Tjalling Koopmans
…Sjoerds". One of Sjoerd Koopmans's sisters, Gatske Koopmans, and her husband Symon van der Meer were the paternal grandparents of Nobel Prize winner Simon van der Meer. Tjalling Koopmans and Simon van der Meer were therefore first cousins once removed. Tjalling had two brothers, one of whom was theologian Rev. Dr Jan…