Digging — quite literally — into our planet’s past to study its paleoclimate has shed light on bygone ice ages and hints at trouble ahead for our now-warming planet.

The history of climate change offers clues to Earth’s future

They started out so small, one could fit on the palm of your hand, but to make groundbreaking discoveries, physicists had to think really big — as in, vast machines with the power and capacity to reveal the tiniest building blocks of our universe.

How particle accelerators came to be

Serendipitous discoveries led to drugs like Prozac and to new insights into the physical basis of this debilitating disorder. But scientists continue to search for deeper understandings and therapies that will bring relief to those who still struggle.

IMAGE CREDIT: LIGHTLY STRANDED / SHUTTERSTOCK.COM

How antidepressants changed ideas about depression

La Troglodytes aedon es una pequeña ave de color café que se encuentra a lo largo de todo el continente americano. Un estudio realizado en Costa Rica reveló que estas aves cambian su canto en la ciudad para contrarrestar los efectos del ruido que producimos los humanos.  Aquí se puede escuchar su canto, captado en las inmediaciones de la Universidad de Costa Rica, en San José, por el ornitólogo Luis Sandoval Vargas. CRÉDITO: LUIS SANDOVAL VARGAS

Troglodytes aedon (house wren) is a small brown bird found throughout the Americas. A study conducted in Costa Rica revealed that these birds change their song in the city to counteract the effects of noise produced by humans.  Here you can hear their song, captured in the vicinity of the University of Costa Rica, in San José, by ornithologist Luis Sandoval Vargas. CREDIT: LUIS SANDOVAL VARGAS

Canto de un sotorré / The song of the house wren

A key report to President Lyndon B. Johnson in 1965 warned that humankind was “unwittingly conducting a vast geophysical experiment” through the burning of fossil fuels and a consequent buildup of “the invisible pollutant” — carbon dioxide — in the atmosphere. Here’s the story of what happened next to that report — and what didn’t, and why.

Host Adam Levy speaks with Harvard science historian Naomi Oreskes,coauthor of the book Merchants of Doubt: How a Handful of Scientists Obscured the Truth on Issues from Tobacco Smoke to Global Warming. And he talks with environmental scientist Dana Nuccitelli, research coordinator for Citizens’ Climate Lobby, which aims to build political will for climate solutions through citizen volunteers. 

Find the transcript and additional resources at knowablemagazine.org/podcast

Scientists warned about climate change in 1965. Nothing was done.

The fossil Archaeopteryx forever changed our understanding of dinosaurs and the origin of birds, but it took a century after its discovery and a one-page paper to shift scientific consensus. Here’s the story of that landmark 1973 article by American paleontologist John Ostrom, and published in the journal Nature, describing the bird-like features of Archaeopteryx and convincingly arguing that birds were descended from a group of dinosaurs called theropods. 

Host Charlotte Stoddart speaks with paleontologist Julia Clarke of the University of Texas at Austin, whose own research focuses on the early evolution of birds and the origin of flight. 

Find the transcript and additional resources at knowablemagazine.org/podcast.

The fossil that launched a dinosaur revolution

Sloppy by modern standards — and maybe even those back then — a 1955 article on the placebo effect by Harvard anesthesiologist Henry K. Beecher was nonetheless remarkable and influential. It paved the way for sounder drug trials and pushed scientists to better understand how we process pain. To explore its significance, Host Charlotte Stoddart enlisted the help of Ted Kaptchuk, director of the Program in Placebo Studies at the Beth Israel Deaconess Medical Center in Boston, who knows the paper well.

How the placebo effect went mainstream

Quantum mechanics has always included mind-bending ideas. But the concept of quantum entanglement, famously termed “spooky at a distance” by Albert Einstein in a 1947 letter, seemed to challenge the limits of belief. It remained well on the edges of modern physics until John Stewart Bell’s 1964 paper suggesting a way to actually test the baffling idea that two particles can somehow share a measured property even when well separated. 

Host Adam Levy chats with Nicolas Gisin of the University of Geneva about Einstein’s quote, Bell’s test and why it took so many decades for entanglement, the focus on the 2022 Nobel Prize in Physics, to go mainstream. Plus, how the phenomenon could help secure communications with your bank.

Find the transcript and additional resources at knowablemagazine.org/podcast

Quantum entanglement’s long journey from ‘spooky’ to law of nature

This short audio clip of an AI-generated conversation contains a couple examples of interjection slip-ups. In the first example, the listener interjects in an inappropriate way. In the second, the “expert” of the interview flips from one “person” to the other.
You can read more about interjections in the related article authored by Bob Holmes at Knowable Magazine:
https://knowablemagazine.org/content/article/mind/2025/interjections-important-for-conversation-flow

How AI slips up when using speech interjections

Knowable Magazine Podcast co-host Adam Levy talks with linguists Mark Dingemanse and Martina Wiltschko about the importance of the little “throwaway” utterances we use during conversations — such as Mmhmm, Huh? and more. Long ignored by scholarship, these interjections, as they’re termed, are key to keeping conversations flowing. But that realization was recent, because much of early linguistics research was done with written text and not actual, live conversations. Find the transcript and additional resources at knowablemagazine.org/podcast
You can read more about interjections in the related article authored by Bob Holmes at Knowable Magazine:
https://knowablemagazine.org/content/article/mind/2025/interjections-important-for-conversation-flow

Speech interjections aren’t throwaway lines

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The fossil that launched a dinosaur revolution

Knowable Magazine

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