Abstract

I will start by discussing the Herschel observations of M31 , the other big spiral in the Local Group. I will present evidence that the dust in the bulge of M31 is heated from a different source than the dust in the disk, and show the first evidence for variation within a galaxy in the physical properties of dust. Heading outwards into the Universe, I will show results from the Herschel Reference Survey, the first survey of dust in a statistically-complete sample of galaxies. I will use some results from that survey to test a method for estimating the mass of the interstellar medium in tens of thousands of galaxies. I will then present results from the Herschel ATLAS , the largest Herschel open-time project. I will discuss what this survey can tell us about whether nature of nurture is most important for galaxy evolution. I will describe a new programme, based on the Herschel ATLAS results, for studying dark-matter halos and estimating cosmological parameters.