Back to the Future

"He was never in time for his classes... He wasn't in time for his dinner... Then one day... he wasn't in his time at all."

- Tagline for the film

"17-year-old Marty McFly got home early last night. 30 years early."

- Unused tagline for the film

Back to the Future is an American science fiction/comedy movie directed by Robert Zemeckis and released in 1985. It is about a young man named Marty McFly who accidentally travels into the past and jeopardizes his own future existence. The film was followed by two sequels, (1989), and  (1990), forming a trilogy.

Back to the Future, a western Isekai, was written by Bob Gale and Zemeckis, and starred Michael J. Fox and Christopher Lloyd. The movie opened on July 3, 1985 and grossed $210 million at the US box office, making it the highest grossing film of 1985.

1985
On October 25, 1985, Marty McFly, a 17-year old high school senior, visits the home of his friend, an eccentric local scientist named Dr. Emmett L. Brown, but finds that "Doc" is not there. Moments before Marty had walked in, a report came across the television about missing and stolen plutonium. As Marty walks into Doc's house, he kicks his skateboard and it runs into a box of plutonium that is under Doc's bed. Marty, however, does not notice the box and proceeds to hook his guitar up to the giant amplifier. Marty turns the amplifier settings to their highest points and strums his guitar. The amp blows up and sends Marty flying into the shelves behind him. Marty soon after receives a call from Doc asking him to meet him at 1:15 AM in the parking lot at Twin Pines Mall and was told not to use the amplifier, even though he already used it. As Marty agrees, the clocks in Doc's basement chime the hour. When Doc Brown remarks that the clocks are 25 minutes behind, proof that an experiment was successful, Marty realizes that he is late for school.

When Marty gets to school, he is found by his girlfriend Jennifer Parker. She informs Marty that Mr. Strickland is looking for him. Mr. Strickland finds the teens and gives Jennifer and Marty each a tardy slip while reprimanding Marty. After school, Marty and his band, "The Pinheads," audition to play at the school dance, but the band is rejected for being "too darn loud." His band had been playing the song "Power of Love" by Huey Lewis and the News, and the judge who delivers the bad news is played by Huey Lewis himself. Afterwards, Marty confides in Jennifer, about worrying that he will never get a chance to play for an audience. As they sit on a bench in the Courthouse Square of Hill Valley, they are interrupted by a woman insisting that Marty and Jennifer help "save the clock tower." The lady proceeds to hand Marty a flyer about a campaign to save the clock tower, which was struck by lightning at 10:04 p.m. on Saturday, November 12, 1955. Jennifer soon has to leave and, as she is going to be at her grandma's house that night, writes the phone number on the back of the flyer, Marty folds the flyer and puts it in his pocket.

When Marty gets home, he finds that the family car has been totalled by his father George's supervisor, Biff Tannen, who has been drinking and driving (at the same time!), and is complaining that George had not told him the car had a "blind spot" (though most cars have a blind spot). Biff demands to know who is going to pay his dry-cleaning bill, as he spilled beer down his suit in the crash, then bullies George into writing his reports for work while making a rude comment by calling Marty "butthead". The family has dinner, during which it is discovered that Marty's older brother Dave works at a Burger King, his sister Linda has no love life, and his alcoholic mother Lorraine disapproves of girls chasing boys. She remarks that fate brought her and George together from her father hitting George with a car after he mysteriously fell from a tree. Lorraine then mentions their first kiss at the "Enchantment Under the Sea" dance. It is obvious that there is no real passion between Lorraine and George. Marty falls asleep after dinner and is woken up by Doc calling him to bring Doc's video camera to the Twin Pines Mall. Marty meets Doc at the mall to witness and film a demonstration of Doc's latest invention: a time machine made from a modified DeLorean sports car, which must reach 88 miles-per-hour in order to travel through time. Doc tests the car by sending his dog Einstein one minute into the future. Overjoyed by this success, Doc demonstrates to Marty how the time machine works by entering several significant dates into the keypad and telling him that the time machine needs 1.21 gigawatts of electrical power. Doc enters the date November 5, 1955 and explains to Marty that this was the day that he came up with the idea for the flux capacitor, the device that makes time travel possible.

After Doc refills the plutonium chamber of the time machine, a group of Libyan terrorists arrive, from whom he took the plutonium in exchange for a fake bomb. The Libyans shoot Doc, but Marty is able to escape in the DeLorean, accelerating to 88 miles per hour and thus inadvertently sending himself thirty years in the past to November 5, 1955.

1955
Marty, immediately, arrives at the Twin Pines Ranch, which was owned by Otis Peabody. Marty crashes into the barn on Mr. Peabody's property which causes the entire Peabody family to wake up and come outside. On seeing Marty in his radiation suit, it is concluded that he is an alien. Mr. Peabody then gets his shotgun to kill Marty, but Marty is able to escape. In his rush to get away Marty runs over one of the namesake "Twin Pine" trees in the DeLorean, speeding away as Mr Peabody hits his own mailbox with a shotgun blast.

