Science

  • Urchin takeover underlies California’s vanishing kelp forests
    Joshua Smith started diving in Monterey Bay in 2012. Back then, waters along this part of Central California looked very different. He likens its underwater environment at the time to a redwood forest. Towering kelp rose like “tall cathedrals,” recalls this ecologist at the University of California, Santa Cruz. Their tops were lush — so…
  • Cool Jobs: Saliva offers a spitting image of our health
    Purdue University has again canceled its annual cricket-spitting contest. It’s not safe yet, due to the coronavirus pandemic. If it resumes in 2022, though, insects again will be far from the only thing flying through the air. Lots of spit will spray out, too. “Getting saliva on the cricket makes it more aerodynamic,” notes Thomas…
  • Simpler, easier COVID-19 test developed with kids in mind
    Testing for COVID-19 has usually required sticking a cotton swab far into the nose — uncomfortably far up. Two scientists at the University of Milan, in Italy, knew their kids would fight repeated testing that way. Yet as biologists,  Elisa Borghi and Valentina Massa knew repeated testing for the new coronavirus can be important. So…
  • Raindrops on alien worlds will obey Earth-like rules
    Raindrops behave much the same way across the Milky Way, a new analysis finds. This should hold whether we’re talking about a methane torrent on Saturn’s moon Titan or a drizzle of iron on the exoplanet WASP 78b. Regardless of what they’re made of, droplet sizes will always be close to the same size. “You…
  • Let’s learn about dogs
    Dogs are wonderful companions. They’re with us in our toughest times. Some can understand what we say, and even how we say it. They’re always there to celebrate when you come home — even if you’ve only been gone for a few minutes. See all the entries from our Let’s Learn About series In fact,…
  • Staying grounded in space requires artificial gravity
    In lots of books, movies and TV shows, people on spaceships walk around like they would on Earth. In real life, though, astronauts in space float. The difference isn’t just because the books, movies and TV are fiction. It’s that in those fictional worlds, artificial gravity exists. In our world it doesn’t — yet. But…
  • Scientists discover likely source of the moon’s faint yellow tail
    A comet-like tail of sodium atoms streams away from the moon. Over the years, scientists have proposed various ideas for how that sodium got there. Two new studies now pin down a likely source for most of it: swarms of small meteorites that constantly bombard the moon.  First discovered almost 23 years ago, the tail…
  • Scientists Say: Alkaline
    Alkaline (adjective, “AL-kah-line”) This word describes a chemical that is basic. A basic chemical is one that produces hydroxide ions (-OH) in solution. These chemicals have a pH higher than 7.0. Explainer: What are acids and bases? The word “alkaline” comes from the word alkali, which refers to salts of alkali metals. Alkali metal salts…
  • A sea slug’s head can crawl around and grow a whole new body
    Losing your body from the neck down can be just another of life’s annoying — if temporary — setbacks. That is, if you’re one of two kinds of rippling, green-tinged sea slugs. Heads of Elysia cf. marginata sea slugs sometimes pull themselves free from their bodies. The heads just keep crawling around. Within a few…
  • New recycling technologies could keep more plastic out of landfills
    It feels good to recycle. When you sort soda bottles and plastic bags from the rest of your garbage, it seems like you’re helping the planet. The more plastic you put in the blue bin, the more you’re keeping out of landfills, right? Wrong. No matter how much plastic you try to recycle, most ends…
  • Explainer: What are chemical bonds?
