All life consists of rhythmic processes. From the simple pulsations of a single-cell organism to the rising and falling of our breath, life is filled with rhythm. This rhythm is also called "periodicity," meaning that the activity of something falls in cycles.

Much of life is directed by the external rhythms of nature. For example, the earth spins on its axis and rotates around the sun, and around our moon orbits the earth. We attune ourselves to the cycles of the sun and the moon, following the different rhythms they create.

Not only our sleep patterns, but our eating patterns, digestive patterns, even our harvesting and mating patterns are affected by the rhythms of these cycles.

The Discovery of Entrainment

The history of entrainment is linked to Dutch scientist Christian Huygens. In 1665, while working on the design of the pendulum clock, Huygens found that when he placed two pendulum clocks on a wall near each other and swung the pendulums at different rates, they would eventually end up swinging in at the same rate. This is due to their mutual influence on one another.

Another example of entrainment is the setting of two similar pianos within the same room. If a note is struck on one piano, the same musical string on the other unit will begin to vibrate in unison as a result of the vibrational stimulus set within the environment.

Entrainment is a Universal Law

A phenomenon of resonance first observed in the 17th century, entrainment has an effect on all of us. Entrainment is defined as "the tendency for two oscillating bodies to lock into phase so that they vibrate in harmony". It is also defined as a synchronization of two or more rhythmic cycles.

The principle of entrainment is universal, appearing in chemistry, pharmacology, biology, medicine, psychology, sociology, astronomy, architecture and more. The classic example shows individual pulsing heart muscle cells. When they are brought close together, they begin pulsing in synchrony.

Another example of the entrainment effect is women who live in the same household often find that their menstrual cycles will coincide.

Musical Entrainment

The entrainment process is quite evident in music. It is possible to have rhythmic entrainment, melodic entrainment and dynamic entrainment.

Entrainment music has the potential to (1) resonate with the listener’s feelings, (2) transform negativity into positivity, and (3) promote a state of liveliness or serenity.

Certain sounds, in specific sequence can help bring the listener from one place to another. This process is also known as the “isoprinciple”.

Entrainment and Synchronous Resonance

Entrainment is an aspect of sound that is closely related to rhythms and the way these rhythms affect us. It is a phenomenon of sound in which the powerful rhythmic vibrations of one object will cause the less powerful vibrations of another object to lock in step and oscillate at the first object's rate.

This phenomenon of nature has to do with the conservation of energy. It seems that nature finds it more economical in terms of energy to have periodic events that are close enough in frequency to occur in phase or in step with each other.

Itzhak Bentov illustrates an excellent example of entrainment in his book "Stalking the Wild Pendulum". If you have a room full of pendulum-type grandfather clocks and start the pendulums in motion at different times, they will all swing differently. However, if you walk out of this room and come back the next day, you will find that all the pendulums are swinging together at the same rate. This locking in step of rhythms is entrainment.

Entrainment is actually an aspect of resonance. Resonance may be defined as the frequency at which an object most naturally wants to vibrate. One object may set another object into motion if it shares the same resonant frequency.

If, for example, you strike a tuning fork of 100 cycles per second and bring it near another tuning fork of that same frequency, the second tuning fork will be set in motion. Even though it has not been struck, the second fork will begin to vibrate and sound merely by being in the same field as the tuning fork which was actively struck.

We have all seen a singer break a glass with his or her voice. This is another example of resonance. This also occurs between two guitar strings, one struck and one unstruck. Resonance is a cooperative phenomenon between two objects that share the same frequency.

With resonance you are meeting the natural vibrations of an object with its own vibrations, thereby setting it into motion. Thus resonance may be conceived of as being passive in nature.

The Active Nature of Entrainment

Entrainment, on the other hand, appears to be an active phenomena. With entrainment you are changing the natural oscillatory patterns of one object and replacing them with the different oscillatory patterns of another object. You are actively changing the vibrations (the frequency or rhythm) of one object to another rate.

The oscillators of television sets, radio receivers and other similar equipment lock on to each other and entrain. With television sets, when you turn the knobs you are adjusting the frequency of your set's oscillators to match the frequency of the station's oscillators. When the frequencies come close to one another, they suddenly lock, as if they "want" to pulse together. Usually, the fastest oscillator will force the slower ones to operate at its pace.

Living things are like television sets in that they also oscillate; they pulse, they vibrate, they have rhythm. These rhythms of life allow for entrainment.

Entrainment is found throughout nature. Fireflies blinking on and off entrain with each other. Female college roommates often have menstrual cycles that synchronize together. Muscle cells from the heart, when they move closer together, suddenly shift in their rhythm and start pulsing together, perfectly synchronized.

This entrainment also takes place when two people have a good conversation. Their brainwaves oscillate synchronously. Such entrainment is seen in the relationship between students and their professors. Psychotherapists and clients entrain with each other, as do preachers and their congregation.

Within our own bodies, we are constantly locking in our own rhythms. Our heart rate, respiration and brain waves all entrain to each other.

Slow down your breath, for example, and you slow down your heartbeat and your brainwaves.

Conversely, if you are able to slow down your brain waves, you can affect your heart rate and respiration. This is one of the principles of biofeedback and is a base principle of Mr. Brainwave's consciousness research.