Episodi

  • Eternal Calcium

    Eternal Calcium
    Feb 20 2026
    Take a moment to look at your hands. Move them around, and watch how the bones work. Think about what your hands have done in your lifetime alone. They learned to write. Drove your first car. Took the hand of the person you’d marry. They work every day, in an office, shop, or laboratory. And they held, or will hold, your children for the very first time. Your hands will touch every part of your time on Earth— but the minerals that make them up are eternal. The calcium in the bones of your hands is older than Earth itself. It formed after the Big Bang through supernova explosions and became concentrated in rocky planets. Once on Earth, it may have spent 500 million years drifting in seawater, or passing through generations of ancient sea creatures. 200 million years more in the age of dinosaurs, making up the bones of tyrannosaurs or the eggshells of Pteranodons. Your calcium then journeyed through 100 million years of mammals—finally pausing for a geologic split second to form your hands. After your hands have held their last cup of coffee or played their last song, no matter how your remains are disposed of, your calcium will one day reenter the earth. Who knows where it might end up next? Perhaps it could pass through the bones of generations of future humans. One of whom just may take a tiny part of you, once again, to another galaxy.
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    2 min
  • Tiny Titan

    Tiny Titan
    Feb 20 2026
    By looking at fossilized dinosaur nests, scientists have determined that most dinosaur babies needed to be nurtured by their parents, like modern birds. However, a new discovery points to a different upbringing for some of the biggest dino species. Recently, paleontologists discovered the fossil of a baby titanosaur from Madagascar. As an adult, this species could grow to 50 ft long. Yet their eggs were smaller than soccer balls, and their hatchlings weighed just 7 lb. How did they get from the size of a human baby to bigger than a city bus? While the infants of many species look very different from adults, this fossil baby was almost a perfect copy. The scientists used CT scans to look inside its bones and discovered patterns of very rapid growth showing that, since hatching, it had added 10 times its weight in a matter of weeks. A study of its joints then showed it would have been much more agile than its lumbering parents. Taken together, its adultlike proportions, rapid growth, and athleticism suggest that this little sauropod—unlike humans—would have had to fend for itself right after hatching, like many modern lizards. Its ability to find large quantities of food to be able to grow that quickly must have been key to its success. Scientists still don’t know much about the parenting habits of dinosaurs, but this tiny titan is shedding new light.
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    2 min
  • Lithium Power

    Lithium Power
    Feb 20 2026
    If you look at Earth from space, you’ll see a mysterious white spot on the west side of South America, in Bolivia. It’s so big that it looks like a flaw in the satellite photo. But it’s actually the world’s largest deposit of lithium, which has eroded from the Andes Mountains to form an enormous salt flat. Lithium is a very special element. It’s the lightest metal, with an atomic number of 3. Only hydrogen and helium are lighter, and they’re gases. It’s also highly reactive, because its third electron, circling alone in an outer orbit, is eager to bond with other elements. These two qualities, light weight and reactivity, make it perfect for rechargeable batteries. In fact, the lithium-ion battery has changed the world. It has allowed portable computers and mobile phones to become increasingly lighter and smaller, fundamentally altering the way we work, communicate, and access information. Continued advances in lithium batteries are expected to make electric cars cheaper and lighter, with the ability to drive longer on a single charge. They may also lead to widespread power-grid batteries. These could provide better, more portable storage of electricity to stabilize the output of renewable energies, when the wind’s not blowing or the sun’s not shining. This has made lithium a highly valuable commodity and could turn the Bolivian salt flat, once a remote tourist destination, into a powerful economic resource for the world.
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    2 min
  • CSI Pliocene: Lucy

    CSI Pliocene: Lucy
    Feb 20 2026
    When did our ancestors leave the trees and begin to lead a life on solid ground? Some real life CSI has given us a big clue. Lucy—the 3-million-year-old skeleton of one of our oldest known human relatives—was recently on a museum tour of the United States. During her visit, University of Texas scientists examined her skeleton with geological CT scanners, similar to medical CAT scans but with higher resolution. Fossil bones often break as they’re buried, but Lucy’s upper arm showed something unusual. It was compressed, with sharp fracture lines and tiny bone fragments intact. The team called in an orthopedic surgeon, who confirmed that this injury in modern humans only occurs when they extend their arms to try to break a fall from considerable height. So they began to look for other fracture evidence of a fall—and found it, in her ankle, knee, pelvis, and ribs. They then looked to modern chimpanzees, which are about the same size as Lucy. Chimps nest in trees at heights of up to 35 ft, high enough that a fall could result in the same type and degree of fracturing found in Lucy. Further studies using the CT data showed that her ratio of arm strength to leg strength was more like chimps than humans. Both findings suggest that 3 million years ago, our ancestors may have lived a significant part of their lives in the trees.
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    2 min
  • Geodynamo