Marty encounters many differences between 1985 and 1955, including a cleaner, less run-down ambiance in the Courthouse Square. While searching for a younger Doc Brown, he meets his father in a cafe and finds that even back then he was practically under Biff's heel. Following George, he finds him in a tree with binoculars, spying on Lorraine undressing. Suddenly George falls from the tree into the path of a car, but Marty pushes him out of the way and is hit instead. George runs off as the owner (Lorraine's father) shouts for help. Marty wakes up to find his mother watching over him, however it is a now teenage Lorraine caring for him and its clear she likes the stranger, who she calls "Calvin Klein" because she sees the name on his underwear. He has dinner with Lorraine's family, claims that he has seen the episode of The Honeymooners ("The Man from Space") on TV even though it is brand new, and meets his Uncle Joey, a future "jailbird" who loves being in his playpen. Disturbed by his "mother's" flirtations, Marty is shocked because she is entirely different from the prudish woman he remembers.

Marty quickly leaves after feeling uncomfortable and finds Doc, who disbelieves his story until Marty mentions the flux capacitor and how Doc came up with the idea. He then shows Doc the DeLorean. Amazed that one of his inventions will work, Doc realizes that he's got to get Marty home. After watching Marty's film of the time machine experiment, Doc is shocked to hear his future self explain that the DeLorean needs 1.21 gigawatts, and he runs off screaming "1.21 gigawatts?!" and Marty asks loudly "What the hell is a gigawatt?!" Doc realizes that he has no access to anything that would produce "1.21 gigawatts" of electrical power on demand and concludes that only harnessing the electrical power of a lightning bolt would give the flux capacitor that power it needs. Marty then shows him the flyer from 1985 that gives the exact time and place of a lightning bolt, one week away. Doc sets out to build a device that will let them channel the lightning bolt into the flux capacitor ultimately sending Marty back to 1985.

This excites Marty, suggesting that Doc shows him around town while he waits. Doc stops him in mid-sentence, stating that he cannot leave his house. Anything he does risks altering future events. Doc then asks Marty if he had talked to anyone else today beside him. Marty admits that he ran into his parents. Shocked at this revelation, Doc tells Marty that his encounter with his parents has jeopardized Marty's own existence. A photograph Marty carries of himself, Dave, and Linda documents this peril: part of Dave, the eldest, appears to have been "erased" from the photo, soon to be followed by Linda, and finally, unless disaster is averted, Marty. Suddenly realizing that pushing his father out of the way of the car is what caused his current problem, Marty sets out to get the two back together before it's too late.

Marty begins with trying to persuade George to ask Lorraine to the dance, but George is too nervous. They also have trouble with Biff, who is after Lorraine. After a couple unsuccessful attempts at getting George and Lorraine together, Marty dresses up in his radioactive suit and rudely awakes George while sleeping. Marty claims to be "Darth Vader" from the planet "Vulcan." The next morning, George finds Marty because he is now convinced that he must woo Lorraine. In Lou's Cafe, George attempts to woo Lorraine, but Biff comes in and harasses George. In an attempt to take up for his father, Marty trips Biff which leads to an exciting chase. Marty runs out of the cafe and creates a makeshift skateboard from a young boy's scooter. Marty is then able to outsmart and outmaneuver Biff and his gang, who are in a car. Biff subsequently runs into a manure truck. The whole incident makes Lorraine even more attracted to Marty, and she asks Marty to the dance.

Marty accepts the invitation, but forms a plan for George to get Lorraine. Marty tells George that his plan is to 'take advantage' of Lorraine in the car, so that George can come rescue her. On the night of the dance, however, Lorraine is more than willing to let Marty take advantage of her, having swiped some liquor for the event. She eventually plants a kiss on Marty, but it only last a couple of seconds suddenly growing uncomfortable, comparing it to "kissing my brother". Biff interrupts and gets in the car with Lorraine, while Biff's gang locks Marty in the trunk of the band's car. Marty is soon freed from the trunk, and he runs back to where Biff and Lorraine are. When George arrives, expecting Marty, he finds Biff harassing Lorraine instead. Biff offers George the chance to walk away as Lorraine pleads for help, but despite his fear George tells Biff to leave Lorraine alone. Biff responds by getting out of the car and twisting George's arm back, threatening to break it. Lorraine tries to force Biff to let go, but he pushes Lorraine to the ground and laughs at her. At this, George becomes infuriated; suddenly, he breaks free of Biff's grip and knocks him out with a single punch to the chin which Marty arrives just in time to witness. George and Lorraine head off to the dance, as the assembled students can't believe that George just knocked out Biff. Marty is also shocked, but happy, that his father finally stood up to Biff, however, the photograph is still fading.

It turns out that singer-guitarist Marvin Berry cut his left hand while trying to free Marty from the trunk using a screwdriver, meaning that the live music is seemingly over, robbing George and Lorraine of the opportunity to kiss on the dance floor. Marty volunteers to play the guitar instead, however, suddenly finding himself the only one left on the photograph, in which, Lorraine and George dancing was the only thing keeping him in existence. During the first number, "Earth Angel", Mark Dixon, a student, cuts in between George and Lorraine. Despite Lorraine asking George to help, he initially walks away from the confrontation. Marty suddenly collapses on stage and sees that his image is now fading from the photograph and reality (he proves this as he raises his right hand to see that he is literally fading from existence as his hand starts to become translucent). Thankfully George gets back his new-found confidence, pushes Dixon to the floor and proceeds to kiss Lorraine. At the moment of the kiss, Marty begins playing the guitar again with a renewed vigor. Looking at the photograph, Marty is fully restored before Dave and Linda also reappear, thus Marty's future existence, along with those of his brother and sister, is assured. At the band's request, Marty plays one more song, "Johnny B. Goode." Marvin Berry calls his cousin, Chuck Berry, and tells that he found the "new sound" Chuck was looking for. Marty does Chuck Berry's trademark duck walk, and then gets carried away imitating other guitar heroes: windmilling his arm and kicking over his amplifier in imitation of Pete Townshend, lying on the stage kicking his legs in imitation of Angus Young, playing behind his head like Jimi Hendrix, and tapping in the style of Eddie Van Halen. In the face of uncomprehending stares from the audience, Marty says, "I guess you guys aren't ready for that yet. But your kids are gonna love it."

