Scientists just discovered oxygen being produced without sunlight — without photosynthesis — at the bottom of the ocean. This “dark oxygen” could fundamentally change the story we tell of life on Earth and in the rest of the universe. Guest: Alycia Smith, ecologist at Heriot-Watt University For show transcripts, go to vox.com/unxtranscripts For more, go to vox.com/unexplainable And please email us! unexplainable@vox.com We read every email. Support Unexplainable by becoming a Vox Member today: vox.com/members Learn more about your ad choices. Visit podcastchoices.com/adchoices

For decades, search and rescue teams followed an accepted playbook. Now, scientists are helping them reimagine how to find lost people. Guests: Robert Koester, author of Lost Person Behavior, and Paul Doherty, search and rescue researcher For show transcripts, go to vox.com/unxtranscripts For more, go to vox.com/unexplainable And please email us! unexplainable@vox.com We read every email. Support Unexplainable by becoming a Vox Member today: vox.com/members Learn more about your ad choices. Visit podcastchoices.com/adchoices

Inflation is one of the most significant issues shaping the 2024 election. But how much can we actually do to control it? For show transcripts, go to vox.com/unxtranscripts For more, go to vox.com/unexplainable And please email us! unexplainable@vox.com We read every email. Support Unexplainable by becoming a Vox Member today: vox.com/members Please take a second to help us learn more about you! vox.com/podcastsurvey Learn more about your ad choices. Visit podcastchoices.com/adchoices

Venus is the hottest, scariest planet in the solar system, but billions of years ago it may have been a lot like Earth, complete with an ocean of water. So, how did Venus go to hell? And could Earth be next? This is the final episode of our four-part series, Lost Worlds, and it originally ran on December 1, 2021. For more, go to http://vox.com/unexplainable It’s a great place to view show transcripts and read more about the topics on our show. Also, email us! unexplainable@vox.com We read every email. Support Unexplainable by making a financial contribution to Vox! bit.ly/givepodcasts Learn more about your ad choices. Visit podcastchoices.com/adchoices Learn more about your ad choices. Visit podcastchoices.com/adchoices

Mars was once a very different planet, with rivers, lakes, and — potentially — life. NASA’s latest Mars rover is on a mission to find traces of past life. What happens if it does? This is the third episode of our new four-part series, Lost Worlds. For more, go to http://vox.com/unexplainable It’s a great place to view show transcripts and read more about the topics on our show. Also, email us! unexplainable@vox.com We read every email. Support Unexplainable by making a financial contribution to Vox! bit.ly/givepodcasts Learn more about your ad choices. Visit podcastchoices.com/adchoices

In all our searching of the universe, we’ve never seen another moon like ours. It's big, it's weird, it's played a huge role in shaping our planet. But how did we get it? Every possible story points to cataclysm. This is the second episode of our new four-part series, Lost Worlds. For more, go to http://vox.com/unexplainable It’s a great place to view show transcripts and read more about the topics on our show. Also, email us! unexplainable@vox.com We read every email. Support Unexplainable by making a financial contribution to Vox! bit.ly/givepodcasts Learn more about your ad choices. Visit podcastchoices.com/adchoices

Was there a technologically advanced species living on Earth long before humans? And if one had existed, how would we know? This is the first episode of our new four-part series, Lost Worlds. For more, go to http://vox.com/unexplainable It’s a great place to view show transcripts and read more about the topics on our show. Also, email us! unexplainable@vox.com We read every email. Support Unexplainable by making a financial contribution to Vox! bit.ly/givepodcasts Learn more about your ad choices. Visit podcastchoices.com/adchoices Learn more about your ad choices. Visit podcastchoices.com/adchoices

Insect populations are shrinking all over the world, and entomologists are buzzing with questions: Why is this happening? How quickly? And, most concerningly, what does it mean for food supplies or even life as we know it? For more, go to http://vox.com/unexplainable It’s a great place to view show transcripts and read more about the topics on our show. Also, email us! unexplainable@vox.com We read every email. Support Unexplainable by making a financial contribution to Vox! bit.ly/givepodcasts Learn more about your ad choices. Visit podcastchoices.com/adchoices Learn more about your ad choices. Visit podcastchoices.com/adchoices

