Harvard University Press Blog

Q&A with Tom Siegfried, author of The Number of the Heavens: A History of the Multiverse and the Quest to Understand the Cosmos

In The Number of the Heavens, Tom Siegfried, the award-winning former editor of Science News, shows that one of the most fascinating and controversial ideas in contemporary cosmology—the existence of multiple parallel universes—has a long and divisive history that continues to this day. We spoke to him about the possible existence of a multiverse and the controversy surrounding it.

Trying to conceptualize something like the universe, let alone a multiverse, feels like a big undertaking. Where should people start in trying to comprehend the existence of something so vast?

You have to start small, say with the Earth. When H. G. Wells wrote his history of the world, he imagined shrinking the Earth to the size of a ball one inch across. The sun would then be a globe of fire, 9 feet across, a little more than 300 yards away. The planet Neptune, on this reduced scale, would be more than five miles away. The nearest star, the Alpha Centauri system, would be about 40,000 miles away. And the farthest objects observable in space would be something like 100 trillion miles away, even on the scale with the Earth smaller than a golf ball. Put another way, it takes light eight minutes to reach the Earth from the sun, four years to travel from the sun to the nearest star, and billions of years to travel to the farthest visible objects. That’s all within the universe we can see. If there’s a multiverse, countless other such spaces, of similar extent, exist beyond what we can see.

This book breaks down an eternal debate about whether there is one universe or many. You describe it like a long-running TV sitcom, where characters keep cycling out but common themes continue to reemerge. What are some of those common themes?

One common theme is that logic rules out more than one universe, because the universe contains everything so there can be only one. But the definition of “universe” at any point in time may turn out to be incorrect—it has often been the case that what people believed to be the universe was not, in fact, everything that existed. So the definition of universe needed to change.

Another common theme is that universes beyond our sight are not a proper subject for science—if we can’t see them, it is meaningless to believe that they exist. But advances in technology (such as better telescopes) can bring previously unseen objects into view. And in some cases the explanation for things that we can see unavoidably entail the existence of other things we cannot. Similar arguments were made against the existence of atoms—they could not be seen, so they could not be real. But plenty of evidence indirectly indicated their existence, and modern microscopes can image them. It’s not a coincidence, I think, that the ancient Greek philosophers who proposed the existence of atoms also believed in the existence of multiple universes. 

What is your favorite figure from this historic debate about the multiverse? Whose work have you found particularly compelling? 

Many to choose from. I guess I like Bernard le Bovier de Fontenelle the best, because he was a popularizer of science like me. He articulated the 17th-century case for a plurality of worlds better than anyone. But I should also mention Ormsby MacKnight Mitchel. He single-handedly made Cincinnati the leading center for astronomy in America in the 1840s, and was a most enthusiastic advocate for the view that the distant fuzzy nebulae in space were “island universes” like the Milky Way.

You mentioned that many serious scientists today consider the theory of the multiverse to be unscientific. Please explain.

There is a widespread view among scientists that the multiverse is an idea that cannot be tested, or “falsified,” and therefore it is not scientific. Many other scientists challenge that view, however. For one thing, the requirement of falsifiability is no longer widely accepted by many scientists and philosophers. For another, the notion of a multiverse is not itself a theory, but is rather a prediction of other theories that can, in fact, be tested in various ways.

Books and movie often portray the idea of a parallel universe as this alternate reality, where another version of you is living a totally different life. Does this idea of alternate selves hold up with scientists, or is it wishful thinking?

The idea of alternate selves is most closely connected with the Many Worlds Interpretation of quantum mechanics. In that interpretation, each of us does split into additional versions of ourselves as quantum measurements are made. Some physicists advocate strongly for this view, while others reject it. It’s a debate that will not be resolved anytime soon.

It’s also possible that the universe is infinite, and in a multiverse there could be an infinite number of universes. If so, and if the number is truly infinite and not just really big, all possible combinations of atoms will occur over and over again in different places. And so there would be other combinations of atoms identical to those that make up you (and me, and everybody else). Whether that would count as another version of you or just somebody exactly like you is a good question.