Marty has a last chat with his parents and leaves to rejoin Doc Brown, who has suspended a cable from the top of the clock tower to channel the lightning into the DeLorean. Just as Marty is getting ready to take the DeLorean to the starting line Doc drew, Doc discovers a letter that Marty had written earlier describing Doc's death. Doc, not wanting to alter the future, tears it up unread and intends to throw it away. Before he can however, a tree limb falls onto the cable, disconnecting it. Doc puts the torn pieces of the letter in his coat pocket and runs to fix the cable. Marty continually tries to tell Doc about the future, but runs out of time and has to return to the DeLorean. Getting in the car, Marty bemoans that he needed more time... then realises that, as he's in a time machine, he has all the time he wants as long as he hit the cable at the lightning strike and resets the time circuits to take him back earlier than he left, so he can save Doc. Meanwhile, Doc fixes one wire only to disconnect another. He slides down the wire and reconnects it, just as the lightning hits the tower. Marty accelerates to 88 miles per hour and contacts the cable just as the lightning speeds through the electrified wire, sending the DeLorean back to the future, Doc runs along the fire trails, shouts in laughter at his successful experiment and the last of 1955 seen is Doc looking at the clock tower.

Back to 1985
Marty returns to 1985 ten minutes before he left, but the car stalls again. While frantically trying to start the car, the Libyans drive past and Marty has no choice but to run to the mall (now called Lone Pine Mall due to Marty having run over one of the pine trees in 1955). Marty arrives too late, and sees Doc being shot and his other self driving the DeLorean back in time while the terrorists crash into a Fox Photo booth. As Marty rushes down, he begins weeping over Doc's loss. Doc suddenly sits up, opening his radiation suit to reveal a bulletproof vest. He then pulls out the letter Marty wrote him, yellowed with age and taped back together from the shreds he tore it into 30 years before. Marty asks Doc why he kept the letter if he was worried about screwing up the future. Doc simply tells Marty, "Well, I figured, what the hell."

Doc drives Marty home, and then departs for the year 2015. In the morning, Marty discovers his house is different; there is a new BMW in the driveway (in place of the wrecked Chevrolet Nova), Linda has an active social life and Dave has an office job. Lorraine and George arrive home from playing tennis, both more fit and attractive, and much more affectionate to one another than when Marty left. Lorraine now approves of Marty seeing Jennifer and George also shows more self-confidence, even catching Biff in a fib. Biff, who is now timid and instead of being George's supervisor now has an auto detailing service, runs in with the delivery of George's first novel, a science-fiction story called A Match Made In Space. Marty then finds that the Toyota Hilux pick-up truck that he previously coveted is now his as a gift from his parents. As Marty and Jennifer are about to take a ride in the truck, Doc reappears in the DeLorean, telling Marty to come with him to the future, that something has got to be done about their kids. He hurries Marty and Jennifer into the car. As Doc pulls out of the driveway, Marty points out that there is not enough road to accelerate to 88 mph, with Doc replying, "Roads? Where we're going, we don't need roads," and flies off in the now fusion-powered and hover-converted DeLorean, leading to the events of Back to the Future Part II.

Anachronisms

 * Marty goes back to November 5, 1955. At the movie theatre on in town, it shows Cattle Queen of Montana (1954) as the feature currently playing. That film was released on 18 November 1954, and would not still be playing almost a year later. There’s nothing to indicate it was shown in Hill Valley straight after release, Besides, some films have had continuous runs at the same cinema lasting much longer than this. According to the reference book Film Facts by Patrick Robin son, South Pacific ran continuously at the Dominion in Tottenham Court Road for 4 years 22 weeks from April 1958 to 30 September 1962, The double bill featuring Young Frankenstein and The Rocky horror picture Show ran at the Time Centre at Baker Square fror 4 years 9 months from January 1981 to October 1985, and Emmanualle ran non stop for 10 years at Paramount City in Paris from 26 June 1974 to 26 February 1985. (Page 223). In addition, Screen 6 of Atlanta’s CNN Centre 6 shows Gone With the Wind twice a day on every day of the year^. (Page 225)
 * When Doc Brown is on the clock tower, there is a close-up of his shoes, with the cable hanging on them. He appears to be wearing shoes with a Velcro strap. Velcro had been invented, but wasn't yet in commercial use. The shoes are obviously inappropriate for 1955. Doc could have modified his shoes with his own version of Velcro.

