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In 1798 Thomas Robert Malthus famously predicted that short-term gains in living standards would inevitably be undermined as human population growth outstripped food production, and thereby drive living standards back toward subsistence. We were, he argued, condemned by the tendency of population to grow geometrically while food production would increase only arithmetically. For 200 years, economists have contended that Malthus overlooked technological advancement, which would allow human beings to keep ahead of the population curve....

A recent audit of fire prevention measures has scorched the Los Alamos National Laboratory, the facility that created the atomic bomb during World War II and is now the home of top-level national security and radioactive material research. The report [pdf] by the U.S. Department of Energy (DoE) inspector general reveals that the lab had failed to address problems pointed out three years ago in an evaluation that found at least 800 fire prevention “deficiencies”....

P. Murali Doraiswamy is the head of biological psychiatry at Duke University and is a Senior Fellow at Duke’s Center for the Study of Aging. He’s also the co-author of The Alzheimer’s Action Plan, a guide for patients and family members struggling with the disease. Mind Matters editor Jonah Lehrer chats with Doraiswamy about recent advances in Alzheimer’s research and what people can do to prevent memory loss. LEHRER: What do you think are the biggest public misconceptions of Alzheimer’s disease?...

The 21st-century equivalent of the cavalry has come charging in to rescue cities in China and South Asia in their battles against air pollution and global warming. And it’s also beginning to help out on the traffic-choked streets in London, New York, São Paulo and Los Angeles. This is the electric bicycle, or “e-bike,” a technology that blends the simplicity and mobility of a traditional bicycle with the speed of a moped or motorized scooter, but without the internal combustion engine....

As coronavirus outbreaks surge worldwide, research teams are racing to understand a crucial epidemiological puzzle — what proportion of infected people have mild or no symptoms and might be passing the virus on to others. Some of the first detailed estimates of these covert cases suggest that they could represent some 60% of all infections. Many scientists have suspected that there is an undetected pool of covert cases showing limited to no symptoms because an increasing number of infected people cannot be linked to known COVID-19 cases or travel to epidemic hotspots....

To Emily Dickinson, it was “fixed melancholy.” To essayist George Santayana, it was “rage spread thin.” The turns of phrase conjure different emotions, but these two writers were describing the same disorder: depression. The variance is more than a matter of literary or philosophical differences; it also reflects the fact that one was a woman, the other a man. Therapists have long known that men and women experience mental illness differently....

The market for brain-training software continues to grow, but evidence of the programs’ ability to boost memory or intelligence in a broadly applicable way (rather than simply making people better at the task they are practicing) remains scarce. New studies offer a tantalizing suggestion that certain programs may work—but the bulk of the research is murky. Neuroscientist Peter Snyder of Brown University reviewed nearly 20 software studies and concluded that, as a group, they were underwhelming....

Dear EarthTalk: To what extent does human population growth impact global warming, and what can be done about it? – Larry LeDoux, Honolulu, HI No doubt human population growth is a major contributor to global warming, given that humans use fossil fuels to power their increasingly mechanized lifestyles. More people means more demand for oil, gas, coal and other fuels mined or drilled from below the Earth’s surface that, when burned, spew enough carbon dioxide (CO2) into the atmosphere to trap warm air inside like a greenhouse....

Dear EarthTalk: Lead was long ago phased out of automobile gasoline, but it is still in aviation fuel and is now the largest source of lead emissions in the U.S. What’s being done?—L. Eber, Rye, N.Y. Yes, aviation fuel emerged as the largest source of lead emissions in the U.S. once lead was phased out of automotive gasoline beginning in the 1970s. While jets, which comprise the majority of commercial aircraft, don’t use leaded fuel, smaller, piston-engine planes use enough leaded aviation fuel (nicknamed “avgas”) to account for half of the lead pollution in American skies, making it a real air quality issue....

We all carry our DNA around with us—in every cell of our bodies—but some biotech trailblazers are toting their genomes with them, too. In a recent talk Jay Flatley, president and CEO of sequencing giant Illumina, recalled being asked by his doctor to get a certain genetic test. But Flatley was able to pull up his full genome on his iPad then and there instead of sending a spit sample off to the lab....

