When are humans most happy? To gather data on this question, Matt Killingsworth built an app, Track Your Happiness, that let people report their feelings in real time. Among the surprising results: We're often happiest when we're lost in the moment. And the flip side: The more our mind wanders, the less happy we can be.

What is altruism? Put simply, it's the wish that other people may be happy. And, says Matthieu Ricard, a happiness researcher and a Buddhist monk, altruism is also a great lens for making decisions, both for the short and long term, in work and in life.

Is outer space really the silent and lifeless place it's often depicted to be? Perhaps not. Astrophysicist and musician Matt Russo takes us on a journey through the cosmos, revealing the hidden rhythms and harmonies of planetary orbits. The universe is full of music, he says -- we just need to learn how to hear it.

Want to not only fall asleep quickly but also stay asleep longer? Sleep scientist Matt Walker explains how your room temperature, lighting and other easy-to-fix factors can set the stage for a better night's rest.

As the CEO of Public Radio International, Alisa Miller works to bring the most significant news stories to millions -- empowering Americans with the knowledge to make choices in an interconnected world.

Jon Ronson is a writer and documentary filmmaker who dips into every flavor of madness, extremism and obsession.

The MIT Media Lab's John Maeda lives at the intersection of technology and art, a place that can get very complicated. Here he talks about paring down to basics.

At TEDGlobal 2010, author Matt Ridley shows how, throughout history, the engine of human progress has been the meeting and mating of ideas to make new ideas. It's not important how clever individuals are, he says; what really matters is how smart the collective brain is.

Designer John Maeda talks about his path from a Seattle tofu factory to the Rhode Island School of Design, where he became president in 2008. Maeda, a tireless experimenter and a witty observer, explores the crucial moment when design met computers.

As the popularity of remote working continues to spread, workers today can collaborate across cities, countries and even multiple time zones. How does this change office dynamics? And how can we make sure that all employees, both at headquarters and at home, feel connected? Matt Mullenweg, cofounder of Wordpress and CEO of Automattic (which has ...

Humans have been battling heartburn for hundreds, if not thousands, of years. But recently the incidence has risen, making it a common complaint worldwide. What causes this problem, and how can it be stopped? Rusha Modi details the causes and treatments of heartburn.

What if the government ran more like Silicon Valley? Engineer Matt Cutts shares why he decided to leave Google (where he worked for nearly 17 years) for a career in the US government -- and makes the case that if you really want to make an impact, go where your help is needed most.

Caffeine wakes you up, and alcohol makes you nod off, right? It's not that simple. Sleep scientist Matt Walker takes us into the eye-opening ways that these drinks affect the quantity and quality of our sleep.

It's not just your imagination -- you're more irritable when you're low on zzzzs. Sleep scientist Matt Walker explains how our nightly slumber affects the emotional centers in our brains, and why we can think of sleep as first aid for our feelings.

Jer Thorp’s work focuses on adding meaning and narrative to huge amounts of data as a way to help people take control of the information that surrounds them.

As a child, entrepreneur Matthew Shifrin received a gift that changed his life -- a Lego set with instructions hand-written in Braille. In this charming and personal talk, he tells the story of his years-long mission to share the sensory experience he remembers with the larger blind community. "If there's something you're passionate about and yo...

In this talk-performance hybrid, drummer, percussionist and TED Fellow Kasiva Mutua shares how she's breaking the taboo against female drummers in Kenya -- and her mission to teach the significance and importance of the drum to young boys, women and girls. "Women can be custodians of culture, too," Mutua says.

The euphonium, with its sweet brass sound, is rarely heard outside of traditional brass bands. Cutting loose on the euph, prodigy Matthew White performs Nat McIntosh's hip-hop-inflected "The Warrior Comes Out to Play."

Sugar pills, injections of nothing -- studies show that, more often than you'd expect, placebos really work. At TEDMED, magician Eric Mead does a trick to prove that, even when you know something's not real, you can still react as powerfully as if it is. (Warning: This talk is not suitable for viewers who are disturbed by needles or blood.)

Pick up a book, magazine or screen, and more than likely you'll come across some typography designed by Matthew Carter. In this charming talk, the man behind typefaces such as Verdana, Georgia and Bell Centennial (designed just for phone books -- remember them?), takes us on a spin through a career focused on the very last pixel of each letter o...

How much do you know about intellectual disabilities? Special Olympics champion and ambassador Matthew Williams is proof that athletic competition and the camaraderie it fosters can transform lives, both on and off the field. Together with his fellow athletes, he invites you to join him at the next meet -- and challenges you to walk away with yo...

Matt Mills and Tamara Roukaerts demonstrate Aurasma, a new augmented reality tool that can seamlessly animate the world as seen through a smartphone. Going beyond previous augmented reality, their "auras" can do everything from making a painting talk to overlaying live news onto a printed newspaper.

Matthew O’Reilly is a veteran emergency medical technician on Long Island, New York. In this talk, O’Reilly describes what happens next when a gravely hurt patient asks him: “Am I going to die?”

We've all been told to get a good night's sleep before a test -- finally, here's the reason why. Sleep scientist Matt Walker explains how getting enough sleep affects how our brains store and process memories.

What trials unite not only Harry Potter or Frodo Baggins but many of literature's most interesting heroes? And what do ordinary people have in common with these literary heroes? Matthew Winkler takes us step-by-step through the crucial events that make or break a hero. [Directed by Kirill Yeretsky, narrated by Matthew Winkler, music by Stephen L...

Sleep is your life-support system and Mother Nature's best effort yet at immortality, says sleep scientist Matt Walker. In this deep dive into the science of slumber, Walker shares the wonderfully good things that happen when you get sleep -- and the alarmingly bad things that happen when you don't, for both your brain and body. Learn more about...

What does a bill like PIPA/SOPA mean to our shareable world? At the TED offices, Clay Shirky delivers a proper manifesto -- a call to defend our freedom to create, discuss, link and share, rather than passively consume.

As the creator of a large chunk of the Marvel Universe, Stan Lee knows a thing or two about conjuring new superheroes from thin air. In this instructional and charmingly idiosyncratic talk, Lee shares a few lessons on how to write your own superpowered characters and deploy them in stories that connect with the largest possible audience.

On the heels of a long and bruising camel ride, Keith Bellows became fascinated with the "SUV of the sand," and with the many thorny aspects of their personalities (and mating habits) most of us would rather not dwell upon.

Brewster Kahle is an inventor, philanthropist and digital librarian. His Internet Archive offers 85 billion pieces of deep Web geology -- a fascinating look at the formation of the Internet over the years, and a challenge to those who would keep knowledge buried.