You write, “The possibility of a multiverse implies larger lessons about how science should be done” and “The rules of science that work well for explaining nature in a lone universe may not apply in a multiverse.” Could you speak more to this? How would science change by taking the rules of a multiverse into account? 

The traditional goal of science (or at least of physicists) is to explain the world by deduction from a small number of fundamental laws and principles. Ideally, in this view, one deep theory would enable calculations of all the physical features of the universe. This view implicitly assumes that the universe is governed everywhere (and at all times) by the same laws. If so, and there is only one universe, then this is a sensible approach to doing science. But rigorously applying the rules that stem from this approach deny the possibility of other universes from the beginning. If, in fact, other universes exist, the premises upon which the standard approach rests no longer apply. In that case the explanation for phenomena we observe may be that multiple possibilities are realized in different universes, and ours is the way it is because its peculiar features permit us to live here. It’s like the way no fundamental law determines the Earth’s temperature. It’s not the only planet—it’s one of many, and its temperature is what it is because that’s the temperature suitable for habitation. 

Q&A with Jo Dunkley, author of Our Universe: An Astronomer’s Guide

Jo Dunkley combines her expertise as an astrophysicist with her talents as a teacher and writer in Our Universe: An Astronomer’s Guide, a lively and exceptionally clear introduction to the structure and history of the universe and its enduring mysteries. We spoke with her about the book and her seemingly limitless topic.

Needless to say, the universe is a big subject. How do you even start to explain something so vast?

The universe is really big but it turns out that it fits together in a pretty well-organized way, with planets around stars, collections of stars making up galaxies, then galaxies filling the bigger space around us. So I start here on Earth and move gradually out to the farther reaches of the universe, scaling down larger and larger sizes into manageable spaces like basketball courts that are easier to visualize. I also connect the big concepts to real people, telling the stories of the astronomers who have made, or are still making, our discoveries.

The book conveys the kind of wonder about astronomy that draws us to the stars as children. Is it easy to keep that kind of wonder in your daily work as you wrestle with cutting-edge technical debates?

Not always, no. I do often get sidetracked by the technical details of analyzing data. But that’s one of the reasons I love writing about my science for the general public—and talking about it, too. It reminds me of the bigger picture and brings back my wonder. And even in my daily research I do get regular reminders about how exciting the questions are that we are asking. For example, right now I am trying to work out how fast the whole of space is growing. There are a lot of technical challenges to doing that, but I love the fact that we can even ask this question.

Many of us who haven’t taken science courses since high school assume astronomy can’t possibly be for us. We think we’d get lost. Is it a subject that can or ought to appeal to those who don’t think of ourselves as scientific?

Absolutely. You don’t need difficult math or complex science to grasp the big ideas in astronomy and to appreciate how beautiful the universe is. Looking up to the skies and asking questions about what’s up there is something humans have been doing for millennia. It is a subject for all of us. 

The book makes it clear that we have a lot left to learn about the universe. What are some of the questions that you think are the most pressing or the most promising to pursue in the years ahead?

One very exciting question is how common planets like ours are in the universe: rocky planets that could perhaps host life. New telescopes will help enormously with that question. And we have found out that most of the universe is made of invisible stuff that we can’t see with our telescopes. We call it dark matter, and there seems to be much more of it than the normal atoms that we are made of. We suspect that it is a new type of particle as-yet unknown in nature. I hope we will soon find out!

The book features many of the great names we would expect to see—the Galileos and Einsteins—but you also draw attention to unheralded and underappreciated astronomers, many of them women. Is it fair to say that some of the lost remarkable work done over the past 100 years has been done by women, either as individuals or in teams, like the Harvard Computers?

They have had a huge impact. The Harvard Computers in the early twentieth century, including Annie Jump Cannon, Henrietta Swan Leavitt, and later Cecilia Payne-Gaposchkin, were responsible for making sense of the different types of stars, understanding how to measure vast distances in the universe, and figuring out what stars are actually made of. Other pioneering women include Vera Rubin, who solidified the evidence for invisible dark matter, and Jocelyn Bell Burnell. She discovered an entirely new type of spinning star that is so dense that a teaspoonful would weigh as much as a mountain.

