Douglas Adams chose 42 as the Ultimate Answer of Life, the Universe, and Everything simply because he thought it was the funniest-sounding of all two-digit numbers. "A completely ordinary number, a number not just divisible by two but also six and seven. In fact it's the sort of number that you could, without any fear, introduce to your parents."
At the time of production, BBC policy required all television comedy to have a canned "laugh track". Before its broadcast debut, episode 1 was screened to 100 science fiction fans (with laugh track and a rather amusing introduction by Peter Jones). Armed with the fans' feedback, Douglas Adams and Alan J.W. Bell were able to convince BBC executives to change the policy, and the laugh track was removed before broadcast.
The wardrobe crew were shocked to discover, halfway through filming, that only one dressing robe had been purchased for Arthur, and the line had been discontinued by the manufacturer. The cast & crew were then ordered to be particularly gentle with the robe for the remainder of production. Towards the end of the series, it was rumored that a second series would be made, and when shooting wrapped the robe was locked away to preserve it in case it would be needed again.
Because the set for the Golgafrincham captain's bathtub on prehistoric Earth was located out-of-the-way in the woods, there were few options on how to get the tub filled with warm water that the actor could sit in for filming. In the end, the solution was to buy a truckload of hot water from a local paper mill. When the truck arrived, it was discovered that the water was waste water from paper production, which had numerous semi-toxic chemicals in it. The actor was not told until after filming had wrapped. [Source: "Don't Panic!" behind-the-scenes DVD extra, 2001]
EASTER EGG: On the Region 1 and Region 2 DVDs, disc 1, sit at the main menu. After a minute or so, the film will start automatically. Return to the main menu, and wait again. After another minute or so, the video will start again, but will begin to distort. A message will then appear explaining that your DVD player has been affected by the Infinite Improbability Drive.
David Dixon was cast primarily because he had a serious face, but "weird" eyes. It's nearly impossible to see in the film, but he wore *purple* contact lenses while playing Ford, to make his eyes look even stranger.
The original concept came to Douglas Adams in the early 1970s whilst backpacking around the continent with a copy of "The Hitch Hiker's Guide To Europe". He found himself lying drunk in a field in Innsbruck, looking up at the stars. He decided that someone should write a Hitch Hiker's Guide to the Galaxy; several years later he would remember the idea and write a BBC radio show around it. Later in life, Adams said that he had related the "drunk in a field" story so many times in interviews that he had lost all memory of the actual event, and simply repeated the anecdote verbatim.
Sandra Dickinson auditioned speaking in her natural American accent but offered to speak in a British accent during production. But Douglas Adams was so impressed with her audition that he encouraged her to speak in her normal voice.
Zaphod's second, remote controlled mechanical head constantly malfunctioned on the set, resulting in it lolling to the side or staring blankly into the distance. In addition, if Mark Wing-Davey became overly active whilst wearing the costume (something that was very prone to happening, due to the show's plot and Zaphod's inherent character), the motion would often strip the gears inside the head. Wing-Davey later said in interviews that the cost of building and maintaining the head probably exceeded his salary for the program.
The story was originally written as a radio series of six shows broadcast on BBC Radio 4 between 8th March 1978 and 12th April 1978. As well as this TV series the story spawned further radio series, records, books, a stage production, a computer adventure game, a film (The Hitchhiker's Guide to the Galaxy (2005)), and even a towel.
EASTER EGG: On the Region 1 and Region 2 DVDs, disc 1, select "Set-Up", then go left. Enter the code "1-1-4-6" to see a video of the destruction of Earth, followed by the recipe for the Pan-Galactic Gargle Blaster.
The program gives the answer to life, the Universe and every thing as "42". Then the program gives us the question to life, the Universe and everything as "What do you get if you multiply six by nine?". In base 13, 6 x 9 = 42, but Douglas Adams said several times that "nobody writes jokes in base 13".
Three models of Slartibartfast's air car were built, for various shots. The first, when Arthur gets in, was mounted on top of a truck. Using a careful camera angle, the truck was not seen as it began to drive away, moving the "car" out of frame. Then, a shot of the air car flying was done using a crane and cables. The actors were replaced by stunt men for this shot, as the car was at some points more than 200 feet above the valley floor. Finally, the underground sequence was filmed in a mining tunnel; this "air car", and a camera, were mounted on a dolly that rolled along rail tracks.
