Architect Alastair Parvin presents a simple but provocative idea: what if, instead of architects creating buildings for those who can afford to commission them, regular citizens could design and build their own houses? The concept is at the heart of WikiHouse, an open source construction kit that means just about anyone can build a house, anywhere.

Thinking about death is frightening, but planning ahead is practical and leaves more room for peace of mind in our final days. In a solemn, thoughtful talk, Judy MacDonald Johnston shares 5 practices for planning for a good end of life.

In art school, Phil Hansen developed an unruly tremor in his hand that kept him from creating the pointillist drawings he loved. Hansen was devastated, floating without a sense of purpose. Until a neurologist made a simple suggestion: embrace this limitation ... and transcend it.

If youre lucky enough to live without want, its a natural impulse to be altruistic to others. But, asks philosopher Peter Singer, whats the most effective way to give? He talks through some surprising thought experiments to help you balance emotion and practicality -- and make the biggest impact with whatever you can share.

Its not a demo, more of a philosophical argument: Why did Sergey Brin and his team at Google want to build an eye-mounted camera/computer, codenamed Glass? Onstage at TED2013, Brin calls for a new way of seeing our relationship with our mobile computers -- not hunched over a screen but meeting the world heads-up.

Why cant two slices of pizza be used as a slide clicker? Why shouldnt you make music with ketchup? In this charming talk, inventor Jay Silver talks about the urge to play with the world around you. He shares some of his messiest inventions, and demos MaKey MaKey, a kit for hacking everyday objects.

Can a person disappear in plain sight? That’s the question Liu Bolin‘s remarkable work seems to ask. The Beijing-based artist is sometimes called “The Invisible Man” because in nearly all his art, Bolin is front and center — and completely unseen. He aims to draw attention to social and political issues by dissolving into the background.

In our digital world, social relations have become mediated by data. Without even realizing it, we’re barricading ourselves against strangeness -- people and ideas that dont fit the patterns of who we already know, what we already like and where we’ve already been. A call for technology to deliver us to what and who we need, even if it’s unfamiliar. (Filmed at TED@Intel.)

Clinical psychologist Meg Jay has a bold message for twentysomethings: Contrary to popular belief, your 20s are not a throwaway decade. In this provocative talk, Jay says that just because marriage, work and kids are happening later in life, doesn’t mean you can’t start planning now. She gives 3 pieces of advice for how twentysomethings can re-claim adulthood in the defining decade of their lives.

Sir Ken Robinson outlines 3 principles crucial for the human mind to flourish -- and how current education culture works against them. In a funny, stirring talk he tells us how to get out of the educational "death valley" we now face, and how to nurture our youngest generations with a climate of possibility.

Leaving a high-flying job in consulting, Angela Lee Duckworth took a job teaching math to seventh graders in a New York public school. She quickly realized that IQ wasn’t the only thing separating the successful students from those who struggled. Here, she explains her theory of “grit” as a predictor of success.

In a heart-melting moment, TED Talks Education host John Legend sits at the piano to sing "True Colors," giving the lyrics a special meaning for kids and teachers. "So dont be afraid / to let them show / your true colors / are beautiful, like a rainbow."

Why, why, why does our education system look so similar to the way it did 50 years ago? Millions of students were failing then, as they are now -- and it’s because we’re clinging to a business model that clearly doesn’t work. Education advocate Geoffrey Canada dares the system to look at the data, think about the customers and make systematic shifts in order to help greater numbers of kids excel.

Young poet, educator and activist Malcom London performs his stirring poem about life on the front lines of high school. He tells of the “oceans of adolescence” who come to school “but never learn to swim,” of “masculinity mimicked by men who grew up with no fathers.” Beautiful, lyrical, chilling.

Pearl Arredondo grew up in East Los Angeles, the daughter of a high-ranking gang member who was in and out of jail. Many teachers wrote her off as having a problem with authority. Now a teacher herself, she’s creating a different kind of school and telling students her story so that they know its okay if sometimes homework isn’t the first thing on their minds.

It took a life-threatening condition to jolt chemistry teacher Ramsey Musallam out of ten years of “pseudo-teaching” to understand the true role of the educator: to cultivate curiosity. In a fun and personal talk, Musallam gives 3 rules to spark imagination and learning, and get students excited about how the world works.

Until recently, many teachers only got one word of feedback a year: “satisfactory.” And with no feedback, no coaching, there’s just no way to improve. Bill Gates suggests that even great teachers can get better with smart feedback -- and lays out a program from his foundation to bring it to every classroom.

For foreigners, learning to speak Chinese is a hard task. But learning to read the beautiful, often complex characters of the Chinese written language may be less difficult. ShaoLan walks through a simple lesson in recognizing the ideas behind the characters and their meaning -- building from a few simple forms to more complex concepts. Call it Chineasy.

