Worldchanging.com founder Alex Steffen argues that reducing humanity's ecological footprint is incredibly vital now, as the western consumer lifestyle spreads to developing countries. A quiz, thought provoking question, and links for further study are provided to create a lesson around the 10-minute video. Educators may use the platform to easily "Flip" or create their own lesson for use with their students of any age or level.

With wisdom and wit, Anupam Mishra talks about the amazing feats of engineering built centuries ago by the people of India's Golden Desert to harvest water. These structures are still used today -- and are often superior to modern water megaprojects. A quiz, thought provoking question, and links for further study are provided to create a lesson around the 17-minute video. Educators may use the platform to easily "Flip" or create their own lesson for use with their students of any age or level.

Science writer Margaret Wertheim re-creates the creatures of the coral reefs using a technique invented by a mathematician -- simultaneously celebrating the amazements of the reef, and deep-diving into the hyperbolic underpinnings of coral creation. A quiz, thought provoking question, and links for further study are provided to create a lesson around the 15-minute video. Educators may use the platform to easily "Flip" or create their own lesson for use with their students of any age or level.

In this visually dazzling talk, Jonathan Drori shows the extraordinary ways flowering plants -- over a quarter million species -- have evolved to attract insects to spread their pollen: growing 'landing-strips' to guide the insects in, shining in ultraviolet, building elaborate traps, and even mimicking other insects in heat. Jonathan Drori commissioned the BBC's very first websites, one highlight in a long career devoted to online culture and educational media -- and understanding how we learn. A quiz, thought provoking question, and links for further study are provided to create a lesson around the 14-minute video. Educators may use the platform to easily "Flip" or create their own lesson for use with their students of any age or level.

David McCandless turns complex data sets (like worldwide military spending, media buzz, Facebook status updates) into beautiful, simple diagrams that tease out unseen patterns and connections. Good design, he suggests, is the best way to navigate information glut -- and it may just change the way we see the world. A quiz, thought provoking question, and links for further study are provided to create a lesson around the 18-minute video. Educators may use the platform to easily "Flip" or create their own lesson for use with their students of any age or level.

MIT researcher Deb Roy wanted to understand how his infant son learned language -- so he wired up his house with videocameras to catch every moment (with exceptions) of his son's life, then parsed 90,000 hours of home video to watch "gaaaa" slowly turn into "water." Astonishing, data-rich research with deep implications for how we learn. Deb Roy studies how children learn language, and designs machines that learn to communicate in human-like ways. On sabbatical from MIT Media Lab, he's working with the AI company Bluefin Labs. A quiz, thought provoking question, and links for further study are provided to create a lesson around the 20-minute video. Educators may use the platform to easily "Flip" or create their own lesson for use with their students of any age or level.

"Rock-star physicist" Brian Cox talks about his work on the Large Hadron Collider at CERN. Discussing the biggest of big science in an engaging, accessible way, Cox brings us along on a tour of the massive project. A quiz, thought provoking question, and links for further study are provided to create a lesson around the 15-minute video. Educators may use the platform to easily "Flip" or create their own lesson for use with their students of any age or level.

Physicist Brian Greene explains superstring theory, the idea that minscule strands of energy vibrating in 11 dimensions create every particle and force in the universe. A quiz, thought provoking question, and links for further study are provided to create a lesson around the 19-minute video. Educators may use the platform to easily "Flip" or create their own lesson for use with their students of any age or level.

Capt. Charles Moore of the Algalita Marine Research Foundation first discovered the Great Pacific Garbage Patch -- an endless floating waste of plastic trash. Now he's drawing attention to the growing, choking problem of plastic debris in our seas. A quiz, thought provoking question, and links for further study are provided to create a lesson around the 7-minute video. Educators may use the platform to easily "Flip" or create their own lesson for use with their students of any age or level.

By dissecting a cockroach ... yes, live on stage ... TED Fellow and neuroscientist Greg Gage shows how brains receive and deliver electric impulses -- and how legs can respond. A quiz, thought provoking question, and links for further study are provided to create a lesson around the 6-minute video. Educators may use the platform to easily "Flip" or create their own lesson for use with their students of any age or level.

