2021

Nobel Prize in Physics

Weather Turns Out to Have a Signature

Syukuro Manabe · Klaus Hasselmann · Giorgio Parisi

By the late 1960s, Syukuro Manabe had already demonstrated with a column-of-atmosphere model that doubling atmospheric CO₂ would raise surface temperatures by roughly two degrees — a figure that has aged remarkably well. Klaus Hasselmann then contributed something harder: a mathematical framework for extracting a genuine signal of human influence from the chaotic noise of natural climate variability, which is what allows scientists to say not just that the climate is changing but that we are the ones changing it. Giorgio Parisi, working in an apparently unrelated field, found that disordered systems from spin glasses to flocking starlings obey hidden probabilistic laws — laws that turned out to be indispensable for understanding the complex feedbacks in Earth's own climate. The committee split the prize between two physicists who gave us the bad news with precision and one who gave us the conceptual tools to understand why bad news comes in such complicated shapes.

Nobel Prize in Chemistry

A Third Way to Build a Molecule

Benjamin List · David W.C. MacMillan

For most of the twentieth century, chemists building complex molecules had two catalytic options: metal complexes, which are powerful but often finicky, expensive, and rather ungrateful if you ask them to work in the presence of water or air; and enzymes, which are elegant but belong to biology and rarely consent to operate outside it. In 2000, Benjamin List at the Scripps Research Institute and David MacMillan at Berkeley independently discovered a third path — small organic molecules, containing no metals at all, that could accelerate asymmetric reactions with the selectivity previously reserved for enzymes. List used the amino acid proline; MacMillan coined the term "organocatalysis" and built chiral imidazolidinone catalysts that sparked a field. Neither was aware the other was working on the same idea. The practical consequence is a generation of pharmaceutical syntheses that are cleaner, cheaper, and less likely to leave toxic metal residues in the final product — the kind of advance that matters most to the people who will swallow those products.

Nobel Prize in Physiology or Medicine

The Flesh Has Proteins Shaped for Feeling

David Julius · Ardem Patapoutian

The question of how a nervous system translates the physical world into felt experience — why hot coffee burns, why pressure on the skin is registered as pressure at all — is one that philosophy fretted over for centuries before biology had the tools to answer it properly. David Julius cracked open the problem in 1997 by asking what in a neuron actually responds to capsaicin, the compound that makes chilli peppers sting; the answer was TRPV1, an ion channel that opens in response to both chemical irritants and temperatures above about 43°C, elegantly explaining why spice and heat feel similar. Ardem Patapoutian took a different approach — he poked individual cells with a very fine pipette until he found ones that responded electrically to mechanical force, then used that assay to identify Piezo1 and Piezo2, the channels that underpin the sense of touch and proprioception. Together, they resolved a question that had seemed almost too fundamental to be answerable: the flesh knows the world because it has specific proteins shaped, over millions of years, precisely for the task.

Nobel Prize in Literature

Displacement, Written From the Inside

Abdulrazak Gurnah

Abdulrazak Gurnah was born in Zanzibar in 1948 and left for Britain as a young man, arriving as a refugee at a moment when the British were not at their most welcoming. He has spent the decades since — quietly, persistently, in novels that most English-language readers had never encountered before the committee's call — attending to the long aftermath of colonialism as it is actually lived: not in grand rhetorical gestures but in the specific gravity of displacement, in the way people carry identities formed in one place into lives assembled in another. His tenth novel, "Afterlives," came out a year before the prize; the Swedish Academy honoured him for an uncompromising and compassionate penetration of the effects of colonialism and the fate of the refugee in the gulf between cultures. The surprise of his name on the announcement, to many readers, was itself a kind of comment on which literatures we have been paying attention to.

Nobel Peace Prize

Honoured for Refusing to Lose

Maria Ressa · Dmitry Muratov

Maria Ressa co-founded Rappler in the Philippines in 2012 and spent the following years reporting on extrajudicial killings under the Duterte administration; as a reward, she accumulated multiple criminal convictions on charges that most press-freedom organisations regarded as instruments of harassment. Dmitry Muratov had edited Novaya Gazeta in Russia since 1995, presiding over a paper that investigated corruption and Chechen atrocities with conspicuous courage and was repaid with the murders of six of its journalists, including Anna Politkovskaya. The Nobel Committee made a pointed choice: rather than honouring someone who had won, it honoured two people who had simply refused to lose. Ressa later auctioned her medal to raise funds for press freedom; Muratov, after Russia's invasion of Ukraine, did the same — donating the proceeds to UNICEF for Ukrainian child refugees. Some prizes earn compound interest.

