In the original script for Back to the Future, Doc Brown’s time machine was nothing like the iconic DeLorean in the final film. In the film, Doc Brown's time machine is a car and the image of the DeLorean has become synonymous with the classic 1980s sci-fi trilogy. But director Robert Zemeckis and executive producer Steven Spielberg likely had no idea how much their creative choice would influence pop culture for decades – they just liked the spaceship vibe of the DeLorean’s gull-wing doors as Marty exited the DeLorean in 1955 like an alien from a UFO. That could have been dramatically different if their original idea for the time machine had gone ahead.
The DeLorean time machine first appears in Back to the Future when Doc Brown tells Marty McFly to meet him at a mall parking lot. The actual time machine within the DeLorean is called a “flux capacitor,” which is powered by Coca-Cola – and, of course, a little help from plutonium. Doc Brown acquired the plutonium from a terrorist group that had asked him to build a bomb. When the terrorist group discovers that Doc Brown hasn’t done as they asked, they ambush Doc Brown and Marty McFly. Marty escapes alone in the DeLorean and is transported back to the year 1955, where the DeLorean breaks down. But with the help of a slightly younger Doc Brown, Marty gets the DeLorean time machine running again and returns to his home in 1985.
It’s hard to imagine the time machine in Back to the Future being anything other than a DeLorean, but in the original script, the time machine wasn’t even a car – and the flux capacitor didn’t exist, either. Instead, the time machine was a laser device called a “power converter” that was housed in a refrigerator, which was then loaded onto a truck and driven into a nuclear blast that would have powered the time machine. Marty would have been transported back in time by entering the fridge to shelter himself from the blast (not unlike Indiana Jones in Indiana Jones: Kingdom of the Crystal Skull). Converting the time machine to a device powered by plutonium and housed within a DeLorean seemed to remove a lot of extra steps, but it accomplished a more important goal as well.
At the time, many household fridges still had latches that would hold the door shut and keep food fresh, but the unintended effect of this feature was that children would sometimes climb into fridges, close the door, and be unable to open the fridge from the inside – tragically, some of those children died. Steven Spielberg was worried that children watching the film would see Marty getting inside the fridge and try to recreate the scene in their homes.
The creators then made the right call in changing Back to the Future's time machine to a DeLorean for more than one reason. In the process, they came up with something better for children to watch, but their new idea was also more interesting and uniquely Back to the Future. The DeLorean, a car that would have otherwise become lost to the memories of future generations, became a symbol of 80s pop culture that has stayed popular for more than thirty years. Most kids born after 2000 won’t recognize a floppy disc or cassette tape, but because of Back to the Future, there's a good chance they still know the DeLorean.