Archives for April 2017

Bird Fact Friday – Weekly Warbler: Blackpoll

From page 182-183 in The Warbler Guide:

The Blackpoll Warblers (fall birds) have yellowish throat and breast in contrast with the white lower belly. They have bold white wing bars, and distinct eyeline with broken eyering. The Blackpoll Warblers have contrasting tertial edging, and flight feathers white-edged on tips. Their streaking in sides and back is always present even when faint. Their long wings indicate a long-distance migrant: up to 7,000 miles each way—more than any other warbler.

The Warbler Guide
Tom Stephenson & Scott Whittle
Drawings by Catherine Hamilton
Warbler Guide App
Species Account Example: American Redstart Male

Warblers are amwarblerong the most challenging birds to identify. They exhibit an array of seasonal plumages and have distinctive yet oft-confused calls and songs. The Warbler Guide enables you to quickly identify any of the 56 species of warblers in the United States and Canada. This groundbreaking guide features more than 1,000 stunning color photos, extensive species accounts with multiple viewing angles, and an entirely new system of vocalization analysis that helps you distinguish songs and calls.

The Warbler Guide revolutionizes birdwatching, making warbler identification easier than ever before. For more information, please see the author videos on the Princeton University Press website.

Visit PUP at Communiversity 2017

Every year the Arts Council of Princeton organizes Communiversity ArtsFest, an event that features over 200 booths showcasing original art and contemporary crafts, unique merchandise, and culinary masterpieces from local chefs, plus six stages of continuous live entertainment. Communiversity ArtsFest draws over 40,000 art lovers and fun seekers to downtown Princeton, making it Central New Jersey’s largest and longest running cultural event. After a successful showing in 2016, Princeton University Press is excited to participate again this year. Stop by our booth (121-A, right across from the Nassau Hall gates) to enter giveaways, pick up some book swag, or chat with our local authors and staff about our latest titles across a variety of disciplines.

Presenting the trailer for Heretics!: The Wondrous (and Dangerous) Beginnings of Modern Philosophy

This entertaining and enlightening graphic narrative tells the exciting story of the seventeenth-century thinkers who challenged authority—sometimes risking excommunication, prison, and even death—to lay the foundations of modern philosophy and science and help usher in a new world. With masterful storytelling and color illustrations, Heretics! offers a unique introduction to the birth of modern thought in comics form—smart, charming, and often funny. A brilliant account of one of the most brilliant periods in philosophy, Heretics! is the story of how a group of brave thinkers used reason and evidence to triumph over the authority of religion, royalty, and antiquity. Watch the trailer here:


Heretics!: The Wondrous (and Dangerous) Beginnings of Modern Philosophy by Steven Nadler & Ben Nadler from Princeton University Press on Vimeo.

HereticsSteven Nadler is the William H. Hay II Professor of Philosophy and Evjue-Bascom Professor in the Humanities at the University of Wisconsin–Madison. His books include Spinoza: A Life, which won the Koret Jewish Book Award, and Rembrandt’s Jews, which was a finalist for the Pulitzer Prize. He lives in Madison. Ben Nadler is a graduate of the Rhode Island School of Design and an illustrator. He lives in Chicago. Follow him on Instagram at @bennadlercomics.

Kenneth Rogoff: The Compactness of Big Bills

Today in our blog series by Kenneth Rogoff, author of The Curse of Cash:

From Rachel Maddow of MSNBC, comes a video story marvelously explaining why criminals, tax evaders, and corrupt official so love large denomination notes. Here, an apparently corrupt Nigerian official (who pleads innocence) finds $100s very convenient for stashing cash. The story comes at the top of the show.

I am grateful to Larry Kintisch of Blauvelt NY for drawing my attention to this story. Yes, there is a world of difference between a “less-cash society” as my book argues, and a cash-less society that the cash lobby likes to point to as a scare tactic for maintaining the absurd status quo.

The paperback edition of The Curse of Cash: How Large Denomination Bills Aid Tax Evasion and Crime and Constrain Monetary Policy will be coming out early this summer; now with an analysis of Indian demonetization and other issues that have arisen in the past year.

Read other posts in the series here.

Welcome to the Universe microsite receives a Webby

We’re pleased to announce that the accompanying microsite to Welcome to the Universe by Neil DeGrasse Tyson, Michael A. Strauss, and J. Richard Gott has won a People’s Choice Webby in the Best Use of Animation or Motion Graphics category. Congratulations to Eastern Standard, the web designer, on a beautifully designed site.

