Knowable

Bonus episode: 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. You can read more about interjections in the related article authored by Bob Holmes at Knowable Magazine. Find the transcript of this episode, plus other podcast episodes at knowablemagazine.org/podcast.

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

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

PODCAST: 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.

The journey to understanding these critically important molecules, in their thousands of different flavors, began with a chance discovery. Today, after decades of painstaking lab work and dizzying technological leaps, the field of protein science is exploding.

Freud thought that dreams were the gateway to our unconscious mind. Today, many scientists think the opposite: that the dreaming brain is quite similar to our awake, conscious state. But dreaming is a very personal experience and one that we can't share — making the phenomenon very difficult to study. We still don't know for sure why we dream, but in this episode, we'll hear how psychologists, neuroscientists and philosophers have been trying to answer that question. Hyperlinks to scientists and papers in mainbar

Memory, the mystery: Just in the past half-century, our understanding of how exactly our brains remember has taken huge leaps. Amazingly, this is just the beginning. The Knowable Magazine podcast from Annual Reviews explores the limits to what's knowable — and how thinking about big questions in science and technology evolve over time.

Replacing or assisting the human heart with a machine would save countless lives. But the quest to build an artificial heart has had many gruesome missteps and caused researchers to reimagine how to keep our blood flowing. The Knowable Magazine podcast from Annual Reviews explores the limits to what's knowable — and how thinking about big questions in science and technology evolve over time.