Meldea

Meldea, a young wave-tamer, holds a tuning fork that shakes a glowing string into waves.

The Physics

Around 1859 Franz Melde tied a string to the prong of a tuning fork and pulled it taut (Ann. Phys. 185, 193, 1860). At the right tensions the string broke into steady standing waves, with nodes that stood still and loops that blurred. Change the tension and the number of loops jumps.

f = n√(T/μ)/(2L)

• f: frequency of the string vibration (Hz)
• n: number of loops
• T: tension (N)
• μ: mass per unit length (kg/m)
• L: length of the string (m)

With the fork driving along the string, the string vibrates at half the fork's frequency; driven sideways, at the same frequency.

Honest caveat: Real strings stretch and have stiffness, so loops are not perfectly evenly spaced.

On the sticker

Meldea holds a tuning fork at one end of a glowing orange wavy string. Printed text: MELDEA with the line f = n√(T/μ)/(2L). Pixel-art kiss-cut vinyl sticker, white, in 2″, 3″, 4″ and 6″ sizes.