Winning a Webby is especially gratifying because it honors how much fun we had making the site. We knew we wanted an unconventional approach that would mirror both the complexity and accessibility of the book it was meant to promote. Our wonderful in-house team and creative partners, Eastern Standard took on this challenge, and we are so happy with the results.
—Maria Lindenfeldar, Creative Director, Princeton University Press 

Creating this microsite was a wonderful experiment for us at Princeton University Press.  We wanted to explore how we, as a publisher, could present one of our major books to the public in a compelling way in the digital environment.  Ideally, we had a vision of creating a simple site with intuitive navigation that would give readers an inviting mini-tour through the topics of the book, Welcome to the Universe, by Neil deGrasse Tyson, Michael Strauss, and Richard Gott.  The animation was meant to be subtle, but meaningful, and to gently encourage user interaction, so that the focus would always remain immersing the reader in the content of the book – what we feel is the most interesting part!  We were very happy with how it turned out and now all the more thrilled and honored that the site was chosen for a Webby!
—Ingrid Gnerlich, Science Publisher, Princeton University Press

Everyone’s favorite genius takes the spotlight

Along with Einstein fans everywhere, we’re fairly excited to binge-watch National Geographic’s upcoming series, “Genius”, premiering Tuesday, April 25. The first episode shows a young Einstein (Johnny Flynn), poring over the nature of time, a concept well covered in our An Einstein Encyclopedia along with most any other topic that could interest an Einstein devotee, from fame, to family, to politics, to myths and misconceptions. In Genius, prepare to see a show-down between a feisty young Einstein and a particularly rigid teacher. Engrossing to watch—and bound to leave viewers wanting more. Not to worry: “Teachers, education and schools attended” are covered in depth in the Encyclopedia, as are “Rivals”.

Episode 2 of Genius promises to show Einstein embarking, after much head-butting, on a love affair with the determined Mileva Maric. Often remembered as the lone, eccentric, Princeton-based thinker, Einstein’s youthful relationship with Maric sometimes comes as a surprise even to Einstein fans. And yet in 1903, a young Albert Einstein married his confidante despite the objections of his parents. Her influence on his most creative years has given rise to much discussion—but theirs was only one of several romantic interests over the course of Einstein’s life that competed with his passion for physics. Einstein’s love life has been the subject of intense speculation over the years, but don’t believe everything you hear: “Romantic Interests: Actual, Probable, and Possible”, all included in the Encyclopedia, won’t leave you guessing.

Mileva Maric, first wife of Albert Einstein

 An Einstein Encyclopedia is the single most complete guide to Einstein’s life, perfect for browsing and research alike. Written by three leading Einstein scholars who draw on their combined wealth of expertise gained during their work on the Collected Papers of Albert Einstein, this accessible reference features more than one hundred entries and is divided into three parts covering the personal, scientific, and public spheres of Einstein’s life.

With science celebrated far and wide along with Earth Day this past weekend, what better time to get your dose of genius and #ReadUp.



Andrew Lo on Adaptive Markets: Financial Evolution at the Speed of Thought

Half of all Americans have money in the stock market, yet economists can’t agree on whether investors and markets are rational and efficient, as modern financial theory assumes, or irrational and inefficient, as behavioral economists believe. In this groundbreaking book, Andrew Lo cuts through this debate with a new framework, the Adaptive Markets Hypothesis, in which rationality and irrationality coexist. Adaptive Markets shows that the theory of market efficiency isn’t wrong but merely incomplete. Lo’s new paradigm explains how financial evolution shapes behavior and markets at the speed of thought. An ambitious new answer to fundamental questions in economics, Adaptive Markets is essential reading for anyone who wants to know how markets really work. We asked him to explain the Adaptive Markets Hypothesis, the strengths and limitations on the current theories, and how this new thinking can be practically applied.

What led you to write this book?

AL: Ever since I was a graduate student in economics, I’ve been struggling with the uncomfortable observation that economic theory doesn’t seem to work in practice. As elegant as this theory is, there are so many examples where the data just don’t support the theory that, after a while, I started wondering just how useful our theories were. For example, stock market prices don’t follow random walks, market prices don’t always seem rational, and people often make poor decisions, especially when it comes to financial matters. But it takes a theory to beat a theory. Rather than just criticizing existing theories, I decided to develop an alternative—this book describes the personal journey I took to arrive at that alternative, which I call the Adaptive Markets Hypothesis.

What’s the Adaptive Markets Hypothesis?

AL: The Adaptive Markets Hypothesis is my solution to the longstanding debate in financial economics between two competing camps. One camp consists of the disciples of the Efficient Markets Hypothesis, who believe that investors are rational decision makers and market prices fully reflect all available information. The opposing camp consists of the psychologists and behavioral economists who believe that investors are irrational and market prices are driven by “animal spirits.” It turns out that both camps have correctly captured certain aspects of human behavior, but neither camp offers a complete picture of how investors and markets behave. The Adaptive Markets Hypothesis fills this gap.