Celebrating Women in Science

On International Women in Science Day, the world celebrates the countless women who dedicated their skills, talents, and lives to the sciences. In this spirit, today we share books by some exceptional female authors. Executive Editor for Life Sciences Janice Audet pays tribute to each individual’s work and her efforts to advancing science.

Jo Dunkley, Professor of Physics & Astrophysical Sciences at Princeton University, studies the origins and evolution of the universe. She shares her passion for discovery with her students and the public, in particular with young women interested in scientific research. In recognition of her efforts to encourage and raise the profile of women in science she was awarded the 2017 Rosalind Franklin Award from the Royal Society. In Our Universe: An Astronomer’s Guide, we see Professor Dunkley at her best, tackling big questions in an approachable way that conveys her commitment to advancing our knowledge of the universe.

Cecilia Heyes authored Cognitive Gadgets: The Cultural Evolution of Thinking to challenge established ideas and stimulate new conclusions. Trained as an experimental psychologist, Dr. Heyes studies evolutionary biology, philosophy of mind, animal cognition, and cognitive neuroscience. With her incredible breadth of knowledge, Heyes questions entrenched views, examining different ways to understand how the world works. It is this curiosity that led her to examine how evolution, learning, and developmental and cultural processes shape human cognition. Heyes posits that humans learn what and how to think through cultural, rather than genetic, evolution. This thought-provoking publication was chosen as one of the Best Non-Fiction Books of 2018 by Marginal Revolution.

Scientist, researcher, and admitted “fly pusher” Stephanie E. Mohr loves the common fruit fly. In her highly accessible book, First in Fly: Drosophila Research and Biological Discovery, Mohr reminds us the enormous impact tiny Drosophila has made. No other animal model has contributed as much, nor provided more answers to many of the most important and challenging questions in biology and medicine. First in Fly was chosen as a Forbes Best Book about Biology, 2018, and a Smithsonian Best Science Book of the Year, 2018. Through her unmatched skill as a science communicator, Mohr inspires us to re-appreciate the contribution of Drosophila and highlights the lasting value of research investment.

Pardis Sabeti and her laboratory members were already collaborating with colleagues when, in 2014, Sierra Leone suffered the largest Ebola Outbreak in decades. This opportune partnership would eventually lead to the sequence of 99 samples from 78 different patients during the first three weeks of the outbreak—invaluable research into the origins of Ebola and transmission of the virus. Sabeti, along with journalist Lara Salahi, coauthored the resultant Outbreak Culture: The Ebola Crisis and the Next Epidemic. Salahi’s critical interviews and investigative reporting highlighted scientific, medical, and social issues associated with an Ebola breakout. Sabeti and Salahi, together, tell a story of what went wrong during the Ebola outbreak. Through their timely work, they hope to increase the understanding of the contours of outbreak culture and what new approaches are necessary to ensure superior outcomes in the future.

Anna Marie Skalka began her career in science at a time, the 1960s, when female postdoctoral researchers were a rarity. After decades of determination and dedication Skalka was internationally recognized with the 2018 Sigma Xi William Procter Prize for Scientific Achievement for her seminal research on the biochemical mechanisms of retroviruses. Long known as a pioneer researcher in virology and a trailblazing woman in science, Dr. Skalka’s engaging Discovering Retroviruses: Beacons in the Biosphere takes us on a journey into the world of retroviruses, from evolution to present day. Her unique exploration of humanity’s longstanding interconnection with viruses leaves the reader with the promise of retrovirus therapeutics in our not-so-distant future.

In each of these publications we honor women scientists. In their work, we see personal inspiration, long-term dedication, and the profound and unyielding search for answers. Each, in her own way, has had the courage to follow her own ideas, the patience to assist countless others, and the generosity to share her knowledge and passion. In appreciation, we honor these women in science who continue to make important contributions in the scientific community and across in the world.

