name the self thought physicist found a pendulum which swings srtaight, back and fourth?

Answer 1

The pendulum was discovered by Ibn Yunus during the 10th century, who was the first to study and document its oscillatory motion. Its value for use in clocks was introduced by physicists during the 17th century, following observations from Galileo.

pendulum (plural pendulums or pendula), is a weight (or bob) on the end of a rigid rod (or a string/rope), which, when given an initial push, will swing back and forth under the influence of gravity over its central (lowest) point.

Answer 2

Do you mean a Foucault Pendulum which illustrates the rotation of the earth?
See:
http://www.calacademy.org/products/pendulum/

Answer 3

gabriel