AL: By drawing on recent research in psychology, neuroscience, evolutionary biology, and artificial intelligence, I show that human behavior is the result of several different components of the brain, some of which produce rational behavior while others produce more instinctive emotional behavior. These components often work together, but occasionally they compete with each other. And for obvious evolutionary reasons, rationality can be trumped by emotion and instinct when we’re confronted with extreme circumstances like physical threats—we “freak out.” The problem is that these hardwired responses to physical threats are also triggered by financial threats, and freaking out is generally not the best way to deal with such threats. Therefore, investors and markets have a split personality: sometimes they’re quite rational but every so often, they freak out.

Are you suggesting that the Efficient Markets Hypothesis, which dominates financial thinking today, is wrong?

AL: No! On the contrary, the Efficient Markets Hypothesis is one of the most useful, powerful, and beautiful pieces of economic reasoning that economists have ever proposed. Generations of investors and portfolio managers have been saved from bad investment decisions because of the Efficient Markets Hypothesis, which says that if something seems too good to be true, it probably is. The Efficient Markets Hypothesis is not wrong; it’s merely incomplete. Its focus is the behavior of investors and markets in normal business environments, where the “wisdom of crowds” rules the day. What’s missing is the “madness of mobs,” when investors are reacting emotionally and instinctively in response to extreme business environments—good or bad—leading either to irrational exuberance or panic selling. The Adaptive Markets Hypothesis provides a more complete framework in which both types of behaviors are possible. The combination of these behaviors yields a much richer set of implications for price dynamics, investment strategies, risk management, and financial regulation.

Who is the intended audience for this book?

AL: My intention was to write this book for the general reader, but only time will tell whether or not I’ve succeeded. In fact, I’m hoping that there’s something for everyone in this book. For example, readers wondering whether or not it’s possible to beat the stock market using mathematical models will want to read Chapter 2, “If You’re So Smart, Why Aren’t You Rich?” For readers already convinced that it’s possible and want to understand the neuroscientific basis of irrational behavior, they’ll want to read Chapter 3, “If You’re So Rich, Why Aren’t You Smart?” No book on finance would be complete without a discussion of how the recent financial crisis could have happened to us—a country with one of the most sophisticated financial systems in the world—and that’s Chapter 9, “Fear, Greed, and Financial Crisis.” And for readers interested in getting a glimpse of the future of the financial industry and the amazing things that can be accomplished with finance if used properly, there’s Chapter 12, “To Boldly Go Where No Financier Has Gone Before.” Although the book is based on my academic research, I’ve worked hard to translate “academic-speak” into plain English, using simple analogies and real-life examples to make the research come alive. In fact, there’s not a single equation or mathematical formula in the book, which is no easy feat for someone from MIT!

In Adaptive Markets you take an interdisciplinary view of financial markets, bringing in cognitive neuroscience, biology, computer science, and engineering. How did you come to bring all of these seemingly disparate fields together and why is that important?

AL: Although I do enjoy learning new things and have broad-ranging interests, when I started my academic career as a financial economist, I had no interest or intention in doing “interdisciplinary” research. I was perfectly happy spending my days and nights working on traditional neoclassical financial economics—portfolio theory, derivatives pricing models, asset pricing models, financial econometrics, and so on. But the more I tried to fit financial theories to data, the more frustrated I became that these theories performed so poorly. So I started trying to understand why the theories broke down and how they could be fixed. I began by studying behavioral economics and finance, which led me to psychology, which then to the cognitive neurosciences, and so on. I was dragged—sometimes kicking and screaming—from one field of study to the next in my quest to understand why financial markets don’t work the way we think (and want them to). This process ultimately led me to the Adaptive Markets Hypothesis, which is a very satisfying (for me, at least) integration of various disciplines that have something to say about human behavior. I’m especially pleased by the fact that Adaptive Markets reconciles the two competing schools of thought in financial economics, both of which are compelling in their own right even though they’re incomplete.

Why do we need to understand the evolution of finance?

AL: Many authors and academics will use evolution as a metaphor when referring to the impact of change. In Adaptive Markets, I use evolution quite literally because financial markets and institutions are nothing short of evolutionary adaptations that Homo sapiens has developed to improve our chances of survival. Therefore, if we really want to understand how the financial system works, how it changes over time and circumstances, and what we can do to improve it, we need to understand the evolution of finance. And unlike animal species, which evolve from one generation to the next, the financial system evolves at the speed of thought.

You argue that economics wishes it were more like the hard science of physics where 99% of all observable phenomena can be explained with three laws. Will we ever have a complete understanding of how financial markets function?

AL: It’s true that most economists—myself included—suffer from a psychological disorder called “physics envy.” We wish we could explain 99% of economic behavior with three laws like the physicists but this is a pipe dream. The great physicist Richard Feynman put it best when he said, “Imagine how much harder physics would be if electrons had feelings!” I tell all my students at the start of the semester that all economic theories are approximations to a much more complex reality, so the key question for investors and portfolio managers is not “is the theory correct?” but rather, “how good is the approximation?” The answer to this question lies largely in the environment, which plays a huge role in evolutionary theories. Whether we’ll ever be able to develop a truly complete theory of human behavior—and, therefore, how financial markets function—is hard to say. But I do believe that we can get much closer to that complete theory through the Adaptive Markets Hypothesis.

