Wouldn't Marty's parents and Biff Tannen be amazed and freaked out that their son Marty is identical to Calvin, the kid that played a major part in all their lives, and who they would definitely remember? [It's 30 years later, I doubt they remember a guy who they only knew for a few days back when they were teenagers well enough to recognise him as Marty.]

In the scene where Marty is playing "Johnny B. Good" there is an overhead view of the dance in the gymnasium. If you look quickly, you can spot the 3 point line on the gym court. The three point line did not come into existence until the late 1970s. [Having just watched the scene in the gym three times, there is definitely NOT a three point line on the floor in any shot. In fact, it was intentionally supposed to be a VERY short basketball court. The top of the keys almost touched. There wasn't even room for a full center jump circle. (I have seen gyms like this even in the 80s.) Several shots show the floor and none of them shows a line that could be considered a three point line. It simply is not there and wouldn't be there since they didn't shooot the scene on an NBA gym which would be the only gym that would have one in 1984-1985 during the filming of this movie.]

When they're refilling the car with plutonium, after putting it in, Doc removes his helmet, and says "it's safe now, everything's lead lined". Fair enough, except he then takes the container the plutonium was in back to the box (which contains a lot more plutonium), flips the lid, and shoves it back in. If that process was safe, which bit of the reloading process was dangerous? [The safety gear was in case anything went wrong when the plutonium was being sucked into the car, not for handling the plutonium.]

In the scene where Marty & Doc are watching the videotaped experiment, Doc picks up the camcorder to admire it. As he does, a wire that was connected to it falls off, yet the playback is unaffected. [If the wire was the AC adapter, and the battery had charge left, playback wouldn't have been affected. Doc would have likely had the AC adapter and all the patch cables in his suitcase stored in the DeLorean's hood-trunk. Perfectly reasonable assumption, since hosehold-standard voltage hasn't changed for many decades, and it isn't likely to be changed in 2010 (Doc's original idea for his destination year).]

When Marty encounters Doc Brown for the first time in '55, Brown asks him who is now the president (in the future) and Marty responds "Ronald Reagan" (pronounced Raygen); then Brown says "Ronald Reagan the movie actor?" When Ronald Reagan was a movie actor, he pronounced his last name "Reegan" (he changed the pronunciation later when he got into politics), so Brown shouldn't have been able to make the association. [Doc may have easily made the association, even if he had thought Marty pronouncing it incorrectly. Many times, people hear what they think they hear, and if you say the name quickly either way, it could be taken as either pronounciation.]

In the scene where Marty is playing Johnny B. Goode, and someone cuts into George and Lorraine's dance, Marty starts disappearing. Then he comes back, pushes the guy down, and kisses Lorraine, resulting in Marty reappearing. But George did that on his own, without Marty interfering, so why should he have disappeared in the first place? He was always going to come back and assert himself - it's not like the timeline was being changed. [ According to the films, the future is never set. For instance, in the third film, at first it's Doc's name on the tombstone, then no one's name, then Marty's name starts to appear, then finally the tombstone diasppears altogether. This happens in response to how Doc and Marty act and make decisions. The same idea applies to the dance- when it looks like George is just going to walk away, Marty's existence is in danger, but when George changes his mind and returns to Lorraine, the future has changed, and Marty's existance is secure.]

After Marty gets off the stage after playing "Johnny B Goode" he runs into his future parents. His father thanks him for all his good advice. His mother asks him if they are ever going to see him again. Wouldn't they just assume that Marty will be back in school on Monday? [Although I don't think it is ever said, it is made clear throughout the film that Marty (posing as Doc's nephew) is only at the school for a short time, whilst staying with his 'uncle'. The night of the dance is obviously his last night before returning to his normal school.]

In the beginning, Doc and Marty meet at the Twin Pine Mall, and we learn that Doc has built a time machine, which runs on plutonium. He has a heavy case filled with several containers of plutonium, one of which he inserts into the DeLorean. Doc is then killed and Marty flees to 1955. When he goes back to 1985, he plans to get there ten minutes early in order to prevent Doc's death. However, the car runs out of gas and Marty has to run to the Lone Pine Mall on foot, thus getting there too late. He is devastated that Doc is dead. Why? There is more plutonium two feet from him, in the truck. He can just take some, put it in the car, and come back ten minutes early again--or thirty minutes, or an hour, or a day, or whatever he wants. [True, but this solution probably wouldn't occur to him moments after he saw Doc murdered, so it is conceivable that he would grieve for a while and then hit on the idea if Doc hadn't been wearing body armor.]

