📏〰️↗️

#wave vector #spatial frequency #wavenumber #wavelength #periodicity

⏳💎🔄

#time crystal #periodicity #crystal structure #non-equilibrium matter #repeating state

🕰️☀️<->🌙

#diel period #24 hour time #day night switch #time cycle #periodicity

🌊〰️⏱️

#natural cycle #ocean rhythm #repeating pattern #periodicity #tide