In this well-argued talk, Timothy Bartik makes the macro-economic case for preschool education -- and explains why you should be happy to invest in it, even if you dont have kids that age (or kids at all). The economic benefits of well-educated kids, it turns out, go well beyond the altruistic. (Filmed at TEDxMiamiUniversity.)

Rita Pierson, a teacher for 40 years, once heard a colleague say, "They dont pay me to like the kids." Her response: "Kids dont learn from people they don’t like.’” A rousing call to educators to believe in their students and actually connect with them on a real, human, personal level.

What if Andy Warhol had it wrong, and instead of being famous for 15 minutes, we’re only anonymous for that long? In this short talk, Juan Enriquez looks at the surprisingly permanent effects of digital sharing on our personal privacy. He shares insight from the ancient Greeks to help us deal with our new “digital tattoos.”

Economics PhD Sebastião Salgado only took up photography in his 30s, but the discipline became an obsession. His years-long projects beautifully capture the human side of a global story that all too often involves death, destruction or decay. Here, he tells a deeply personal story of the craft that nearly killed him, and shows breathtaking images from his latest work, Genesis, which documents the worlds forgotten people and places.

Taylor Wilson was 14 when he built a nuclear fusion reactor in his parents garage. Now 19, he returns to the TED stage to present a new take on an old topic: fission. Wilson, who has won backing to create a company to realize his vision, explains why hes so excited about his innovative design for small modular fission reactors -- and why it could be the next big step in solving the global energy crisis.

Nilofer Merchant suggests a small idea that just might have a big impact on your life and health: Next time you have a one-on-one meeting, make it into a "walking meeting" -- and let ideas flow while you walk and talk.

Tech columnist David Pogue shares 10 simple, clever tips for computer, web, smartphone and camera users. And yes, you may know a few of these already -- but theres probably at least one you dont.

When we drive, we get into a glass bubble, lock the doors and press the accelerator, relying on our eyes to guide us -- even though we can only see the few cars ahead of and behind us. But what if cars could share data with each other about their position and velocity, and use predictive models to calculate the safest routes for everyone on the road? Jennifer Healey imagines a world without accidents. (Filmed at TED@Intel.)

As machines take on more jobs, many find themselves out of work or with raises indefinitely postponed. Is this the end of growth? No, says Erik Brynjolfsson -- it’s simply the growing pains of a radically reorganized economy. A riveting case for why big innovations are ahead of us … if we think of computers as our teammates. Be sure to watch the opposing viewpoint from Robert Gordon.

The US economy has been expanding wildly for two centuries. Are we witnessing the end of growth? Economist Robert Gordon lays out 4 reasons US growth may be slowing, detailing factors like epidemic debt and growing inequality, which could move the US into a period of stasis we cant innovate our way out of. Be sure to watch the opposing viewpoint from Erik Brynjolfsson.

Does texting mean the death of good writing skills? John McWhorter posits that there’s much more to texting -- linguistically, culturally -- than it seems, and it’s all good news.

Remember the days you struggled just to make a yo-yo spin, and if you were really fancy, to “walk the dog”? You ain’t seen nothin’ yet. Japanese yo-yo world champion BLACK tells the inspiring story of finding his lifes passion, and gives an awesome performance that will make you want to pull your yo-yo back out of the closet.

Deep brain stimulation is becoming very precise. This technique allows surgeons to place electrodes in almost any area of the brain, and turn them up or down -- like a radio dial or thermostat -- to correct dysfunction. Andres Lozano offers a dramatic look at emerging techniques, in which a woman with Parkinsons instantly stops shaking and brain areas eroded by Alzheimers are brought back to life. (Filmed at TEDxCaltech.)

When Joshua Prager was 19, a devastating bus accident left him a hemiplegic. He returned to Israel twenty years later to find the driver who turned his world upside down. In this mesmerizing tale of their meeting, Prager probes deep questions of nature, nurture, self-deception and destiny.

Today, thanks to better early detection, there are 63% fewer deaths from heart disease than there were just a few decades ago. Thomas Insel, Director of the National Institute of Mental Health, wonders: Could we do the same for depression and schizophrenia? The first step in this new avenue of research, he says, is a crucial reframing: for us to stop thinking about “mental disorders” and start understanding them as “brain disorders.” (Filmed at TEDxCaltech.)

Its 2013, yet 2.5 billion people in the world have no access to a basic sanitary toilet. And when theres no loo, where do you poo? In the street, probably near your water and food sources -- causing untold death and disease from contamination. Get ready for a blunt, funny, powerful talk from journalist Rose George about a once-unmentionable problem.

