Bill Gross, the founder of Idealab, talks about his life as an inventor, starting with his high-school company selling solar energy plans and kits. Learn here about a groundbreaking system for solar cells -- and some questions we haven't yet solved.

Bill Gross has founded a lot of start-ups, and incubated many others -- and he got curious about why some succeeded and others failed. So he gathered data from hundreds of companies, his own and other people's, and ranked each company on five key factors. He found one factor that stands out from the others -- and surprised even him.

It doesn't matter whether you love or hate guns; it's obvious that the US would be a safer place if there weren't thousands of them sold every day without background checks. Dan Gross, president of the Brady Campaign to Prevent Gun Violence, makes a passionate, personal appeal for something that more than 90 percent of Americans want: background...

At TED2010, Bill Gates unveils his vision for the world's energy future, describing the need for "miracles" to avoid planetary catastrophe and explaining why he's backing a dramatically different type of nuclear reactor. The necessary goal? Zero carbon emissions globally by 2050.

In the US, the very same blood test can cost $19 at one clinic and $522 at another clinic just blocks away -- and nobody knows the difference until they get a bill weeks later. Journalist Jeanne Pinder says it doesn't have to be this way. She's built a platform that crowdsources the true costs of medical procedures and makes the data public, rev...

Richard Branson talks to TED's Chris Anderson about the ups and the downs of his career, from his multibillionaire success to his multiple near-death experiences -- and reveals some of his (very surprising) motivations.

"When we tell women that sex isn't worth the risk during pregnancy, what we're telling her is that her sexual pleasure doesn't matter ... that she in fact doesn't matter," says sex researcher Sofia Jawed-Wessel. In this eye-opening talk, Jawed-Wessel mines our views about pregnancy and pleasure to lay bare the relationship between women, sex and...

Economist Eleni Gabre-Madhin outlines her ambitious vision to found the first commodities market in Ethiopia. Her plan would create wealth, minimize risk for farmers and turn the world's largest recipient of food aid into a regional food basket.

At the EG conference in December 2007, artist Jonathan Harris discusses his latest projects, which involve collecting stories: his own, strangers', and stories collected from the Internet, including his amazing "We Feel Fine."

Daniel Goleman, author of "Emotional Intelligence," asks why we aren't more compassionate more of the time.

The leader of Britain's Conservative Party says we're entering a new era -- where governments themselves have less power (and less money) and people empowered by technology have more. Tapping into new ideas on behavioral economics, he explores how these trends could be turned into smarter policy.

Women have made enormous progress over the last century -- challenging the status quo, busting old taboos and changing business from the inside out. But when it comes to political representation, there's still a long way to go, says activist Cecile Richards. In this visionary talk, Richards calls for a global political revolution for women's equ...

Thinking startup? David S. Rose's rapid-fire TED U talk on pitching to a venture capitalist tells you the 10 things you need to know about yourself -- and prove to a VC -- before you fire up your slideshow.