"We're not in a clean energy revolution; we're in a clean energy crisis," says climate policy expert Michael Shellenberger. His surprising solution: nuclear. In this passionate talk, he explains why it's time to overcome longstanding fears of the technology, and why he and other environmentalists believe it's past time to embrace nuclear as a viable and desirable source of clean power.

What is a concussion? Probably not what you think it is. In this talk from the cutting edge of research, bioengineer (and former football player) David Camarillo shows what really happens during a concussion -- and why standard sports helmets don't prevent it. Here's what the future of concussion prevention looks like.

Is there life beyond Earth? Join NASA's director of planetary science James Green for a survey of the places in our solar system that are most likely to harbor alien life.

"Venus is too hot, Mars is too cold, and Earth is just right," says planetary scientist Dave Brain. But why? In this pleasantly humorous talk, Brain explores the fascinating science behind what it takes for a planet to host life -- and why humanity may just be in the right place at the right time when it comes to the timeline of life-sustaining planets.

"A forest is much more than what you see," says ecologist Suzanne Simard. Her 30 years of research in Canadian forests have led to an astounding discovery -- trees talk, often and over vast distances. Learn more about the harmonious yet complicated social lives of trees and prepare to see the natural world with new eyes.

Neuroengineer Ed Boyden wants to know how the tiny biomolecules in our brains generate emotions, thoughts and feelings -- and he wants to find the molecular changes that lead to disorders like epilepsy and Alzheimer's. Rather than magnify these invisible structures with a microscope, he wondered: What if we physically enlarge them and make them easier to see? Learn how the same polymers used to make baby diapers swell could be a key to better understanding our brains.

Throughout history, speculation has spurred beautiful, revolutionary science -- opening our eyes to entirely new universes. "I'm not talking about science that takes baby steps," says Eric Haseltine. "I'm talking about science that takes enormous leaps." In this talk, Haseltine passionately takes us to the edges of intellectual pursuit with two ideas -- one that's already made history, and the other that's digging into one of humanity's biggest questions with admirable ambition (and a healthy dose of skepticism from many).

TED Fellow Prosanta Chakrabarty explores hidden parts of the world in search of new species of cave-dwelling fish. These subterranean creatures have developed fascinating adaptations, and they provide biological insights into blindness as well as geological clues about how the continents broke apart million of years ago. Contemplate deep time in this short talk.

Wanda Diaz Merced studies the light emitted by gamma-ray bursts, the most energetic events in the universe. When she lost her sight and was left without a way to do her science, she had a revelatory insight: the light curves she could no longer see could be translated into sound. Through sonification, she regained mastery over her work, and now she's advocating for a more inclusive scientific community. "Science is for everyone," she says. "It has to be available to everyone, because we are all natural explorers."

Ninety-six percent of genome studies are based on people of European descent. The rest of the world is virtually unrepresented -- and this is dangerous, says geneticist and TED Fellow Keolu Fox, because we react to drugs differently based on our genetic makeup. Fox is working to democratize genome sequencing, specifically by advocating for indigenous populations to get involved in research, with the goal of eliminating health disparities. "The research community needs to immerse itself in indigenous culture," he says, "or die trying."