The underground tunnel on Magrathea was an active mine, and the lighting seen is fluorescent lights that already existed. The production crew asked for these to be turned off for filming, but were told that the lights had been on for years, and most of them would fail if they were ever turned off and back on. Since there was no budget to replace any burned-out tubes, the lights were left on.
In the original radio broadcast, the worst poet in the universe was given a name of a real person (Paul Neil Milne Johnstone, a classmate of Douglas Adams). Under threat of legal action, Adams altered the name slightly for the television series and novel.
EASTER EGG: On the Region 1 and Region 2 DVDs, disc 2, in the "Inner Planets" menu (the first menu shown), make sure the subtitles are turned *off*, then highlight "Communicate", and go left. You will see an Earth icon in the center of the screen. Press Select to see a segment called "The Full Version of The Opening Titles". This version is actually the same length as the regular version, but the "O tunnel" the astronaut travels through is replaced by the opening "vortex" from 1970s-era episodes of Doctor Who (1963).
At the request of Mark Wing-Davey, two stuffed "sausage-shaped" panels were added to the Zaphod costume, along the inside of each thigh. The implication was that, along with an extra head and extra arm, Zaphod had two penises. The original design was for them to be nine inches long, but the wardrobe department requested that they be reduced to seven. They are not visible in any shots in the final edited series, although they can be seen - if you know what you're looking for, and care to - in some production stills. [Source: "Don't Panic!" behind-the-scenes DVD extra, 2001]
The names Slartibartfast, Majikthise, and Vroomfondel were intended to *sound* like rude words, whilst slipping under the radar of the censors. According to Douglas Adams, "Slartibartfast" started out as "Phartiphukborlz", and then he played around with the syllables until he had "something which sounded that rude, but was almost, but not quite, entirely inoffensive."
The theme music, "The Journey of the Sorcerer", was written by Bernie Leadon and originally recorded by the Eagles. Although the Eagles' version (from the "One Of These Nights" album) was used in the BBC4 Radio version of Hitch Hiker's, the TV version used a new recording arranged by Paddy Kingsland.
Douglas Adams said that he was pleased with the smooth way the TV series worked out, largely as a result of the radio series: the jokes had already been tried and tested, and the narration (something that he never would have considered if the TV version had come first) became the voice of the Book, providing an easy framework for many of the show's best gags.
Although this series follows very closely to the plot and dialogue of the first six episodes of the radio series (a.k.a. the "Primary Phase", first broadcast in 1978), it also includes some minor references to elements of radio episodes 7-12 (a.k.a. the "Secondary Phase", first broadcast in 1980). For example, the book entry on Sirius Cybernetics Robots shows a Frogstar Warrior Robot; Ford advises Arthur on the need to possess a towel for galactic hitchhiking; and the book's entry on Disaster Area shows the word "Belgium", which, in the Hitchhikers' universe, is the rudest word imaginable.
The Ford Prefect was first manufactured in the United Kingdom in October 1938, remaining in production until 1941. The Prefect was returned to production in 1945 and was offered in various models until 1961. Manufactured primarily in the UK and Ireland, it was also assembled and sold in other countries, including Malaysia, New Zealand, South Africa, and Australia.
EASTER EGG: On the Region 1 and Region 2 DVDs, disc 2, click "Outer Planets", then turn *on* the subtitles. Highlight "Deleted Scene from The Hitchhiker's Guide to the Galaxy: Episode #1.2 (1981)", then go left, to show a "Don't Panic" icon in the upper left corner. Press Select to view the animated "computer display" shown on the Heart of Gold main screen. It shows, in order: a breakdown of the "sector ZZ9 Plural ZA" spatial reference; data about the improbability of rescuing Ford and Arthur; a comparison of the found planet to known parameters of the legendary Magrathea; tactical plots of the flight over Magrathea; readouts on the incoming missiles; and simulations of the missiles turning into a whale and bowl of petunias. Note that because this animation was solely intended as animated set dressing, it is completely silent with no sound effects or narration.
Alan J.W. Bell relates that he was working on a "making-of" documentary about Star Wars: Episode V - The Empire Strikes Back (1980), in a cutting room in Ealing, when Kevin Davies overheard a sound, stuck in his head and said "Excuse me, is that R2-D2?". Davies (a huge Hitchhikers' fan) then recognized Bell's name, and recommended his employer (Rod Lord Animation) for the graphics in the TV version.