How can investors and portfolio managers incorporate the Adaptive Markets Hypothesis into their investment philosophies?

AL: The Adaptive Markets Hypothesis has a relatively straightforward but sweeping implication for all investment philosophies, and that has to do with change. During normal business environments, the principles of Efficient Markets are an excellent approximation to reality. For example, from the 1930s to the early 2000s, a period where the U.S. stock market had relatively consistent average returns and volatility, a long-only passive investment strategy of 60% stocks and 40% bonds produced pretty decent returns, particularly for those who were investing over a 10- or 20-year horizon. The problem is that this approach doesn’t always work. When market conditions change and we experience large macro shocks like the financial crisis of 2008, then simple heuristics like 60/40 no longer work as well because financial markets have changed in their dynamics. Today’s markets are now much more responsive to intervention by governments and their central banks and punctuated by the irregular cycle of fear and greed. So since 2007 and 2008, we’ve seen a very different market dynamic than over the previous six decades. The point of Adaptive Markets is not simply to be wedded to any static theory, but rather to understand how the nature of markets can change. And once it does change, we need to change with it. John Maynard Keynes put it best when, in responding to criticism that he flip-flopped on the gold standard, he said, “When the facts change, sir, I change my mind. What do you do?”

Can you give an example of how change might impact today’s investors?

AL: One important implication of Adaptive Markets for investors and portfolio managers is that passive investing is changing and we have to adapt. John Bogle—the founder of the Vanguard Group and the father of passive investing and index funds—had an incredibly important insight in the 1970s which he calls the “Cost Matters Hypothesis:” reducing trading costs can have a huge impact on wealth accumulation. Bogle has done more for the individual investor than anyone else I can think of; he democratized the investment process. Thanks to technological innovations like automated trading, electronic market-making, and big data analytics, we’re ready to take the next evolutionary step that builds on Bogle’s legacy. For example, like the trend in healthcare towards personalized medicine, we can now create personalized indexes that are passive portfolios designed to achieve specific goals for a given individual. You might be more risk tolerant than your neighbor so your portfolio will have more equities, but because you work in the financial industry and she works in big pharma, your personalized portfolio will have fewer financial stocks and hers will have fewer biopharma stocks. Also, personalized indexes can manage the risk more actively to suit an individual’s threshold of “pain.” Current financial wisdom criticizes investors who don’t invest for the long run, and I’ve always thought such criticism to be terribly unfair. After all, how easy is it for someone to stick with an investment that’s lost 50% of its value over just a few months? Well, that’s exactly what happened between the fourth quarter of 2008 and the first quarter of 2009. Traditional investment advice is a bit like trying to prevent teenage pregnancies by asking teenagers to abstain—it’s not bad advice, but it’s unrealistic. Why not manage the risk of an individual’s portfolio more actively so as to reduce the chances of freaking out?

Finance has developed a bad reputation in the popular press, particularly in the aftermath of the recent financial crisis. Does the Adaptive Markets Hypothesis have anything to say about this and how things can be improved?

AL: Absolutely. At the heart of all bad behavior, regardless of the industry or context, is human nature. Humans are the Curious George of the animal kingdom, but there’s no “man in the yellow hat” to bail us out when we get into trouble. Homo sapiens has evolved in some remarkable ways and we’re capable of extraordinary things, both good and bad. The same social and cultural forces that give rise to wonderful organizations like the Peace Corps, the Red Cross, and Doctors without Borders can sometimes lead to much darker and destructive organizations. The only way for us to deal more effectively with the negative aspects of society is to acknowledge this dual nature of human behavior. Chapter 11 of Adaptive Markets, titled “Fixing Finance,” is devoted entirely to this objective. We have to be careful not to throw out the baby with the bathwater—the financial system definitely can be improved, but we shouldn’t vilify this critically important industry because of a few bad actors.

What are some specific proposals for how to fix finance?

