In physics, the Landau–Hopf theory of turbulence, named for Lev Landau and Eberhard Hopf, was until the mid-1970s the accepted theory of how a fluid flow becomes turbulent. The theory says that as a fluid flows faster, it develops more and more Fourier modes. At first a few modes dominate, but under stronger forcing the modes become power-law distributed, as in Kolmogorov's theory of turbulence.