When Marty first arrives in '55, he has to walk 2 miles into Hill Valley from where he leaves the car. But back in '85 he can get from downtown (crash near the movie theater) to the Mall in less than 10 minutes. Why need a skateboard when you can run that fast? [In 1955 Marty drives for a while from the future 'Twin pines/Lone Pine' mall spot to where he parked the car (the future Lyon Estates). It was dark when he started driving and daylight when the car gave out on him. Not knowing that he was in the past he probably tried to drive from downtown Hill Valley to his home. The mall is a lot closer to downtown Hill Valley. Maybe even in Hill Valley.]

In the scene where Doc is demonstrating the time machine for the first time, he enters several dates he could conceivably go to, one of which is the birth of Christ, which he enters as Dec. 25, 0000, but there is no year 0. It goes from 1 B.C. to 1 A.D. [Yeah, it's something Doc should have known, but he was simply demonstrating the circuits to Marty, so I dunno if this could be counted as a filming mistake. If Doc was that concerned with inputting the actual date, it would have been (according to historians) sometime in March or April of 4BC.]

Watch the "shooting" scene in the beginning in slow motion. You will notice Eric Stoltz running for cover instead of Michael J. Fox. (Eric Stoltz was the original Marty.) [All the shots of Marty running are quite clearly Michael J Fox].

Doc uses plutonium in the DeLorean's flux capacitor via a container of liquid. Plutonium is typically formed in rods of packed pellets, not in a liquid form. [The liquid just surrounds the little rod of plutonium in it. Watch when Doc refils the Delorean, he turns the cylinder and the little rod gets sucked down. That is one of the rods you are talking about.]

In the scene where Marty is trying to call Doc from the coffee shop, his digital watch beeps. He is never shown removing it and it's the last we see of the watch. Wouldn't Marty have used the digital watch as proof to Doc he was from 1985? Would it not have been more accurate for timing in the scene when Marty drives towards the clock tower (to go back to '85) than of the analog alarm clock? [We do see the watch two more times in the movie. When Marty and Doc are uncovering the car to get ready to send him back to 1985, Marty has the watch on, but when he drives the car down the street it is back off. Then we see it again when Marty gets back to 1985 and is at the mall watching himself getting chased by the Libyans.]

Who wrote the song "Johnny B Goode"? It can't have been Chuck Berry, because his cousin Marvin held the telephone up while Marty was playing the song on stage, and Chuck heard it first then. It can't have been Marty either, because he heard the Chuck Berry version of the song while he was growing up. So we have a paradox - nobody ever wrote the song. Whoops - end of the universe time. [Not a paradox at all - originally Chuck Berry wrote it and Marty heard it, but in the altered timeline Chuck Berry got his inspiration from Marty. Not a paradox, just a change].

When the time machine comes back from its first ride with Einstein, the car spins and isn't icy. However, when a different angle is shown, the car has ice on it. [The shot of Marty and Doc is long enough for ice to form, given how cold it is].

When Marty finally goes back to 1985 they pan up to a shot of the clock tower, then at the bottom of the screen it suddenly says 1985. The shot is still on the clock tower but if you look at the trees and branches in the shot they have not changed for 30 years? [It doesn't pan up to it, it's a cut. There's nothing to suggest that the shot of the clock tower is meant to be in 1955].

Do you honestly think that Marty's parents wouldn't think it was the slightest bit odd that their son happens to look and talk and dress EXACTLY like the boy that hooked them up in high school? [Ever realized all of a sudden that someone you know bears a resemblance to someone you knew a long time ago? Sure - it happens... (either Marty's parents haven't reached that point yet, or they simply never noticed - it's been 18 years, remember...)]

The speedometer of a Delorean doesn't go past 85 mph. There is a Delorean shop in the town I live in with about twenty Deloreans behind a fence. I checked it out and none of them had a speedometer that goes past 85. Makes you wonder how it was any different in the car they used for the movie. [DeLoreans come with an option for a 165MPH speedometer.]