A groundbreaking study claims to have found a way for a fully paralyzed person to communicate entirely via thought. Today, Explained breaks down the science and asks: Is it too good to be true? For more, go to http://vox.com/unexplainable It’s a great place to view show transcripts and read more about the topics on our show. Also, email us! unexplainable@vox.com We read every email. Support Unexplainable by making a financial contribution to Vox! bit.ly/givepodcasts Learn more about your ad choices. Visit podcastchoices.com/adchoices

Dreams are weird, but can they be a scientific tool? Can they teach us anything about humanity? About ourselves? For more, go to http://vox.com/unexplainable It’s a great place to view show transcripts and read more about the topics on our show. Also, email us! unexplainable@vox.com We read every email. Support Unexplainable by making a financial contribution to Vox! bit.ly/givepodcasts Learn more about your ad choices. Visit podcastchoices.com/adchoices

What are the scientific, family, and privacy implications? For more, go to http://vox.com/unexplainable It’s a great place to view show transcripts and read more about the topics on our show. Also, email us! unexplainable@vox.com We read every email. Support Unexplainable by making a financial contribution to Vox! bit.ly/givepodcasts Learn more about your ad choices. Visit podcastchoices.com/adchoices

Octopuses are largely solitary animals, but there have been rare times — notably in the movie My Octopus Teacher — where they seem to have become comfortable around humans. But is it really possible to be friends with an octopus? For more, go to http://vox.com/unexplainable It’s a great place to view show transcripts and read more about the topics on our show. Also, email us! unexplainable@vox.com We read every email. Support Unexplainable by making a financial contribution to Vox! bit.ly/givepodcasts Learn more about your ad choices. Visit podcastchoices.com/adchoices

Most deep-water creatures are bioluminescent. Marine biologist Edie Widder has spent the last 40 years trying to figure out why. For more, go to http://vox.com/unexplainable It’s a great place to view show transcripts and read more about the topics on our show. Also, email us! unexplainable@vox.com We read every email. Support Unexplainable by making a financial contribution to Vox! bit.ly/givepodcasts Learn more about your ad choices. Visit podcastchoices.com/adchoices

It’s hard to figure out the economic value of a wild bat or any other part of the natural world, but some scientists argue that this kind of calculation could help protect our environment. For show transcripts, go to vox.com/unxtranscripts For more, go to vox.com/unexplainable And please email us! unexplainable@vox.com We read every email. Support Unexplainable by becoming a Vox Member today: vox.com/members Learn more about your ad choices. Visit podcastchoices.com/adchoices

In the 1920s, the scientist Werner Heisenberg came up with a wild idea that broke reality as Western science knew it. And it's still unsettling to think about. Benjamin Labatut's recent book, When We Cease to Understand the World, makes readers feel the aftershocks of the revelation, asking, "What's real?" For more, go to http://vox.com/unexplainable It’s a great place to view show transcripts and read more about the topics on our show. Also, email us! unexplainable@vox.com We read every email. Support Unexplainable by making a financial contribution to Vox! bit.ly/givepodcasts Learn more about your ad choices. Visit podcastchoices.com/adchoices

Why stop at five senses? Just how much of the world can we perceive? And how much is out there that’s still out of reach, hiding in the dark? This is the sixth and final episode of our six-part series, Making Sense. For more, go to http://vox.com/unexplainable It’s a great place to view show transcripts and read more about the topics on our show. Also, email us! unexplainable@vox.com We read every email. Support Unexplainable by making a financial contribution to Vox! bit.ly/givepodcasts Learn more about your ad choices. Visit podcastchoices.com/adchoices

Close your eyes and try to imagine an apple. Can you see anything? Aphantasia is the inability to see with your mind’s eye. Since it was discovered, scientists have been asking the question: What is the mind’s eye even for? This is the fifth episode of our six-part series, Making Sense. For more, go to http://vox.com/unexplainable It’s a great place to view show transcripts and read more about the topics on our show. Also, email us! unexplainable@vox.com We read every email. Support Unexplainable by making a financial contribution to Vox! bit.ly/givepodcasts Learn more about your ad choices. Visit podcastchoices.com/adchoices

