Jean-Michel Marin and myself have thus started our “research in pair” in CIRM, Luminy, for a fortnight. We are working on the second edition of Bayesian Core and, despite working round the clock on the project (except for a one hour run around Mont Puget this morning), we are not going as fast as planned… Today, we worked in parallel on the normal and the regression chapters, looking for a sexy normal dataset to replace the larceny (normaldata) and the large and delicate CMB datasets. We eventually settled for a modern version of the Michelson-Morley dataset (available in R as morley), produced by K.K. Illingworth in 1927. I hope the spectral data and the relevance of the experiment will not be lost on the readers.