I'm Steve Strogatz, and this is The Joy of Why, a podcast from Quantum Magazine that

takes you into some of the biggest unanswered questions in math and science today.

In this episode, we're going to ask, how will it all end?

Imagine you're walking along one day in the city, you're weaving in and

out of other pedestrians walking on the sidewalk, you hear cars honking, quiet conversations,

seeping out of coffee shops nearby. This is our everyday world as we know it. But what happens

if one day that world simply implodes and ceases to exist? What would it be

like if everything suddenly came to an end? We do know that stars, including our own sun, have a limited

lifespan. They'll burn out someday, even if it's not in our lifetime. But what about our galaxy,

or the entire universe?

What will the end of everything be like?

And how could it happen?

This isn't the makings of a superhero movie.

This is the type of theoretical physics that Dr. Katie Mack thinks about, a lot.

Dr. Mack is a theoretical cosmologist at the Perimeter Institute for Theoretical Physics in Waterloo, Canada, about an hour outside of Toronto.

She's the Stephen Hawking Chair in Cosmology and Science Communication Research, where one

of her goals is making physics more accessible to the public.

Dr. Mack also is the author of the well-received book, The End of Everything,

Astrophysically Speaking, published in August of 2020.

It details the five main theories of how scientists think the universe will end. Katie, thanks for joining us

today. Thank you very much for having me. It's a real treat for us. Can I start with a personal

question? What drew you to this topic thinking about the end of the universe? Why does that

...