POSSIBLY the question, What is the fourth dimension? may admit of an indefinite number of answers. I prefer, therefore, in proposing to consider Time as a fourth dimension of our existence ...

Electrons moved in two dimensions when influenced by a magnetic field, hinting at how a similar effect would occur in the fourth dimension.

Here it is explained that they were once human beings ... Fortunately, although the fourth episode is missing, the all important sequence showing the change of the First Doctor into the Second ...

Patrick Troughton took a holiday during the making of Episode 2. His absence was explained by having the Doctor unconscious for the whole episode. For the first time in the show’s history ...