Build a Better Flytrap

The tiny, innocuous fruit fly has been a subject of research for more than a century, and is discussed in upwards of 100,000 scientific publications. Its surprising parallels with humans—the fruit fly has a beating heart, a brain, and other organs comparable to our own; exhibits complex behaviors including sleep and aggression; and slows down with age—have made it an ideal subject for research that’s furthered our understanding of biology, health, and disease. In First in Fly: Drosophila Research and Biological Discovery, Stephanie Elizabeth Mohr celebrates the power and importance of curiosity-driven pure research conducted with fruit flies, providing historic and contemporary examples of the profound knowledge such work has afforded. After First in Fly, readers will have a new appreciation for the beauty of the fruit fly, and the common genetic threads that connect us to other creatures. And yet, for many of us, that recognition won’t likely dislodge the lived experience of the fruit fly as a miraculously multiplying kitchen nuisance. For that, Mohr offers up the flytrap described below.

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Although researchers take great care to contain fruit flies in a lab setting, some inevitably get free, and once free, the flies will follow enticing scents to places they are unwelcome, such as a lunchroom or a yeast research lab. Drosophila researchers are not likely to bring insecticides into the lab—we are for the most part trying very hard to keep fruit flies alive, after all, so that we can perform genetic crosses and do other types of studies. But even the most dedicated fly researchers recognize that rogue flies can be a nuisance. We have developed an effective strategy for capturing flies that have escaped from their culture vials: we place simple flytraps in strategic locations around the lab. The same approach can be used in a home to get rid of an unwanted infestation or to collect wild flies for study. In the 2014 BioSCAN project, volunteers in Los Angeles, California, placed flytraps in their backyards as part of a species survey. These backyard collections led to identification of several new species of phorid flies, as well as the observation that Drosophila flavohirta, a species not previously found in the Americas, has taken up residence in Los Angeles.

To make a trap, first gather the following: an empty bottle, a rubber band or tape, and a tablespoon of something attractive to the flies, such as fruit juice, cider, champagne, wine, red wine vinegar, mushy banana, tired grapes, or overripe mango. The materials should be assembled as shown, then placed in areas frequented by the flies. The paper cone or a similar cover with a single small opening is essential: an open jar constitutes a fly feeder rather than a flytrap. The opening in the paper cone or cover should be just large enough for the small flies to fit through. Flies will be attracted by the bait and enter the chamber. Once inside, they are unlikely to try to escape, and even if they try, it will be next to impossible for them to find the tiny hole through which they entered.

This is a live trap method. To get rid of the flies, seal and throw away the trap within a few days. If forgotten, the trap is likely to become the birthplace of a next generation of flies. Before tossing the trap out, the curious might examine the flies to determine what species of flies were caught and whether they have unusual or interesting attributes. Should you decide to culture the flies, sliced bananas with a sprinkle of baker’s yeast should suffice as a food source, and a piece of cloth secured with a rubber band or a plug of cotton can be used to stopper the top without depriving the flies of oxygen. Be careful not to let the food dry out or expose the flies to prolonged heat or cold. To anesthetize the flies for close examination, place the trap on ice for five to ten minutes. If the food is very mushy, put the trap on its side, so the anesthetized flies do not get stuck in the food, or use a funnel to transfer the flies to an empty bottle before placing them on ice. A small paintbrush, makeup brush, or crab pick can be used as a pusher, and a magnifying glass, macro lens attachment on a camera, or smartphone-compatible microscope can help you inspect your flies closely. Further information, including food recipes and video demonstrations, can be found online. Who knows? Isolation of a spontaneous mutation, observation of an interesting behavior, or some other chance finding might launch a groundbreaking study.

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You can read more about First in Fly at the Atlantic.

Can We See Life Out There?

In Life through Time and Space, Wallace Arthur brings together the latest discoveries in biology and astronomy to examine our deepest questions about where we came from, where we are going, and whether we are alone in the cosmos. The answer to that last question is almost certainly negative, but, below, Arthur addresses a slightly different puzzle: life is probably out there—but can we see it?

