So I’ve already had my question regarding the timeline in BTTF2 answered regarding how Biff was able to return to the same timeline in 2016 after the act of giving a younger version of himself the Sports Almanac. A deleted scene actually shows Biff being ‘erased from existence’ shortly after hiding behind the car across the street, and we also never see another inside view of Marty’s home – only Doc and Marty returning to the Delorean. The explanation being that the timeline changed around Doc and Marty without their knowledge, and that Biff had either been shot to death in the new timeline by Lorraine, or that he simply no longer existed because his past was changed so significantly.
All that said, I awoke this morning after falling asleep while watching BTTF1, and had the thought that makes the already complex idea of time travel even more complex (for me, a layman). Say you build a time machine capable of going backwards and forwards in time – don’t you also need to factor in as part of your ‘destination coordinates’ the estimated position of the planet in that time? Consider that the Earth is traveling through space in its orbit at 66,000mph, while rotating at speeds of up to 1000mph at the equator… If you actually manage to remove yourself from the timeline in order to travel, without a precise calculation of exactly where your destination is in the 3rd dimension (X,Y,Z), you could end up floating in space, embedded beneath the earth, floating (and falling) from several thousand feet in the air, or at a completely alternate location on the surface.
I don’t claim to be an expert in the concept of time travel beyond Hollywood or novels, and this topic may have been discussed before… but I just got a kick out of this being the first thought that entered my head when I woke up this morning. 🙂