Going the whole nine yards, dressing to the nines, being on cloud nine. In pop culture, in ancient folklore, in music, even in sports the number nine is everywhere. In the last episode of our series, The Greatest Numbers of All Time, we explore nine and its uncanny connections. *This episode originally aired on Sept. 29, 2023.

Five: a simple, easy number with a diabolical side. As we continue our series, The Greatest Numbers of All Time, meet the Janus-faced figure of five and find out how the number has acquired its personality for people in the arts and sciences. *This episode originally aired on Sept. 28, 2023.

From curses to charms to incantations and evocations, speaking thrice gives power — today, and in the ancient past. As our number series continues, we enter the powerful and spiritual realm of three. *This episode originally aired on Sept. 27, 2023.

It's a time of reflection and looking ahead. Host Nahlah Ayed invites IDEAS producers into the studio to share ideas they are working on for 2025. You’ll hear about income inequality, Nietzsche, the power of itch, the intrigue of the yellow traffic light and the fascinating story of Henry Box Brown — an enslaved man from Virginia who mailed himself to freedom.

It's nothing — and it's everywhere. Zero has confounded humanity for thousands of years. On IDEAS, we explore the infinite danger and promise of the void in a series called The Greatest Numbers of All Time. *This episode originally aired on Sept. 26, 2023.

A childhood full of Christmasses in Wales has left IDEAS producer Tom Howell pining for a certain kind of nostalgic poem this winter. So he turns to poets to put into words a strange feeling of homesickness, nostalgia, and yearning. *This episode originally aired on December 17, 2020.

A profile of the legendary jazz drummer and composer Jerry Granelli who passed away in 2021. Over his career, he accompanied many of the greats: Mose Allison, Sly Stone and The Grateful Dead. Most famously, he was a member of the Vince Guaraldi Trio that recorded the iconic album: A Charlie Brown Christmas. *This episode originally aired on December 21, 2021.

Christmas is a minefield of deep philosophical quandaries, like — is it ethically correct to lie to children? Who does a gift really benefit the giver, or receiver? How do we really know Santa exists, or doesn't? Join us on a dramatic journey through the philosophy of Christmas. *This episode originally aired on December 23, 2020.