What is the origin of 'sleep tight'?
Read moreOne of the mysteries of the English language finally explained.
noun
A symmetrical open plane curve formed by the intersection of a cone with a plane parallel to its side. The path of a projectile under the influence of gravity follows a curve of this shape.
- ‘The solutions to the equations describing the motions produced by this law are called conic sections - ellipses, hyperbolae and parabolae - which you get by intersecting a plane and a cone.’
- ‘Newton and Kepler left behind the tools for constructing flight paths from simple conic sections - bits of parabolas, hyperbolas, ellipses, and the ubiquitous circle - and their use is now a highly developed art.’
- ‘Menaechmus is famed for his discovery of the conic sections and he was the first to show that ellipses, parabolas, and hyperbolas are obtained by cutting a cone in a plane not parallel to the base.’
- ‘There are three non-degenerate conics: the ellipse, the parabola, and the hyperbola.’
- ‘Long-period comets can have orbits ranging from eccentric ellipses to parabolas to even modest hyperbolas.’
Origin
Late 16th century: modern Latin, from Greek parabolē ‘placing side by side, application’, from para- ‘beside’ + bolē ‘a throw’ (from the verb ballein).
