Dust suffuses our diffuse universe, obscures our view, and is a direct product of the formation of stars and galaxies. In this era of large area digital surveys it is both necessary and possible to explore dust in our universe at a level once unheard of. I will discuss new results on dust, both extreme in precision and extreme in position. In my discussion of high precision dust observations, I show how crucial accurate dust maps are to our understanding of cosmology, and I will introduce a new cosmological parameter: the opacity of the universe, tau_z. I will show new results (and a new class of objects) using dust in low density environments, both at the surface of our own galaxy and filling the virial radii of galaxies throughout the universe. I will introduce the idea of exploring feedback from galaxies by studying their dust, and using these observations to constrain our models of galaxy formation.

We are constantly intrigued by how dramatically galaxies evolve when we probe closer to the cosmic dawn. Ten billion years ago, galaxies were forming stars ten times more fiercely than they do today. This phenomenon can be understood in the framework of cold dark matter simulations only if star formation is suppressed in massive dark matter halos. However, the physical mechanisms responsible for the suppression are unclear. Starburst galaxies in massive halos offer a unique laboratory to constrain the suppression processes, because, unlike most galaxies, such processes have apparently failed to operate in these starbursts. Thanks to the Herschel Space Telescope, for the first time we have identified a sample of gravitationally lensed massive starbursts at the peak epoch of cosmic star formation. I will show how high-resolution multi-phase observations in combination with gravitational lensing have helped us gain a comprehensive understanding of these unusual galaxies. I will also describe future projects aimed at constraining the star formation history and the halo-scale gas supply of such massive starbursts. By contrasting with normal galaxies, the results of these studies will be fundamental to a physical understanding of galaxy evolution. Finally, I will present my vision of this field with future ground- and space-based observatories.

Samir Salim (Indiana University)