Continuity

 * When Marty hitches a ride on the back of a truck, as he waves to the girls in the fitness center you can see he has a watch on his left hand. But when he meets Jennifer in school moments later, it has gone. He could have chosen to take it off between waving to the girls and meeting Jennifer.
 * When George and Marty are in the diner the first time, being accosted by Biff, George is looking at one of them in one shot, and when the shot changes, his gaze cuts sharply to the other one. He could have shifted his attention between them.
 * When Marty is pretending to be Darth Vader, the hair dryer in his belt appears and disappears According to the IMDB entry, some extra footage, wherein Marty moves the hair dryer, was cut from the final version.
 * Strickland holds his hands over his ears then puts them down after Marty plays "Johnny B Goode", then in the wide shot of the crowd Strickland has his hands over his ears again. Probably making sure his hearing is undamaged.
 * When George opens a bottle for Marty he has very disheveled, but a few moments later when they are out of the cafe George's hair is perfectly styled. George could have quickly combed it between shots.
 * The key bunch Marty used to try starting the stalled Delorean, shortly after he mounted the cable hook at the back of the car in 1955, was different from the bunch he used to start the again-stalled car shortly after his return to 1985. In fact, the one he used in the later scene consisted of just one key in a metal hoop. He probably removed the others and hid them in the car.
 * When Marty returns to 1985, he crashes the DeLorean into the church (that was a theatre in 1955), yet he pulls it out and the body of the car is flawless. The car probably has modified bodywork to protect it from any damaging effects of time travel. 
 * In the diner scene in 1955, Marty explains to young George McFly and Goldie Wilson that Goldie will be mayor in the future. Right after Marty says this, Goldie pauses and George looks at Marty. In the very next shot, George is looking at Goldie. George could be switching attention from Marty to Goldie to see Goldie’s reaction.
 * On the night that Marty leaves 1955 and travels back to the future, the swirling storm that generates the crucial lightning bolt instantaneously ceases once he has departed and Doc is seen walking the street with an expression of delight. The bolt could have been from the tail end of the storm.

Factual errors
====Errors made by characters (possibly deliberate errors by the filmmakers)====
 * The JVC camcorder requires constant pressure to operate the rewind feature, not just a single push and release. Doc Brown could have modified it for some reason.
 * When the Libyans are chasing Marty, the AK-47 the shooter is using jams not once, but twice. One of the most well-known qualities of this weapon is that it almost never jams, even when filled with water or sand. Maybe the ammo is slightly incompatible?
 * The "Libyan" driver wears a Saudi headdress. Most likely a disguise to allow entry into the United States, due to Libya being hostile to the United States at the time, as opposed to Saudi Arabia.
 * When Marty wakes up in his bed in 1985, in the bookcase behind his head there's a yellow magazine named "RQ". This stands for "Reference Quarterly", a trade journal of reference librarians. In the DVD commentary track by producers Bob Gale and Neil Canton, they admit that the set dresser made a mistake in putting it in, as a teenager would have no reason to have a copy of "RQ". Doc Brown could have arranged for Marty to have the magazine.
 * When Marty stays at the Baines house he asks where Doc Brown lives. Mister Baines tells him the directions. Marty then refers to the "John F. Kennedy Drive". Mr. Baines replies "Who the hell is John F. Kennedy?", even though JFK was already a prominent heir, a WWII Naval hero, and a US Senator from Massachusetts. (IMDB) Apparently Mr. Baines is not into politics.
 * When Doc Brown is running out of the house after hearing that Ronald Reagan is the president in 1985, he assumes that Jane Wyman is the First Lady. While Jane Wyman was Ronald Reagan's wife, they divorce seven years before the film takes place. By 1955, Reagan was already married to Nancy Davis. The Doc probably doesn’t approve of divorce, and would therefore still regard Jane Wyman as Ronald Reagan’s 'legitimate' wife.
 * In the movie Doc says that the time machine is electrical, yet he uses a nuclear reaction to generate power. There is but one type of nuclear reaction that directly generates electrical energy called beta decay, and it is predominantly used for long-term low power output, unlike the high-yield output required by the time circuits. All other nuclear power sources generate heat that is only later transformed into electricity using heat engines and alternators. (IMDB) It is possible this power source was in fact invented by Doc.
 * Doc's 1955 house has a doorbell; the button is clearly visible on the right side of the doorframe as Doc opens the door. Yet Marty knocks on the door instead of ringing the doorbell. Perhaps Marty believes the doorbell either doesn’t work, or would be too quiet.