For thousands of years, there have been four basic tastes recognized across cultures. But thanks to Kumiko Ninomiya (a.k.a. the Umami Mama), scientists finally accepted a fifth. So could there be even more? This is the fourth episode of our six-part series, Making Sense. For more, go to http://vox.com/unexplainable It’s a great place to view show transcripts and read more about the topics on our show. Also, email us! unexplainable@vox.com We read every email. Support Unexplainable by making a financial contribution to Vox! bit.ly/givepodcasts Learn more about your ad choices. Visit podcastchoices.com/adchoices

Dogs can smell cancer, Covid-19, and many other health problems in humans. Now, scientists are trying to duplicate these powers in robotic sniffers. But there’s a big challenge here: Scientists don’t really understand how smell works. This is the third episode of our six-part series, Making Sense, and it originally ran on March 10, 2021. For more, go to http://vox.com/unexplainable It’s a great place to view show transcripts and read more about the topics on our show. Also, email us! unexplainable@vox.com We read every email. Support Unexplainable by making a financial contribution to Vox! bit.ly/givepodcasts Learn more about your ad choices. Visit podcastchoices.com/adchoices

Doctors can save the lives of premature infants, but the process is often painful. Luckily, a solution might be as simple as a parent’s loving touch. This is the second episode of our new six-part series, Making Sense. For more, go to http://vox.com/unexplainable It’s a great place to view show transcripts and read more about the topics on our show. Also, email us! unexplainable@vox.com We read every email. Support Unexplainable by making a financial contribution to Vox! bit.ly/givepodcasts Learn more about your ad choices. Visit podcastchoices.com/adchoices

In the same way optical illusions trick our eyes, audio illusions can trick our ears. This raises a fundamental question: What is hearing, and how much of it is made up by our brains? This is the first episode of our new six-part series, Making Sense. You can find more of Diana Deutsch’s auditory illusions at https://bit.ly/3Mdh6H4, Matthew Winn's research at http://www.mattwinn.com/Research.html, and Mike Chorost's writing at https://michaelchorost.com For more, go to http://vox.com/unexplainable It’s a great place to view show transcripts and read more about the topics on our show. Also, email us! unexplainable@vox.com We read every email. Support Unexplainable by making a financial contribution to Vox! bit.ly/givepodcasts Learn more about your ad choices. Visit podcastchoices.com/adchoices

Methane traps more than 80 times as much heat as CO2 over the short term. So we could make a real difference on climate change this decade if we could stop leaking so much methane into the atmosphere. But before researchers and regulators can figure out how to do that, the methane hunters need to find the leaks. For more, go to http://vox.com/unexplainable It’s a great place to view show transcripts and read more about the topics on our show. Also, email us! unexplainable@vox.com We read every email. Support Unexplainable by making a financial contribution to Vox! bit.ly/givepodcasts Learn more about your ad choices. Visit podcastchoices.com/adchoices

Can science help us predict whether a relationship will succeed? Or is it all just chaos? For more, go to http://vox.com/unexplainable It’s a great place to view show transcripts and read more about the topics on our show. Also, email us! unexplainable@vox.com We read every email. Support Unexplainable by making a financial contribution to Vox! bit.ly/givepodcasts Learn more about your ad choices. Visit podcastchoices.com/adchoices

What does it sound like on Mars? On Jupiter? Titan? This collaboration between the podcast Twenty Thousand Hertz and the composer Melodysheep imagines the soundscapes of other worlds. For more, go to http://vox.com/unexplainable It’s a great place to view show transcripts and read more about the topics on our show. Also, email us! unexplainable@vox.com We read every email. Support Unexplainable by making a financial contribution to Vox! bit.ly/givepodcasts Learn more about your ad choices. Visit podcastchoices.com/adchoices

Seventy-five percent of the seafloor remains unmapped and unexplored, but the first few glimpses scientists have gotten of the ocean’s depths have completely revolutionized our understanding of the planet. For show transcripts, go to vox.com/unxtranscripts For more, go to vox.com/unexplainable And please email us! unexplainable@vox.com We read every email. Support Unexplainable by becoming a Vox Member today: vox.com/members Please take a second to help us learn more about you! vox.com/podcastsurvey Learn more about your ad choices. Visit podcastchoices.com/adchoices

