Abstract
Modified Newtonian dynamics (MOND) is a modification of Newtonian law of gravity or inertia proposed by Milgrom (1983) as an alternative to cosmic dark matter. MOND has been remarkably successful in explaining systematic properties of spiral and elliptical galaxies and predicting in detail the observed rotation curves of spiral galaxies with only one additional parameter - a critical acceleration which is on the order of cosmologically interesting value of . Milgrom proposed that gravitation field needs modifications when the field strength g is weaker than a critical value . This simple algorithm yields flat rotation curves for spiral galaxies and a mass-rotation velocity relation of the form that forms the basis for the observed luminosity- rotation velocity relation–the Tully-Fisher law. We will demonstrate that the evidence for dark matter can be equally well interpreted as evidence for MOND.