citizen scientist n. (a) a scientist whose work is characterized by a sense of responsibility to serve the best interests of the wider community (now rare); (b) a member of the general public who engages in scientific work, often in collaboration with or under the direction of professional scientists and scientific institutions; an amateur scientist. — Oxford English Dictionary
The universe is too big to explore without you. — Zooniverse, Citizen Science Alliance
In the winter of 1854-5, William Huggins sold his once-prosperous mercer shop and moved with his wife Margaret to Lambeth, at the time a relatively new and prosperous suburb on the South Side of the Thames, across from the bustle and bad air of London.  It was a place with quiet nights and good seeing. There, they entered retirement from the business life and took up the avocation of star-gazing. William was already a Fellow of the Royal Astronomical Society, clearly an enthusiast. They built an observatory for his ‘hobby’ in the back yard with personal funds.
The first notations in his notebooks were sketches of Mars; there was no apparent plan or observational strategy. No proposal had been written and sent out for peer review, no feedback received from colleagues or funding agents. Just an amateur spending time with the things he loved to contemplate: the stars and planets, perhaps the occasional comet. Unlike the professional astronomers just a few miles away at Greenwich, funded by direct government subsidy, William Huggins had the luxury of following his own interests. The Astronomer Royal had dozens of drudges on staff, young men trained to perform the menial tasks of calling out transits and marking time. The Royal Observatory at night was a bustle of activity, a kind of factory for astronomical knowledge. The Huggins duo of husband and wife had only themselves, by all accounts a contented middle-aged Victorian couple, but with strange night habits.
Within a few short years of puttering, Huggins had invented a thermometric device that allowed him for the first time to directly measure the feeble flux of light energy from a star, converting that star’s brightness into a voltage. He also measured the spectra of stars and nebulae, and he calibrated these spectra against his own laboratory samples. This made him one of the very first human beings to know what the stars are made of. It also meant he could measure the velocity of a star along the line of sight, to detect whether it was moving toward us or away from us, and how fast. This was a form of measurement that would be applied to galaxies in the 20th century, where it would lead to our discovery of the expansion of the universe itself.
Huggins and his wife Margaret were also among the very first to develop the means to do long-exposure photography through a telescope. The talent for photography was something she brought to their collaboration, having worked in a portrait shop as a younger woman, something not uncommon in the Victorian age. Photographic portraits of middle-class families were popular, and shops did a brisk business. It was one of the few trades to offer openings for a young woman. Long-exposure photography revealed that the dark spaces between the stars were awash in a dim light from distant clouds of hydrogen and helium, and it changed our view of the heavens forever.
All the while, the amateurs William and Margaret Huggins worked away in their home observatory. We can imagine the two of them enjoying a nice warm cup of tea on a chilly night, exchanging conversation about the family or world events while gazing at the stars or a comet rising above the trees.
The Kepler Space Telescope, now retired, sought planets orbiting distant stars. Over a thousand exoplanets are now confirmed Kepler discoveries. The project has already spanned a generation in time, involved teams of researchers on multiple continents, and cost the taxpayers well over a half-billion dollars to design, build, and launch. But once the Kepler data was downlinked and digitized it became almost weightless. Any citizen of planet Earth with internet access can join the search using the online portal Planet Hunters. Created by Kepler scientists, this tool enables amateurs to work in that liminal space where pattern recognition algorithms are not yet as discerning as the human eye and brain. At the launch of Planet Hunters (now Planet Hunters TESS) in 2010, the professionals didn’t know if the public would respond to their call for help, but over 300,000 hunters gathered online, leading now to almost a dozen papers in professionally refereed journals and several new planets confirmed.
