Meet the winners of the 2024 Ig Nobel Prizes

Curiosity is the driving force behind all science, which may explain why so many scientists sometimes find themselves going in some decidedly eccentric research directions. Did you hear about the WWII plan to train pigeons as missile guidance systems? How about experiments on the swimming ability of a dead rainbow trout or that time biologists tried to startle cows by popping paper bags by their heads? These and other unusual research endeavors were honored tonight in a virtual ceremony to announce the 2024 recipients of the annual Ig Nobel Prizes. Yes, it's that time of year again, when the serious and the silly converge—for science.

Established in 1991, the Ig Nobels are a good-natured parody of the Nobel Prizes; they honor "achievements that first make people laugh and then make them think." The unapologetically campy awards ceremony features miniature operas, scientific demos, and the 24/7 lectures whereby experts must explain their work twice: once in 24 seconds and the second in just seven words. Acceptance speeches are limited to 60 seconds. And as the motto implies, the research being honored might seem ridiculous at first glance, but that doesn't mean it's devoid of scientific merit.

Viewers can tune in for the usual 24/7 lectures, as well as the premiere of a "non-opera" featuring various songs about water, in keeping with the evening's theme. In the weeks following the ceremony, the winners will also give free public talks, which will be posted on the Improbable Research website.

Without further ado, here are the winners of the 2023 Ig Nobel prizes.

Peace

Citation: B.F. Skinner, for experiments to see the feasibility of housing live pigeons inside missiles to guide the flight paths of the missiles.

This entertaining 1960 paper by American psychologist B.F. Skinner is kind of a personal memoir relating "the history of a crackpot idea, born on the wrong side of the tracks intellectually speaking but eventually vindicated in a sort of middle class respectability." Project Pigeon was a World War II research program at the Naval Research Laboratory with the objective of training pigeons to serve as missile guidance systems. At the time, in the early 1940s, the machinery required to guide Pelican missiles was so bulky that there wasn't much room left for actual explosives—hence the name, since it resembled a pelican "whose beak can hold more than its belly can."

Skinner reasoned that pigeons could be a cheaper, more compact solution since the birds are especially good at responding to patterns. (He dismissed the ethical questions as a "peacetime luxury," given the high global stakes of WWII.) His lab devised a novel harnessing system for the birds, positioned them vertically above a translucent plastic plate (screen), and trained them to "peck" at a projected image of a target somewhere along the New Jersey coast on the screen—a camera obscura effect. "The guiding signal was picked up from the point of contact of screen and beak," Skinner wrote. Eventually, they created a version that used three pigeons to make the system more robust—just in case a pigeon got distracted at a key moment or something.

There was understandably a great deal of skepticism about the viability of using pigeons for missile guidance; at one point, Skinner lamented, his team "realized that a pigeon was more easily controlled than a physical scientist serving on a committee." But Skinner's team persisted, and in 1944, they finally got the chance to demonstrate Project Pigeon for a committee of top scientists and show that the birds' behavior could be controlled. The sample pigeon behaved perfectly. "But the spectacle of a living pigeon carrying out its assignment, no matter how beautifully, simply reminded the committee of how utterly fantastic our proposal was." Apparently, there was much "restrained merriment."

Even though this novel homing device was resistant to jamming, could react to a wide variety of target practice, needed no scarce materials, and was so simple to make that production could start in 30 days, the committee nixed the project. (By this point, as we now know, military focus had shifted to the Manhattan Project.) Skinner was left with "a loftful of curiously useless equipment and a few dozen pigeons with a strange interest in a feature of the New Jersey coast." But vindication came in the early 1950s when the project was briefly revived as Project ORCON at the Naval Research Laboratory, which refined the general idea and led to the development of a Pick-off Display Converter for radar operators. Skinner himself never lost faith in this particular "crackpot idea."

Botany

Citation: Jacob White and Felipe Yamashita, for finding evidence that some real plants imitate the shapes of neighboring artificial plastic plants.

In 2013, botanists discovered an unusual plant growing in the rainforests of southern Chile, dubbed Boquila trifoliolata. This woody vine had the unusual ability to mimic the leaves of up to three different host plants. What was the secret to this complex mimicry of not just the shape of other plant leaves but also their color, leaf orientation, and vein patterns, among other characteristics? One possibility was the release of chemical volatile signals; another was horizontal gene transfer between the host plant and the Boquila vine. Or perhaps it was the result of plant vision.