In 1812, four men at Cambridge University met for breakfast. What began as an impassioned meal grew into a new scientific revolution, in which these men -- who called themselves “natural philosophers” until they later coined “scientist” -- introduced four major principles into scientific inquiry. Historian and philosopher Laura Snyder tells their intriguing story.

When Eric Dishman was in college, doctors told him he had 2 to 3 years to live. That was a long time ago. Now, Dishman puts his experience and his expertise as a medical tech specialist together to suggest a bold idea for reinventing health care -- by putting the patient at the center of a treatment team. (Filmed at TED@Intel)

What motivates us to work? Contrary to conventional wisdom, it isnt just money. But its not exactly joy either. It seems that most of us thrive by making constant progress and feeling a sense of purpose. Behavioral economist Dan Ariely presents two eye-opening experiments that reveal our unexpected and nuanced attitudes toward meaning in our work. (Filmed at TEDxRiodelaPlata.)

Your smartphone may feel like a friend -- but a true friend would give you a smile once in a while. At TED2013, Keller Rinaudo demos Romo, the smartphone-powered mini robot who can motor along with you on a walk, slide you a cup of coffee across the table, and react to you with programmable expressions.

At age 12, Freeman Hrabowski marched with Martin Luther King. Now hes president of the University of Maryland, Baltimore County (UMBC), where he works to create an environment that helps under-represented students -- specifically African-American, Latino and low-income learners -- get degrees in math and science. He shares the four pillars of UMBCs approach.

Trivia whiz Ken Jennings has made a career as a keeper of facts; he holds the longest winning streak in history on the U.S. game show Jeopardy. But in 2011, he played a challenge match against supercomputer Watson -- and lost. With humor and humility, Jennings tells us how it felt to have a computer literally beat him at his own game, and also makes the case for good old-fashioned human knowledge. (Filmed at TEDxSeattleU.)

3D printing has grown in sophistication since the late 1970s; TED Fellow Skylar Tibbits is shaping the next development, which he calls 4D printing, where the fourth dimension is time. This emerging technology will allow us to print objects that then reshape themselves or self-assemble over time. Think: a printed cube that folds before your eyes, or a printed pipe able to sense the need to expand or contract.

There is a corruption at the heart of American politics, caused by the dependence of Congressional candidates on funding from the tiniest percentage of citizens. Thats the argument at the core of this blistering talk by legal scholar Lawrence Lessig. With rapid-fire visuals, he shows how the funding process weakens the Republic in the most fundamental way, and issues a rallying bipartisan cry that will resonate with many in the U.S. and beyond.

Imagine an electric vehicle that can get you to work -- or anywhere in a six-mile radius -- quickly, without traffic frustrations or gasoline. Now imagine you can pick it up and carry it with you. Yes, this souped-up skateboard could change the face of morning commutes.

One afternoon, Kees Moeliker got a research opportunity few ornithologists would wish for: A flying duck slammed into his glass office building, died, and then … what happened next would change his life. [Note: Contains graphic images and descriptions of sexual behavior in animals.]

When two people are trying to make a deal -- whether they’re competing or cooperating -- what’s really going on inside their brains? Behavioral economist Colin Camerer shows research that reveals just how little we’re able to predict what others are thinking. And he presents an unexpected study that shows chimpanzees might just be better at it than we are. (Filmed at TEDxCalTech.)

In the Masai community where 13-year-old Richard Turere lives, cattle are all-important. But lion attacks were growing more frequent. In this short, inspiring talk, the young inventor shares the solar-powered solution he designed to safely scare the lions away.

Mark Shaw demos Ultra-Ever Dry, a liquid-repellent coating that acts as an astonishingly powerful shield against water and water-based materials. At the nano level, the spray covers a surface with an umbrella of air so that water bounces right off. Watch for an exciting two-minute kicker.

Our bodies and homes are covered in microbes -- some good for us, some bad for us. As we learn more about the germs and microbes who share our living spaces, TED Fellow Jessica Green asks: Can we design buildings that encourage happy, healthy microbial environments?

Composer and conductor Eric Whitacre has inspired millions by bringing together "virtual choirs," singers from many countries spliced together on video. Now, for the first time ever, he creates the experience in real time, as 32 singers from around the world Skype in to join an onstage choir (assembled from three local colleges) for an epic performance of Whitacres "Cloudburst," based on a poem by Octavio Paz.

Today we know the molecular cause of 4,000 diseases, but treatments are available for only 250 of them. So what’s taking so long? Geneticist and physician Francis Collins explains why systematic drug discovery is imperative, even for rare and complex diseases, and offers a few solutions -- like teaching old drugs new tricks.