    Geodynamo
    Feb 20 2026
    You may remember that our magnetic field forms a protective bubble around Earth called the magnetosphere. It keeps solar winds and cosmic rays from scouring away our atmosphere, and protects spacecraft, satellites, astronauts, and air travelers. But where does the magnetic field come from? The inner core of Earth is very, very hot—about 6,000°C, the same as the surface of the sun. At that temperature, you’d expect it to be liquid or even gas. But because the pressure at the core is so extraordinary, about 2 million times what it is on the surface, the inner core stays solid. In fact, it’s 85 percent solid iron. The outer core of Earth is also mostly iron, but because the pressure is lower, it’s liquid. As lighter elements, at different temperatures, gradually rise through the liquid iron, they cause convection currents to form, like cream swirling in your coffee. Meanwhile, Earth’s rotation causes spinning eddies to develop. This somewhat-organized circulation of liquid metal creates electric currents, which charge Earth’s iron core, turning it into a giant electromagnet. The magnetic field in the core is thought to be more than 10 times stronger than on the surface —and strong enough to extend 400,000 miles into space. Which is what allows it to protect us from the hazards of space.
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    2 min
  • Diamond Data

    Diamond Data
    Feb 20 2026
    If you look inside a diamond, you may find something even more valuable than its spectacular brilliance. Diamonds form deep within Earth’s mantle, of pure carbon. Their atomic bonds are so strong that they’re Earth’s hardest mineral and our best conductor of heat. These properties make diamonds valuable for industrial purposes—like on drill bits or rock saws, or in electronics for extreme environments. But that’s not the big surprise. A diamond’s pure carbon structure makes it very clear. But sometimes trace amounts of boron or nitrogen, the elements on either side of carbon on the periodic table, will sneak in. Boron turns a diamond blue, like the famous Hope Diamond. Nitrogen turns it yellow. Normally, this would make a diamond less desirable. But it’s nitrogen that could make diamonds more valuable than ever. Scientists at the City College of New York have figured out how to activate the nitrogen with red and green lasers, allowing them to store and erase data in three dimensions along the diamond’s crystal structure, at the atomic level. Think about that. The technology is in its early stages, but researchers believe a diamond the size of a grain of rice could store the entire Library of Congress—five hundred times. Think about that. In the future, diamonds could open the possibility for tiny computers or medical devices to bring a shine to our lives that we can only imagine.
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    2 min
  • Great Extinctions

    Great Extinctions
    Feb 20 2026
    99.9 percent of all known species that have ever existed on Earth are gone—extinct. Most of them disappeared in five great extinction events. The first two happened several hundred million years ago. One was caused by a major ice age; the other, by falling oxygen levels in the world’s oceans. The next big extinction, 250 million years ago, is called the Great Dying, because 96 percent of living species were wiped out. This one, and the one that followed at 200 million years, seem to have been triggered by a hotter climate. There are many theories about what caused them, including meteorites, major lava flows, hydrate melts, and other climate events. Probably some of each. One thing is consistent: dying species left empty environmental niches, which surviving species could then evolve to fill. In this way, these two extinctions allowed dinosaurs to dominate Earth. Their rule lasted 200 million years, until volcanic activity started their decline. Then, around 65 million years ago, an asteroid famously hit Earth. Ash darkened the skies and plunged Earth into global winter, triggering the last great extinction. Dinosaurs died off, and small animals with warm blood had a huge advantage. This gave rise to the age of mammals, and some of them, millions of years later, became you and me. In this way, each extinction made it possible for new and often more advanced life forms to replace the old ones. Without that asteroid, we wouldn’t be here.
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    2 min
  • Life on a Giant Magnet

    Life on a Giant Magnet
    Feb 20 2026
    Compasses point north, by following Earth’s magnetic field. It’s amazing when you think about it—there’s an invisible force, flowing out of Earth’s South Pole and diving back into its north pole, pulling all compass needles to the north with it. Even more amazing is that the magnetic field is keeping us alive right now. Without it, there would be no life on Earth. We’re talking Mars. Here’s how it works: Our magnetic field is generated in Earth’s core. It flows outward through the crust and surrounds Earth like a giant bubble, called the magnetosphere, which extends more than 400,000 miles into space. But on the side that faces the sun, solar winds squash it down to just 40,000 miles. It’s the force of that magnetic field, pushing back against the solar winds, that keeps them from scouring away Earth’s atmosphere. Scientists even think that, billions of years ago when Earth was forming, our magnetic field helped trap the gases that made up our atmosphere in the first place. By contrast, when a planet loses its magnetic field, its atmosphere declines with it, like we see on Mars. Magnetic field means atmosphere means life on Earth. That’s pretty mind-blowing! So the next time you see a compass, take a moment to remind yourself that our lives are made possible because we’re living on a giant magnet.
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    2 min