White and Yamashita conducted experiments with B. trifoliolata vines and artificial Wisteria vines. They concluded that volatile signaling and horizontal gene transfer were unlikely since B. trifoliolata were able to mimic the artificial leaves even when they weren't in direct contact. A plant vision system is thus a promising explanation and grounds for further experiments, they wrote, particularly in light of recent research showing that plants can not only communicate via chemical volatiles but can also perceive sound. We welcome our new plant overlords.

Anatomy

Citation: Marjolaine Willems, Quentin Hennocq, Sara Tunon de Lara, Nicolas Kogane, Vincent Fleury, Romy Rayssiguier, Juan José Cortés Santander, Roberto Requena, Julien Stirnemann, and Roman Hossein Khonsari, for studying whether the hair on the heads of most people in the Northern Hemisphere swirls in the same direction (clockwise or counter-clockwise?) as hair on the heads of most people in the Southern Hemisphere.

The question of nature versus nurture looms large when it comes to hereditary traits, even if we're talking about what seems like a relatively trivial trait—say, hair whorls on humans and whether the whorls are oriented clockwise or counter-clockwise. This is apparently an area of active research, with several studies linking hair whorls to all kinds of physical and cognitive traits, including whether one is left- or right-handed or even gay (although the authors note that these have since been "invalidated"). Willems et al. wanted to learn more about the possible geographic effects on hair whorls as a "vortex phenomenon."

So they conducted a retrospective study of hair whorls in children from three different groups: a Northern Hemisphere general population (Paris, France), a Southern Hemisphere general population (Santiago, Chile), and 74 same-sex twins (37 pairs) born in Paris. The results: Twins had hair whorls that rotated in the same direction, indicating a strong genetic influence. And the researchers found that hair whorls in children from the Southern hemisphere were oriented counterclockwise more frequently than in children from the Northern hemisphere, indicating possible environmental factors, although the team could not rule out genetic effects from specific population characteristics.

We can't help but indulge in a bit of side-eye at the paper's odd insistence that "further investigation" is warranted to determine if one of those environmental factors could be the Coriolis force, specifically citing the long-debunked myth that water swirls clockwise down the drain in the Southern Hemisphere and counter-clockwise in the Northern Hemisphere. At least the authors admit there is unlikely to be any "straightforward link" to the orientation of hair whorls.

Medicine

Citation: Lieven A. Schenk, Tahmine Fadai, and Christian Büchel, for demonstrating that fake medicine that causes painful side effects can be more effective than fake medicine that does not cause painful side effects.

We're all familiar with often long list of possible side effects that inevitably accompany commercials for various medications. Surely the best possible treatment for a condition should be free of side effects, right? Especially since the expectation of side effects can increase the likelihood that one will experience them—the so-called "nocebo effect." Schenk et al. beg to differ, arguing that some mild side effects might actually lead to better treatment outcomes, based on recent research into active placebos. These are drugs that can have a noticeable effect on patients without addressing their primary symptoms; it's been shown that active placebos actually have larger placebo effects than inert placebos, which could influence the conclusions of randomized clinical trials.

Schenk et al. tested their hypothesis by recruiting 77 healthy people for a clinical trial, divided into two randomized groups. The participants were told they would receive fentanyl nasal sprays, followed by the application of heat-related pain using a thermode. They were told the nasal spray could produce a mild burning sensation in the nose as a side effect. Unbeknownst to the particulates, the nasal sprays did not contain fentanyl. One version was neutral, and another contained capsaicin to produce a mild burning pseudo-side effect. The results showed that placebo nasal sprays with a fake side effect reduced pain more than the placebo nasal spray with no side effect—simply because participants expected a burning sensation and thus assumed the spray was working.

Physics

Citation: James C. Liao, for demonstrating and explaining the swimming abilities of a dead trout.

