Numbers get their due credit in this podcast. Even if we're not aware of them, numbers are essential to how we experience the world. IDEAS explores the most bizarre, surprising, mind-blowing and fundamental numbers in the universe.

This panel discussion was recorded live at The Perimeter Institute for Theoretical Physics in Waterloo, Ontario.

Guests in this episode:

Asimina Arvanitaki is a particle physicist and the aristarchus chair in theoretical physics at the Perimeter Institute.

Ben Webster is an associate professor in the pure mathematics department at the University of Waterloo, and he’s also an associate faculty member at the Perimeter Institute.

Matthew Johnson is a professor of physics and astronomy at York University, and he's also an associate faculty member at the Perimeter Institute.

That's not something you expect to hear in an interview. But the Harvard historian and author of All That She Carried, Tiya Miles did not hesitate to say these words to IDEAS host, Nahlah Ayed. What prompted the bold statement comes down to a question — seemingly for Miles the perfect one to ask.

Their conversation resonated with many listeners, including a potter in Australia who shares how this story sustains him after the loss of his wife. Also in this podcast, we find out how IDEAS inspires everything from sonnets, to art, and to recreating historic feasts.

*This is the second episode in our 60th anniversary series. It originally aired on Dec. 2, 2025.There's more to listen to here:

How an IDEAS episode on traffic changed a doctor's practice

CBC Massey Lecturers reveal how the talks changed them

How IDEAS saved a listener from sending a regrettable email

The best — and worst — ideas of the last six decades

Not many people like to think about traffic but Joanna Oda says this very topic on IDEAS in 2005 permanently changed the way she views medical care as a doctor. "It helped me understand how things that make sense for you as an individual contribute to a collective problem." She adds, the episode introduced her to the idea that one car has a big impact.

This episode is the first episode in our special week-long series to mark our 60th anniversary. It originally aired on Dec. 1, 2025.

Listen to other episodes in this series:

The time when a guest said, "I love you!"

CBC Massey Lecturers reveal how the talks changed them

How IDEAS saved a listener from sending a regrettable email

The best — and worst — ideas of the last six decades

If you inherited $120 million dollars, could you give away 75 per cent of your wealth? Abigail Disney did. She's an heiress to the Disney fortune. The philanthropist, filmmaker and activist offers an insider perspective into the twisted perils of extreme wealth — on society and the human psyche.

Part two in a series called The Billionaire Age. Listen to Part One: How did we get here?

*Please note: Part three will be available as a podcast on June 8 at 5 pm.

Guest in this episode:

Abigail E. Disney is an award-winning filmmaker, writer, philanthropist, and activist. Her films include The American Dream and Other Fairy Tales, the Emmy Award-winning The Armor of Light — both co-directed with Kathleen Hughes — and Pray the Devil Back to Hell. As a philanthropist and activist, she has championed peacebuilding, gender justice, and systemic cultural change.

She is Chair and Co-Founder of Level Forward, an ecosystem of storytellers, entrepreneurs, and social change-makers dedicated to balancing artistic vision, social impact, and stakeholder return. She also founded Peace is Loud, a nonprofit that uses storytelling to advance social movements, and the Daphne Foundation, which supports organizations working for a more equitable, fair, and peaceful New York City.

She is currently working on a book about wealth, power, and privilege.

For the past decade, Canadians have been split 50/50 on new pipelines — that's changed. Two recent opinion polls found roughly three quarters of eligible voters in Canada want at least one new pipeline built to export more fossil fuels. Yet, 70 per cent of people consider climate change a serious threat. IDEAS producer Tom Howell explores the incompatibilities and future scenarios. *This episode originally aired on Oct. 7, 2025.

If you liked this episode, you may want to listen to this podcast: A machine that could save us from war — and global warming

Renowned natural history writer Robert Macfarlane traveled to Ecuador, India and Quebec, pondering the question of whether rivers are living beings — the premise behind much of the movement to legally recognize the rights of nature. He found that the answer to that question is more complicated and wondrous — and more life-altering and world-changing — than he could have imagined. *This episode originally aired on Sept. 3, 2025.

Alexandria has been the source of invention, innovation, and beauty for millennia — capturing the imagination of Napoleon, the Prophet Muhammad and, of course, Alexander the Great. He envisioned a place that thrived on cultural, intellectual, economic, political and religious exchange. IDEAS examines the big ideas of this port city in Egypt with Islam Issa, author of Alexandria: The City That Changed the World.

Part three in our ongoing series about how port cities shaped the world as we know it.

Listen to Part Two: How port cities of Elmina shaped the world

Listen to Part One: How port cities like Singapore shaped the world

Egg freezing is considered a kind of "fertility insurance" for the future — a way to buy more time to make a decision about having a family. However, as IDEAS contributor Alison Motluk discovers, uncertainty around parenthood is just one of many reasons why egg freezing is one of the fastest-growing reproductive technologies in the world. She explores those reasons and digs into the social politics, gender realities, and big business of egg freezing.*This episode originally aired Oct. 22, 2025.

If you liked this episode, you might want to listen to Birth gives us life. But do you know its history?