One of the latest frontiers in the push for clean energy is the effort to capture the energy of human movement. The World's Clark Boyd reports on the development of a new paving tile that captures the energy of footsteps and turns it into electricity.
A group of military veterans is barnstorming across America on a bus. The veterans are calling on US leaders to get the nation running on clean energy. The World's Jason Margolis took a ride on the bus.
Computer servers at big data centers around the globe generate a lot of heat. A company in Finland has figured out a way to capture that wasted energy and use it to heat homes. The World's Technology Correspondent Clark Boyd has the story from Helsinki.
From the South Sudanese capital Juba, Matthew Brunwasser reports on the role of oil in Sudan's recent history. Now the south may take the majority of wells if the referendum currently under way results in an independent South Sudan.
Sao Paulo is a tough place to get around. The city of 11 million, South America's largest, has notorious traffic. There is one quick way to navigate the streets of Sao Paulo though: Ride a bike. Problem is, you put your life at risk when you do.