same was possible on Earth, and many of the scientists who spent significant portions of their careers working on Venus and its atmosphere, such as astronomer Carl Sagan and climate scientist James Hansen, were instrumental in raising the alarm of possible climate change on Earth.

Degroot’s book is replete with examples like these. We learn how the dust storms that make Mars so hostile forced scientists to grapple with the possibility of a similar scenario being caused by nuclear weapons. And then, in 1994, there was the collective witnessing of comet Shoemaker-Levy 9 tearing through Jupiter’s atmosphere, which sounded the alarm indicating that we should look out for similar threats to Earth.

But Ripples on the Cosmic Ocean is also great fun to read, with countless excursions to lesser known sagas in the history of scientific thought. These often involve odd and colourful figures. One such is Immanuel Velikovsky, a US-Russian psychoanalyst who seems to fascinate Degroot. Velikovsky consulted ancient mythology to come up with some surprisingly accurate predictions (alongside a lot of not so stellar ones) about Venus, and who, from the 1950s to the 1970s, became a thorn in the side of the scientific establishment.

While Degroot is convincing when he argues how important it is to look out to space, he seems on shakier ground when it comes to how to treat future observations and space exploration. Especially, as he acknowledges, because we live in an unprecedented time of space exploration, spurred by billionaire-funded private space companies like Elon Musk’s SpaceX and Jeff Bezos’s Blue Origin.

Degroot says we might be able to find a different path, one that doesn’t involve exploiting space for the gain of a privileged few, which, throughout history, was often the motivation for studying the solar system, as the colonial elite sought knowledge they could exploit to expand empire. Instead, we should be enriching our lives on Earth, supporting “a vision of the ocean in which we build in the water to support our home, for everyone’s collective benefit”, writes Degroot.

One example he gives is space-based solar power, which might involve putting solar panels on the moon that beam energy back to Earth. Given the rudimentary state of experiments testing this, however, the argument isn’t particularly persuasive.

Still, Degroot does make it clear that a decision will need to be made one way or the other: the history of understanding the solar system makes this unavoidable. “Humanity’s past was influenced, in part, by ripples on the cosmic ocean,” he writes. “More will come, no matter what we do. Now we are gaining the capacity to make our own waves. Our future may depend on how we make them.”

Three other great books on the solar system

Pale Blue Dot A vision of the human future in space
Carl Sagan
Astronomer Carl Sagan’s book Pale Blue Dot – inspired by an image of Earth taken by NASA’s Voyager spacecraft – is a meditation on what the solar system can teach us about our place in the universe.

The War of the Worlds
H. G. Wells
This classic features in Dagomar Degroot’s book (see main review), when he retells the famous story of how a US radio adaptation was so convincing, listeners panicked, believing Earth really was being invaded by Martians.

A City On Mars
Kelly Weinersmith and Zach Weinersmith
Living off-planet is looking pretty problematic, say the Weinersmiths, a cartoonist and biologist author couple who describe the brutal reality of life on Mars with scientific precision and beautiful illustrations.