Lists and Stories

How Do Microwaves Work? Microwave ovens were life altering from the moment they began humming and heating in homes of the 1970s. The sprinter to the conventional oven’s cross-country runner, microwaves quickened the process of cooking and reheating meals, saving time and increasing the potential for leisure over work. The...
How Do Monkeys and Apes Trim Their Fingernails? Have you ever seen a monkey getting a manicure? Though that line sounds like the beginning of a bad joke, it actually has some scientific merit. Monkeys and apes are primates, an order of mammals that have forward-facing eyes, large brains compared with their body weight, and—where other mammals...
How Do Ocean Currents Affect the Biosphere? Ocean currents are streams of water in the ocean whose circulation is produced by gravity, wind friction, and water density variations. The biosphere (the relatively thin life-supporting layer at or near Earth’s surface) is influenced by ocean currents in several ways. Currents transport seeds,...
How Do Penguins Tell Each Other Apart? Imagine for a second that you’re an emperor penguin coming back to your colony after a swim. You need to find your mate and your chick, but how? Emperor penguins don’t make nests, so there’s no fixed spot where you can go and expect to meet up with your family. There’s just a huge crowd of penguins...
How Do Scientists Predict Tsunamis After Earthquakes? Earthquakes, landslides, volcanic eruptions, and even meteoroid and comet strikes can produce tsunamis—trains of waves that extend over the ocean’s surface in ever-widening circles, much like the waves produced by a pebble falling into a shallow pool. When these waves reach shallow water, friction...
How Do the Symptoms of COVID-19 Differ from Those of Cold and Flu? October marks the start of cold and flu season in the Northern Hemisphere, where, in 2020, many countries also have been heavily affected by coronavirus disease 2019 (COVID-19). But cold, flu, and COVID-19 are all contagious respiratory diseases, so how can those who become ill tell if what they...
How Do Tornadoes Form? The average tornado—a mostly harmless cyclone of air that connects a storm cloud above and Earth’s surface below—has a lifespan of only a few minutes. However, when they move away from the average, tornadoes are considered some of the most destructive weather events in the world. The wildest of...
How Do Vaccines Work? Vaccines work by imitating infection to encourage the body to produce antibodies against infectious agents. In doing so, the body’s immune system adds to its memory, so if the body ever encounters the same infectious agent again, it is ready to fight it off. There are several different types of...
How Do We Know How Far Away the Stars Are? The closest star, Proxima Centauri, is 4.24 light-years away. A light-year is 9.44 trillion km, or 5.88 trillion miles. That is an incredibly large distance. Walking to Proxima Centauri would take 950 million years. If you turned it up and went as fast as Apollo 11 went to the Moon, it would still...
How Do We Know That Dinosaurs May Have Had Feathers? Modern birds are living dinosaurs, having evolved from a line of theropod dinosaurs more than 150 million years ago. According to fossil evidence, some dinosaurs from long ago even had feathers—or structures that had various aspects of modern bird feathers before birds evolved. In the mid-1990s...
How Do We Know What Dinosaurs Sounded Like? All animals make sounds. Many sounds are made as an animal moves through its environment, such as the thud or patter of its feet on the ground, the scraping of its body against rocks, a brushing as it passes through vegetation, and a splashing at the surface of water, as well as sounds associated...
How Do You Balance a Chemical Equation? Balancing chemical equations is a useful skill in chemistry. The basis of chemical reactions is the idea that atoms and molecules frequently recombine into other molecules. Reactants are the substances that enter a chemical reaction, while products are formed as the result of the reaction. Some...
How Do You Get a Nobel Prize? The Nobel Prizes, announced annually in the fall since 1901, cover five different disciplines: chemistry, physics, literature, peace, and physiology/medicine. Additionally, there is an economics prize awarded at the Nobel ceremony (not technically a Nobel prize). That means you’ve got at least...
How Do You Read Phylogenetic Trees? A phylogenetic tree is a diagram that displays the evolutionary history of a group of organisms. The trees can represent relationships between any related groups, from all life on Earth to specific subspecies of algae. Phylogeny assumes that every organism shares a common ancestor and that all...
How Do You Rewild an Environment? In the field of ecology, rewilding is formally known as ecological restoration, and it is complicated! The first challenge is deciding on the goal for the restoration. Will you try to make the area look like it did immediately before it was degraded? Or should you aim for how it was before the...
How Do You Tell the Difference Between Total, Annular, Solar, and Lunar Eclipses? Traditionally, eclipses are divided into two major types: solar and lunar. Solar eclipses occur when the Moon passes between Earth and the Sun, leaving a moving region of shadow on Earth’s surface. Lunar eclipses occur when Earth passes between the Sun and the Moon, casting a shadow on the Moon....
How Does A Ventilator Work? Mechanical ventilators have played an important, if controversial, role in the treatment of patients with severe coronavirus disease 2019 (COVID-19)—helping critically ill persons breathe in the near term, but with potentially harmful trade-offs for lung function over the long term. For COVID-19...
How Does Bluetooth Work? You get that important call you’ve been waiting for, and you scramble for earphones in your bag. You groan as you find them, wires all a-tangle like yesterday’s spaghetti. And then, when you try to transfer photos from the phone to your computer, you can’t find that elusive USB cable in your desk....
How Does GPS Work? The Global Positioning System—better known as GPS—has 31 satellites orbiting Earth. These satellites carry atomic clocks that keep very accurate time. The GPS satellites transmit this time to receivers on Earth. By comparing the time at the receiver to the time transmitted by the satellite and then...
How Does Soap Work? Soap is able to clean hands and dishes because of some pretty nifty chemistry. Soap molecules have on one end what’s known as a polar salt, which is hydrophilic, or attracted to water. The other end of the molecule is a nonpolar chain of fatty acids or hydrocarbons, which is hydrophobic—meaning...