High Energy Magic Building
The youngest building in Unseen University. Formerly the squash court, but given the current fashion among wizards to favour building bodies of a different kind, redundant as a venue for a high-fitness high-energy sporting pastime. However, it has lately become probably the building with the most academic activities. The more serious student wizards, under the guidance of Ponder Stibbons (Head of Inadvisably Applied Magic, Reader in Invisible Writings, and Camerlengo), analyze known magical spells and particles of magic themselves. The research students here have worked out, for example, that the Rite of AshkEnte can be performed with only a few essential ingredients, without all the magical rubbish like skulls and dribbly candles. One of the major tasks, however, is the splitting of the Thaum, the matter that makes up magic itself. The High Energy Magic Building is home to Hex, the University's thinking engine. For more information on the wizard's interests see Wizard's magic. The building has appeared mainly in the Science of Discworld series in which overenthusiastic student wizards created interesting, but extremely dangerous experiments tampering with the fabrics of space and time.
The roof of the HEM sports two massive bronze spheres which discharge excess magic; these are colloquially known as The Wizards' Balls.
A more significant problem - Brazeneck College seeking to rival UU - has recently emerged, and this is testing Ponder's guile as a Head of Department...
Annotation
A squash court at a university, converted into a research base into high-energy work one step away from being magic (it achieved the old alchemists' dream of turning one metal into another, after all) with the consequent risk of generating so much magic that it blew a great big uncontrolled hole in the (wrong part of) the earth. Pratchett may be referring here to CP-1 (Chicago Pile Number 1), Roundworld's first self sustaining nuclear reactor. CP-1 was created by a team led by Enrico Fermi and Leo Szilard in a rackets court in the University of Chicago, rackets is similar, but distinct to squash. It's quite likely Pratchett would have known about this historical reactor through his earlier career as press officer for CEGB (Biography).