Scientists are constantly searching for asteroids that could crash into Earth. But if they find one, will they be able to do anything about it? NASA has launched a spaceship that will slam into an asteroid to find out. For more, go to http://vox.com/unexplainable It’s a great place to view show transcripts and read more about the topics on our show. Also, email us! unexplainable@vox.com We read every email. Support Unexplainable by making a financial contribution to Vox! bit.ly/givepodcasts Learn more about your ad choices. Visit podcastchoices.com/adchoices

When scientists examined the DNA of ancient bones found near a Himalayan lake, they were forced to confront a seemingly impossible conclusion. This episode originally ran on March 24, 2021. For more, go to http://vox.com/unexplainable It’s a great place to view show transcripts and read more about the topics on our show. Also, email us! unexplainable@vox.com We read every email. Support Unexplainable by making a financial contribution to Vox! bit.ly/givepodcasts Learn more about your ad choices. Visit podcastchoices.com/adchoices

In 2017, researchers published an explosive finding: Sperm counts may be declining in some countries around the world. Media outlets began worrying about a potential Spermageddon, but other researchers have pumped the brakes. Because scientists know surprisingly little about sperm. Also, Noam created a list on the Hark podcast app where he talked about some of his favorite bitesize moments of the show so far. And it’s easy to share with friends! https://bit.ly/3tib6pd For more, go to http://vox.com/unexplainable It’s a great place to view show transcripts and read more about the topics on our show. Also, email us! unexplainable@vox.com We read every email. Support Unexplainable by making a financial contribution to Vox! bit.ly/givepodcasts Learn more about your ad choices. Visit podcastchoices.com/adchoices

Scientists are closer than ever to harnessing fusion power — the same process that powers the sun — by essentially making a small star here on Earth. Fusion could give humanity its best shot at solving the climate crisis, but the technology has yet to be perfected and would require billions more in investments. Is it worth the bet? For more, go to http://vox.com/unexplainable It’s a great place to view show transcripts and read more about the topics on our show. Also, email us! unexplainable@vox.com We read every email. Support Unexplainable by making a financial contribution to Vox! bit.ly/givepodcasts Learn more about your ad choices. Visit podcastchoices.com/adchoices