Sveriges Riksbank Prize in Economic Sciences

New Jersey Ran the Experiment for Us

David Card · Joshua D. Angrist · Guido W. Imbens

The central problem of economics as an empirical science is that you cannot run controlled experiments on societies: you cannot raise the minimum wage in one country and hold it flat in an identical control country and compare the results. For most of the twentieth century, this limitation pushed economists toward elaborate theoretical models whose connection to reality was, to put it generously, aspirational. David Card showed that reality sometimes runs its own experiments: in a landmark 1994 study with Alan Krueger, he compared fast-food employment in New Jersey — which had just raised its minimum wage — with neighbouring Pennsylvania, which had not. Employment in New Jersey went up slightly, demolishing a piece of conventional wisdom. Joshua Angrist and Guido Imbens formalised the mathematics of such natural experiments, clarifying when and why comparisons of this kind can be trusted to reveal genuine causation. The prize was, in effect, awarded to the concept of empirical humility — the recognition that asking the right question about a messy real-world event beats building an elegant model of a world that does not exist.

Ig Nobel Prize in Biology

Cats Have Learned Your Frequency

Susanne Schötz

Susanne Schötz, a phonetics researcher at Lund University, spent several years recording and analysing the sounds domestic cats produce specifically when addressing their human companions — chirps, trills, meows, and a range of intermediate sounds that differ measurably from the vocalisations cats use with each other. The hypothesis under examination was whether cats consciously modulate their acoustics to manipulate human behaviour, tuning a particular whine to a frequency humans find difficult to ignore. The data suggested they do. Cat owners, who have suspected this for approximately eight thousand years, will feel vindicated. The fact that it required a formal phonetic study to confirm what is apparent to anyone who has been woken at four in the morning by a creature demanding breakfast is either a triumph of scientific rigour or a damning indictment of it — possibly both.

Ig Nobel Prize in Ecology

A Pavement Habitat, Chewed and Discarded

Leila Satari

Leila Satari and colleagues collected discarded chewing gum from pavements across several European cities, subjected the grey pellets to metagenomic DNA analysis, and found inside them surprisingly diverse bacterial communities — distinct assemblages that varied by geography, by gum brand, and by how long the gum had been adhered to the ground. The implication, drawn with admirable scientific straight-facedness, is that chewing gum functions as a miniature habitat: a small, rubbery, entirely unasked-for ecosystem deposited at intervals by a species that imagines itself the planet's most sophisticated organism. Whether the bacteria mind the conditions is not recorded.

Ig Nobel Prize in Chemistry

A Thriller Smells Different From a Comedy

Jörg Wicker

Jörg Wicker and colleagues installed sensors in a German cinema and measured the volatile organic compounds accumulating in the air during screenings of seventeen different films. What they found was that the chemical composition of the audience's collective exhalation changed in predictable ways depending on the emotional content on screen: isoprene spiked during tense scenes, carbon dioxide tracked crowd engagement, and the overall chemical fingerprint of a thriller was measurably different from that of a comedy. This means a cinema audience, in aggregate, is expressing its feelings in a medium it does not know it is using, and that it is in principle possible to classify a film's emotional arc from the smell of the room. Cinema as olfactory phenomenon is not how the medium's inventors imagined their legacy.

Ig Nobel Prize in Economics

Heavier Cabinets, Higher Corruption Scores

Pavlo Blavatskyy

Pavlo Blavatskyy, an economist at Montpellier Business School, measured the body-mass index of cabinet ministers in post-Soviet countries using photographs and cross-referenced the result against standard corruption indices. He found a statistically significant positive correlation: countries with heavier politicians tended to score worse on corruption measures. The study does not establish a mechanism — perhaps corruption buys richer food, or perhaps the same cultural conditions that enable one also permit the other, or perhaps the correlation is a coincidence dressed up as a finding — and Blavatskyy is careful to say so. Causality, as always in economics, is left as an exercise for the reader.

