3a:T54b,A 1970s Soviet spacecraft is hurtling down from space—and no one knows where it will land. All 28 of the most populous cities in the U.S. are slowly sinking. Investments and overconsumption make the wealthiest 10 percent of the global population responsible for two thirds of climate-change-related warming. Recommended reading: Cuttlefish May Communicate with Discolike Arm Gestures https://www.scientificamerican.com/article/cuttlefish-may-communicate-with-discolike-arm-gestures/ This Soviet Spacecraft Will Soon Crash-Land on Earth https://www.scientificamerican.com/article/what-to-know-about-kosmos-482-the-soviet-spacecraft-crash-landing-on-earth/ Tell us what you think! Take our survey for the chance to win some SciAm swag! http://sciencequickly.com/survey E-mail us at sciencequickly@sciam.com if you have any questions, comments or ideas for stories we should cover! Discover something new every day: subscribe to Scientific American and sign up for Today in Science, our daily newsletter. Science Quickly is produced by Rachel Feltman, Fonda Mwangi, Kelso Harper, Naeem Amarsy and Jeff DelViscio. This episode was hosted by Rachel Feltman. Our show is edited by Alex Sugiura with fact-checking by Shayna Posses and Aaron Shattuck. The theme music was composed by Dominic Smith. Learn more about your ad choices. Visit megaphone.fm/adchoices3b:T4c0,

Today, we’re letting the science rip in a seriously gassy showdown. It’s helium versus neon! One is famous for making balloons float and voices squeaky -- the other is prized for its beautiful glow. Brains On star Sanden Totten and science writer and comedian Kasha Patel go head to head in this elemental debate. Which team do you think won? Cast your vote at smashboom.org!

In the meantime, check out the Smash Boom Best Listening Party Kit here! And if you donate to the show, you’ll get to vote on the topic of this season’s bonus episode, which is only available to donors of the show. Support the show at smashboom.org/donate. Follow us on social at @SmashBoomBest on Twitter, Facebook, and Instagram!

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3c:T47b,Are chemical elements critical for the modern economy in dangerously short supply? It's a question that Justin Rowlatt poses a century and a half after the Russian chemist Dmitry Mendeleev published the original periodic table.Justin speaks to two chemists - Andrea Sella of University College London explains the significance of Mendeleev's scheme to the modern world, while David Cole-Hamilton talks us through an updated version of the table he has just published that highlights chemical elements that could run out within the next century unless we learn to make better use of them.However, perhaps we don't need to worry just yet, at least not for two of those red-flagged elements. Thomas Abraham-Jones describes how he happened across the world's biggest reserve of helium in the African savannah, while Rick Short of Indium Corporation explains why the metallic element his company is named after is in abundant supply, so long as you don't mind sifting an awful lot of dirt for it.Producer: Laurence Knight(Picture: Manuscript of Mendeleev's first periodic system of elements; Credit: Science & Society Picture Library/SSPL/Getty Images)3d:T58a,

The $1,000 balloon