Geometrically, a parabola is the set of all points in the plane which are equally distant from a fixed point, called the focus, and a fixed line, called the directrix. We will say more about this geometric definition below. Algebraically, a parabola is...

In mathematics, the parabola (pronounced /pəˈræbələ/, from the Greek παραβολή) is a conic section generated by the intersection of a right circular conical surface and a plane parallel to a generating straight line of that surface. A...

A team of French doctors planned to slice a cyst off a man's arm Wednesday in the world's first zero-gravity surgery, operating aboard an airplane soaring and diving in and out of weightlessness. The experiment is part of...

Free of his wheelchair and tethered only to heart rate and blood pressure monitors, astrophysicist Stephen Hawking on Thursday fulfilled a dream of floating weightless on a zero-gravity jet, a step he hopes leads to further space adventures."It was amazing," Hawking said after the flight.The...

Renowned physicist Stephen Hawking savored weightlessness, flipping in the air after years of being able to make only tiny facial movements. But he hopes it is only the appetizer."Space, here I come," Hawking said Thursday after going on a two-hour jet flight that creates 25-second...