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Over the past decade and a half, countries around the world have taken unprecedented steps to shift their energy dependence from fossil fuels to alternative resources. Tariffs and subsidies have spurred the growth of wind and solar, regional emissions markets have imposed costs on carbon, and government funds have poured in to support the development of new, low-carbon technologies. And yet carbon emissions from the energy sector continue to rise. From 1991 to 2010, they grew at a rate of 1....

There’s no easy way to admit this. For years, helpful letter writers told us to stick to science. They pointed out that science and politics don’t mix. They said we should be more balanced in our presentation of such issues as creationism, missile defense and global warming. We resisted their advice and pretended not to be stung by the accusations that the magazine should be renamed Unscientific American, or Scientific Unamerican, or even Unscientific Unamerican....

Physics has missed a long-scheduled appointment with its future—again. The latest, most sensitive searches for the particles thought to make up dark matter—the invisible stuff that may comprise 85 percent of the mass in the cosmos—have found nothing. Called WIMPs (weakly interacting massive particles), these subatomic shrinking violets may simply be better at hiding than physicists thought when they first predicted them more than 30 years ago. Alternatively, they may not exist, which would mean that something is woefully amiss in the underpinnings of how we try to make sense of the universe....

The World Health Organization predicts that an additional 250,000 people will die annually between 2030 and 2050 from conditions caused or exacerbated by climate change, the Geneva-based agency reported yesterday in an update of climate mortality estimates. But the causes of sickness and death will shift over that period as child deaths from malnutrition and diarrheal disease decline across much of the world, while mortality rises from things like mosquito-borne malaria, heat exposure and other conditions, especially in South Asia and sub-Saharan Africa....

For decades the number of satellites orbiting Earth rose at a gentle pace, but growth has soared recently. By July 2019 more than 2,200 satellites were aloft. In the 1980s and 1990s the action was in geosynchronous orbit (blues), says Jonathan McDowell, an astrophysicist at the Center for Astrophysics|Harvard & Smithsonian. But now the action is in the lowest Earth orbits (yellows), he says, and increasingly dominated by young companies rather than government, military or academic owners....

In 1930 food-packing companies were enthralled with the relatively new and improved film called cellophane, a transparent polymer made from cellulose. Cellophane wrappers could help keep packaged food fresh yet would still allow customers a view of the contents. Sealing cellophane packages satisfactorily was a problem, however, until the 3M Company invented and trademarked Scotch tape—a name that the public nonetheless widely uses for all adhesive-backed cellophane tapes. (The analogous product Sellotape, introduced seven years later in Europe, has the same problems with generic use of its name....

NASA astronaut Kayla Barron floated into an International Space Station module in January with a roll of yellow tape and an unusual assignment: setting up the first of six “trenches” for an archaeological investigation. Back on Earth, archaeologists Alice Gorman of Flinders University in Australia and Justin Walsh of Chapman University in California watched and offered feedback. They had previously mined existing video footage to study astronaut culture, but their Sampling Quadrangle Assemblages Research Experiment, dubbed SQuARE, marks the first real off-world “dig....

The oldest civilization of ancient Mexico and Central America has finally yielded solid evidence of a writing system. Researchers who analyzed a stone block covered in a sequence of faint symbols have declared it the oldest conclusive writing sample from the New World, dating to around 900 B.C. or earlier and belonging to the region’s oldest complex society, the Olmec. “Imagine if you will this extraordinary civilization that we’ve known about for 100 years suddenly to become literate....

Scientists have documented a new way in which the West Nile virus can propagate. The findings indicate that the virus can pass from one mosquito to another while they feed on previously uninfected animals. This mode of transmission is significantly faster than the assumed cycle of infection for the disease, which may help to explain why West Nile has spread so rapidly across North America. Prior to this discovery West Nile virus was thought to pass via mosquitoes in the following way: an infected mosquito dining on a bird’s blood would pass the West Nile virus into the bird’s bloodstream and after a few days high levels of the virus would be detectable in the bird....

Key concepts Light Physics Color Wavelength Introduction Have you ever watched a sunset and wondered why the sky suddenly changes from blue to orange and red? Even during the day the sky can have multiple colors ranging from bright blue to gray or white. Where do these colors come from? In this activity you will find out—and simulate your own sunset in a glass! Ready to watch the sun go down?...

