The Wikipedia description in our post talks about “tidal resonance”. In university physics class, I learned about resonance via examples in vibration. Resonance occurs when an external force or vibration matches an object’s natural frequency, leading to a dramatic increase in the amplitude of its oscillations.
A natural frequency is the specific rate at which an object or system vibrates when it is disturbed and allowed to oscillate freely. Every physical object, from a simple pendulum to a complex bridge, possesses one or more natural frequencies. When an an object begins to oscillate at a frequency that approaches its natural frequency, the amplitude (amount) of vibration increases dramatically.
Think of a soprano hitting a high note that shatters a glass. Or the old Tacoma Narrows Bridge (“Galloping Gertie”). Wind speeds over 35 mph caused the bridge to begin to oscillate at the natural frequency of the steel structure – causing very large amplitude movement of the bridge resulting in its eventual collapse in 1940.