The European mission will instead study the influence of dark energy by looking for subtle distortions in the way galaxies appear as they line up on the sky, and by measuring the patterns in the threedimensional distribution of galaxies through time.
"It's a long way to go, and is like a combination of playing three-dimensional chess and bridge and trying to run a NASA space programme, all at the same time, " he added.
Yet he also absorbed the daring new techniques that were emerging at the time, illustrated here by the work of Masaccio and Uccello with their grasp of three- dimensional form and the rules of perspective.