Your body is made of cells -- but how does a single cell know to become part of your nose, instead of your toes? The answer is in your body's instruction book: DNA. Joe Hanson compares DNA to detailed manual for building a person out of cells -- with 46 chapters (chromosomes) and hundreds of thousands of pages covering every part of you.

What's so special about Leonardo da Vinci's Vitruvian Man? With arms outstretched, the man fills the irreconcilable spaces of a circle and a square -- symbolizing the Renaissance-era belief in the mutable nature of humankind. James Earle explains the geometric, religious and philosophical significance of this deceptively simple drawing.

In the deepest, darkest parts of the oceans are ecosystems with more diversity than a tropical rainforest. Taking us on a voyage into the ocean -- from the deepest trenches to the remains of the Titanic -- marine biologist David Gallo explores the wonder and beauty of marine life. A quiz, thought provoking question, and links for further study are provided to create a lesson around the 8-minute video. Educators may use the platform to easily "Flip" or create their own lesson for use with their students of any age or level.

Psychologist Philip Zimbardo asks, "Why are boys struggling?" He shares some stats (lower graduation rates, greater worries about intimacy and relationships) and suggests a few reasons -- and challenges the TED community to think about solutions. A quiz, thought provoking question, and links for further study are provided to create a lesson around the 5-minute video. Educators may use the platform to easily "Flip" or create their own lesson for use with their students of any age or level.

Leslie Dodson's research focuses on the intersection of micro-enterprise and digital technologies in developing communities. She brings more than 25 years of experience and insight from a career as a broadcast journalist to the academic community. Leslie has been posted to Tokyo, London, New York and throughout Latin America, where she covered high-tech and bio-tech for CNBC and MSNBC, and international finance and the global emerging markets for CNN, NHK-Tokyo and Reuters. Along with covering international business, Leslie has reported on environmental issues from the Arctic, India, Nepal, Ecuador, Burundi and Uganda. A quiz, thought provoking question, and links for further study are provided to create a lesson around the 21-minute video. Educators may use the platform to easily "Flip" or create their own lesson for use with their students of any age or level.

Is the beloved paper dictionary doomed to extinction? In this infectiously exuberant talk, leading lexicographer Erin McKean looks at the many ways today's print dictionary is poised for transformation. As the CEO and co-founder of new online dictionary Wordnik, Erin McKean is reshaping not just dictionaries, but how we interact with language itself. A quiz, thought provoking question, and links for further study are provided to create a lesson around the 16-minute video. Educators may use the platform to easily "Flip" or create their own lesson for use with their students of any age or level.

Using newts, coyotes and mice, Jason Munshi-South shows how animals develop genetic differences in evolution, even within an urban city. A quiz, thought provoking question, and links for further study are provided to create a lesson around the 5-minute video. Educators may use the platform to easily "Flip" or create their own lesson for use with their students of any age or level.

In this video interview with Francine Christophe, a Holocaust survivor, you will learn about her experience as an eight-year-old Jewish girl at Bergen-Belsen camp. You'll be amazed to learn about her selfless act, and the great reward that she experiences years after being liberated.

Why do transnational extremist organizations succeed where democratic movements have a harder time taking hold? Maajid Nawaz, a former Islamist extremist, asks for new grassroots stories and global social activism to spread democracy in the face of nationalism and xenophobia. A powerful talk from TEDGlobal 2011. A quiz, thought provoking question, and links for further study are provided to create a lesson around the 18-minute video. Educators may use the platform to easily "Flip" or create their own lesson for use with their students of any age or level.

Ted Talk: On March 15th, 44 BCE, Roman dictator Julius Caesar was assassinated by a group of about 60 of his own senators. Why did these self-titled Liberators want him dead? And why did Brutus, whose own life had been saved by Caesar, join in the plot? Kathryn Tempest investigates the personal and political assassination of Julius Caesar.