viralcontent6.9 on Instagram: ""Cadence" by Reuben Margolin uses precise simple harmonic motion where two white hands oscillate sinusoidally while a red T-frame rotates, their periods perfectly synchronized so slots align at intersection points—cam-follower engineering creating contactless "penetration" illusion �. A single motor pulls 216 strings through tapered maple links in an open-cell hexagonal matrix, generating fluid waveforms with 120° intersection freedom for silent, lifelike motion �.