Climate change-induced disasters including sea-level rise, extreme heat and crop losses will cost the country several billion dollars annually in the decades ahead, a report sponsored by wealthy environmental activist Tom Steyer, former New York City Mayor Michael Bloomberg (I) and past Treasury Secretary Henry Paulson said today. “Risky Business: The Economic Risks of Climate Change to the United States”—an analysis more than a year in the making—projects losses across sectors and by region of the country....

The Los Angeles City Council last week voted unanimously to ban new oil wells and phase out existing ones, a move leaders in the nation’s second-most populous city called essential for health reasons. The council declared oil wells “non-conforming” with the city’s land use requirements. A city commission now will study how to phase out more than 5,200 existing oil and gas wells. It could be done quickly for some, but others might take as long as 20 years, according to Councilman Paul Krekorian, a key backer of the oil drilling ban....

From the COVID vaccine to pulsars to computer programming, women are at the source of many scientific discoveries, inventions and innovations that shape our lives. But in the stories we’ve come to accept about those breakthroughs, women are too often left out. Each season at Lost Women of Science, we’ll look at one woman and her scientific accomplishment: who she was, how she lived and what she found out. Katie Hafner, a longtime reporter for the New York Times, explains the science behind each woman’s work and explores the historical context in which she lived....

More than 70 medical and public health organizations issued a call to action on climate change yesterday, calling it the “greatest public health challenge of the 21st century.” The climate agenda urges government officials and policymakers to take on a series of priorities, including shifting away from coal and natural gas to renewable energy, supporting greenhouse gas emission reductions, and ensuring residents have access to safe and affordable drinking water. Groups backing the agenda include the American Medical Association, American Academy of Pediatrics and American Heart Association....

Baby mice exposed in the womb to low doses – but not high doses – of bisphenol A were fatter and had metabolic changes linked to obesity and diabetes, according to a new study published Thursday. Building on previous studies that link the hormone-altering chemical to changes in body weight and glucose tolerance, the new research fuels an ongoing controversy over whether federal testing of chemicals is adequate to protect people from low doses....

When a concert opens with a refrain from your favorite song, you are swept up in the music, happily tapping to the beat and swaying with the melody. All around you, people revel in the same familiar music. You can see that many of them are singing, the lights flashing to the rhythm, while other fans are clapping in time. Some wave their arms over their head, and others dance in place....

Rice, like most plants, needs water. In fact, it needs more water than most: the shoots of this marsh plant are typically partially submerged. But rice, like most crops, still does not stand up to total submersion. Despite being the staple of flood-prone regions, most strains of rice die if submerged for more than four days and even short-term inundation can stunt growth and impact harvests. Now researchers have identified a gene that confers the ability to survive extended submersion in some rice cultivars and successfully introduced it into those that lack this critical protection....

A stellar explosion known as a nova that was detected in 2000 formed a two-lobed shell of material ejected from the star. Shaped like a bow tie, it continues to swell at great velocity. But, curiously, the coat of ejecta flowing outward from the star lacks hydrogen, the most common gas in the universe. Such a nova had never been observed before, says Danny Steeghs, an astrophysicist at the University of Warwick in England....

Key Concepts Light Refraction Reflection Index of refraction Introduction If you pour water into a clear glass, what color is it? It’s clear, right? But what happens if you try to look through it to see the world on the other side of the glass? It looks a little distorted, maybe a little fuzzier and uneven. If water is clear, why can’t we see through it clearly? The answer has to do with how light moves through water, glass and other transparent materials....

In its first six months of operation, the Large Hadron Collider near Geneva has yet to find the Higgs boson, solve the mystery of dark matter or discover hidden dimensions of spacetime. It has, however, uncovered a tantalizing puzzle, one that scientists will take up again when the collider restarts in February following a holiday break. Last summer physicists noticed that some of the particles created by their proton collisions appeared to be synchronizing their flight paths, like flocks of birds....