Learn English – Shift the pendulum

idioms

I came across the idiom "shift the pendulum" or "a swing of the pendulum". I suppose the idiom means a major change but I can't understand the point because when you shift the pendulum from the central line, it starts swinging and then gradually stops. There's no major change. Maybe it means to motivate or to start a move. Please help me understand this idiom.

Best Answer

It is more common to say the pendulum is swinging (or has swung).

To say this means that thought, practice or political leanings (for instance) have shifted in one direction, but it is expected that at some future time they will swing back —because they have in the past.

An example is educational theory with regard to phonics. For some years, schools will try to teach spelling without teaching phonics, but they inevitably revert to teaching phonics.

As these swings can take years, the metaphor assumes the decay of the amplitude of swing to be negligible.