Humans have invented six devices that combine to make work easier. These six simple machines are the wheel and axle, the lever, the inclined plane, the pulley, the screw and the wedge.
A Falcon 9 rocket topped with the CSG-2 radar satellite lifted off from Cape Canaveral Space Force Station Monday (Jan. 31) at 6:11 p.m. EST (2311 GMT).
Archaeologists have found three pendants from Holocaust victims at the Sobibor Nazi death camp in Poland over the past decade.
An explanation of the grandfather paradox, and how it might be solved via the physics of time travel