Noam wrote an end-of-year song with Today, Explained host Sean Rameswaram, so we thought to drop it here as a little end-of-year surprise. Lyrics: 2021, it was gonna be fun Get a couple shots and then you’re done Then the second the year’d begun We had an insurrection 2021, it was gonna be fun Get a couple shots and then you’re done Then the second the year’d begun We had an insurrection Yeah it wasn’t just what we hoped to see We might have started too optimistically So if we keep our expectations low Maybe the world won’t seem so terrible Yeah it wasn’t just what we hoped to see We might have started too optimistically So if we keep our expectations low Maybe the world won’t seem so terrible Dial back to when the year had begun We were looking forward to the end of hibernation  But it didn’t even last a week No it didn’t even last a week, mm-hmm On the sixth day of 2021 Vanilla Isis tried to flip the election But looking back we can’t agree  On the facts, no, we can’t agree, mm-mm Pretty soon we were signing up for shots (shots!) Talking about shots (shots!) Shots shots shots (shots!) Everyone was a pharma fan With the Pfizer fam, the Moderna clan (J&J) But we should have known Delta would happen  Most of humanity not getting vaxxed and Fourth wave — fifth wave, in rhythm That’s one more wave than feminism! 2021, it was gonna be fun Get a couple shots and then you’re done But according to Joe Ro-gun You should take Ivermectin Yeah it wasn’t just what we hoped to see We might have started too optimistically But if we keep our expectations low Maybe the world won’t seem so terrible A booster, I’m not sure I need it.  Dune on the IMAX, I seen it. Back to the good life, I dreamed it. (Arrakis) Wake up, reality, don’t fit. Hope you don’t need a house or a condo (a condo) Hope you don’t need a trip to Toronto (Toronto) Hope you don’t need some gas for your Durango (Durango)  Hope you don’t need a can of dried mangos (dried mangos) Everyone is feeling frustration Quitting jobs — the Great Resignation Blaming Biden for rising inflation While billionaires shoot off to space, racing Did we fix the grid in Texas? (yes) Figure out how wide the Suez is? (yes) Don’t ask me All I see on TV  It's just fights on Critical Race Theory 2021, it was gonna be fun Get a couple shots and then you’re done Moving onto issue number one: Whether to allow abortions! Yeah it wasn’t just what we hoped to see We might have started too optimistically But if we keep our expectations low Maybe the world won’t seem so terrible I just want to be free Of thinking about Covid-19 I just want to see Something done about global warming And I still don’t get NFT’s Can’t understand crypto currency and And we can’t agree on anything But at least we got together to free Britney (Oh baby baby) 2021, it was gonna be fun Get a couple shots and then you’re done Then the second as the year’d begun We had an insurrection And people lied about the last election And made it harder to vote in elections At least we don’t have another election Wait, I think there’s another election... 2021, it was gonna be fun Get a couple shots and then you’re done Then the second we thought we’d won We’re learning how to say "Omicron" Guess you never know what’s gonna come through Making plans for things you’ll never do  But take it from a brown guy (and a Jew) There’s always 2022. This song was written and performed by Sean Rameswaram and Noam Hassenfeld, produced by Noam, engineered by Efim Shapiro, and features additional vocals from Christina Animashaun. For more, go to http://vox.com/unexplainable It’s a great place to view show transcripts and read more about the topics on our show. Also, email us! unexplainable@vox.com We read every email. Support Unexplainable by making a financial contribution to Vox! bit.ly/givepodcasts Learn more about your ad choices. Visit podcastchoices.com/adchoices

Most of the matter in the universe is dark matter, an invisible, untouchable, mysterious substance. Scientists don’t know what exactly dark matter is, despite decades of searching. But recently, they got a new clue in the form of an extremely tiny dancer. This episode is a remix of two prior episodes of Unexplainable, which has been airing on broadcast radio through a partnership with American Public Media. For more, go to http://vox.com/unexplainable It’s a great place to view show transcripts and read more about the topics on our show. Also, email us! unexplainable@vox.com We read every email. Support Unexplainable by making a financial contribution to Vox! bit.ly/givepodcasts Learn more about your ad choices. Visit podcastchoices.com/adchoices

How can we solve the problem of ocean plastic if we don’t know where most of the plastic is? For more, go to http://vox.com/unexplainable It’s a great place to view show transcripts and read more about the topics on our show. Also, email us! unexplainable@vox.com We read every email. Support Unexplainable by making a financial contribution to Vox! bit.ly/givepodcasts Learn more about your ad choices. Visit podcastchoices.com/adchoices

Until 1993, many researchers excluded women from clinical drug trials, leaving doctors in the dark about how new treatments work in more than half the population. This is the story of why that happened, the women who fought to change it, and what we still don’t know about how sex and gender affect health. For more, go to http://vox.com/unexplainable It’s a great place to view show transcripts and read more about the topics on our show. Also, email us! unexplainable@vox.com We read every email. Support Unexplainable by making a financial contribution to Vox! bit.ly/givepodcasts Learn more about your ad choices. Visit podcastchoices.com/adchoices

Venus is the hottest, scariest planet in the solar system, but billions of years ago it may have been a lot like Earth, complete with an ocean of water. So, what killed Venus? And could Earth be next? For more, go to http://vox.com/unexplainable It’s a great place to view show transcripts and read more about the topics on our show. Also, email us! unexplainable@vox.com We read every email. Support Unexplainable by making a financial contribution to Vox! bit.ly/givepodcasts Learn more about your ad choices. Visit podcastchoices.com/adchoices

Will scientists ever fully understand the human brain? In their quest for knowledge, they’ve tried knives, magnets, computers, blood, and even a good metaphor. For more, go to http://vox.com/unexplainable It’s a great place to view show transcripts and read more about the topics on our show. Also, email us! unexplainable@vox.com We read every email. Support Unexplainable by making a financial contribution to Vox! bit.ly/givepodcasts Learn more about your ad choices. Visit podcastchoices.com/adchoices