AL: Well, before we can fix finance, we need to understand where financial crises come from, and the Adaptive Markets Hypothesis has a clear answer: crises are the product of human behavior coupled with free enterprise. If you can eliminate one or both of these two components, you can eliminate financial crises. Otherwise, financial crises are an avoidable fact of modern life. Human misbehavior is a force of Nature, not unlike hurricanes, flash floods, or earthquakes, and it’s not possible to legislate away these natural disasters. But this doesn’t mean we can do anything about it—we may not be able to prevent hurricanes from occurring, but we can do a great deal to prepare for them and reduce the damage they do. We can do a lot to prepare for financial crises and reduce the damage they do to those individuals and institutions least able to withstand their devastating consequences. This perspective is important because it goes against the traditional narrative that financial crises are caused by a few greedy unscrupulous financiers and once we put them in jail, we’ve taken care of the problem. The Adaptive Markets perspective suggests something different: the problem is us. Specific proposals for dealing with crises include: using new technologies in data science to measure economic activity and construct early warning indicators of impending crises; studying crises systematically like the way the National Transportation Safety Board studies airplane crashes so we know how to make the financial system safer; creating adaptive regulations that change with the environment, becoming more restrictive during booms and less restrictive during busts; and systematically measuring individual behavior and corporate culture quantitatively so we can engage in “behavioral risk management.”

Now that you’ve written this book, where do you see your research going from here?

AL: Well, this is still early days for the Adaptive Markets Hypothesis. There’s so much left to be done in exploring the implications of the theory and testing the implications empirically and experimentally whenever possible. The Efficient Markets Hypothesis took decades and hundreds of academic studies to get established, and the same will be true of this one. One of my goals in writing this book is to motivate my academic and industry colleagues to start this vetting process. In the same way that Darwin’s theory of evolution had to be tested and challenged from many different perspectives, the Adaptive Markets Hypothesis has to go through the gauntlet of academic scrutiny. One important implication of the Adaptive Markets perspective is that we need to change the way we collect data and test theories in financial economics. For example, traditional tests of financial theories involve collecting stock market prices and analyzing the statistical properties of their risks and returns. Contrast this approach with how an ecologist would study a newly discovered tropical island in an effort to preserve it. He would begin by first cataloguing the flora and fauna, identifying the key species, and measuring their biomasses and behaviors. Next, he would determine the food chain, environmental threats, and predator/prey relationships, and then turn to population dynamics in the context of the changing environment. Ultimately, such a process would lead to a much deeper understanding of the entire ecosystem, allowing ecologists to determine the best way to ensure the long-term health and sustainability of that island. Imagine doing the same thing with the financial industry. We would begin by cataloguing the different types of financial institutions and investors, measuring their financial biomass, and identifying key species—banks, hedge funds, pension funds, retail investors, regulators, etc.—and their behaviors. Then we would determine the various types of business relationships and interdependencies among these species, which are critical for mapping the population dynamics of this financial ecosystem. This approach seems sensible enough, but it’s not yet being done today (except by my collaborators and me!).

How do you continue to evolve your own thinking? What do you do?

AL: Someone very wise once said that the beginning of wisdom is humility, and I’m convinced that this is how we make progress as a civilization. Once we’re convinced that we have all the answers, we stop asking new questions and learning. So I’m continually looking for new ways to understand financial market behavior, and constantly humbled by how little I know compared to how much we have yet to discover. In this respect, I guess I’m an intellectual opportunist—I don’t care where an idea comes from or what academic discipline it belongs to; if it gives me new insight into an existing problem, I’ll use it and build on it. I’m currently working on several applications of the Adaptive Markets Hypothesis to investments, risk management, and financial regulation, and also hoping to test the theory in the context of individual and institutional investment decisions. The initial results are quite promising and show that financial industry participants adapt much more quickly than we thought. These results point to several important unintended consequences that have clear implications for how we should regulate the industry so as to reduce the chances of another financial crisis.

Andrew W. Lo is the Charles E. and Susan T. Harris Professor at the MIT Sloan School of LoManagement and director of the MIT Laboratory for Financial Engineering. He is the author of Hedge Funds and Adaptive Markets: Financial Evolution at the Speed of Thought. He is also the founder of AlphaSimplex Group, a quantitative investment management company based in Cambridge, Massachusetts.

Tuesday’s Trot – Quarter Horse

From page 432 in Horses of the World:

A great equestrian nation, the United States has a large number of breeds, among the most famous and admired. It also has the greatest number of horses of any country in the world; in 2011 around 10,150,000 horses were counted (with Texas in the lead, followed by California, Florida, and Oklahoma). The United States has favored the breeding of horses with excellent character, with a great diversity of coat colors, and with supplemental gaits that are encouraged or developed in many breeds.

Due to their incredibly fast starts and bursts of speed, Quarter Horses are also used in racing, often practiced today on straight, 300-meter courses.

Today, we’re bringing you 5 fun facts about America’s most popular horse—the Quarter Horse:

1. The Quarter Horse is an incredible sprinter and is the fastest in the world over quarter-mile courses, 440 yards (around 402 m), from which it derives its name (it was first called the Quarter Running Horse).

The head is characteristic: rather small, with a wide forehead; large, wide-spaced eyes; narrow muzzle; and large nostrils.

2. The Quarter Horse, one of the oldest of American breeds, descends from Iberian and Eastern horses, crossed with the ancestors of English Thoroughbreds.