Ig Nobel Prize in Medicine

Orgasm Beats the Decongestant, Briefly

Olcay Cem Bulut

Olcay Cem Bulut recruited a small group of participants with nasal congestion and, with the rigour that the subject demanded, measured their nasal airflow before and after sexual orgasm, then compared the relief obtained to that produced by a standard over-the-counter decongestant spray. Orgasm won, briefly but convincingly, the effect lasting about forty-five minutes — slightly less than the commercial product, but achieved through means that most people regard as preferable. The mechanism is sympathetic nervous system activation causing vasoconstriction of nasal blood vessels, which is the kind of sentence that makes you appreciate why researchers are sometimes reluctant to explain their work at dinner parties.

Ig Nobel Prize in Peace

A Beard Is a Shock Absorber

Ethan Beseris

Ethan Beseris and colleagues proposed, with experimental support, that the human beard exists partly as a biological shock absorber — that the mass of facial hair cushions blows to the mandible during fist fights, reducing the risk of fracture in the way a bicycle helmet reduces the risk of skull injury, only considerably less aerodynamic. They tested this by dropping weights onto samples of synthetic bone padded with varying amounts of fibre, measuring force transmission in each case. The hairy samples absorbed more impact. The hypothesis that evolution equipped half of humanity with a chin buffer against the other half says something either darkly plausible or deeply fanciful about our species' history, and it is not entirely clear which.

Ig Nobel Prize in Physics

Nobody Collides in a Crowded Corridor

Alessandro Corbetta · Jasper Meeusen · Chung-min Lee · Roberto Benzi · Federico Toschi

Alessandro Corbetta and colleagues at Eindhoven spent years recording the movements of pedestrians crossing a busy corridor, accumulating millions of trajectories in order to understand why walkers so reliably avoid colliding with one another — a self-organisation that, when it works, requires no explicit coordination at all, and yet emerges from nothing more than each person's small anticipatory adjustments. Their statistical analysis treated the crowd as a physical system, extracting the forces of mutual avoidance from the raw data of ordinary foot traffic. The finding is that walking through a throng is a continuous, unconscious negotiation, and that the near-misses which feel like chaos are in fact the visible edge of a remarkably orderly process — the reason a crowded railway concourse resolves itself, most of the time, without anyone being knocked over.

Ig Nobel Prize in Kinetics

One Distracted Walker Trips Up the Crowd

Hisashi Murakami · Claudio Feliciani · Yuta Nishiyama · Katsuhiro Nishinari

Hisashi Murakami and colleagues took up the complementary and more troubling question of when this graceful self-organisation breaks down — specifically, what happens when some of the walkers are distracted, their attention absorbed by a phone rather than the people in front of them. Staging experiments in which pedestrians walked toward one another while a few were made to perform a mental arithmetic task, the team found that a distracted person degrades the flow not only for themselves but for everyone around them, because the silent anticipatory dance depends on both parties reading each other's intentions. When one walker stops signalling, the whole system stumbles — which is the physics behind that particular shuffling stand-off of mutual misdirection that happens the moment someone glances down at a screen.

Ig Nobel Prize in Transportation

Rhinos Fly Better Upside Down

Robin Radcliffe

Robin Radcliffe and colleagues were motivated by a genuine conservation problem: southern white and black rhinoceroses sometimes need to be airlifted between reserves, and given that a rhinoceros weighs somewhere between one and two tonnes and is not philosophically inclined toward cooperation, the question of the safest transport orientation matters quite practically. They compared respiratory function in animals suspended upside-down from a helicopter — the most space-efficient configuration — against alternatives including lying on their sides on a stretcher. The inverted position proved no worse for respiratory health, and in some physiological measures slightly better, than the alternatives. The rhinoceroses, sedated throughout, were unavailable for comment on their preferences.

Ig Nobel Prize in Entomology

Roaches Also Enlisted in the Navy

John Mulrennan Jr. · Roger Grothaus · Charles Hammond · Jay Lamdin

John Mulrennan Jr. and colleagues, working for the United States Navy, confronted a problem that submariners had endured in dignified silence for decades: cockroaches thrive aboard submarines, which are warm, humid, generously provisioned with food, and — crucially — sealed environments from which neither the crew nor the insects can easily depart. Their study, plainly titled 'A New Method of Cockroach Control on Submarines,' documented an improved approach to purging the vessels of their uninvited passengers, tested against the peculiar constraints of a space where you cannot simply open the windows and where the air is shared by everyone breathing it. The work is a reminder that the romance of undersea exploration coexists, at close quarters, with the same domestic infestations that afflict any kitchen — only here the kitchen is a steel tube several hundred metres beneath the surface, and the extermination must be conducted with rather more thought about what one is prepared to release into the air.