Computer simulations are showing how tiny variations in the Sun’s brightness can have a big influence on weather above the Pacific Ocean.The simulations match observations that show precipitation in the eastern Pacific varies with the Sun’s brightness over an 11-year cycle. However, the model does not indicate a relationship between solar activity and the rise in global temperature over the past century.“This is not a global warming thing,” says Gerald Meehl, a modeller at the National Center for Atmospheric Research in Boulder, Colorado, and first author of the study....

LAS VEGAS—Pretty soon, car buyers will make their decisions about which vehicle to buy based not on styling, horsepower or color but rather on software. That is the vision that Ford Motor Co. CEO Alan Mulally laid out here Thursday at the Consumer Electronics Show (CES) when he and several company executives demonstrated new components of Ford SYNC technology that will allow drivers hands-free access to modern necessities, including text messages and the Internet....

For me, the secret is always the lead—that’s journalist jargon for the opening of a story, the one provocative idea that will capture a reader’s interest. Once I’ve found that gem, the rest of the narrative seems to flow easily from the gray matter in my head down to my fingers pounding on the keyboard. Where do such creative sparks come from? How can we conjure them whenever we want? And why can that be so infernally difficult to do, anyway?...

In the 2015 summer blockbuster Ant-Man, the character Hank Pym, a scientist who has invented a suit that can shrink a person down to the size of an insect, remarks that ants can perform amazing feats, but they need a leader to tell them what to do. Pym wears a small device behind his ear that allows him to instruct the ants to act as a phalanx of attackers that helps the ant-sized human hero defeat an evil mastermind....

The narrow profile of plasma and liquid-crystal-display (LCD) televisions has caught the public’s eye, but the sets are still far more expensive than the conventional cathode-ray tubes (CRTs) that have long dominated the market. Nevertheless, CRTs have lost some luster. Manufacturers are responding by designing a much shallower picture tube. Several makers have unveiled prototype slim TVs, which could be sold in the U.S. by this summer. A 30-inch (diagonal) set will be about 16 inches deep instead of 24 inches and be priced somewhat higher....

When we think of food going stale, we typically think of products such as bread. You might think that bread starts to stale days after it is made. But the process of staling actually begins as soon as the loaf leaves the oven and begins to cool. How quickly bread goes stale depends on what ingredients are in it, how it was baked, and the storage conditions. Breads are essentially networks of wheat flour protein (gluten) molecules and starch molecules....

A key step in showing that incompleteness is natural and pervasive was taken by Alan M. Turing in 1936, when he demonstrated that there can be no general procedure to decide if a self-contained computer program will eventually halt. To demonstrate this result, let us assume the opposite of what we want to prove is true. Namely, assume that there is a general procedure H that can decide whether any given computer program will halt....

The tornado that devastated Moore, Okla., has now officially been placed into the highest category—5 on the so-called Enhanced Fujita Scale, meaning winds in excess of 320 kilometers-per-hour. Scientific American corresponded with meteorologist Harold Brooks, a senior scientist at the National Oceanic and Atmospheric Administration’s (NOAA) National Severe Storms Laboratory in Norman, Okla. [An edited transcript of the interview follows.] What are the key ingredients of a powerful twister like this?...

1972 Neutrino Trap “It is believed that the sun’s radiant energy originates with thermonuclear reactions deep in the interior. One product should be a flood of neutrinos: massless, uncharged particles that interact so little with other particles that solid bodies such as the earth are virtually transparent to them. Raymond Davis, Jr., of the Brookhaven National Laboratory has devised a detector to test the theory. It is buried a mile under solid rock in the Homestake Gold Mine in Lead, S....

Major Paul “Goose” Gosden, U.S. Marine Corps, piloted his UH-1 Huey close air support helicopter across the Kuwait-Iraq border through the night’s oily blackness. His aircraft was first to cross into Iraqi airspace in the second Gulf War, in support of Cobra attack helicopters tasked to destroy observation posts on Safwan Hill, near the infamous Highway of Death. Their mission was the opening salvo of Operation Iraqi Freedom, designed to kick in the door for the U....