Discussing the Rudolphine court with Melvyn Bragg were Peter Forshaw (always good value for money - Voynichians may remember him from the Mentorn Voynich documentary on BBC4), Howard Hotson, and Adam Mosley: the topics ranged across alchemy, the occult, Hussite heresy, astronomy, Cabinet of Wonders (including a dodo!), botanical collections, automata, natural magic, paintings, Cornelius Drebbel, Tycho Brahe, Charles University, astrology, John Dee, Kepler, etc etc... oh yes, and the Voynich Manuscript as well (about 5 minutes in), which Melvyn Bragg seemed particularly fascinated by. Maybe he's seen the Big Fat List of forthcoming Voynich novels? :-o
The programme-makers thoughtfully included a Rudolph-centred bibliography here, which you may find useful (though with Hugh Trevor-Roper listed, I have to say it's not particularly contemporary).