Turing Award

The Scaffolding Nobody Thinks About

ACM A.M. Turing Award

Jack Dongarra

Jack Dongarra began writing numerical software at Argonne National Laboratory in the late 1970s, when scientific computing meant painstaking hand-tuning of linear algebra routines to squeeze performance from whatever hardware happened to be available that year. What he built — LINPACK, then LAPACK, then the Message Passing Interface standard for parallel computation — was the unglamorous but indispensable scaffolding on which virtually all of computational science now rests: the libraries that solve systems of equations, that distribute work across thousands of processors, that make it possible for a physicist's code to run on a machine ten times faster than the one it was written for without being rewritten from scratch. LINPACK also became the benchmark for the TOP500 list of the world's fastest supercomputers, a minor act of world domination that ensures Dongarra's name appears in every serious conversation about high-performance computing. The deep irony of foundational software is that the better it works, the less anyone thinks about it.

Lasker Award (Basic Medical Research)

Pink Salt Flats to a Switch for Neurons

Albert Lasker Basic Medical Research Award

Peter Hegemann · Dieter Oesterhelt · Karl Deisseroth

Dieter Oesterhelt, working in the 1970s on halobacteria — the archaea that turn salt flats pink — found that their membranes contained a protein called bacteriorhodopsin that pumped ions across the membrane when struck by light, a discovery that at the time seemed an interesting curiosity of extreme environments. Peter Hegemann, decades later, found that certain green algae contained related proteins called channelrhodopsins that opened ion channels in response to light, allowing the algae to steer toward or away from illumination. Karl Deisseroth, a Stanford neuroscientist, grasped what these two findings implied if combined with molecular biology: if you could express channelrhodopsins in specific neurons, you could switch those cells on or off with a flash of light, with millisecond precision, in a living animal. The field that resulted — optogenetics — has transformed what neuroscience can ask, enabling researchers to activate or silence specific circuits in the brain with a selectivity that electrical stimulation could never achieve. The path from pink salt flats to the neuroscience of memory, addiction, and depression ran through two biologists and one psychiatrist who noticed that microbial proteins could be tools.

Lasker Award (Clinical Medical Research)

One Nucleoside Swap, Two Billion Doses

Albert Lasker Clinical Medical Research Award

Katalin Karikó · Drew Weissman

Katalin Karikó spent much of the 1990s and early 2000s being told, politely and then less so, that messenger RNA was not a viable platform for medicine. The body's innate immune system treats synthetic mRNA as an alarm signal and responds by destroying it before it can instruct any cells to make protein — which is a reasonable response to foreign genetic material, though inconvenient if you are trying to write a drug. Karikó, a Hungarian-born biochemist who had taken a demotion and a pay cut rather than abandon the idea, partnered with Drew Weissman, an immunologist at Penn, and together they found in 2005 that substituting pseudouridine for uridine in the mRNA sequence quieted the immune reaction without impairing the instructions. That modification is why the Pfizer-BioNTech and Moderna COVID-19 vaccines worked: two billion doses of a technology that rested, ultimately, on a single nucleoside swap identified by two scientists who could not get their paper read at major journals.

Parker Solar Probe enters the solar corona

Humanity Finally Went Inside the Sun's Atmosphere

The solar corona — the Sun's outer atmosphere, visible during eclipses as a halo of pale fire — has been observed from Earth for millennia and studied closely since the nineteenth century, yet until 2021 no spacecraft had ever actually entered it. NASA's Parker Solar Probe, launched in 2018 and named, unusually, after a living scientist, spent its first years using Venus flybys to shrink its orbit progressively closer to the Sun. On 28 April 2021, during its eighth perihelion pass, it crossed the Alfvén critical surface at approximately 18.8 solar radii — the boundary where the solar wind accelerates beyond the speed at which it can communicate perturbations back to the Sun — and became the first human-made object to sample the corona directly. The instruments encountered magnetic switchbacks, folded structures in the field that had been inferred from remote observations but never touched, and plasma conditions that will take years to fully analyse. Humanity had looked at the Sun's atmosphere from the outside for all of recorded history; 2021 was the year we went in.