Liao has been studying the physics of swimming fish for over a decade, but his most novel experimental approach is undoubtedly found in a 2006 paper on passive propulsion in vortex wakes. Liao and his co-authors wanted to explore how fish might reduce their energy expenditure while swimming by harnessing energy from swirling vortices—essentially body surfing. They chose rainbow trout as a good subject for experiments since these fish are known to be good at minimizing their energy expenditure, based on Liao's prior work showing that the trout alter their swimming motion to synchronize with incoming wakes.

The twist: This time, they wanted to specifically show that fish can swim upstream without expending any mechanical energy of their own. So Liao et al. used a dead rainbow trout that had ceased to be. And voila! The dead fish exhibited "unnervingly similar kinematics to a live fish, with the exception that it cannot put on the brakes," Liao wrote in a 2022 primer. They also extended the experiments to include test runs with rigid foil with similar results. In short, "a fish or foil can extract sufficient energy from a vortical stream to overcome its own drag, implying that a flapping body can follow another wake-producing body, even at a distance, without expensing any energy," Liao et al. concluded.

Physiology

Citation: Ryo Okabe, Toyofumi F. Chen-Yoshikawa, Yosuke Yoneyama, Yuhei Yokoyama, Satona Tanaka, Akihiko Yoshizawa, Wendy L. Thompson, Gokul Kannan, Eiji Kobayashi, Hiroshi Date, and Takanori Takebe, for discovering that many mammals are capable of breathing through their anus.

This is perhaps one of the more unusual research developments to come out of the COVID-19 pandemic and its associated assortment of ventilators and artificial lungs to assist patients' breathing and prevent respiratory failure. Okabe et al. took their inspiration from the humble loach, a freshwater bottom-dwelling fish found throughout Eurasia and northern Africa. The loach (along with sea cucumbers) employs intestinal breathing (i.e., through the anus) rather than gills to survive under hypoxic conditions, thanks to having lots of capillary vessels in its intestine. The technical term is enteral ventilation via anus (EVA).

But would such a novel breathing method work in mammals? The team thought it might be possible and undertook experiments with mice and micro-pigs to test that hypothesis. The experiments involved intra-anally administering oxygen gas or a liquid oxygenated perfluorocarbon to the unfortunate rodents and porcines. Yes, they gave the animals enemas. They then induced respiratory failure and evaluated the effectiveness of the intra-anal treatment.

The result: Both treatments were pretty darned effective at staving off respiratory failure with no major complications. The authors think this could work in human patients, too. We're suddenly feeling particularly motivated to keep up with our COVID boosters and mask up in crowded public spaces.

Probability

Citation: František Bartoš, Eric-Jan Wagenmakers, Alexandra Sarafoglou, Henrik Godmann, and many colleagues, for showing, both in theory and by 350,757 experiments, that when you flip a coin, it tends to land on the same side that it started.

Flipping a coin is a time-honored practice that many consider to be the epitome of a chance event—hence our reliance on a coin flip to fairly decide certain outcomes, such as which of the Wright brothers got to attempt the first flight in 1903 or who got first pick in the 1979 NBA draft, resulting in Magic Johnson playing for the Los Angeles Lakers rather than the Chicago Bulls. A physicist will tell you that a coin toss isn't random but purely deterministic under classical Newtonian mechanics, with the perceived randomness arising from small fluctuations in initial conditions like starting position, upward force, and angular momentum, for example.

The standard model of coin flipping predicts a 50/50 chance of a coin landing either heads or tails, i.e., there is no heads-tails bias. But in 2007, a Stanford statistician named Persi Diaconis proposed that the act of flipping a coin introduces a small wobble—a change in the direction of the axis of rotation throughout the coin's trajectory that causes a coin to spend more time in the air with the initial side facing up. So there should be a slight same-side bias, such that there should be a 51 percent chance that a coin lands on the same side as it started.

Bartoš et al. wanted to test the Diaconis model. There have been many prior coin-tossing experiments, from Count de Buffon in the 18th century to the 40,000 coin flips collected in a 2009 experiment specifically designed to test Diaconis's hypothesis. (The results were ambiguous.) Bartoš et al. surpassed them all, collecting a total of 350,757 coin flips by 48 people (all but three of the authors), all recorded on video for posterity.

