Speaker: Prof. John Lipa

Institution: Stanford University

For more than 100 years stellar motions in galaxies were known to be anomalous, that is, not easily explained by Newton’s law of gravity. The advent of Einstein’s General Relativity did not appear to change the situation. Many types of gravitating matter were suggested to solve the problem, but those belonging to the Standard Model of physics have been ruled out. We are left with solutions involving new physics in the form of ‘dark matter’. This talk will briefly review the situation and touch on some alternative explanations.