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For sure it’s there. The odds of it not being there are negligible. By “there” I mean somewhere in our home galaxy, the Milky Way. But can we see it? Strange question perhaps, since the obvious answer would appear to be “no.” But it’s always worth poking under the skin of seemingly obvious answers. And sometimes the first step in this poking process is refining the question.

One version of our question here is “do any of the stars we can see with the unaided eye have inhabited planets?” The likely answer to this version is “yes.” This positive answer is yielded by doing a few exceedingly simple sums. To a rough approximation, we can see about 10,000 stars from a dark sky location. Well, that’s for folk with really good eyesight. But even for others, like me, the answer is still in the thousands. The proportion of those stars that have planets orbiting them is probably well over 90%, based on exoplanet searches to date. And most of those stars will have multiple planets, not just one. Last month, the first 8-planet system other than our own was discovered, when an extra planet was found orbiting the star Kepler-90.

If the average number of planets per star is 5 (though it’s probably higher) then we can see the host stars of about 50,000 planets. That’s great, but now we need to guestimate what fraction of these have life. If we use our own solar system as a yardstick, the answer is ¹⁄₈th, which works out at 6250. But that’s probably too high. To err on the cautious side let’s assume that our initial answer was out by an order of magnitude in the wrong direction. In this case the right answer is 625. And if we want to be really cautious we could go with two orders of magnitude, in which case the right answer is still over 60. Could it in fact be zero? Well, yes, but that’s really not likely. So in one sense we can see the home of alien life, but only in the sense of its host star rather than its host planet.

Another version of the question with which we started is: can we see life from other planetary systems because it has come to see us? The probable answer to this question—at least in my view—is “no.” However, our recent visit from the elongated interstellar object called 'Oumuamua might make us think again. I wouldn’t urge belief in the accuracy of all those YouTube depictions that see it as an alien spacecraft disguised as a long thin rock. But then again, no one has come up with a convincing explanation of how a natural object in space comes to be approximately cylindrical. In our own system there are more than a million asteroids. Not one of them, as far as we know, is of this shape.

A third version of the question emerged from discussion at the end of a talk I gave at a famous second-hand bookshop—Barter Books—in the ancient English town of Alnwick, a talk that was tied in with the launch of Life through Time and Space. A member of the audience took issue with my carbon chauvinism, but not in the usual way, by proposing silicon-based life. Rather, he asked if it might be possible for life to be made of dark matter. What a fascinating question!

My gut feeling is that such a form of life isn’t possible. But just supposing that it is—this would mean that we couldn’t see it even if it landed here on Earth. Of course, we can’t go too far with this line of thought because we don’t yet know what dark matter is made of; we just know that MACHOs are less likely than WIMPs. Nevertheless, the vast majority of matter in our galaxy is dark, not light, so we shouldn’t altogether ignore it.

So, to summarize: We can see the home stars of as-yet undiscovered life. And we can see a very odd-shaped interstellar visitor, but it’s probably uninhabited. We can’t see any DML (to coin a new acronym) if it exists, even if it’s currently sitting just across the table. What will change in the next decade or so? One distinct possibility is that we will see the signatures of life in exoplanet atmospheres. Here’s a specific hypothesis: we will first see such signatures in the year 2030. This, like all good hypotheses, is ultimately testable—but it won’t be so until December 31st 2030, or, more realistically to allow for data analysis, early in the year 2031.

The Future of Russia as an Energy Superpower

Russia’s energy wealth has long been the main pillar of the country’s economy, but what’s the long-term future of that financial security in a world that is gradually moving toward decarbonization? Thane Gustafson, whose Wheel of Fortune: The Battle for Oil and Power in Russia we recently released in a paperback edition, addressed that question earlier this fall when he delivered the Chatham House’s Annual Russia Lecture. The text of his address is below.