Incorrectly regarded as goofs

 * In the opening scene, Doc's invention overflows Einstein's food bowl. When Marty enters, you see an empty bowl, but that's the water bowl.
 * Although not widely used until after the establishment of the SI in 1960, the metric prefix "giga-" was invented in 1951, so Doc could indeed have known it in 1955.
 * As George is approaching Lorraine in Lou's Diner in 1955, a customer nearby asks for a Cherry Coke. While Cherry Coke wasn't sold as a ready-made drink until 1985, Coke flavored with cherry or vanilla syrup was standard soda fountain fare in 1955.
 * Despite the more popular pronunciation of giga being 'giga,' 'jigga' is also an acceptable pronunciation.
 * Although the configuration of the gull wing doors on the DeLorean would make it impossible to open the doors once it was inside Doc's truck, he has a remote control for the car, so he wouldn't need to be inside the vehicle to load or unload it.
 * Since most pre-1965 silver coinage was out of circulation before 1985, Marty shouldn't have been able to pay for his coffee. However, the coffee Marty purchases only costs a nickel, a coin which did not change its metallurgical configuration during the transition.
 * When Marty Arrives in 1955 and crashes in to the barn, the DeLorean does not appear to be covered in ice, like it did a short while before, when returning to 1985 following Doc's 'one-minute experiment' in the parking lot. Since it's all imaginary, we can assume it has different settings.
 * DeLorean speedometers only go up to 85 miles per hour, but the one used in the movie goes up to 95 miles per hour. However, Doc presumably "doctored" it, or fitted a different one.
 * When Doc is at the Twin Pines mall and tests the DeLorean with Einstein, it appears that the car runs with an automatic transmission: Doc doesn't move any shifter mechanism or clutch on the remote. When Marty gets into the car shortly thereafter and for the rest of the movie, the DeLorean has a manual transmission. However it would clearly be within Doc's engineering abilities to retool the transmission or replace it with a custom one similar to a "manumatic", capable of going from manual to automatic depending on conditions. An automatic would be more suitable for a remote controlled vehicle. But a manual would be superior for someone in the driver’s seat when precise speed control is essential, especially in the scene when you see Marty shift when escaping the Libyans.
 * The guitar cord Marty plugs into the amplifier in 1985 is a TRS cable (tip, ring, sleeve), it has 2 bands going around the plug. The plug Marty plugs into his guitar is a right angled instrument cable (1 band around the plug). It is commonly thought that if Marty had been using a TRS cable he would have had another single banded cable hanging from his guitar (y-cable) but this is not necessarily the case as a TRS jack can be wired with the ring and sleeve shorted together making the ring and sleeve assembly appear electrically and mechanically to the jack socket as the same electrical contact like the right angled jack he plugs into his guitar.
 * SPOILER: When Marty returns to 1985, in under 10 minutes he runs a distance shown as 2 miles on a 1955 sign. That sign shows the distance by road, and he took a short cut.
 * SPOILER: It can appear to viewers that Einstein the dog is alive in both 1955 and 1985. Back to the Future Part III (1990) retroactively explains that the 1955 puppy is Copernicus, Einstein's predecessor.
 * SPOILER: At the beginning of the movie the name of the mall was Twin Pine Mall. When Marty arrives back to 1985, the sign at the entrance of the mall parking lot reads Lone Pine Mall. This is due to the fact that Marty knocked down one of the twin pines when he crashed into it when arriving back in 1955. Therefore, when history is changed because of this, there's only one pine tree on the spot where the mall is built, making it The Lone Pine Mall.
 * SPOILER: After Marty gets back to 1985 and sees his parents, they don't say anything about how much he looks like Marty from 1955. However, this obviously isn't the first time they've seen their son. They may have noticed the resemblance and may have mentioned it earlier. Alternatively, there is no reason to think they would notice how their son looks like a person they met 30 years ago for one week who they never saw again after that and whom they have no photographs of.
 * SPOILER: Marty went to the past wearing Nike trainers. When he was being chased by Biff he was wearing Converses. Then when he went back to future he was wearing Nikes again. Marty brought no other clothes with him, but it's conceivable that he obtained a pair of Converse with his other period-correct clothes.
 * SPOILER: After Marty returns to 1985, Doc Brown, forewarned by Marty's note, manages to survive being shot by wearing body armor. In 1985, there was no ballistic vest in existence capable of protecting against a long burst of 7.62mm rifle fire from an AK-47 at a range of a few metres (and presumably, he had not yet traveled into the future and found one that was). However, Doc could have invented it himself.
 * SPOILER: Doc Brown had to determine exactly which moment the lightning would strike the clock tower. 10:04 pm isn't accurate enough to set up the alarm clock in such a way as to make the DeLorean intersect with the cable the exact moment the lightning strikes. However, according to Doc, the flier says that the lightning strikes at "precisely" 10:04, presumably up to the second, which is what really happened. How the "historical preservation society" determined the precise moment of the strike is never explained, but they could have conceivably determined that by studying the clock's mechanism.
 * SPOILER: Doc is touching the wire when the lightning strikes the clock tower, but he doesn't seem to be electrocuted. However, most of the lightning's energy was absorbed by the flux capacitor (otherwise the time machine wouldn't have worked), and most of the remaining energy went into the ground. Electrical current prefers to move through the most conductive material in its path, which, in this case, would be a thick metal cable and not a human body (this is how the birds can sit on the power lines). Plus, Doc was wearing gloves, which made him even less electrically conductive. Still, even after all these reductions, the current which passed through his body was powerful enough to knock Doc off his feet.

Revealing mistakes

 * When the Libyans first fire upon the van, the bullets do not inflict any visible marks, leaving the van looking as if nothing had happened to it. The motion of their van could have caused the Libyans to miss.
 * Despite all of the DeLorean's collisions with objects or buildings (i.e. the barn, the theater by the clock tower, the trash can, etc.), there is still no visible damage to the car whatsoever. Even stainless steel is not scratch-proof. There would at least be a broken headlight, turn signal, damage to the time travel cables on outside of the car, or some other such thing. But there isn't even a scratch on the metal or windows. Doc could have modified the car to provide extra protection.
 * SPOILER: When Marty realizes he can save Doc by going ten more minutes into the past than originally planned, he actually resets the Time Circuits to go eleven more minutes into the past. He probably added another minute for luck
 * SPOILER: When Doc is walking across the ledge of the clock tower when the camera is looking up towards the ledge, you can see that the section Doc breaks off is clearly marked (it's darker than the rest of the ledge). Probably a botched repair of wear and tear.