3. The Quarter Horse has a particularly docile nature, is cooperative, adaptable, calm, and reliable following many years of selection for good character.

4. The Quarter Horse excels in Western riding (reining, trail, cutting, and others), its specialty, but it also makes a good carriage horse and is used for trekking, racing, polo, and so forth. Its excellent, reassuring character makes it good for beginning riders.

5. The breed is the most popular in the world, and it is very widespread with around 5 million horses registered with the American Quarter Horse Association.

Horses of the World
Élise Rousseau
Illustrated by Yann Le Bris
Translated by Teresa Lavender Fagan
Sample Entry

Horses of the World is a comprehensive, large-format overview of 570 breeds of domestic and extant wild horses, including hybrids between the two and between domestic breeds and other equids, such as zebras. This beautifully illustrated and detailed guide covers the origins of modern horses, anatomy and physiology, variation in breeds, and modern equestrian practices. The treatment of breeds is organized by country within broader geographical regions—from Eurasia through Australasia and to the Americas. Each account provides measurements (weight and height), distribution, origins and history, character and attributes, uses, and current status. Every breed is accompanied by superb color drawings—600 in total—and color photographs can be found throughout the book.

Describing and depicting every horse breed in existence, Horses of the World will be treasured by all who are interested in these gorgeous animals.

Anurag Agrawal: Monarchs vs. Milkweed

by Anurag Agrawal

Coevolution is a special kind of evolution. And monarchs and milkweeds exemplify this special process. In particular, what makes coevolution special is reciprocity. In other words, coevolution is one species that evolves in response to the other, and the other species evolves in response to the first. Thus, it is a back-and-forth that has the potential to spiral out of control. In some arms races, the two organisms both benefit, such as that between some pollinators and flowering plants. But coevolution is more common among antagonists, like predators and their prey.

When biologists first described coevolution, they likened it to an arms race. An arms race, such as that between political entities, occurs when two nations reciprocally increase their armament in response to each other. So how does an arms race between monarchs and milkweeds, or between cats and mice, or between lions and wildebeest, or between plants and their pathogenic fungi, proceed? When coevolution occurs, it proceeds with “defense” and “counter defense.” And one of the few rules of coevolution is that for every defense that a plant or prey mounts, the predator mounts a counter defense, or an exploitative strategy to overcome the defense.

Once a monarch butterfly lays an egg on a milkweed plant, the natural history of coevolution unfolds. For every defense that the plant mounts, milkweed mounts a counter defense. Once the caterpillar hatches, it must contend with a bed of dense hairs that are a barrier to consumption of the leaf. But monarchs are patient, and have coevolved with the milkweed. So their first strategy is to shave that bed of hairs such that the caterpillar has access to the leaves that lie beneath.


For every defense there’s a counter defense. But next, when the monarch caterpillar sinks its mandibles into the milkweed leaf, it encounters a sticky, poisonous liquid called latex. In this video we will see how the monarch caterpillar deactivates the latex bomb that the milkweed puts forward.

And so the arms race continues, with reciprocal natural selection resulting in coevolution between monarchs and milkweeds. In my book, Monarchs and Milkweed, I outline the third level of defense and counter defense between these two enemies. Milkweed next mounts a remarkable and highly toxic defense chemical called a cardiac glycoside. But, yes, again the Monarch has evolved the means to not only not be poisoned by the cardiac glycoside, but to sequester it away and put it to work in defense of the Monarch itself from its enemies, such as predatory birds. For more on the Monarch – Milkweed arms race see this video, filmed in Ithaca, New York outside of Cornell University where we conduct our research.

AgrawalAnurag Agrawal is a professor in the Department of Ecology and Evolutionary Biology and the Department of Entomology at Cornell University. He is the author of Monarchs and Milkweed: A Migrating Butterfly, a Poisonous Plant, and Their Remarkable Story of Coevolution.

Joshua Holden: Quantum cryptography is unbreakable. So is human ingenuity

Two basic types of encryption schemes are used on the internet today. One, known as symmetric-key cryptography, follows the same pattern that people have been using to send secret messages for thousands of years. If Alice wants to send Bob a secret message, they start by getting together somewhere they can’t be overheard and agree on a secret key; later, when they are separated, they can use this key to send messages that Eve the eavesdropper can’t understand even if she overhears them. This is the sort of encryption used when you set up an online account with your neighbourhood bank; you and your bank already know private information about each other, and use that information to set up a secret password to protect your messages.

The second scheme is called public-key cryptography, and it was invented only in the 1970s. As the name suggests, these are systems where Alice and Bob agree on their key, or part of it, by exchanging only public information. This is incredibly useful in modern electronic commerce: if you want to send your credit card number safely over the internet to Amazon, for instance, you don’t want to have to drive to their headquarters to have a secret meeting first. Public-key systems rely on the fact that some mathematical processes seem to be easy to do, but difficult to undo. For example, for Alice to take two large whole numbers and multiply them is relatively easy; for Eve to take the result and recover the original numbers seems much harder.

