Ever gaze up at the starry night sky? This stunning view is at risk of disappearing -- unless we act now, says astrophysicist Kelsey Johnson. In this fascinating, unexpectedly funny talk, she explains how light pollution affects almost every species on earth (including us) and shares five "stupidly simple" things you can do to help solve the problem.

How do you raise money to get an idea off the ground, support a community, or help change the world? Take a crash course on the secret art of successful fundraising with development strategist Kara Logan Berlin as she shows how you can learn to ask for the resources you need -- and get them, too.

What kinds of stories move us to act? To answer this question, creative technologist Heidi Boisvert is measuring how people's brains and bodies unconsciously respond to different media. She shows how she's using this data to determine the specific narrative ingredients that inspire empathy and justice -- and spark large-scale social change.

Alejandro Durán uses art to spotlight the ongoing destruction of our oceans' ecosystems. In this breathtaking talk, he shows how he meticulously organizes and reuses plastic waste from around the world that washes up on the Caribbean coast of Mexico -- everything from water bottles to prosthetic legs -- to create vivid, environmental artworks that may leave you mesmerized and shocked.

Ever wondered how your smartphone works? Take a journey down to the atomic level with scientist Cathy Mulzer, who reveals how almost every component of our high-powered devices exists thanks to chemists -- and not the Silicon Valley entrepreneurs that come to most people's minds. As she puts it: "Chemistry is the hero of electronic communications."

Have you ever doubted your abilities, feared you were going to be discovered as a "fraud"? That's called "impostor syndrome," and you're definitely not alone in feeling it, says entrepreneur and CEO Mike Cannon-Brookes. In this funny, relatable talk, he shares how his own experiences of impostor syndrome helped pave the way to his success -- and shows how you can use it to your advantage, too.

In India (and many other countries), girls and women still find themselves silenced by traditional rules of politeness and restraint, says social scientist Deepa Narayan. In this frank talk, she identifies seven deeply entrenched norms that reinforce inequality -- and calls on men to help usher in change.

What happens when humans and robots make art together? In this awe-inspiring talk, artist Sougwen Chung shows how she "taught" her artistic style to a machine -- and shares the results of their collaboration after making an unexpected discovery: robots make mistakes, too. "Part of the beauty of human and machine systems is their inherent, shared fallibility," she says.

Could the strange orbits of small, distant objects in our solar system lead us to a big discovery? Planetary astronomer Mike Brown proposes the existence of a new, giant planet lurking in the far reaches of our solar system -- and shows us how traces of its presence might already be staring us in the face.

As many as 3,000 languages could disappear within the next 80 years, all but silencing entire cultures. In this quick talk, language activist Daniel Bögre Udell shows how people around the world are finding new ways to revive ancestral languages and rebuild their traditions -- and encourages us all to investigate the tongues of our ancestors. "Reclaiming your language and embracing your culture is a powerful way to be yourself," he says.