FINDING A TOXIC SOURCE
In “Penguin Cartography” [Advances], Gayoung Lee reports on research by marine biologist John Reinfelder and his colleagues about the accumulation of mercury in penguins. The story highlights gold mining as a source of such mercury. But according to an October 2010 article in the Woods Hole Oceanographic Institution’s (WHOI’s) journal Oceanus, most of the mercury in the oceans has been created by coal power plants. This link is important because burning coal is also a major source of the carbon in the atmosphere that is causing climate change.
TERRENCE DUNN VANCOUVER, WASH.
On supporting science journalism
If you’re enjoying this article, consider supporting our award-winning journalism by subscribing. By purchasing a subscription you are helping to ensure the future of impactful stories about the discoveries and ideas shaping our world today.
REINFELDER REPLIES: The WHOI article Dunn notes was published before the United Nations Environment Program’s Global Mercury Assessment 2018, which shows that artisanal and small-scale gold mining constitute the largest single source of anthropogenic mercury emissions (representing 38 percent of such emissions). Coal combustion is the second-largest source (representing 21 percent).
INSIGHT ON INSIGHT
In “The Wonder of Insight,” John Kounios and Yvette Kounios explore the neurocognitive underpinnings of the “aha! moment.” I wonder whether the authors—or others in the field—have explored similar neurocognitive mechanisms in the experience of humor, particularly the moment of “getting” a joke. Much like insight, the punchline of a joke often reconfigures our understanding of preceding information, and the moment of laughter seems to share the element of sudden recognition or restructuring.
MARK HALLIWELL SMITH BEVERLY HILLS, CALIF.
The authors assert that “messages about rewards can enhance insight—but only when they are displayed so briefly that a person cannot consciously perceive them.” Yet rewards’ effect on insight is nuanced and context-dependent. Highly important rewards might sometimes shift focus toward immediate goals and thus limit the broad, exploratory thinking that is beneficial for insight. But in other contexts, they can boost motivation, persistence and creative problem-solving. Moreover, the authors seem to present a strict dichotomy by suggesting that only subliminal rewards can boost insight, potentially overlooking the role of conscious incentives.
JAMAL I. BITTAR TOLEDO, OHIO
Up to my early 20s, I was a highly creative person and produced beautiful paintings. Since I finished college and went into a line of work that requires a lot of analytical thinking, I have struggled to be artistically creative again. Until now, I thought I was just too mentally exhausted to produce new ideas. But after reading this article, I wonder if highly analytical tasks and constant deadlines at work are suppressing the part of my brain that used to make me creative.
AILYN MONTES MIAMI, FLA.
THE AUTHORS REPLY: Smith likens jokes to puzzles and suggests their punchlines can cause one’s initial understanding to become restructured. There is a fair amount of research on this topic. But “getting” a joke can impose a burden on the would-be life of the party: When you haven’t rehearsed the joke sufficiently, you might mentally fixate on the punchline and give away the meaning of the joke while telling it. When you see something in a new light, it can be hard to remember it in the old light.
Bittar argues that explicit rewards can motivate creativity. Research shows that the prospect of such a reward can incentivize people to persist on solving a problem, making them more likely to come up with a good idea. Research also shows, however, that offering explicit rewards can narrow the scope of thought to ideas closely related to the goal, making it more difficult for a person to explore remote associations and fringe ideas that could be fodder for a creative insight. And recent research does suggest that subliminal rewards, in particular, can energize thought without narrowing one’s thinking. Outside-the-box thinking is more likely when one’s eyes are not on the prize.
Montes’s reflections on how work-related pressures can sap one’s creativity will ring true for many people. The kind of relaxed reverie that can give birth to an insight can be easily crushed by anxiety, the constant pressure to stay on task and a lack of sleep. That’s why many creative ideas unexpectedly emerge during vacations. It’s also why some businesses take their creative teams on vacationlike retreats.
AH, SUGAR, SUGAR
“Sweet Surprise,” by Saima S. Iqbal [Advances; February], reports on a study on exposure to sugar restrictions among mid-20th-century infants in the U.K.: economist Tadeja Gračner and her team found that such exposure mitigated chronic ailments later in life. Is the relevant “sugar” sucrose, which is 50 percent glucose and 50 percent fructose? If so, is glucose or fructose, or both, the culprit for subsequent ailments?
RAJESH KULKARNI VIA E-MAIL
GRAČNER REPLIES: Throughout the article, “sugar” refers primarily to added sugar—sugar that is added to foods rather than naturally occurring, or intrinsic, sugar. These additives can come in many forms, including but not limited to honey, table sugar, molasses and high-fructose corn syrup. Our study did not specifically examine the exact sources of added sugar.
OBJECTIVE SPHERICITY
“The Roundest Object in the Universe,” by Phil Plait [The Universe; February], asserts that, among known astronomical objects, the sun is the closest to a perfect sphere. I realize Plait was talking about natural objects, but I was surprised that he made no mention of Gravity Probe B. That orbiting experiment, which tested predictions of Einstein’s general theory of relativity, used four fused quartz spheres as its gyroscopes, and these objects were more spherical than the sun.
DON JENNINGS COLLEGE PARK, MD.
PLAIT REPLIES: I should have made it clear that I was exploring the question of the most spherical natural object. As many people have noted, there are some artificial objects vying for the title. They indeed include the gyroscopic rotors developed for NASA’s Gravity Probe B mission, which launched in 2004. These ball-bearing-like gyroscopes were 3.8 centimeters across and deviated from sphericity by the thickness of just a few atoms. Unfortunately, there wasn’t room in the article to mention them. So right after it was published online in November 2024, I followed up with more information in issue number 801 of my Bad Astronomy Newsletter. Other contenders for roundest object are the spheres used to measure Avogadro’s constant, the number of atoms or molecules in one mole of a given substance. Having a nearly perfectly round object isn’t just a matter of idle interest; our understanding of the universe can depend on it!
CLARIFICATIONS
In “The Traumatic Roots of Addiction” [October 2024], Maia Szalavitz refers to the train bound for Auschwitz with her father and his mother onboard as what was abandoned by the Nazis in 1944.
The online version of “Deep-Sea Mining Begins,” by Willem Marx [May], now describes Alisher Usmanov as a businessperson.
