When two or more events begin and end at the same time and have equal time values, they are synchronous. Synchronous events are indistinguishable from one another in time.
When two or more events interact with one another at regular time intervals, they are said to be in phase.
When events coincide with one another in time, they are in phase, and are synchronous.
Synchronous events result in various phenomena depending on the conditions under which they occur. When astronomical events are synchronized with one another, they produce effects such as a solar or lunar eclipse, or planetary conjunction. Geospheric cycles such as light-dark periods, tidal, seasonal, or glacial and interglacial periods evolve as a result of astronomical events which occur at regular time intervals.
In addition, various phenomena are caused by the synchronization of clocks. Two clocks which are situated on the same hard surface will eventually become synchronized due to the sympathetic vibrations which are transmitted from one clock to the other along the surface. Certain biological clocks including fertile periods of female animals tend to become synchronized when they are in close proximity for long periods.
Events which interact with one another and have equal or opposite phase produce interference patterns.
Interference is caused by wave patterns which are deflected from a surface or boundary interface in the direction of the source.
For example, two sound waves of the same frequency which are in opposite phase will create an acoustic phenomenon known as a stationary wave. In a stationary wave, the alternating pressure disturbances of each wave are aligned exactly opposite each other, such that the two waves cancel one another producing the perception of silence.
Three clocks placed on a wooden mantle will eventually beat in rhythmic unison due to vibrations transferred from one clock to another through the medium of wood. Three young women, all roommates, may experience their menstrual cycles at the same time each month, harmonically coordinated by means of pheromones.
If you believe that synchronicity and resonance occur at every order of magnitude and scale, blink your eyes.
– J. H.