Popular Science Summer 2021

AROUND THE 100TH BIRTHDAY of a close friend’s grandmother, we asked her to name the single greatest invention she’d seen in her lifetime. She’d been around when the first cars rolled off Ford’s assembly line, when commercial airliners made flying across the country or around the globe an everyday occurrence, and as person-to-person communication moved from copper lines to cell towers. Despite how much change she’d lived through, her reply came quickly and without hesitation: air conditioning. An artificial oasis cooled to a brisk 68 degrees on a blazing summer afternoon? Nothing could compare. For all the comfort it’s brought, though, AC is the quintessential example of the complicated relationship modern humans have with heat. Our desire for indoor chill in the steamy months feeds into the very problem it was…

You’ll find me playing softball, baseball, or pretty much any outdoor sport. There’s almost nothing I enjoy more than being active under the blazing sun.John Kennedy, DIY editor I’m a sucker for photographing during sunrise in the summer. After a chilly night, you’ll sometimes get amazing fog moving through trees or over water.Stan Horaczek, senior gear editor Scanning for shorebirds on a marshy Jersey beach. Then I’ll wade around in a river to cool off and peel an Alphonso mango (or two) as a refreshing treat.Purbita Saha, senior editor Eating a hoagie in the sand, getting a little too hot, then taking a nap in the cool AC. Sliding into cold, crisp sheets makes me nostalgic for the shore!Rachel Feltman, executive editor I love waking up late to make breakfast…

EARTH IS EVER SHIFTING. Continents drift, ice ages come and go, odd and wonderful creatures take shape only to one day vanish. Reviewing the history of our world, some might be tempted to dismiss the warming we are experiencing as just another of these planetary ebbs and flows. Yet scientific consensus is clear: Not only is the climate rapidly changing, but humans are to blame. Each decade for the last 40 years has replaced the preceding one as the hottest on record, and historical data proves this acceleration isn’t natural. But decadal temperature increases are hard to feel. Here are some signs that Homo sapiens are behind this trend, and a couple of effects you can feel yourself. A / Fossil-fueled skies Since 1800, global CO2 levels have climbed more…

YELLOWSTONE NATIONAL PARK is stunning, yet even by that measure, the Grand Prismatic Spring astonishes. Sulfuric water, heated by the supervolcano beneath northwest Wyoming, burbles from a fissure 121 feet below the pool’s surface and radiates out 370 feet in concentric bands. Although hot enough to sear skin and scorch plants, the pond teems with heat-loving microbes called cyanobacteria. These organisms, among Earth’s oldest, have adapted to life in this hostile environment and give the popular attraction its signature hues. Here’s how they create a terrestrial rainbow. Blue At a scalding 189°F, the thermic feature’s aquamarine center is much too harsh for most life-forms. This renders the mineral-​rich H2O dazzlingly clear. But it appears azure for the same reason the ocean does: The translucent liquid absorbs red wavelengths and reflects…

A WARMING WORLD will make summers increasingly uncomfortable, but that doesn’t mean air-conditioning bills need to rise too. For centuries, architects have helped folks brave the heat using tools like natural ventilation and passive cooling. The key is controlling how the structure interacts with solar energy. Designing with the sun’s rays in mind can keep a dwelling comfortable with minimal impact on the planet and the wallet, making staying cool a breeze. Summertime shade Deciduous trees block rays during the ice-cream-and-lemonade months, but let them through during winter. Awnings and overhangs also work. Building into a hillside provides cover and takes advantage of the soil’s insulation. Reflective roofs Insulating the roof or attic keeps the cold in and the hot out (and vice versa when days turn frigid). Light-colored shingles,…

SINCE ITS FORMATION IN 1983, Kīlauea’s Pu‘u‘ō‘ō cone had risen and fallen as magma fluctuated throughout the volcano’s vibrant East Rift Zone. But on April 30, 2018, Pu‘u‘ō‘ō announced its retirement with a rumble. The once-brimming basin drained down into the earth like an unclogged sink. Newly liberated lava crept from the summit toward the Big Island’s eastern tip. Soon Leilani Estates, a community of around 2,000, would confront the eruption firsthand. Fissures exploded with ash, noxious gas, and molten lava across roads and into backyards. Pu‘u‘ō‘ō’s swan song ultimately destroyed some 700 homes. Then the foundation of the Hawaiian Volcano Observatory (HVO)—​established by the US Geological Survey (USGS) in 1912—began to crack. On May 16 the staff was forced to evacuate. “We scattered to the winds and took what we…