Corals in the Pacific Ocean have been dying at an alarming rate, particularly from bleaching brought on by increased water temperatures. But it's not too late to act, says TED Fellow Kristen Marhaver. She points to the Caribbean -- given time, stable temperatures and strong protection, corals there have shown the ability to survive and recover from trauma. Marhaver reminds us why we need to keep working to protect the precious corals we have left. "Corals have always been playing the long game," she says, "and now so are we."

A handful of people working at a handful of tech companies steer the thoughts of billions of people every day, says design thinker Tristan Harris. From Facebook notifications to Snapstreaks to YouTube autoplays, they're all competing for one thing: your attention. Harris shares how these companies prey on our psychology for their own profit and calls for a design renaissance in which our tech instead encourages us to live out the timeline we want.

Loneliness doesn't always stem from being alone. For architect Grace Kim, loneliness is a function of how socially connected we feel to the people around us -- and it's often the result of the homes we live in. She shares an age-old antidote to isolation: cohousing, a way of living where people choose to share space with their neighbors, get to know them, and look after them. Rethink your home and how you live in it with this eye-opening talk.

The divisiveness plaguing American politics today is nothing new, says constitutional law scholar Noah Feldman. In fact, it dates back to the early days of the republic, when a dispute between Alexander Hamilton and James Madison led the two Founding Fathers to cut ties and form the country's first political parties. Join Feldman for some fascinating history of American factionalism -- and a hopeful reminder about how the Constitution has proven itself to be greater than partisanship.