Original broadcast date: June 19, 2015. We live our lives by the calendar and the clock, but time is also an abstraction, even an illusion. In this hour, TED speakers explore how our sense of time changes depending on who and where we are. Guests include director Cesar Kuriyama, poet Rives, psychologists Dan Gilbert and Laura Carstensen, and cosmologist Sean Carroll.

Why do many of us hate, even fear math? Why are we convinced we're bad at it? This hour, TED speakers explore the myths we tell ourselves and how changing our approach can unlock the beauty of math. Guests include budgeting specialist Phylecia Jones, mathematician and educator Dan Finkel, math teacher Eddie Woo, educator Masha Gershman, and radio personality and eternal math nerd Adam Spencer.

Original broadcast date: August 25, 2017. How much of who we are is biology? How much is learned? And how much can we change? This hour, TED speakers on how genes and experience collaborate — and compete — to make us who we are. TED speakers include neuroscientist Robert Sapolsky, epigeneticist Moshe Szyf, pediatrician Nadine Burke Harris, and psychologist Brian Little.

What makes someone lucky? Can luck be controlled, is it random, or is it based on something else entirely? This hour, TED speakers explore ideas about why some people seem so much luckier than others. Guests include former professional poker player Liv Boeree, professor of entrepreneurship Tina Seelig, community activist Amy Hunter, journalist Mark Sutcliffe, and youth services advocate Eshauna Smith.

(Original broadcast date: June 16, 2017.) Many of us are lured by the promise of self-improvement, but find it hard to follow through. In our 100th episode, TED speakers reveal ways to discover our better selves. TED speakers include entrepreneur Jia Jang, Headspace co-founder Andy Puddicombe, psychologist Emily Balcetis, technologist Matt Cutts, and New York Times columnist David Brooks.

How does bias distort our thinking, our listening, our beliefs... and even our search results? How can we fight it? This hour, TED speakers explore ideas about the unconscious biases that shape us. Guests include writer and broadcaster Yassmin Abdel-Magied, climatologist J. Marshall Shepherd, journalist Andreas Ekström, and experimental psychologist Tony Salvador.

Original broadcast date: July 17, 2015. In a world with limited resources, can we find ways to salvage what's disappearing? Can we innovate our way out of a finite landscape? This hour, TED speakers explore ideas about living with less. Guests include ethnobotanist Mark Plotkin, ecologist Jon Foley, economist Ramanan Laxminarayan, community organizer Rob Hopkins, and researcher Navi Radjou.

The Me Too movement has changed the way we think and talk about gender discrimination. This hour, TED speakers explore how the conversation has moved beyond a hashtag, and where we go from here. Guests include Me Too movement founder Tarana Burke, actor and activist Ashley Judd, writer Laura Bates, and anti-sexism educator Jackson Katz.

(Original broadcast date: May 26, 2017). Helping others feels good, but why do some go farther than others? This hour, TED speakers explore ideas about altruism — what motivates us to be altruistic, what limits us and do we ever go too far. TED speakers include psychologist Abigail Marsh, clinical psychologist Cheryl Steed, philosopher Peter Singer, and writer Larissa MacFarquhar.

We often forget to say the words "thank you." But can those two words change how you — and those around you — look at the world? This hour, TED speakers on the power of gratitude and appreciation. Guests include author AJ Jacobs, author and former baseball player Mike Robbins, Dr. Laura Trice, Professor of Management Christine Porath, and former Danish politician Özlem Cekic.