A phenomenon in which an object with a natural resonant frequency is excited by the vibrations of another object vibrating at the same frequency. For example, a singer breaking a wine glass with her voice demonstrates an extreme sympathetic vibration of the glass, excited by the vibrations of the singer's voice.
Now, here, you see, it takes all the running you can do, to keep in the same place. If you want to get somewhere else, you must run twice as fast as that.
The Red Queen in Lewis Carroll's Through the Looking Glass