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The last time I had the honor of giving a speech here at Chatham House was thirteen years ago, in 2004. The talk was entitled “The Russian Oil Miracle.” Five years before, after sinking to a low point equal to about half of the Soviet-era record of 1988, Russian oil production had abruptly turned around, and between 1999 and 2004, it had regained much of the lost ground. During those years, Russia accounted for all of the net addition of crude to world oil supply.

What we could not see at the time, however, was that 2004 was the last of the miracle years, which were essentially based on capturing the “Soviet dividend.” By 2004 much of the Soviet dividend had been extracted, and while Russian oil production has continued to grow steadily since then, progress has been very gradual, and every year the net increase in production is far outstripped by the volume of drilling required to produce it, as each year’s production must overcome the built-in decline rate of existing fields as well as the diminishing returns from new ones. The Russian oil industry is very much in the position of an athlete that is running uphill against a slope that is steadily growing steeper.

But it is not my purpose today to deliver an update of the Russian Oil Miracle, but rather, to ask a very different sort of question, reflecting the revolutionary changes that have taken place in the world of energy, and especially in our perceptions of it, in just a decade-and-a-half, and to reflect with you on the implications of these changes for Russia as an energy producer and as—I think we can fairly use the term—a “petro-state.” Namely—what happens to Russia as an energy superpower as global demand for oil approaches a peak?

Cycles within Cycles: How to Think about the Energy Future of Russia

Trying to predict the future of Russian energy, and indeed of Russia itself, is like predicting climate change. And here I’m not talking about Mark Twain’s famous wisecrack that “everybody talks about the weather, but nobody does anything about it.” Rather, what I mean is the classic difficulty in any conversation about climate change—namely, that of distinguishing between long-term cycles and near-term ones, or, to put it another way, between signal and noise. Rising ocean levels are signal, whereas last year’s winter temperatures in Washington are noise.

Let me take as one example the cycles of global crude oil prices and their impact on the Russian economy. Russia has gone through four economic crashes since the mid-1980s, all four of them connected to the rise and fall of commodity prices and specifically oil. The precise causes and course of each of these cycles has been different from case to case. Yet the following would have seemed like a safe prediction just a few years ago:

• The cycle of peak and trough in global commodity prices will continue—that is what commodities do—and since oil markets are increasingly globalized and commoditized, the same cyclical pattern will govern oil prices as well—and gas too, by the way, as liquefied natural gas (LNG) increasingly turns gas into a globally traded commodity.
• And with each downturn—possibly at more frequent intervals in the future than in the past, but roughly once every decade—Russia will be thrown into recession, although with improved macroeconomic management (as in the last downturn) the extent of the decline may be cushioned. Conversely, as Alexei Kudrin has been warning for a decade, the stimulative effect of each upswing in oil prices will also be smaller each time, as the dependence of the Russian state budget on oil revenues increases.

The Science and Politics of Identifying the Dead

Earlier this month, the New York City medical examiner’s office positively identified the remains of a man killed in the 2001 attacks on the World Trade Center—the first positive identification in over two years. Below, Jay Aronson, author of Who Owns the Dead? The Science and Politics of Death at Ground Zero, considers some of the questions raised by the open-ended effort to identify the dead.

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The recent identification of the 1641st victim of the September 11, 2001 World Trade Center attacks highlights both the continuing development of DNA profiling technology and the ongoing commitment of the Office of the Chief Medical Examiner (OCME) to endeavor to identify the remains of 9/11 victims. Before this, the most recent identification occurred in March 2015 when 26-year-old Fiduciary Trust employee Matthew David Yarnell was identified using newly available testing methods.

In Who Owns the Dead? I chronicle the efforts of scientists, construction workers, politicians, and uniformed service personnel to recover and identify the remains of the victims of the World Trade Center attacks. The identification of Yarnell and the most recent victim are the fruits of a promise made by Medical Examiner Charles Hirsch that his office would never end its efforts to identify the missing.

