The universe started with a bang — but how will it end? With astonishing visuals, cosmologist and TED Fellow Katie Mack takes us to the theoretical end of everything, some trillions of years in the future, in a profound meditation on existence, wonder and the legacy of humanity within the immensity of time and space.

Where’s the best free comedy show in town? Tom Sullam, cofounder of the annual Comedy Wildlife Photography Awards, shares hilarious animal photos that dissolve the distance between humans and nature. The result? A joyful case for caring about what we’re at risk of losing.

If a company plants trees to offset its pollution, is that climate progress — or is it greenwashing? Critics of carbon markets say it’s the latter. But Sandeep Roy Choudhury, who’s spent two decades financing climate projects from rural cookstoves to coastal forests, says the real failure is discouraging companies from even trying. Hear his case for why we shouldn’t let perfection block meaningful action on climate change. (Recorded at TED Countdown Summit 2025 on June 17, 2025)

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