Newton's cradle Newton's cradle Newton’s cradle is a device that demonstrates conservation of momentum and energy using a series of swinging spheres. When one sphere at the end is lifted and released, it strikes the stationary spheres, transmitting a force through the stationary spheres that pushes the last sphere upward. The last sphere swings back and strikes the still nearly stationary spheres, repeating the effect in the opposite direction. The device is named after 17th-century English scientist Sir Isaac Newton. It is also known as Newton's balls or Executive Ball Clicker. A typical Newton's cradle consists of a series of identically sized
An Englishman, an Irishman and a Scotsman cocky, stupid, or naïve, while the home national is smart, practical, or in any case ultimately victorious. The joke need not necessarily involve nationalities. Jokes about the hard sciences may begin "A mathematician, a physicist and an engineer..." An Englishman, an Irishman and a Scotsman "An Englishman, an Irishman and a Scotsman" is the opening line of a category of joke popular in Ireland and the United Kingdom. The nationalities involved may vary, though they are usually restricted to those within Ireland and the UK, and the number of people involved is usually three or sometimes four. In Ireland, the