Perseverance lands on Mars and Ingenuity makes first powered flight on another world

A Lunchbox-Sized Helicopter Over an Ancient Lakebed

On 18 February 2021, the Perseverance rover entered the Martian atmosphere at nearly twenty thousand kilometres per hour and, seven minutes later, set down in Jezero Crater — once, three billion years ago, a lake delta, and chosen precisely because ancient lakes are promising places to look for biosignatures. The entry, descent, and landing sequence is entirely automated, the signal delay making any Earth-based intervention impossible; NASA engineers watch the telemetry arrive and learn, simultaneously, whether their spacecraft has landed or cratered. On 19 April, the small helicopter clipped to Perseverance's belly — Ingenuity, weighing 1.8 kilograms, its rotors spinning at roughly 2,500 RPM to generate lift in an atmosphere a hundred times thinner than Earth's — rose to three metres, hovered for thirty-nine seconds, and returned to the surface. It was the first powered, controlled flight on another world, a quiet tribute to the Wright Brothers (a piece of their original Flyer flew aboard) and a proof of concept that Mars exploration need not be strictly horizontal.

James Webb Space Telescope launches

Thirty Years of Patience, Launched on Christmas

The James Webb Space Telescope was first proposed in 1989, approved in 1996 with a budget of five hundred million dollars and a launch date of 2007, and eventually cost approximately ten billion dollars and thirty years of institutional patience before leaving the ground. On Christmas Day 2021, an Ariane 5 rocket lifted it from the Guiana Space Centre at Kourou, and over the following month it performed a sequence of deployment steps — sunshield, primary mirror segments, secondary mirror — each of which, if it failed, would have been catastrophic and irreversible and unrepairable, since JWST orbits at the L2 Lagrange point 1.5 million kilometres from Earth, far beyond the reach of any servicing mission. Its 6.5-metre gold-beryllium mirror is designed to detect infrared light from the first galaxies, light that set out when the universe was less than a billion years old. The Christmas launch date was an accident of scheduling; the thirty-year wait was not.

Death of E.O. Wilson

The Ant Man Who Coined Biodiversity

Edward O. Wilson

Edward Osborne Wilson arrived at Harvard in the 1950s as an entomologist of exceptional gifts — his monograph on the ants, co-authored with Bert Hölldobler and published in 1990, runs to over seven hundred pages and remains the standard reference — and spent the following decades expanding his field of vision outward with what his critics occasionally found alarming enthusiasm. Sociobiology, the 1975 book that proposed evolutionary explanations for social behaviour across species including humans, attracted a famously hostile reception from colleagues who worried about its political implications; Wilson replied, essentially, that being accurate was more important than being comfortable. He also coined the term "biodiversity," gave conservation biology a coherent conceptual framework, and wrote several books for general readers that treated the natural world with a seriousness and a tenderness that never lapsed into sentimentality. He died on 26 December 2021, aged 92, having spent a long life insisting that the study of other species was not a distraction from understanding our own, but the precondition of it.

Death of Steven Weinberg

The Paper That Unified Two Forces, Ignored at First

Steven Weinberg

Steven Weinberg shared the 1979 Nobel Prize in Physics for work he had published in a single paper in 1967 — a paper that was initially ignored for years before the physics community caught up with it — demonstrating that electromagnetism and the weak nuclear force, which are responsible for radioactive decay, are two aspects of a single underlying interaction. The electroweak theory became a cornerstone of what would be called the Standard Model, the most precisely tested physical theory in history. Weinberg was also, without serious competition, the finest prose writer in theoretical physics: "The First Three Minutes," published in 1977, described the first moments of the universe with a clarity and intellectual authority that made it a landmark of popular science, and he continued writing books and essays for general audiences into his eighties. He was also famously direct in his views on the relationship between science and religion — a directness that did not always endear him to everyone but which he maintained with consistent rigour. He died in Austin, Texas, on 23 July 2021, aged 88, leaving behind a Standard Model and a prose style that neither physics nor science writing has quite replaced.