Rapid back-and-forth movements or oscillations; also informal term for emotional atmosphere or intuitive feelings about people or situations.
From Latin vibratus, past participle of vibrare 'to shake, brandish.' The physical science meaning came first, with the metaphorical 'good vibes' usage emerging in 1960s counterculture.
The leap from describing physical oscillations to describing emotional 'vibes' reflects how humans often understand abstract concepts through physical metaphors. Modern physics shows that vibrations are fundamental to everything from sound waves to quantum mechanics.
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