If you just stood up and shouted, “It’s Mount Everest, duh!” then take a seat. Not only is Everest’s official height constantly changing, but three other mountains might actually be king of the hill. For show transcripts, go to vox.com/unxtranscripts For more, go to vox.com/unexplainable And please email us! unexplainable@vox.com We read every email. Support Unexplainable by becoming a Vox Member today: vox.com/members Please take a second to help us learn more about you! vox.com/podcastsurvey Learn more about your ad choices. Visit podcastchoices.com/adchoices

Slime molds can navigate mazes, control robots, and make complicated decisions, all without a central nervous system. If this weird gooey blob can think, does that mean scientists are thinking about intelligence all wrong? For more, go to http://vox.com/unexplainable It’s a great place to view show transcripts and read more about the topics on our show. Also, email us! unexplainable@vox.com We read every email. Support Unexplainable by making a financial contribution to Vox! bit.ly/givepodcasts Learn more about your ad choices. Visit podcastchoices.com/adchoices

Every year, thousands of marine mammals end up trapped on beaches, but it’s often hard to figure out why. It’s even harder to figure out how much humans are to blame. For more, go to http://vox.com/unexplainable It’s a great place to sign up for our newsletter, view show transcripts, and read more about the topics on our show. Also, email us! unexplainable@vox.com We read every email. Support Unexplainable by making a financial contribution to Vox! bit.ly/givepodcasts Learn more about your ad choices. Visit podcastchoices.com/adchoices

Why do so many people think they can see and hear ghosts, and what does that say about our conscious experience of the world? For more, go to http://vox.com/unexplainable It’s a great place to sign up for our newsletter, view show transcripts, and read more about the topics on our show. Also, email us! unexplainable@vox.com We read every email. Support Unexplainable by making a financial contribution to Vox! bit.ly/givepodcasts Learn more about your ad choices. Visit podcastchoices.com/adchoices

A recent study of tens of thousands of birds has shown that birds are growing smaller over time. It could be due to climate change, and if so, we ought to consider: How else might humans be altering the literal shape of life on Earth — now and in the future? For more, go to http://vox.com/unexplainable It’s a great place to sign up for our newsletter, view show transcripts, and read more about the topics on our show. Also, email us! unexplainable@vox.com We read every email. Support Unexplainable by making a financial contribution to Vox! bit.ly/givepodcasts Learn more about your ad choices. Visit podcastchoices.com/adchoices

The Nobel Prize has rewarded some amazing discoveries. It’s also contributed to scientific tunnel vision. This week, how the Nobel impacted our understanding of an enormous cosmic mystery, and what a new and improved Nobel Prize could look like. For more, go to http://vox.com/unexplainable It’s a great place to sign up for our newsletter, view show transcripts, and read more about the topics on our show. Also, email us! unexplainable@vox.com We read every email. Support Unexplainable by making a financial contribution to Vox! bit.ly/givepodcasts Learn more about your ad choices. Visit podcastchoices.com/adchoices

To look into deep space is to look back in time. With the upcoming launch of the James Webb Space Telescope, scientists hope to see “cosmic dawn,” a period long ago when the first starlight transformed the universe. But what happened before cosmic dawn? The Webb can’t tell us, though future telescopes could. For more, go to http://vox.com/unexplainable It’s a great place to sign up for our newsletter, view show transcripts, and read more about the topics on our show. Also, email us! unexplainable@vox.com We read every email. Support Unexplainable by making a financial contribution to Vox! bit.ly/givepodcasts Learn more about your ad choices. Visit podcastchoices.com/adchoices

After decades of planning, NASA is finally (finally!) set to launch the successor to the Hubble. The new Webb telescope will be a paradigm shift for astronomy, exploring places in the cosmos that have been completely invisible to us until now. But first, it has to safely reach a point nearly a million miles away from the Earth. For more, go to http://vox.com/unexplainable It’s a great place to sign up for our newsletter, view show transcripts, and read more about the topics on our show. Also, email us! unexplainable@vox.com We read every email. Support Unexplainable by making a financial contribution to Vox! bit.ly/givepodcasts Learn more about your ad choices. Visit podcastchoices.com/adchoices

