Prior to this point in time, somewhere in the past, the timeline skewed into this tangent creating an alternate 1985. Alternate to you, me and Einstein, but reality for everyone else.
16 seconds sound clip from the Back to the Future Part II movie soundboard.
You can hear this line at 00:52:41.083 in the Blu-ray version of the movie.
Quote context
[...]
- The lab is an awful, awful, awful, awful mess. Attaboy.
- Here, here, here. Let me illustrate.
- Imagine that this line represents time. Here's the present, 1985, the future and the past.
- It's the top of Biff's cane. I mean, Old Biff from the future.
- Correct. It was in the time machine because Biff was in the time machine with the sports almanac.
[...]