Where amateur scientists like William and Margaret Huggins once worked largely in isolation, modern citizen science has a different character entirely: discoveries are made by large numbers of people collaborating remotely. New knowledge emerges through the accretion of many small and mostly anonymous discoveries. The Zooniverse website, home to Planet Hunters, lists almost fifty projects in areas ranging from astronomy to zoology. There are also citizen science projects like iNaturalist and the YardMap Network that gather field data for biodiversity studies, and SkyWarn that trains severe weather spotters. The leveraging effect is dramatic: a handful of professional astronomers created the website Planet Hunters; the number of citizen scientists that have used the portal outnumber the entire community of professional astronomers worldwide by roughly a factor of thirty. 
While a ‘citizen lawyer’ is a lawyer who uses his or her knowledge of the law to promote a more robust civil society, the term ‘citizen scientist’ refers not to a professional, but to an amateur. At its best citizen science is a marriage of two ideals: the ideal of scientific research as a form of public service, and the ideal of citizenship as engagement. Meanwhile, professional scientists live by the ethic of all working dogs that earn their keep: Run fast, bite hard. This can make it difficult for the amateurs to keep up. As pattern recognition algorithms used by the professionals improve, as their drones and robotic tools become ever more capable, will that liminal working space for the amateur shrink to vanishing, or will it continue to exist in some new locus? Will there still be a place for citizen science in a generation or two? Does it really matter?
So long as scientific research is carried out openly and with a commitment to serving the public good, openings for citizen science will arise. So long as scientific research is closed and secretive, citizen science is not only impossible, but the risk of scientific research and the new technologies that flow from it miscarrying are increased. Citizen science is therefore a bellwether, a sign of a healthy two-way relationship between scientists and the public.
The question of whether citizen science will be part of the picture in a generation or two is therefore entwined with the question of who professional scientists serve. The public, or some other master? This question will only gain in importance in the world we are making, a world where the boundaries between humans and machines blur as ever more subtle augmentations become available, where the substrates for our creative writing now include not only paper and silicon, but also DNA, where our algorithms leap cognitive barriers, challenging our understanding of what makes humans special.
Two generations ago, nuclear weapons were the great science-delivered existential challenge to human societies, feeding our flash-bang nightmares. Our moral imagination seemed overpowered. Two world wars had caused casualties in the tens of millions, while nuclear war planners spoke of collateral deaths in the hundreds of millions. The human imagination can only absorb so much death without becoming numb. Now we have a longer list of anxieties: pandemics and climate change, asteroid strikes, synthetic biology run amuck, artificial intelligence unleashed. While a few of these threats have always been with us, others are human-created and new, born of recent discoveries in science and advances in technology.
Some of the research that feeds our anxieties is carried out in societies that don’t even pretend to be democratic, societies that consider liberal democracy a flawed model headed for the ash-heap of history. Societies where science serves only the state. In the old Soviet Union, for example, scientists had to request permission to submit work for publication by answering the question: “How does this work improve the lives of the peasants?” It was a kind of Cheshire Cat smile, a vestigial remnant of early idealism. Decades after the Revolution the question provoked only cynicism. By the 1980s the Soviet Union was a society where scientists pretended to work for the common good, and bureaucrats pretended to care.
It is therefore no coincidence that citizen science today exists primarily in democratic settings, given that some of the research extends well beyond the bounds of astronomy — a politically safe space — into fields more directly impinging on policy, such as public health, climate change, biodiversity, and environmental science. Among the various Wikipedia entries for citizen science, one contains a list of over 150 scientific research projects open to public participation. Nearly all are based in Australia, Europe, New Zealand, and the United States. While their democratic institutions are flawed in many ways, these are countries with a long tradition of civil society, where the polity is still somewhat responsive to the voice of the activated citizen. Citizen science is a hopeful symptom, therefore, a sign that the civic body has a pulse.