Cast

 * Michael J. Fox as Marty McFly
 * Christopher Lloyd as Dr. Emmett Brown
 * Lea Thompson as Lorraine Baines McFly
 * Crispin Glover as George McFly
 * Thomas F. Wilson as Biff Tannen
 * Claudia Wells as Jennifer Parker
 * Marc McClure as Dave McFly
 * Wendie Jo Sperber as Linda McFly
 * George DiCenzo as Sam Baines
 * Frances Lee McCain as Stella Baines
 * James Tolkan as Mr. Strickland
 * J. J. Cohen as Skinhead
 * Casey Siemaszko as 3-D
 * Billy Zane as Match
 * Harry Waters, Jr. as Marvin Berry
 * Donald Fullilove as Goldie Wilson
 * Lisa Freeman as Babs
 * Cristen Kauffman as Betty
 * Elsa Raven as Clock Tower lady
 * Will Hare as Pa Peabody
 * Ivy Bethune as Ma Peabody
 * Jason Marin as Sherman Peabody
 * Katherine Britton as Daughter Peabody
 * Jason Hervey as Milton Baines
 * Maia Brewton as Sally Baines
 * Courtney Gains as Dixon
 * Richard L. Duran as Libyan terrorist
 * Jeff O'Haco as Libyan driver
 * Johnny Green and Jamie Abbott as Scooter kids
 * Norman Alden as Lou
 * Read Morgan as Cop
 * Sachi Parker and Robert Krantz as Bystanders
 * Gary Riley and Karen Petrasek as Guys
 * George Buck Flower as Red the Bum
 * Tommy Thomas, Granville Young, David Harold Brown and Lloyd L. Tolbert as Starlighters
 * Paul Hanson, Lee Brownfield and Robert DeLapp as The Pinheads
 * Charles L. Campbell as 1955 Radio Announcer and KKHV weatherman
 * Deborah Harmon as Newscaster
 * D'Janine King-Lasky and Tom Tanagen as Students
 * Huey Lewis as Audition Judge
 * Arthur Tovey as Wilbur
 * Tom Willett as Pedestrian

Michael J. Fox is, in fact, only ten days younger than Lea Thompson, and is almost three years older than Crispin Glover. However, it is less weird once one realizes that a large portion of the movie takes place in 1955, when George and Lorraine are essentially roughly Marty's age.

Titles in other languages

 * De Volta para o Futuro (Brazil)
 * Regresso ao Futuro (Portugal)
 * Regresso al Futuro (Spain)
 * Paluu tulevaisuuteen (Finland)
 * Retour vers le futur (France)
 * Ritorno al Futuro (Italy)
 * Zurück in die Zukunft (Germany, Austria, Switzerland)
 * Volver al Futuro (Hispanic America)
 * Návrat do Budoucnosti (Czech Republic)
 * Návrat do Budúcnosti (Slovakia)
 * Tagasi Tulevikku (Estonia)
 * Tilbage til Fremtiden (Danish)
 * Tilbake til Fremtiden (Norwegian)
 * Tillbaka till Framtiden (Swedish)
 * Aftur til Framtíðar (Icelandic)
 * Powrót do przyszłości (Poland)
 * Назад в будущее (Russian)
 * Vissza a jövőbe (Hungarian)
 * Bakku to~u- za- fu~yucha (Japanese)
 * 回到未来 (Chinese)
 * Behazara La'Ateed (Israel)

Recurring gags and catchphrase counts

 * See Recurring gags

Script
The inspiration for the film largely stems from Bob Gale, who discovered his father's high school yearbook and wondered whether he would have been friends with his father as a teenager.

Robert Zemeckis pitched the idea to several companies. Disney turned it down because they thought that a story involving a mother falling in love with her son was too risqué, even if it was a twist of time travel. All other companies said it was not risqué enough, compared to the other teen comedies at the time (see Porky's, Fast Times at Ridgemont High (1982) and Revenge of the Nerds (1984).

Sid Sheinberg, the head of Universal Pictures, made many small changes to the movie. "Professor Brown" was changed to "Doctor Brown" and his chimp Shemp to a dog named Einstein. Marty's mother had previously been Meg, then Eileen, but Sid Sheinberg insisted that she be named Lorraine after his wife Lorraine Gary. According to one of the DVD commentaries, Sheinberg also did not like the title, insisting that no one would see a movie with "future" in the title. In a memo to Robert Zemeckis, he said that the title should be changed to "Spaceman From Pluto", tying in with the Marty-as-alien jokes in the film. Steven Spielberg replied in a memo thanking him for the wonderful "joke memo" and told him everyone got a kick out of it. Sid Sheinberg, too proud to admit he was serious, let the title stand.

