A pendulum is a simple device, consisting of a weighted object attached to a chain or thread.  They are often found with semi precious stones, various metals and even wood at the end of a chain.  For centuries cultures all around the world have used the pendulum. In China they were used to ward off evil. The Egyptians used pendulums to help plant crops. Today, new age Pagans and magical practitioners use them as a means to guide them energetically. The pendulum is a popular divination tool chosen by many to channel subconscious energy.  They are said to work by amplifying the subtle, involuntary hand movements of the users subconscious mind. This means that these answers are coming from the users connection of the higher mind to psychic energies.