science

The northern white rhinoceros is almost gone. Seven of them remain: four in Kenya, two in the United States, one in the Czech Republic. More than ten years have passed since the last of them reproduced. Fortunately, there's more than one way to make a rhino.

These women in San Francisco are twins. They were born at the same time of the same mother. There are two kinds of twins: those who develop from a single egg, and those who develop from two eggs. What are the English names for the two types of twins?

Dark skies do more than just inspire us. Having bright days and dark nights is important to keeping our body chemistry (and that of plants and animals) in balance. How bright are the city lights where you live? Scientists would like you to tell them.

Each year, between 70 and 100 people around the world are attacked by sharks. But what sharks cannot see well, they are less likely to attack. Researchers in Australia say they have made a simple discovery that will help surfers and divers.

Canterbury is "open for business" despite the earthquake damage experienced by Christchurch on 4 September. "Cantabrians are coming together to support each other and get back to business," Peter Townsend told the New Zealand Herald.

Working from the comfort of his home, Sal Khan has made 1,500 videos to educate the world. Subjects range from mathematics and physics to biology and economics. The Kahn Academy is actually a YouTube channel and one very devoted teacher.