In contrast, in the summer of 1990, while the Congress of People’s Deputies met in the Kremlin to debate whether to dissolve the Soviet Union, I attended a mathematics conference hosted by the Joint Institute for Nuclear Research in Dubna, a large research facility, roughly equivalent to Los Alamos National Laboratory in the US. On the three-hour train ride from Moscow to Dubna, I sat next to a man who dutifully carried a McDonald’s meal home to his family from the only public restaurant in Moscow with food worth eating. The queue for Big Macs and string fries was four deep and a mile long, threading back and forth across Pushkin Square, a dense but peaceful mass of humanity. It was a metaphor for an awakening hunger, a giant maze composed of human beings, a citizenry trying to puzzle out the world and themselves, seeking to find their way to a new center, to some better way of life. While Soviet science served the state, the state wanted weapons, power, and prestige. Food that was to eat, decent health care, a clean environment. All these could wait. The professional scientists had more important things to work on.
The role of professional scientist was invented in response to perceived social needs. Although Isaac Newton had been buried in Westminster Abbey for well over a century, at Cambridge in the 1850’s his influence remained considerable. The reverence for him was reflected in the emphasis on theoretical science and mathematics, supported and informed by individual-scale experimental work. Newton and his style of work were viewed as the paragons of excellence and greatly valued, but this came at the expense of support for more ambitious experimental science and applied research.
The terms of the Plumian Professor of Astronomy and Experimental Philosophy, crafted in 1704 with the help of Newton himself, included a “…requirement for the professor to provide a residence, an observatory and an assistant, as well as the necessary instruments.” He was to carry out observations bearing on the “…solar, lunar and planetary theories.” And he was to give courses “…at his residence on Astronomy, Optics, Trigonometry, Mechanics, Statics, Hydrostatics, Magnetics, Pneumatics, and other subjects of the kind…”  These terms read as if the ghost of Newton was to hold the chair in perpetuity. Or not a ghost but Newton himself, turned into an intellectual zombie, forever pondering the same aspects of nature, not allowed to range widely in pursuit of knowledge, not allowed the possibility that entirely new understandings of the world might enliven the poor Plumian.
The self-funded researcher, working in his own rooms, was also a thing trapped in amber, as if the feudal system was to last forever, with master and apprentice the only model for professor and student. The model was that of the talented amateur, brilliant in his academic pursuits, now given a modest sinecure and time to work. This was the future as seen in the early 18th Century by the drafters of the Plumian terms.
A century and a half later, in 1850 Queen Victoria convened a Commission for the purpose of “…enquiring into the State, Discipline, Studies, and Revenues of the University of Cambridge.” The Commission diligently pursued its reforming work, prying into dusty and quiet corners, digging down even into the wine budget for the Vice Chancellor, noting with disapproval that Lady Margaret’s Reader in Divinity was paid a stipend ten times that of the Lucasian Professor of Mathematics.
The polymath and then-current Master of Trinity, William Whewell, counseled against hasty changes of the curricular status quo, going even so far as to argue that experimental science was not a proper subject for higher education.  Though a reformer himself in many ways, Whewell believed in the primacy of mathematical reasoning, and held that one shouldn’t include anything in the science curriculum until it was ‘settled’. By his reckoning this meant students should only learn about topics that were at least a century old. By implication, his Cambridge students wouldn’t hear of electricity, magnetic induction, thermodynamics, or any of the other discoveries that were turning the wider world upside down. Cambridge scholars would remain intellectually aloof as the colonial powers aggressively filled in all the distant nooks and crannies on the map with their imperial visions of how to order human affairs.
In a world changing fast, in 1852 the Queen’s Commission reported back that Cambridge should be awakened from its slumbers, that this dreaming was now a luxury and out of step with the modern world. Amid concerns for the nation’s competitiveness, the needs of industry and the national defense, the industrialization of science education was about to arrive at Cambridge. The professional scientist was now fully born.
