Innholdsfortegnelse for March/April 2024 i Popular Mechanics

THE SHINY, NEW LAS VEGAS SPHERE IS more than just a 17,600-seat amphitheater-style venue hosting a U2 residency. Since its opening in September 2023, it’s become the world’s largest spherical structure, at 516 feet wide and 366 feet tall. Meanwhile, the seating bowl’s 160,000-square-foot spherical LED “immersive surface” lights up at full 16K resolution, making it the highest-resolution LED screen on Earth. To add another wrinkle, the world’s largest beam-forming audio system—think headphone-style sound without the headphones—tucks behind the immersive surface for a one-of-a-kind experience. These three world firsts for shape, sight, and sound took at least 60 patents to produce, securing the Sphere’s spot as a modern engineering marvel. ■ A Sphere Within a Sphere //First things first: Why a sphere? “The Earth is round, so for us to…

THE ENVELOPE ARRIVED at the San Francisco Chronicle in November 1969 without a return address, its directive to the recipient, in handwriting distinctively slanted and words unevenly spaced, to “please rush to editor.” The Chronicle newsroom had seen the scrawl before, on previous letters sent from the Zodiac, a self-monikered serial killer who threatened to go on a “kill rampage” if the paper didn’t publish his writing on its front page. By the time of the November letter, the Zodiac had already attacked seven people, murdering five. His most recent murder—of a San Francisco cab driver, by gunshot—had occurred just four weeks before this new envelope arrived. The Zodiac had mailed the Chronicle a piece of the victim’s bloodied shirt as evidence of the crime. The Zodiac’s letters were replete with…

AN ANCIENT VOLCANO BENEATH NEVADA and Oregon could hold the largest deposit of lithium ever found, scientists revealed last summer in a peer-reviewed paper published in Science Advances. This section of land—called Thacker Pass, or Peehee Mu’huh to the local Paiute people—has been mined since the 1970s, so the new analysis merely confirms what locals have long known about the area. Beginning to extract the lithium in earnest would change the landscape for everything from electric-vehicle batteries to lithium-ion smartphone batteries, and could even hasten the switch toward renewable energy plants that rely on grid storage. But setting up a mine to extract the massive deposit of lithium in Thacker Pass is not a simple task: It will require a wholly new process to separate the lithium from its natural…

A FIRE EXTINGUISHER IS MORE THAN A tool that puts out a fire. It can be the arbiter between life and death. Consider this: Fire with access to air and fuel will double in size every 30 seconds. In three minutes, a fire that starts out the size of one 5-gallon bucket becomes the size of 64 burning buckets. Just 180 seconds after it begins, a fire can be transformed from a nuisance to a room-size, life-threatening inferno. What we state above is a pillar of firefighting science, and we came across it in taking a class on using a fire extinguisher at the newly opened Allen-town Fire Training Academy in Pennsylvania. Our instructor was John Christopher, the fire department’s captain of public affairs. Every week, he teaches a wide…

What if you could take on the intelligence, charm, or confidence of another person just by pretending to be them? Researchers are exploring a type of embodiment in the virtual reality (VR) space called the “proteus effect” to see if it’s possible. Scientists at Stanford coined the term in 2007, and it describes short-term behavioral changes gained through embodying a virtual avatar. At its core, embodiment in VR is a way our minds make meaning out of multiple streams of information, says Daniel Harvie, PhD, a program director of the University of South Australia’s Masters of Advanced Clinical Physiotherapy program. He published a paper in 2022 that explores whether VR embodiment of superheroes can help treat chronic back pain. “We don’t perceive our body directly; instead we perceive a version…

THE HANDHELD CIRCULAR SAW IS PERHAPS THE MOST VERSA-tile power tool for cutting wood. Perfect for a variety of projects, it can be used to cut framing lumber, plywood, and even sheet metal—with the right blade. You’ll probably need one at some point, whether you’re constructing a shed or treehouse, adding a closet, finishing the basement, or building a workbench. Originally, handheld circular saws were bulky, corded machines that, at the time, were a huge time-saver for carpenters building homes. With nearly 100 years behind us since those first saws, they have evolved a lot, as have our expectations. If you had to use one of those original circular saws today, you probably wouldn’t be a happy camper. Today’s saws have dropped bulk, weight, and in many cases, the cord—making…

BEST FULL-SIZE ROUTER Milwaukee 2838-21 18-Volt Cordless Router Kit $600 This top-notch cordless router demonstrates that Milwaukee also builds great tools for woodworkers. Observers of the company know that it is well-known for its metalworking equipment, such as those used by plumbers, electricians, welders, fabricators, sheet-metal mechanics, and HVAC installers. Yet for the last three decades, we’ve marveled that its tools for wood are also excellent. We turned on this router, set its six-speed dial to 5, and neatly carved out deep rabbets in C Select verticalgrain Douglas fir and plain-sawn maple. The tool is well-balanced and easy to handle, and it performs just as flawlessly as the company’s corded counterparts. Advanced wood-workers will appreciate that this machine comes as a complete kit, with two bases (standard and plunge), an…

IN THE MORNING HOURS on June 24, 2021, a section of Champlain Towers South, a 12-story apartment complex in Surfside, Florida, crumpled to the ground. Eyewitness accounts and video footage revealed the progression of the condo’s collapse. Around 1:15 a.m., a loud crash came from the parking garage beneath the L-shaped structure, as the garage’s ceiling, which extended outward to become the building’s pool deck, began to disintegrate. Minutes later, Champlain Towers South’s eastern wing gave way in two stages—with its midsection falling first, followed by the rest of the wing, seconds later. Dust and debris engulfed the building’s west wing, still standing amid a pile of rubble. Ninety-eight people died in the collapse, and hundreds more lost their homes and possessions. It was one of the deadliest structural building…