Light speed is the ultimate speed in our universe. Why we haven't been able to build - or even conceive of - a contraption that goes faster than light.
Thousands displaced from their homes. Disaster agencies still mobilizing medical and social services. A thin layer of ash expected to arrive in Malay Peninsula on Wednesday.
Hundreds of millions return to their home villages around the Chinese New Year. In a week to 10 days, 3.6 billion passenger miles are clocked on trains, buses, and cars.