Over the course of the 19th century, the rapid industrialization of Europe and the US led to large-scale reforms in higher education. Sensing the import of social changes underway, in 1834 Whewell had already coined the neologism ‘scientist’ to emphasize that something new was aborning. Greater numbers of professionally trained scientists and engineers were needed, so factory-style mass education was introduced: the standardization of the curriculum, the adoption of large lecture formats to pass on theory, and cookbook laboratory exercises to teach experimental methods — a pedagogical innovation introduced by MIT in the 1860s. These changes represented a commodification of ideas and people. With these new innovations, the universities could produce large numbers of graduates trained for careers in the industries that were the emerging engines of prosperity and national power. This drive for reform was a 19th century version of our current emphasis on STEM education, born from a growing unease with the status quo and a sense that society needed to focus its efforts and resources on technical education in response to competitive threats.
When attempting to peer ahead we humans are often not bold enough in our predictions, we don’t take our wild ideas seriously enough. We assume the current ‘normal’ is in fact normal, overestimating the solidity of the present, and underestimating the fluidity of the future. We lose sight of that almost infinite capacity for human societies to reinvent and reshape, to create new normals.
I often ask my students if they are augmented. After giving them a few moments to ponder the question, they begin to list ways they inhabit the world in close proximity with technological extensions, or ways in which their bodies have been sculpted: eyeglasses and exercise regimens, clothes, shoes, contact lenses, smart phones and laptops. Chemical augmentations include not just performance enhancing drugs used by athletes, but also drugs to manipulate neurochemistry: Ritalin and Provigil, anti-anxiety medications, and anti-depressants. And then, eventually, one of my students will point out that education itself is a form of augmentation, one that moulds our brain and our very sense of being in the world, the most intrusive augmentation of all. We already live in a world of augmented human beings, we just take much of it for granted. Culture is the water we swim through like fish, oblivious that we are swimming.
Each succeeding generation will take things for granted that now make us squirm. Google Glass will seem quaint when the sensors become corneal implants and therefore undetectable; cochlear implants and other neurotechnologies will expand beyond augmentations for the deaf or those with motor difficulties, to include those who wish to extend the range of human sensory and kinetic capabilities, an advance most likely to be led by a military vanguard. The squirm we feel also reflects the possibility that the liminal and weightless space, the technological lacuna that makes citizen science like Planet Hunters possible, will shift not only because of improvements in computer algorithms, but also because of changes in human cognitive abilities.
The poet Rilke said that beauty is but the beginning of terror.  But terror can also drive the desperate search for beauty, a kind of beauty that transcends the moment and thereby lifts us out of it. As a theoretical physicist, seduced by the eternalized beauty of mathematics, many of my choices in life have been driven by fear and a sometimes overcompensating drive to master that fear intellectually rather than hide from it. It was my way to avoid drowning.
As a child with a lively imagination, growing up during the height of the Cold War, I learned early that hiding was not an option. From our front yard we could see the Vermont range of the western Berkshires, a rolling wave upon wave of green and violet hills. A hundred acres of land, nodding cows, one dog, and a few drowsing cats. Our nearest neighbor lived a mile away down a two-lane country road. It was bucolic. But a few times a day the windows rattled with sonic booms. Fighter jets far overhead and out of sight brought daily reminders that we lived in a world poised on the brink of nuclear war.
For my mother the farm was a kind of exile. It was my father’s dream, not hers. He was like Odysseus, a sailor back from sea and the world war, full of terrible memories, gone to ground in upstate New York. The isolation of the countryside was hard on my mother, and the anxiety of the age compounded her unease. A city girl, she now had nightmares of waking to find herself lost in the middle of the Soviet Union. In the fall of 1957, that chrome-plated basketball with a radio called Sputnik, embryonic symbol of a new age, passed overhead every ninety minutes. A weightless pinpoint of light moving among the silent stars, it was visible at night during my first year of life, though I was oblivious to it. Sputnik and I were portents of things to come, one small and unremarkable, like ten-million other babies born that year, the other a world-shaking machine.
