Fifteen-year-old Tavi Gevinson had a hard time finding strong female, teenage role models — so she built a space where they could find each other. At TEDxTeen, she illustrates how the conversations on sites like Rookie, her wildly popular web magazine for and by teen girls, are putting a new, unapologetically uncertain and richly complex face on modern feminism. TEDTalks is a daily video podcast of the best talks and performances from the TED Conference, where the world's leading thinkers and doers give the talk of their lives in 18 minutes (or less). Look for talks on Technology, Entertainment and Design -- plus science, business, global issues, the arts and much more. Find closed captions and translated subtitles in many languages at http://www.ted.com/translate Follow TED news on Twitter: http://www.twitter.com/tednews Like TED on Facebook: https://www.facebook.com/TED Subscribe to our channel: http://www.youtube.com/user/TEDtalksDirector

View full lesson: http://ed.ted.com/lessons/how-optical-illusions-trick-your-brain-nathan-s-jacobs Optical illusions are images that seem to trick our minds into seeing something different from what they actually are. But how do they work? Nathan S. Jacobs walks us through a few common optical illusions and explains what these tricks of the eye can tell us about how our brains assemble visual information into the 3D world we see around us. Lesson by Nathan S. Jacobs, animation by TED-Ed.

In an unmissable talk about race and politics in America, Theo E.J. Wilson tells the story of becoming Lucius25, white supremacist lurker, and the unexpected compassion and surprising perspective he found from engaging with people he disagrees with. He encourages us to let go of fear, embrace curiosity and have courageous conversations with people who think differently from us. "Conversations stop violence, conversations start countries and build bridges," he says. Check out more TED Talks: http://www.ted.com The TED Talks channel features the best talks and performances from the TED Conference, where the world's leading thinkers and doers give the talk of their lives in 18 minutes (or less). Look for talks on Technology, Entertainment and Design -- plus science, business, global issues, the arts and more. Follow TED on Twitter: http://www.twitter.com/TEDTalks Like TED on Facebook: https://www.facebook.com/TED Subscribe to our channel: https://www.youtube.com/TED

While we like to imagine little green men, it’s far more likely that life on other planets will be microbial. Planetary scientist Nathalie Cabrol takes us inside the search for microbes on Mars, a hunt which counterintuitively leads us to the remote lakes of the Andes mountains. This extreme environment — with its thin atmosphere and scorched land — approximates the surface of Mars about 3.5 billion years ago. How microbes adapt to survive here may just show us where to look on Mars — and could help us understand why some microbial pathways lead to civilization while others are a dead end. TEDTalks is a daily video podcast of the best talks and performances from the TED Conference, where the world's leading thinkers and doers give the talk of their lives in 18 minutes (or less). Look for talks on Technology, Entertainment and Design -- plus science, business, global issues, the arts and much more. Find closed captions and translated subtitles in many languages at http://www.ted.com/talks/nathalie_cabrol_how_mars_might_hold_the_secret_to_the_origin_of_life Follow TED news on Twitter: http://www.twitter.com/tednews Like TED on Facebook: https://www.facebook.com/TED Subscribe to our channel: http://www.youtube.com/user/TEDtalksDirector