The Fourth Dimension
Forest of the Dead
Humans unwittingly living an artificial within a computer is the central theme of recent science fiction trilogy, The Matrix. This film in turn echoes many ideas found in the 1976 Doctor Who story, The Deadly Assassin.
The computer system with the biggest single data storage capacity is believed to be at the CERN computer centre. It has a 2 petabyte hard disk and 10 petabytes of data stored on robotic tape store (a petabyte is equal to one quadrillion bytes).
However, the computer with the biggest networked data storage is the Google computer system. The system is estimated to be in excess of 1 yobibyte - a massive 1x10 to the power 80 bytes.
The current biggest single computer memory system (on one computer) is believed to be the one being used by the British National Health Service, but this will be surpassed by a similar system currently being installed in Finland, where all health care information will be stored in a database totalling approximately 900 petabytes in size.
River Song is not he only archaeologist to have shared adventures with the Doctor. Back in the 1990s, Paul Cornell (Human Nature) created Professor Bernice Summerfield as a companion for the Seventh Doctor in the Doctor Who 'New Adventures' novels. Bernice (aka Benny) appeared in dozens of books before getting her own spin-off series of books and audio adventures, in which she is played by Lisa Bowerman.
You Can Call Me CAL
It's probably a coincidence, but CAL was also the name of the computer graphics company that created the title sequence used between 1987 and 1989 for the Seventh Doctor's adventures. A result of this work was the creation of the first photo-realistic CGI TARDIS, featured in 1987's Time And The Rani.
Nobody has ever died on screen in a Steven Moffat Doctor Who story by any means other than natural causes, and not been subsequently resurrected in some way.
Silence In The Library/Forest Of The Dead is Eve Newton's first major role. Before winning it she had previously auditioned for a part in the St Trinian's film. Presumably not the part that went to Talulah Riley (Miss Evangelista)!
If you look closely at the wall in Charlotte's house you will see two of her drawings are of a blonde girl and a wolf. Make of these what you will...
Charlotte also has a toy Robbie The Robot, from the film Forbidden Planet.
Beam Me Up, Doctor!
In the 2007 Christmas Special, Voyage of the Damned, the Doctor managed to retrieve the data from Astrid Peth's teleport pattern, allowing her to enjoy a 'life' after death, floating through the stars.