That data confirmed Diaconis's prediction of a slight same-side bias. Nor did they find any trace of a heads/tail bias. The group proposed future research to determine whether "wobble tossers" have a more pronounced same-side bias than stable tossers but acknowledged that "the effort required to test this... appears to be excessive, as it would involve detailed analysis of high-speed camera recordings for individual flips." There's only so much tedium one can endure for science.

Chemistry

Citation: Tess Heeremans, Antoine Deblais, Daniel Bonn, and Sander Woutersen, for using chromatography to separate drunk and sober worms.

Active matter is matter that is composed of interacting agents able to extract energy from their environment and turn it into mechanical force. It's a major area of research in many different fields and is of particular interest for applications such as powering micrometers, self-cleaning polluted water, and improving the successful fertilization rate of sperm. Prior research has focused on particles, but Heeremans et al. wanted to learn more about the hydrodynamic properties of larger active polymers with an eye toward figuring out how to separate active polymers based on their activity. (Separation is typically achieved based on size.)

Fortunately, a handy analog exists in nature: T. tubifex worms, whose many segments are roughly akin to the chain-like structure of large polymers. The worms were placed in a specially designed channel inspired by the hexagonal pillar arrays used in chemistry to sort large polymers, scaled up to the size of Tubifex worms. The apparatus was mounted on a light-emitting diode panel for a uniform light background. The worms were divided into high- and low-activity groups, achieved by exposing the low-activity group to ethanol to basically get them drunk. The ethanol mixture also contained a blue dye to better differentiate between low-activity (blue) worms and high-activity (red) worms. The sober worms naturally made it to the end of the channel before their drunken counterparts, offering proof-of-principle that flow through a structured space is a reliable method for sorting active polymers by length and activity.

Demography

Citation: Saul Justin Newman, for detective work in discovering that many of the people famous for having the longest lives lived in places that had lousy birth-and-death recordkeeping.

Human mortality is an inescapable reality, but there are always a few especially hardy people who manage to live past 100. There is a longstanding body of research around the clustering of such people into so-called geographic "Blue Zones," usually attributed to such predictors as strong social connections, high vegetable intake, and certain genetic markers. But Newman noted some troubling indicators inconsistent with the established consensus—remarkable longevity associated instead with poverty, low per capita incomes, and higher crime rates, for example, in Italy, England, and France—and decided to delve a little deeper into the demographic data.

While some might argue that errors in demographic data simply could not happen, Newman found a staggering number of errors in the data for every blue zone. For instance, in 1997, there were 30,000 Italians claiming a pension while turning out to be dead. In Costa Rica, 42 percent of citizens over the age of 99 were found to have "misstated" their age in the 2000 census, shrinking the blue zone in that region after error correction so much that the estimated life expectancy plummeted to the bottom of the pack. And in 2010, more than 230,000 Japanese centenarians turned out to be missing, imaginary, dead, or the result of clerical errors, amounting to an error rate of 82 percent. "If equivalent rates of fake data were discovered in any other field... a major scandal would ensue," Newman wrote. "In demography, however, such revelations seem to barely mention citation."

Biology

Citation: Fordyce Ely and William E. Petersen, for exploding a paper bag next to a cat standing on the back of a cow to explore how and when cows spew their milk.

Dairy farmers are well acquainted with cows that tend to "hold up" their milk at the start of milking as opposed to cows that readily "let down" their milk. In 1941, Ely and Petersen wanted to learn more about the physiological processes at play in the ejection of milk from a cow's udders. And they found a novel way to test the effect of fright on said ejection of milk: They placed a cat on a cow's back as the mechanical milker was being attached and then exploded paper bags every ten seconds for two minutes. Apparently, the paper bags alone were alarming enough since "the cat was later dispensed with as unnecessary," the authors observed. They also tested the effects of injecting adrenalin on a cow's ejection of milk.

Ely and Petersen concluded that the act of "letting down" the milk was best explained as a conditioned reflex due to high intra-glandular pressure caused by oxytocin in the blood. This caused the alveoli and duct muscles to contract, releasing the milk. "Holding up" the milk was due to the presence of adrenalin in the blood, which prevents those muscular contractions so you don't get the high intra-glandular pressure. Perhaps the adrenalin injections were sufficient to reach that second conclusion with no need for a cat or paper bags, but where's the fun in that?