Back To The Future: Part 1 FAQ

The answers and conceptions used on this page may NOT be official. They are discussed and used on the forum at All answers are modified to be suitable for this FAQ, but the idea are credited with the username that were provided at the moment it was collected from BTTF forum.

3.1: In 1985 (Before timetraveling)

3.1.1: When Einstein travels alone 1 minute into the future, shouldn’t he meet himself?

Background: When Doc and Marty travels to 2015, they meet Old Marty. When Einstein travels to the future alone, he does NOT meet himself.

Yes, theoretically Einstein should meet himself, but since he traveled 1 minute into the future and Doc and Marty waited 1 minute the ripple effect already caught up. If Marty and Doc have stayed in 2015, the old Marty would eventually disappear because Marty never returned to 1985 and continued his life. When traveling into the future it will always be the 'most likely future' from that point you travel from. The space and time continuum obviously decided that Einstein wouldn't exist 1 minute into the future.

3.2: In 1955

3.2.1: In the "Darth Vader"-scene, Marty has a modern hair dryer tucked in his belt, obviously not something they had in 1955. Where did this come from?

The hair dryer was in a suitcase that 1985 Doc put into the DeLorean trunk at Twin Pines Mall. There was a scene in which 1955 Doc looks through the contents of that suitcase, picks up the hair dryer and asks "What's this?" "A hair dryer," Marty replies. Doc shakes his head and says, "A hair dryer? Don't they have towels in the future?" However, the scene was cut from the final film for time (see The Secrets of the Back to the Future™ Trilogy).

3.2.2: Why does Marty, as the youngest, still have the same name in Lone Pine timeline?

Background: In the scene where Marty leaves his parents in 1955, after they kissed and got together, Lorraine declares that she wants to name her son after him. Logically she would name her first son Marty. In this case this would be Dave, who is the oldest son, and the real Marty would then have another name. As we know this doesn’t happened, and Marty still have his own name when returning to 1985.

We can assume SPE (Self Preservation Effect) takes care of important events still happens to keep space and time continuum balanced. The 'effect' makes sure that Lorraine and George have kids on the exact same date and in this case the same name as in the original. Even when Lorraine tell Marty she will name her child after him, there may be other events later that effects the name of her first born child.

3.3: In 1985 (After returning from 1955)

3.3.1: When Marty returns to 1985, and see himself go off to 1955, wouldn’t that Marty meet himself in 1955?

Background: We know that the year 1985 Marty returns at the end of the movie are a new timeline because of the sign at the mall says: "Lone Pine Mall", which were changed because of the events he made back in 1955. In BTTF2 we see Doc and Marty go back to 1955, and Marty have to avoid meeting himself.
Beneath are different theories of this matter. Before you start reading, notice that the Marty we see in the start of the movie are referred as Marty (1). The Marty that travels back to 1955 at the end of the movie, are referred as Marty (2). So at the end of the movie, Marty (1) see Marty (2) go off to 1955. The original 1985 up till the actual time-travel are known as TP timeline (Twin Pine), and the year 1985 Marty returns to are basically known as LP timeline (Lone Pine).

  • Alternative answer 1#: After Marty changed 1955, and thereafter became happy in 1985, we can assume the new Marty (2) who grew up in Lone Pine-timeline are little changed, in effect of his new parents. He might been told that he’s been named after a guy called Marty back in 1955. When Marty (2) then travels back to 1955, this would be the changed timeline (altered by Marty (1)), where he without know it follow the same step as Marty (1) and maybe bump into himself. The theory is based on later similar events in the trilogy. Like: When Doc and Marty in BTTF2 travels back to 1955 and end up in the timeline where Marty (1) currentl are, and they have to be aware of Marty not meeting Marty (1). In this theory it would end up with a infinity loops where 1955 constantly will be changed with a new Marty in each loop. The sequel BTTF2 are obviously not affected and continues right after where BTTF1 ends. (Mr.XL – source:
  • Alternative answer2#: From the first theory there will be infinity loop of events in 1955, and when Marty meets himself would likely cause a paradox. It is suggested that SWP (Single Wormhole Preservation) prevents multiple wormhole to happened if timetravel happened on exact the same time and place. This would explain why Marty (2) in Lone Pine 1985 travels back to 1955 and wouldn't meet himself, but actually travels back to a 1955 without Marty (1). It also explains why Doc and Marty doesn’t end up in the original 1985 when they travels from 2015, and when they later travels to 1955 and ends up in the 1955 where Marty (1) altered his parents life, and not the original 1955. Likewise when Marty travels to 1885 to meet Doc. (Mr.XL – source:
  • Alternative answer3#: When Marty (2) go off to 1955 he simply disappear and are erased from existents. However this theory is not satisfied. In the trilogy there are a lot of timetraveling and it doesn't give a consistent answer on when a timetraveler cease to exist when going off to a already altered timeperiod.
  • Alternative answer4#: When we realize 1985 are changed to Lone Pine Mall, we know this happened when Marty (1) went back and hit the pine tree. This is the first altering made by Marty (1) in 1955. When Marty (1) returns to 1985, the change of Twin Pine to Lone Pine effects immediately by the ripple effect, so when Marty arrives to Doc Twin Pine Mall are already changed to Lone Pine Mall, but the ripple effect hasn’t yet cached up to the actual event when Doc buy a bullet proof vest. So what we see here is a mix of LP and TP timeline. Marty (1) actually see Doc been killed and dies, but as Marty runs to Doc, the ripple effect goes beyond Doc purchasing the vest, and then Doc does survive. So Marty (2) travels back to a unaltered 1955 before the ripple effect caches up. (Mr.XL – Source: (NEED TO BE REWRITTEN)
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