Despite these recent successes, Who Owns the Dead? suggests that the promise was problematic at a variety of levels, not least of which that it means that the events of 9/11 can never be fully put to rest and that unidentified remains of victims will be in a permanent state of limbo—neither buried in marked individual graves nor interred in a collective mass grave. Instead, they are housed in the Medical Examiner’s repository seven stories below ground behind a wall of the National 9/11 Museum.

Other than an unknown number of undocumented immigrants who were never officially reported missing, it is highly unlikely that any victims of the attacks suffered an anonymous death. In an interview with CNN, Matthew Yarnell’s mother Michelle Yarnell said that she never doubted that her son had died in the attacks. She said that receiving the call from the OCME about Matthew “opened up all of the old wounds and old pains,” but enabled her family to “finally put everything to rest.” She also noted that she was grateful that the ME’s office was not going to give up in their quest to identify as many remains as possible. “I hope for everyone that lost a loved one there, that they’ll have closure someday, and, hopefully, sooner rather than later.”

Identifications like Yarnell’s and the one that just occurred will likely continue sporadically over the next few decades as DNA extraction technology continues to improve and profiling techniques become ever more sensitive. This will also likely become the norm for future mass disasters in which identification programs are declared open-ended.

One question that needs to be answered, then, is what impact these long-delayed identifications have on families and communities. Do they bring solace and relief after so many years? Are outcomes for families that receive remains years or decades after death different in any way from those of families that receive them early on, or not all? Is the lingering hope that an identification may occur in the future healthy or unhealthy for families that do not receive remains? In cases where families receive partial remains, what are the effects of being informed of the identification of additional remains years later? And, more controversially, whatever the answer to these questions, might the resources expended on extended identification projects be used more helpfully in other ways?

These are questions that must be analyzed empirically by psychologists, sociologists, anthropologists, ethicists, historians, and forensic scientists. We must not assume that we already know the answers.

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Aronson recently spoke with the University of Pittsburgh Humanities Center’s Being Human podcast about his work; you can listen to that conversation via the player below.

 

A Wonderful Story of Spacetime

In Ripples in Spacetime: Einstein, Gravitational Waves, and the Future of Astronomy, internationally-acclaimed science writer Govert Schilling takes us through a century of scientific adventures to one of the biggest discoveries of history: the September 2015 detection of gravitational waves by the Laser Interferometer Gravitational-Wave Observatory (LIGO). Gravitational waves are produced by some of the most large-scale objects and cataclysmic events in the universe, associated with supermassive black holes, pulsars, colliding galaxies, and the Big Bang itself. There’s already a great deal known about how gravitational waves are produced—efforts to detect them have been ongoing since the 1960s—and further detections made with ever more sensitive equipment will provide astronomers with a completely new way of studying the violent universe, perhaps helping physicists finally solve a number of persistent uncertainties about spacetime.

Schilling looks back to the development of the theoretical and technical aspects of gravitational wave detection and also forward to those expectations for the future, all while conveying the persistence, excitement, and scientific significance of the hunt. As British Astronomer Royal Martin Rees notes in his Foreword to the book, Schilling “tells of boisterous controversies, setbacks, and amazing technical achievements by scientists and engineers who struggled for decades to achieve fantastic precision. He relates how they emerged triumphant, revealing clues to the bedrock nature of space and time. It is a wonderful story, engagingly and rivetingly told.”

In the video below, Schilling introduces Ripples in Spacetime.

Humans and Nature, Hopelessly Entangled

Henry David Thoreau, born two hundred years ago today, is known for his stay on Walden Pond but at heart was really one for rivers. So argues Robert Thorson in The Boatman: Henry David Thoreau’s River Years, which shows just how deeply Thoreau’s thinking and writing were connected to paddling and sailing. Thorson’s presentation of Thoreau as a data-driven environmental scientist also gives us a Thoreau for the Anthropocene, an outdoorsman deeply attuned to the ways in which mankind was reshaping the natural world. Perhaps surprisingly, from today’s vantage, Thoreau regarded that reshaping not as pure debasement, but as the unavoidable entwining of human actions with natural processes, a snarl that heightened conditions for his beloved boating, among many other effects. In the passage below, adapted from The Boatman’s Conclusion, Thorson gives us a Thoreau determined to both appreciate the benefits and diminish the detriment of that hopeless entangling.