In the original script, Marty's rock-and-roll caused a riot at the dance that had to be broken up by police. This, combined with Marty accidentally tipping Doc off to the "secret ingredient" that made the time machine work (Coca-Cola) caused history to change. When Marty got back to the 1980s, he found that it was now the 1950s conception of that decade, with air-cars and whatnot, all invented by Doc Brown and running on Coca-Cola. Marty also discovers that rock and roll was never invented (the most popular musical style is now the mambo), and he dedicates himself to starting the delayed cultural revolution. Meanwhile, his dad digs out the newspaper from the day after the dance and sees his son in the picture of the riot.

In the film's script the word "gigawatt" is spelled and pronounced "jigowatt." Bob Gale and Robert Zemeckis had been to a science seminar and the speaker had pronounced it "jigowatt."

Casting and filming
As Back to the Future's producers scouted locations on a residential street in Pasadena, California, Michael J. Fox was elsewhere on that street, filming his second (Midnight Madness was his first) starring feature role, Teen Wolf. The producers became interested in having Fox play Marty McFly. However, Fox initially had to turn down the part because another actor in Family Ties, Meredith Baxter-Birney, was pregnant at the time, and so Fox's character (Alex Keaton) had to "carry the show."

Production of the film began on November 26, 1984 with actor Eric Stoltz portraying Marty McFly, and reportedly shot for more than six weeks, until the return of executive producer Steven Spielberg, who was out of the country at the time. After seeing a rough cut, Spielberg and the writer/directors agreed that Stoltz was a fine actor, but unfortunately not right for the part. Stoltz had played it seriously, and they wanted a lighter touch on the character. They returned to the idea of Michael J. Fox, who this time worked out a shooting schedule that would not interfere with his television commitment. Fox spent his days rehearsing and shooting Family Ties, and then drove to the movie's set to film Back to The Future all night. The movie's day shots were filmed on weekends. Fox reportedly averaged only an hour or two of sleep each night during production, which was completed on April 20, 1985, less than three months before the film's release.

Much of the original footage was retained for the film, for shots in which Eric Stoltz were not visible. Bob Gale later explained in a commentary track on a DVD release that some dialogue scenes with other actors were from the original shoot. A few long shots with Stoltz as Marty McFly still exist in the film, according to Zemeckis and Gale, and there was at least one "teaser" movie poster released with Eric Stoltz's name and face visible. One notable scene that was kept in the final film is the one in which Stoltz as Marty drives the DeLorean in the mall parking lot. Since the shots were fairly distant, with the driver's face not particularly visible, the footage was retained. According to Tom Wilson, another notable scene that was kept in the film was when Stoltz as Marty punches Biff in Lou's Cafe, he stated that since it was a closeup of himself they decided to keep that shot. In the skateboard chase scene, several shots of Eric Stoltz were kept since it was shot from behind him. For whatever reason, Michael J. Fox was given a different undershirt than the one Stoltz wore. It was a red patterned shirt, as opposed to Stoltz's white shirt. Thus, in at least three shots, Stoltz can be distinguished from Fox due to his white shirt. The easiest one to spot is when Marty is clinging onto the front of Biff's car. He is very clearly wearing a white undershirt, and he also looks taller. In the Libyan chase scene, many people mistook the actor jumping into the DeLorean as Stoltz, but in reality, it was a stunt double that looked similar to him, and was also wearing Fox's shoes, which were white Nike shoes, whereas Stoltz wore green converse all stars (which is the reason he drew attention in Lou's Cafe opposed to Fox's puffy vest being mistaken for a life preserver.)

Taglines considered but not used for Back to the Future were:
 * The adventures of Marty McFly.
 * Marty McFly just broke the time barrier. He's only got one week to get it fixed.
 * Meet Marty McFly. He's broken the time barrier. Busted his parents' first date. And, maybe, botched his chances of ever being born.
 * 17-year-old Marty McFly got home early last night. 30 years early.
 * Marty McFly's having the time of his life. The only question is... what time is it?
 * Marty McFly's future is catching up with him.
 * Marty McFly has just come between the most unlikely couple in high school. His parents.
 * Marty McFly took a spin in a new sports car last night. But he never got past '55. 1955.

Michael J. Fox had to learn to skateboard for the film. To find a coordinator for the skateboarding scenes, Bob Gale went to Venice Beach and approached two skateboarders. One turned out to be European skate champ Per Welinder. The skater he was with became the stunt double for Eric Stoltz, but was later replaced in order to match Michael J. Fox's height.

Christopher Lloyd reportedly based his performance as Doc Brown on a combination of physicist Albert Einstein and conductor Leopold Stokowski.

Several key scenes were filmed on the Universal Studios backlot in what is now known as Courthouse Square. The setting of hundreds of other productions, including the current television show Ghost Whisperer, it has suffered major fire damage on two occasions since Back to the Future was made.

The DeLorean time machine
The time machine went through several variations during production. In the first draft of the screenplay the time machine was a laser device that was housed in a room. At the end of the first draft the device was attached to a refrigerator and taken to an atomic bomb test site. Director Robert Zemeckis said in an interview that the idea was scrapped because he did not want children to start climbing into refrigerators and getting trapped inside. In the third draft of the film the time machine was a DeLorean DMC-12, as Zemeckis reasoned that if you were going to make a time machine, you would want it to move. However, in order to send Marty back to the future, the vehicle had to drive into a nuclear test site. Ultimately this concept was considered too expensive to film, so the power source was changed to lightning.

