Modified Newtonian dynamics

Summary

Modified Newtonian dynamics (MOND) is a proposal by Mordehai Milgrom, published in 1983, to change Newton's law of gravity at very small accelerations. Below an acceleration scale $a_0 \approx 1.2 \times 10^{-10} \text{ m/s}^2$, the gravitational acceleration is taken to be about $\sqrt{a_0 g_N}$ instead of the Newtonian value $g_N$. It was designed to explain the flat rotation curves of galaxies without dark matter. It is a non-relativistic rule, and relativistic versions belong to the alternatives to general relativity.