Public-key cryptography was invented by researchers at the Government Communications Headquarters (GCHQ) – the British equivalent (more or less) of the US National Security Agency (NSA) – who wanted to protect communications between a large number of people in a security organisation. Their work was classified, and the British government neither used it nor allowed it to be released to the public. The idea of electronic commerce apparently never occurred to them. A few years later, academic researchers at Stanford and MIT rediscovered public-key systems. This time they were thinking about the benefits that widespread cryptography could bring to everyday people, not least the ability to do business over computers.

Now cryptographers think that a new kind of computer based on quantum physics could make public-key cryptography insecure. Bits in a normal computer are either 0 or 1. Quantum physics allows bits to be in a superposition of 0 and 1, in the same way that Schrödinger’s cat can be in a superposition of alive and dead states. This sometimes lets quantum computers explore possibilities more quickly than normal computers. While no one has yet built a quantum computer capable of solving problems of nontrivial size (unless they kept it secret), over the past 20 years, researchers have started figuring out how to write programs for such computers and predict that, once built, quantum computers will quickly solve ‘hidden subgroup problems’. Since all public-key systems currently rely on variations of these problems, they could, in theory, be broken by a quantum computer.

Cryptographers aren’t just giving up, however. They’re exploring replacements for the current systems, in two principal ways. One deploys quantum-resistant ciphers, which are ways to encrypt messages using current computers but without involving hidden subgroup problems. Thus they seem to be safe against code-breakers using quantum computers. The other idea is to make truly quantum ciphers. These would ‘fight quantum with quantum’, using the same quantum physics that could allow us to build quantum computers to protect against quantum-computational attacks. Progress is being made in both areas, but both require more research, which is currently being done at universities and other institutions around the world.

Yet some government agencies still want to restrict or control research into cryptographic security. They argue that if everyone in the world has strong cryptography, then terrorists, kidnappers and child pornographers will be able to make plans that law enforcement and national security personnel can’t penetrate.

But that’s not really true. What is true is that pretty much anyone can get hold of software that, when used properly, is secure against any publicly known attacks. The key here is ‘when used properly’. In reality, hardly any system is always used properly. And when terrorists or criminals use a system incorrectly even once, that can allow an experienced codebreaker working for the government to read all the messages sent with that system. Law enforcement and national security personnel can put those messages together with information gathered in other ways – surveillance, confidential informants, analysis of metadata and transmission characteristics, etc – and still have a potent tool against wrongdoers.

In his essay ‘A Few Words on Secret Writing’ (1841), Edgar Allan Poe wrote: ‘[I]t may be roundly asserted that human ingenuity cannot concoct a cipher which human ingenuity cannot resolve.’ In theory, he has been proven wrong: when executed properly under the proper conditions, techniques such as quantum cryptography are secure against any possible attack by Eve. In real-life situations, however, Poe was undoubtedly right. Every time an ‘unbreakable’ system has been put into actual use, some sort of unexpected mischance eventually has given Eve an opportunity to break it. Conversely, whenever it has seemed that Eve has irretrievably gained the upper hand, Alice and Bob have found a clever way to get back in the game. I am convinced of one thing: if society does not give ‘human ingenuity’ as much room to flourish as we can manage, we will all be poorer for it.Aeon counter – do not remove

Joshua Holden is professor of mathematics at the Rose-Hulman Institute of Technology and the author of The Mathematics of Secrets.

This article was originally published at Aeon and has been republished under Creative Commons.

Celebration of Science: A reading list

This Earth Day 2017, Princeton University Press is celebrating science in all its forms. From ecology to psychology, astronomy to earth sciences, we are proud to publish books at the highest standards of scholarship, bringing the best work of scientists to a global audience. We all benefit when scientists are given the space to conduct their research and push the boundaries of the human store of knowledge further. Read on for a list of essential reading from some of the esteemed scientists who have published with Princeton University Press.

The Usefulness of Useless Knowledge
Abraham Flexner and Robbert Dijkgraaf


The Serengeti Rules
Sean B. Carroll


Honeybee Democracy
Thomas D. Seeley


Silent Sparks
Sara Lewis


Where the River Flows
Sean W. Fleming


How to Clone a Mammoth
Beth Shapiro


The Future of the Brain
Gary Marcus & Jeremy Freeman


Searching for the Oldest Stars
Anna Frebel


Climate Shock
Gernot Wagner & Martin L. Weitzman


Welcome to the Universe
Neil DeGrasse Tyson, Michael A. Strauss, and J. Richard Gott


The New Ecology
Oswald J. Schmitz


Oswald Schmitz: Reflecting on Hope for Life in the Anthropocene

This post by Oswald Schmitz, author of The New Ecology, was originally published on the March for Science blog. On April 22, PUP’s Physical and Computer Sciences editor Eric Henney will be participating in a teach-in the National Mall, focusing on the social value of direct and engaging scientific communication with the public. 