For decades, Alzheimer’s researchers have been stubbornly pursuing a single theory, but they’re starting to wonder: is this narrow focus the reason we still don’t have a cure? For more, go to http://vox.com/unexplainable It’s a great place to sign up for our newsletter, view show transcripts, and read more about the topics on our show. Also, email us! unexplainable@vox.com We read every email. Support Unexplainable by making a financial contribution to Vox! bit.ly/givepodcasts Learn more about your ad choices. Visit podcastchoices.com/adchoices

Several years after US diplomats in Cuba claimed they were attacked by an invisible weapon, similar incidents continue to be reported around the world. Scientists haven’t been able to determine a definitive cause, but the possibilities point toward something just as mysterious as the illness itself: the inner workings of the human brain. For more, go to http://vox.com/unexplainable It’s a great place to sign up for our newsletter, view show transcripts, and read more about the topics on our show. Also, email us! unexplainable@vox.com We read every email. bit.ly/givepodcasts Learn more about your ad choices. Visit podcastchoices.com/adchoices

Once upon a time, there were no anuses. These ingenious organs allowed our primordial ancestors to grow bigger and more complex, but scientists still don’t understand how they evolved. And they’re still grasping at a mystery that literally surrounds it: Why is the human butt so big? For more go to http://vox.com/unexplainable It's a great place to sign up for our newsletter, view show transcripts, and read more about the topics on our show. Also email us! unexplainable@vox.com We read every email. Support Unexplainable by making a financial contribution to Vox! bit.ly/givepodcasts Learn more about your ad choices. Visit podcastchoices.com/adchoices

Way back when forests first evolved on Earth … they might have triggered one of the biggest mass extinctions in the history of the planet. What can we learn from this ancient climate apocalypse? For show transcripts, go to vox.com/unxtranscripts For more, go to vox.com/unexplainable And please email us! unexplainable@vox.com We read every email. Support Unexplainable by becoming a Vox Member today: vox.com/members Please take a second to help us learn more about you! vox.com/podcastsurvey Learn more about your ad choices. Visit podcastchoices.com/adchoices

This common chronic condition — where tissue similar to what grows inside the uterus grows elsewhere in the body — is barely understood. So why is a condition so prevalent and painful still so unknown? It has a lot to do with who gets to ask research questions. Correction, August 18: An earlier version of this episode implied that the tissue involved in endometriosis is the same as the endometrium, which lines the uterus. It is similar tissue, but not identical. For more, go to http://vox.com/unexplainable It’s a great place to sign up for our newsletter, view show transcripts, and read more about the topics on our show. Also, email us! unexplainable@vox.com We read every email. Support Unexplainable by making a financial contribution to bit.ly/givepodcasts Learn more about your ad choices. Visit podcastchoices.com/adchoices

Two scientists. A billion-dollar wager. One unanswered question: Is the first human who will live to 150 already alive? The technology to make that happen may already be in development. But if it works, there will be new, unsettling questions for humankind to answer. For more, go to http://vox.com/unexplainable It’s a great place to sign up for our newsletter, view show transcripts, and read more about the topics on our show. Also, email us! unexplainable@vox.com We read every email. Support Unexplainable by making a financial contribution to Vox! bit.ly/givepodcasts Learn more about your ad choices. Visit podcastchoices.com/adchoices

Earlier this year, Nicole Yamase explored the bottom of the Challenger Deep, the deepest place in the ocean, where few people have ever been. The rest of the seafloor is almost as mysterious — 80 percent remains unmapped — but the few glimpses scientists have gotten have completely revolutionized our understanding of the planet. For more, go to http://vox.com/unexplainable It’s a great place to sign up for our newsletter, view show transcripts, and read more about the topics on our show. Also, email us! unexplainable@vox.com We read every email. Support Unexplainable by making a financial contribution to Vox! bit.ly/givepodcasts Learn more about your ad choices. Visit podcastchoices.com/adchoices