John PreskillJohn Preskill will be presenting the Nineteenth Arnold Sommerfeld Lecture Series this week. Each semester the Arnold Sommerfeld Center for Theoretical Physics at Ludwig-Maximilians-University (LMU), Munich invites a distinguished theoretical physicist in order to present a short series of lectures with increasing level of specialization. The lecture series includes a public talk for a general audience, a theory colloquium and a specialized seminar. Past Sommerfeld Lecturers include Anthony Leggett, Alexander Polyakov, Peter Zoller, and Frank Wilczek.