Entrainment is a phenomenon of sound in which the powerful vibrations of one object will actually change the vibrations of another object, causing this second object to ‘lock in step’ or synchronize with this first.

The Dutch physicist Christian Huygens, a contemporary of Isaac Newton, discovered entrainment in the 17th century. Huygens was also the inventor of the pendulum “grandfather” clock.

He had a room full of these types of clocks of various sizes. One day he went around the room starting the pendulums of the clocks in motion at different times. When he left the room, the pendulums were all swinging individually. When he returned the next day, he found that all the pendulums of the grandfather clocks were locked in step with the largest of these clocks.

Entrainment is found throughout nature.

Fireflies blinking on and off will entrain with each other. Even human functions will entrain together. Female college roommates and other women living together will often have a menstrual cycle that synchronizes together.

Muscle cells from the heart, when they move closer together, will suddenly shift in their rhythm and pulse together, perfectly synchronized!

We experience entrainment quite often, shifting and changing with the different external vibrations we’re exposed to. We also experience entrainment all the time with regard to our internal rhythms. Our heart rate, breathing rate and brain wave activity all entrain with each other.

If you want to experience this immediately, simply take a few deep, long breaths. By slowing down your respiration in this manner, you are also slowing down your heart rate and your respiration. Conversely, when you slow down your brain waves, you also slow down your heart rate and respiration.

The real time demonstration in the video below provides a striking visual example of the phenomenon. The experiment below was performed with an array of metronomes which were all initially set out of sync.

Watch how rapidly they shift into resonating in harmony with one another!