Even teeny objects obey the law of gravity. A gold ball just 2 millimeters wide, with a mass of about 90 milligrams, is now the smallest object to have its gravitational pull measured. Observations of ...

IMAGINE you could see through everyday objects to the stuff they are made of. If you zoomed in on the arm of a chair, say, you would see that it is made of atoms. Zoom in again and you would see that ...