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Concord’s makeover began when English colonials arrived to create a religiously based communal village on the banks of this lush river meadow. Historian Brian Donahue proved that theirs was a largely sustainable agrarian culture. Yet within a decade they were trying to reengineer their “Great River” landscape by ditching its bedrock outlet. When that failed for lack of technology, they explored the possibility of diverting floodwaters eastward through the meadows of Thoreau’s birthplace, over the watershed divide, and into the Shawsheen Valley. Their pioneering efforts inaugurated more than two centuries of human “improvements” driven by an exponentially rising American population and improved technologies. Maximum development—agricultural land conversions and industrial hydropower development—occurred in Thoreau’s generation. By the time of his death, virtually every square inch of the land had been transformed in some way: rock to quarry, river to canal, brook to millstream, wood to fuel, land to pasture, and field to cropland. The entire valley had become a network of dams, canals, turnpikes, railroads, factories, town streets, and country roads.

John Barry, in his history of American river engineering, describes the cultural zeitgeist of Thoreau’s century: “This was the century of iron and steel, certainty and progress, and the belief that physical laws as solid and rigid as iron and steel governed nature, possibly even man’s nature, and that man had only to discover these laws to truly rule the world. It was the century of Euclidean geometry, linear logic, magnificent accomplishments, and brilliant mechanics. It was the century of the engineer.”

Local monuments to that century were the Billerica dam, the Middlesex Canal, the Fitchburg Railroad, and the Union Turnpike. Each was a battle won in a war against nature launched by General George Washington’s Revolutionary Army. Since the dawn of antiquity, rivers, even more so than coasts, have been the primary battlefields in this war. The U.S. Geological Survey, acting through the U.S. National Research Council, summarized the situation in 2007: “Deforestation, industrialization, urbanization, floodplain cultivation, dams and levee construction, and channelization have altered dramatically natural flow regimes.” Thoreau, by the end of his life, had encountered all of these disruptions and disconnections in his own field studies.

One Line to Rule the World

Spring has arrived, and with it, daylight saving time. As the clocks go forward an hour in the UK, as they did earlier this month in the US, we’re taking a look at how Greenwich became the home of time. A new book by Geographer Royal for Scotland, Professor Charles Withers, asks the question, how did the prime meridian, a singular world-ruling feature, come to be sited in southeast London? Why was it chosen over Washington, Paris, or Beijing? The passage below, excerpted from the prologue of Zero Degrees: Geographies of the Prime Meridian, explains how the choice of Greenwich to mark 0° longitude would go on to solve complex problems of global measurement that had engaged geographers, astronomers, and mariners since ancient times.

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In November 1883, a sixty-seven-year-old English sailor addressed a letter to the world’s geographical societies. There are, he began, “some things that belong to all mankind.” What William Parker Snow had in mind was nothing less than a single prime meridian, a global base point or line to be used by all nations. From such an agreed point of terrestrial measurement, he reasoned, navigators and geographers could plot their voyages and align their maps, and perhaps astronomers could even chart the heavens, all using a standard point of earthly reference. One prime meridian for the world and only one, stressed Parker Snow, would be of “vast benefit to Science and Humanity.”

His appeal for a uniform base of measurement was rooted in personal experience. Born in 1817 in Poole, England, William Parker Snow was a sailor, an author, a sometime Patagonian colonist, a historian of the American Civil War, and, important to his own self-image, a veteran of Arctic exploration. He was also reputed to be psychic and lived, as one contemporary remarked, “on the edge of the Fourth Dimension.” Parker Snow’s supposed otherworldly powers, revealed in a dream in January 1850, convinced him (but few others) of the location of the ill-fated Franklin expedition that was lost in the Arctic in 1847–1848. As a young man, Parker Snow had himself nearly perished at sea during a storm when his vessel had a close encounter with another ship that had derived its mid-ocean position and course from an initial meridian different from his own.