Bill Gates hopes to solve some of the world's biggest problems using a new kind of philanthropy. In a passionate and, yes, funny 18 minutes, he asks us to consider two big questions and how we might answer them. (And see the Q&A on the TED Blog.)

America's school systems are funded by the 50 states. In this fiery talk, Bill Gates says that state budgets are riddled with accounting tricks that disguise the true cost of health care and pensions and weighted with worsening deficits -- with the financing of education at the losing end.

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.

In 2014, the world avoided a global outbreak of Ebola, thanks to thousands of selfless health workers -- plus, frankly, some very good luck. In hindsight, we know what we should have done better. So, now's the time, Bill Gates suggests, to put all our good ideas into practice, from scenario planning to vaccine research to health worker training....

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 1993, Bill and Melinda Gates took a walk on the beach and made a big decision: to give their Microsoft wealth back to society. In conversation with Chris Anderson, the couple talks about their work at the Bill & Melinda Gates Foundation, as well as their marriage, their children, their failures and the satisfaction of giving most of their...

A passionate techie and a shrewd businessman, Bill Gates changed the world while leading Microsoft to dizzying success. Now he's doing it again with his own style of philanthropy and passion for innovation.

When we asked Bill Gates to curate a list of his favorite talks, his first response was, “There are too many to pick, really.” Here, he's whittled it down to 13 essentials.

Melinda French Gates is co-chair of the Bill & Melinda Gates Foundation, where she puts into practice the idea that every life has equal value.

David Christian teaches an ambitious world history course that tells the tale of the entire universe -- from the Big Bang 13 billion years ago to present day.

Donald Sadoway is working on a battery miracle -- an inexpensive, incredibly efficient, three-layered battery using “liquid metal."

With TED-Ed communicator Emilie Soffe as the leading lady, the TED staff puts on a show.