“Astronomy and Statistics”
Daniel Mortlock (Imperial)
Why "the statistical frontiers of astrophysics"? Why not "the statistical frontiers of particle physics", or "the statistical frontiers of neuroscience" or "the statistical frontiers of palmistry?" Any measurement that yields quantitative data inevitably requires statistical analysis, but lack of repeatable experiments in astronomy makes probabilistic methods unusually important, while huge modern astronomical data-sets provide an exciting real-world testing ground for innovative statistical techniques. This introductory talk will explore astronomical statistics through a number concrete case-studies that range from completely straight-forward applications of Bayes's theorem to parameter estimation, through more ambiguous model-selection problems, to the far more open-ended world of data-mining. There will also be particular emphasis on cases in which manifestly erroneous conclusions have been reached, and how this could often have been avoided simply by following Laplace's principle that "probability is nothing but common sense reduced to calculus".