Daily TV & radio - Wednesday

Memories Are Made of These (11.00 am R4). Faltering memory and the tip-of-the-tongue phenomenon.
Stephen Hawking's Universe (2.00, also 5.00, 8.00 BBC Knowledge). Repeat series from 1997 reaches episode six, about the search for a "theory of everything".
Long, Long Ago (3.30 R4). Thor's duel with Hrungnir. The ancient Norse myth retold by Kevin Crossley-Holland.
Thinking Allowed (4.00 R4). Laurie Taylor and guests.
California Bay (7.30 C5). The marine life of Monterey Bay, continued.
» The Money Programme (7.30 BBC2). Fishing quotas and the crisis over North Sea stocks are the subject of the first programme in a new series.
Building Big: Skyscrapers (9.00 National Geographic). On remarkable achievements in construction, from Italy's medieval towers to present-day ambitions to build the world's tallest skyscraper.
The Disease Detectives (9.00 R4). Part three of epidemiology series focuses on the relationship between the experts and public authorities, who sometimes don't want to know about epidemiological findings.
» Night Waves (9.30 R3). New insights on Garibaldi and his legacy.
Kirsty MacColl's Cuba (10.00 R2). Part two of the late singer's explorations of Cuban music and culture.
Omnibus: Nancy Mitford (10.35 BBC1; 11.05 in N. Ireland and Wales). To accompany the Sunday-night serialisation of her Love in a Cold Climate , a profile of the oldest Mitford sister. Was she a radical subversive or just an old snob?
The Diary of Jack the Ripper (11.00 C5). Michael Winner with a new theory and "a number of Ripper historians".