A pendulum is a weight on the end of a string or other arm that is able to swing freely when force is applied. Galileo is often credited with having discovered the principles of the pendulum when he observed the swinging chandeliers in Pisa cathedral. The story may be no more than a myth but the great scientist certainly contributed to the world’s knowledge and understanding of pendulums. Nowadays, pendulums have many real-world uses in science and other fields.
Grandfather clocks, grandmother clocks and other long-case clocks have pendulums to regulate the movement of the escape wheel. The long case is needed to house the pendulum. As clockmaker Harold C. Kelly points out, the clock's escapement, the device that converts continuous rotational motion into back-and-forth motion, in turn maintains the swinging of the pendulum. Invented by Dutch scientist Christiaan Huygens in 1656, the pendulum clock continues to be popular in the era of digital timekeeping.
Crystal Energy Therapy
Crystal Tiger’s Karen Ryan uses a pendulum for crystal energy therapy, a form of treatment some people believe is effective in helping cure relatively harmless conditions such as colds or flus, to long-term acute conditions such as asthma and arthritis. Ryan also suggests that pendulums can be used to answer “yes” or “no” questions, such as “should I stay in my current job?” Swinging the pendulum and noting precisely how it moves is at the core of the technique. This use of pendulums isn't backed up by scientific study, however, so take results with a grain of salt and don't count on getting accurate results.
Pendulums are used in the presentation of magic tricks. Magician Richard Webster makes bold claims for the powers of the pendulum, including the assertion that pendulums can read people’s subconscious minds. Webster further argues that the pendulum is the most underrated device in the magician’s bag of tricks. Learning how to use the pendulum is relatively straightforward, according to Webster, requiring only a few minutes of practice.
Pendulums are used in accelerometers, devices that measure acceleration. Further, they are used in seismometers, which measure seismic activity caused by earthquakes and other movements of the Earth. Pendulums are also used in other scientific instruments. The pendulum is used in religious practices, in the form of a swinging incense burner. In music, the principle of the pendulum is used in the metronome, a device used to ensure musicians keep proper time.