A few years later, me now a rambunctious child and Sputnik a piece of atomized debris in the upper atmosphere, as we were saying our nightly prayers our farmhouse shuddered in the wake of a low-flying jet, come to ground from its abode in the skies above. The plane crashed into a hillside only a mile away. The pilot ejected too low and too late. The searchers found him a few days later in the woods across the road, his parachute tangled in the branches of a tree, neck snapped. About the same time a B-52 caught fire and broke up over Goldsboro, North Carolina, dropping two live hydrogen bombs in a field outside town. 
Sputnik is a signpost in time, as good as any other, for marking when things changed, when something in our collective psyche came awake, some lurking nightmare of annihilation that terrorized us into alertness, like our ancient ancestors startling awake on the African savannah, listening for the footpad of the predator in the night. With Sputnik the modern world was now fully arrived. The human race had shaken off the gravitational bonds of the home planet, but along with it came the notion that a few frightened men could stumble and bring an end to the species. Whether or not this self-annihilation was a credible vision, the fear of it had entered the human mind.
The pre-Socratic philosopher Empedocles argued that the world is made of a few simple things, and governed by a few simple principles. The four elements — earth, air, fire, and water — combine in myriad ways to create all that we see and experience, much like an artist who mixes a few colors on a palette and then, in a few deft strokes, conjures the sea and sky, a landscape, and then peoples it with all manner of things. This great idea is the nascent germ of all modern scientific theory: unity within riotous diversity.
Empedocles also argued that the world was engaged in a kind of yin-yang overturning between ages of Love and Strife. In each age only one is ascendant, but each contains seeds of the other. Without that seed, without the overturning, all is stasis, a kind of death. We can only hope that we are passing through a time of Strife into an age where greater compassion will prevail. Everything is at stake and the pressures for dramatic change — both forward- and backward-looking — are building. The itch for chaos is keenly felt. But we can see the seeds of the compassion we need, if we look for them. Over time, there has been a widening of the circle of our understanding, an enlarging of the list of those deserving of our concern, and a realization that many non-human beings on Earth are in danger due to our actions. In the existence of that very alarm there is hope.
Without the elements of poetry, song, friendship and love to work from, without the freedom to take those few elements onto our palette and to then paint our personal lives as works of art, any future will be a hell-scape. But with that freedom, even if the future of humanity stretches to the stars and changes us beyond what is now recognizably human, even in those futures if our children can still embrace the elemental passions that electrify our being, not as memories of things past but as a living wellspring for creative acts, our children will find purpose and meaning. That is why the future of the citizen and the future of the scientist are so entwined.
Yin and yang, love and strife overturning: within a historical eye-blink of Sputnik, the modern environmental movement began, also a child of the space age, an awakening of the citizenry born when we first looked back to Earth from far above and saw our planet adrift in empty space, a wanderer among the stars, painfully beautiful and endangered. A single image can change the way we think, a single idea can unsettle an entire world view. The revolution was televised, then digitized, made weightless and shareable. Citizen science is but one symptom of that ongoing awakening, a realization that the universe is too big to explore by only a few. A sign that the race remains startled.
 Material in this section is drawn from: Becker, Barbara J. Unravelling Starlight: William and Margaret Huggins and the Rise of the New Astronomy. Cambridge University Press, 2011.
 In “So you want to be an astronomer?” Mercury (Spring, 2008), Duncan Forbes writes that the total number of astronomers is approximately 10,000.
 Quoted in the “Report of the Commission for the Purpose of Enquiring in the State, Discipline, Studies, and Revenues of the University of Cambridge,” page 59. Full text available online as a Google ebook.
 Crowther, James Gerald. The Cavendish Laboratory, 1874-1974. London: Macmillan, 1974,page 7-9.
 From The First Duino Trilogy.
 “US nearly detonated atomic bomb over North Carolina: secret document,” Guardian, Sept. 20, 2013. http://www.theguardian.com/world/2013/sep/20/usaf-atomic-bomb-north-carolina-1961
Image: JPL Visions of the Future, Kepler 186f. Jet Propulsion Laboratory (JPL) / NASA («Courtesy NASA/JPL-Caltech») [Public domain], via Wikimedia Commons.