    Imagine a glass jar holding 118 types of building blocks. Every type is a slightly different color, size and shape. And each represents an atom of a different element on the periodic table. With enough jars, you can use the blocks to build anything — as long as you follow a few simple rules. A…
  • Here’s why people picked certain stars as constellations
    The Big Dipper’s stars are a celestial landmark. Visible in the Northern Hemisphere’s night sky, the stars draw out a shape like a scoop with a handle. Beginner stargazers can easily pick it out. Now, scientists have shown that three factors can explain why certain groups of stars form such recognizable patterns. One is how…
  • Level up your demonstration: Make it an experiment
    Science demonstrations can be real crowd pleasers. In fact, Camille Schrier won the 2020 Miss America crown after performing a science demonstration during the talent portion of the competition. On stage, she mixed common chemicals to create massive mountains of steaming foam — a trick often called “elephant toothpaste.” It wowed the judges. But as…
  • Patterns in brain activity can identify who will struggle to read
    Reading involves several different areas of the brain. A new study finds that connections between these regions can predict how well someone reads. Surprisingly, new data show that the connections that develop while doing mental math computations also predict reading ability. Chris McNorgan works at the University at Buffalo in New York. As a cognitive…
  • Dinosaur-killing asteroid radically changed Earth’s tropical forests
    Some 66 million years ago, a very different type of rainforest thrived in what is now Colombia. Ferns unfurled. Towering conifers reached for the skies. Flowering shrubs bathed in the sunlight that streamed down to them through large gaps in the canopy between those trees. Then an asteroid crashed into Earth. Overnight, everything changed. The…
  • Scientists Say: Pi
    Pi (noun “pye”) This is a mathematical constant — a number whose value never changes. Symbolized by Greek letter π, pi is the ratio of a circle’s circumference — the distance around the outer edge — to its diameter, the length across its center. That ratio is always pi to one. The number pi is…
  • Several plant-like algae can morph into animal-like predators
    Many green algae are made of single cells. They tend to spend much of their day soaking up sunlight, turning it into energy. These swimming plankton appear plant-like. Unless, that is, one gobbles up a nearby bacterial cell. Now it has become an animal-like predator. When ecologist Eunsoo Kim first witnessed this back in 2013,…
  • Explainer: What is a neuron?
    It’s morning. As you sit up in bed, your feet touch the cold floor, so you lift them and put on your socks. In the kitchen, you watch the cereal pour from the box and hear it ping against the bowl. You tip in a stream of milk — carefully — because you spilled it…
  • Search for ‘rewards’ is big driver in remodeling a teen’s brain
    A limp red balloon floats on the computer screen before you. Clicking your mouse inflates it. The bigger it is when you stop, the more money you earn. But if it pops before you stop, you get nothing. Anna van Duijvenvoorde is a psychologist at Leiden University in the Netherlands. Her team uses computer games…
  • Light levitation might help explore Earth’s ‘ignorosphere’
    Two tiny discs rise upward, hovering in midair as bright light illuminates them. “I see it!” gasped Mohsen Azadi. He and several fellow PhD students cheered with excitement. They had helped to discover a new way to fly. There were no motors or propellers to lift the discs. Bright light had done the trick. It…
  • Ingenuity helicopter makes history by flying on Mars
    NASA has just flown a helicopter on Mars. Named Ingenuity, the craft hovered for about 40 seconds above the Red Planet’s surface. This marks the first flight of a spacecraft on a planet other than Earth. In the wee hours on April 19, the helicopter spun its rotor blades and ascended into the thin Martian…
  • Let’s learn about exercise
    Exercise might seem like a chore sometimes, especially when we get told so often that we should exercise more. But we need to get up and start moving. Many of us spend too much time sitting and staring at screens. Most teen girls don’t meet the standards for physical activity. Getting scolded about this, though,…
  • Earth as you’ve never seen it before
    When cartographers — people who make maps — set out to portray the Earth, they have to turn a 3-D sphere into a 2-D map. And that’s a lot harder than it sounds. Smooshing the globe into a flat image usually distorts lots of surface features. Some expand. Others shrink, sometimes by a lot. Now…
  • Scientists Say: Dinosaur
    Dinosaur (noun, “DIE-no-sore”) This is a member of a group of both living and extinct reptiles that are in the clade Dinosauria. A clade is a group of species that share a common ancestor. Dinosaurs appeared between 243 and 233 million years ago. Some grew to enormous size — such as the massive Dreadnoughtus (Dred-NAW-tus)…