Wheelchair users can finally stand up and walk, using robotic legs with computer sensors. The 20-kilogram battery-powered eLEGS prosthetic being tested here enables wearers to walk relatively quietly and comfortably.
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?
It's important to be honest about your weight — and the US government has finally realized this. The Federal Transit Administration, which issues safety requirements for city buses, says the increasing size of many Americans is a potential safety problem.
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.