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EarthDate

EarthDate

Auteur(s): Switch Energy Alliance
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 EarthDate is a short-format weekly audio program delivering concise, science-based stories about the Earth: its geology, environments, and the processes that shape our planet over deep time and today. Beginning in 2026, EarthDate is managed by Switch Energy Alliance and hosted by SEA's founder Dr. Scott W. Tinker. Together, we explore earth systems, natural resources, and their relevance to everyday life, with a focus on clear, accessible science education for broad audiences. EarthDate is written and directed by Emmy-winning filmmaker Harry Lynch, and researched by Lynn Kistler. We search for captivating stories to remind listeners that science can enlighten, educate and entertain.Copyright 2026 EarthDate
Épisodes
  • The Star of India

    The Star of India
    Feb 27 2026
    In October 1964, three young thieves cased the American Museum of Natural History in New York City. They returned that night to scale the museum wall, climb through a bathroom window, and steal 22 of the most precious jewels in the world. Among them were the Eagle Diamond, the DeLong Star Ruby, and, most famous of all, the Star of India sapphire. Sapphires are a variety of corundum, the third-hardest mineral. Pure corundum is clear, but when colored blue by titanium impurities, it’s called a sapphire. When colored red by chromium, it’s a ruby. Mineral inclusions in a sapphire sometimes line up along its crystal lattice to reflect light in a six-pointed star. The Star of India, besides being huge and nearly flawless, has stars that are visible from top and bottom. The thieves didn’t go far with it, renting a luxury apartment near the museum. An informant tipped off the police, who raided the place and captured one of them. The other two fled to Florida; the cops pursued and, a few days later, apprehended them, too—but not before they dispersed the jewels. The Eagle Diamond was never recovered, probably cut into several smaller stones. The philanthropist John D. MacArthur, paid a ransom to have the DeLong Ruby returned to the museum. One of the thieves finally led detectives to the Star of India, which they found with several smaller gems in a wet leather bag in a bus-station locker. It’s Earth’s near-flawless creations that humans still value the most…
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    2 min
  • Green Iceland/Icy Greenland

    Green Iceland/Icy Greenland
    Feb 27 2026
    If you’ve been to Iceland, you know it doesn’t have much ice. In fact, there’s so much grass that on maps it’s colored green. On the other hand, you probably know that Greenland is covered in glaciers. So why is the green one Iceland and the white one Greenland? Legend has it that the Vikings who discovered Iceland wanted to protect it from settlement, so gave it an unflattering name. But it was actually a matter of perspective. The first explorer to Iceland had a terrible trip. His daughter died on the long voyage. He arrived in winter and his livestock froze. That spring, his ship was nearly sunk by icebergs. Fed up, he called it as he saw it: Iceland. And the name stuck. A century later, another Viking explorer was visiting Iceland when he got in a fight with the settlers and was run off the island. He sailed west and found Greenland, which was warmer than today, and the coastal areas were indeed green. Wanting to attract settlers, he called it Greenland. They came, and built farms and grazing operations—which lasted until around 1400, when the climate cooled. Greenland’s glaciers expanded, leaving less green land. Today the Arctic is warming, which means Greenland’s glaciers are melting, and it may one day be greener again. Conversely, cold glacial meltwater entering the ocean from Greenland could blunt the Gulf Stream that warms Iceland, making it icier.
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    2 min
  • Tuskless Elephants

    Tuskless Elephants
    Feb 27 2026
    We often think that evolution takes thousands of years. But in rare cases where humans impact small populations, adaptation can work much faster. Take the case of the tuskless elephant. Nearly all male elephants and most females have tusks. These are just elongated lateral incisors that grow outward once the elephant loses its baby teeth. But a small percentage of elephants are born without these teeth and never develop tusks. In 1919, the South African government brought trophy hunters to the East Cape to exterminate elephants that were eating crops and trampling farms. By 1931, only eight females survived, and half were tuskless—perhaps because they made the least attractive trophies. Instead of natural selection, this was human selection. Fortunately, public opinion forced a change of heart and a preserve was established to protect the elephants. The tuskless matriarchs had tuskless offspring, and today nearly all female elephants in the park lack tusks. A similar thing happened in Mozambique. During a 15-year civil war, soldiers poached elephants for their meat to feed the troops and for their ivory to sell to buy more weapons. Again, elephants with tusks were killed, and by the end of the war, half the females were tuskless. As the population has rebounded, a large portion of females remain without tusks. But with the hunting pressure off, experts think natural selection may again favor animals with tusks—and both groups may eventually become tusked again.
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    2 min
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