The (Sub-)mm is a complex part of the electromagnetic spectrum, letting us probe everything from the nearby cold and dusty universe, to some of the first light in the Universe and the cosmic microwave background itself. World leading observatories like the James Clerk Maxwell Telescope and later ALMA have revolutionised our understanding of what we can learn about the universe in these long wavelength regimes. We’re now hitting up against the resolution and sensitivity limits of observatories like the JCMT, and need to look for new ways of observing the large scale structures in the universe that interferometers like ALMA resolve out. In this talk, I’ll describe the thinking behind the current Horizon 2020 Design Study looking to scope the next generation sub-mm telescope concept, AtLAST, and how you can help shape the science cases for this unique new observatory.
