— Nu
Lowercase nu (ν) is the standard symbol for frequency in wave and quantum physics (E = hν), and for kinematic viscosity in fluid mechanics. It looks like a 'v' — read carefully in formulas.
SI unit: Hz (as frequency); m²/s (as kinematic viscosity)
Used in
- Photon energy E = hν
- Kinematic viscosity in Reynolds number Re = vL/ν