Continuity mistake: In 1955 while the Doc is recording some stuff, while Marty behind him is sleeping on the couch, his head moves from side to side between shots.
Continuity mistake: After visiting Seamus, Marty walks to the Hill Valley train station where a man is by the ticket window. In the next shot the man has disappeared. (00:26:35)
Continuity mistake: When Marty and Doc are jumping on the logs on the train, the sun changes between shots.
Continuity mistake: When Doc realises that his name has disappeared from the tombstone, the date on the tombstone remains, but in the next shot, it disappears. (01:07:47)
Continuity mistake: When Marty is about to race against needles, the camera zooms in towards his car. Notice a big rectangular black object reflected on the car. From opposite angles it disappears and there's just green fields. The black object was most surely a structure to hide the camera equipment.
Continuity mistake: While Marty is fighting Tannen the sun changes between shots.
Continuity mistake: In the end scene where Doc's train comes back to 1985, Marty and Jennifer are literally blown away by the re-emergence of the train. While they are flying in mid-air, the front of the train is passing them by and gets just about to the cab (where the ELB is). However in the next cut, Marty and Jennifer are on the ground watching as the train just starts passing them again, and the train comes to rest at a point before the previous "blown away" cut scene.
Chosen answer: Yes. A "googol" is the number 10 raised to the 100th power, or a 1 followed by 100 zeroes. A "googolplex" is an even larger number - 10 raised to the power of a "googol", or represented as 1 followed by a "googol" zeroes.
BGraz