Contact Scientist: Prof. dr. L.V.E. (Léon) Koopmans
Executive Summary: The first billion years of the Universe (its ‘infancy’) is one of the least explored and understood eras in the Universe, despite enormous observational progress in recent years with optical/uv, infrared and sub-mm ground- and space- based instruments. However, between the first image of the Universe from the Cosmic Microwave Background (CMB) and the first stars and galaxies becoming visible, some half to one a billion years later to large ground- and space-based observatories, observational probes remain incredibly scarce. Redshifts between z~11-1100 are currently devoid of any direct observational probes. Even JSWT in the 2020s will only be able to push direct observations a little further in redshift (z~15) and only for a limited number of bright sources and over a limited field of view.