The DeLorean used in the trilogy was a 1982 DMC-12 model, modified to accommodate a more powerful and reliable Porsche engine (a Porsche engine was never put in any of the DMC time machines). The base for the nuclear-reactor was made from the hubcap from a Dodge Polara. In the 2006 Special-Edition DVD of the BTTF Trilogy, it is incorrectly stated that the DeLorean had a standard 4-cylinder engine. The only engine available on this car was a 130 HP V6. Also, the production ultimately used three real DeLoreans: one for external drive/race scenes, one with a modified interior for entering/exiting the DeLorean, and one stripped down model for interior scenes only.

The DeLorean time machine is a licensed, registered vehicle in the state of California. While the vanity license plate used in the film says OUTATIME (and originally NOTIME), the DeLorean's real life license plate reads 3CZV657.

Music
The film's musical score was by Alan Silvestri, who later wrote music for Forrest Gump and numerous other films, many of them directed by Robert Zemeckis. The memorable themes in his Back to the Future Suite have since been heard in the film's sequels (also scored by Silvestri), in Back to the Future: The Ride, and as ambient music at the Universal Studios theme parks. The hip, upbeat soundtrack, featuring two new songs by Huey Lewis and the News, also contributed to the film's popularity. "The Power of Love" became the band's first song to hit number one on the Billboard Hot 100 and was nominated for an Academy Award. Huey Lewis himself played the high-school band audition judge that rejects Michael J. Fox's band, The Pinheads, as they perform "The Power of Love." The film's soundtrack, which was available on compact disc, also included songs by Eric Clapton, Lindsay Buckingham, Etta James and others. Two 1950s hits Marty encounters when he arrives in 1955, Mr. Sandman by the Four Aces and the Fess Parker recording of The Ballad of Davy Crockett, were not included on the CD release. The material ostensibly by Marty McFly, Marvin Berry and the Starlighters was recorded by Harry Waters, Jr. as Marvin Berry and Mark Campbell as Marty McFly, and the guitar solo by Tim May. (Campbell and May received a Special Thanks acknowledgment in the film's end credits, with the recording credit going to the fictional characters). Berry's group also plays the song "Night Train", first recorded by Jimmy Forrest in 1951.

Critical
Reviews were generally positive. Roger Ebert complimented the direction, writing that Zemeckis "shows not only a fine comic touch but also some of the lighthearted humanism of a Frank Capra. The movie, in fact, resembles Capra's It's a Wonderful Life more than other, conventional time-travel movies.  It's about a character who begins with one view of his life and reality, and is allowed, through magical intervention, to discover another." Even the sequences where Marty's mom has the "hots for him" is regarded as "up-beat... without ever becoming uncomfortable." The BBC applauded the intricacies of the "outstandingly executed" script, remarking that "nobody says anything that doesn't become important to the plot later."

This movie ranked number 28 on Entertainment Weekly's list of the 50 Best High School Movies. As of December 2006, Back to the Future had received a very respectable 94% on Rotten Tomatoes, with 98% rating from the users. In 2006, Back to the Future was voted the 20th greatest film ever made by readers of Empire.

Cultural impact
The series was very popular in the 1990s, even making fans out of celebrities like ZZ Top (who appeared in the third film) and President Ronald Reagan, who referred to the movie in his 1986 State of the Union address when he said, "Never has there been a more exciting time to be alive, a time of rousing wonder and heroic achievement. As they said in the film Back to the Future, 'Where we're going, we don't need roads.'" He also considered accepting a role in the third film as the 1885 mayor of Hill Valley but eventually declined.

In early 2007, the film was spoofed in a DirecTV commercial, with Doc stating: "Great Scott! I forgot to tell Marty when he gets back to the future he needs to get DirecTV HD. It will already have all the best channels and soon will have 3-times more HD capacity than cable. Impossible?!? That's what they said about my Flux Capacitor!" A short version has Doc Brown saying "Great Scott! I forgot to tell Marty to get DirecTV HD! Soon they'll have 3-times more HD capacity than cable! TV from outer space!"

Series continuity
Sequels were not initially planned. Zemeckis later stated that had sequels been envisioned, the first film would not have ended with Jennifer traveling in the DeLorean with Marty and Doc, which created logistical problems in plotting the other films. In addition, the "To Be Continued..." caption was not added until the film was released to video by which time plans for a sequel (eventually two sequels) had been announced (the filmmakers chose to omit the caption from the 2002 DVD release).

Ultimately, the sequels did not fare as well at the box office. While the first installment grossed $210 million (making it the biggest-earning movie of 1985), Parts II (fall of 1989) and III (summer of 1990) made roughly $118 million and $88 million, respectively (still making them hits, but not major hits).

Home video release history

 * December 15, 1990 (VHS)
 * December 17, 2002 (VHS & DVD)
 * October 26, 2011 (Blu-ray & DVD)
 * February 15, 2012 (Zune/Xbox Live, PlayStation Network, and other digital gateways)

Behind the scenes

 * According to some websites, such as imdb.com, Leonard Nimoy was going to direct Back to the Future but was unable to because he was starting work on the story for Star Trek IV: The Voyage Home. In November 2010, Bob Gale spoke to BTTF.com as part of a Myth Debunking story and debunked this rumor and said that "No one but Bob Zemeckis would have ever been allowed to direct Back to the Future because we both had complete control of the script."