Springtime is a welcome reprieve from a prolonged cold winter. It is a time of reawakening when all kinds of species become impatient to get on with their business of living. We hear the trill of mating frogs, see leaves unfurl from their quiescent buds, and behold forest floors and fields unfold rich color from a dizzying variety of blossoming wildflowers. The energetic pace of life is palpable. It is only fitting, then, that we dedicate one spring day each year – Earth Day – to commemorate the amazing variety of life on this planet, and to take stock of the human enterprise and reflect on how our behavior toward nature is influencing its sustainability.

For many, such reflection breeds anxiety. We are entering a new time in Earth’s history—the Anthropocene—in which humans are transitioning from being one among millions of species to a species that can single-handedly determine the fate of all life on Earth. Many see the Anthropocene as a specter of doom, fraught with widespread species extinctions and loss of global sustainability, and attributable to humankind’s insatiable drive to exploit nature.

This view stems from the conventional idea that all living beings on Earth represent a heritage of slow evolutionary processes that occurred over millennia, culminating in the delicate balance of nature we see today. Many despair that humans are now jeopardizing the balance, as species will necessarily be incapable of coping with the onslaught of ever-new and fast-paced changes.


An Aegean Wall Lizard, so named because of its evolved habit to live and hunt in rock walls constructed around crop fields in Greece. Individuals living on the walls have different limb morphology and mobility than counterparts of their species that are found within their original sandy habitats, demonstrating their capacity to adapt and thrive in human developed landscapes. Photo courtesy of Colin Donihue.

As an ecologist, I am torn by the changes I see. I have a deep and abiding respect for the amazing diversity of living organisms, their habits and their habitats. This ethic was shaped during my childhood when I was free to wander the natural environs of my hometown. I could go to those places any time of day, during any season: breathing, smelling, listening, observing, touching and tasting to discover nature’s wonders. That sense of wonder has endured. It’s what keeps me asking the probing questions that let me learn scientifically how species fit together to build up and sustain nature. It thus saddens—sometimes even maddens—me to see nature’s transformation in the name of human “progress.”

But as a scientist, I must admit that these changes are also fascinating. It turns out that rapid human-caused changes present much opportunity for new scientific discoveries. They force me to see and appreciate the dynamism of nature from fundamentally new vantage points. I find that nature can be more resilient than we often give it credit for, a fact that should inspire hope for a bright, sustainable environmental future in the Anthropocene.

Changing the mindset from despair to hope requires letting go of a deeply held notion that nature exists in a fragile balance, and that humankind has a persistent habit of disrupting that balance. Nature is perpetually changeable, with or without human presence. Life’s energetic pace, and the primal drive of all organisms to survive and reproduce, is what builds resilience in the face of change. We are learning how nutrients are perpetually transformed and redistributed by plant and animal species to sustain myriad ecological functions. These functions ensure that we have ample clean and fresh water, deep and fertile soils, genetic variety to produce hardy crops, the means to pollinate those crops, and the capacity to mitigate impacts of gaseous emissions, among numerous other services that humans rely on to sustain their health and livelihoods. Many species also can rapidly acclimate and even evolve within a mere span of a couple of human generations to cope with significant and rapid environmental change. Such adaptability allows many ecological systems to recover from human-caused disturbances and damages within the short time span of a human lifetime, no less.

This capacity for resilience is perhaps our most important evolutionary heritage. It is what gives hope for a sustainable future. The challenge of sustainability, then, is to engage with nature without eroding this capacity. The emerging science-based ethic of earth environmental stewardship can help on this front. It sees humans and nature entwined, where humans have obligations to one another mediated through their mutual relationships with nature.

Earth environmental stewardship strives to sustain nature’s resilience by protecting the evolutionary and ecological interdependence of all living beings and the physical environment. It strives for continuous improvement of environmental performance and human wellbeing through a commitment to use nature’s resources wisely and efficiently as dividends of resilient ecosystem functions. This means protecting entire ecosystems, not just their parts, and ensuring the development of sensible environmental policies and regulations to ensure that ecosystem services benefit all living beings now and in the future.

Effective earth environmental stewardship requires that we take deliberate interest in becoming scientifically informed about how our needs and wants are linked to our local environment and the larger world beyond. So on this Earth Day, it is perhaps fitting to reflect on and celebrate our amazing scientific achievements to understand the durability of nature and the wealth of opportunity it offers for a sustainable future in the Anthropocene.

Oswald J. Schmitz is the Oastler Professor of Population and Community Ecology in the School of Forestry and Environmental Studies at Yale University. His books include Resolving Ecosystem Complexity and The New Ecology: Rethinking a Science for the Anthropocene.