"That's my boy". He gave Leonard credit. So rare!

Every argument between friends becomes instantly bigger if there's a board with markers in the room so you can draw

I bet Kunal was overjoyed he had only one line here!

For those who actually want to know how it works... In Back to the Future, changing the timeline is not instantaneous - the larger the gap of time that has to change, the longer it will take. In most time-travel stories, as soon as a change is made in the past, the entire timeline of events that followed it is completely erased and replaced with the new eventuality. But that's clearly not how it works in Back to the Future; because if it was, then the moment that Marty pushed his father out of the way of his grandfather's car, thus preventing his parents' first meeting and eventual relationship, Marty would've disappeared almost immediately. No, the way that Back to the Future works, is that time itself is a tangible thing that actually exists; and therefore, it can't just disappear and be replaced instantly. The timeline _has to be rewritten:_ gradually and the longer the gap of time, the longer it's going to take. In Back to the Future, the reason that Marty is the _last_ of the children to be erased, when logically he should've been _the first,_ is because, the new timeline continuity started by Marty's interference, was gradually rewriting the future histories of George and Lorraine, overwriting both Dave's and Linda's existence, before working it's way to Marty. In 2015, when Marty takes Marty Jr's place in the meeting with Griff, Doc has _tomorrow's_ newspaper handy. When the Hoverboarding incident occurs that lands Griff and his gang in Jail, the change was instantaneous, because that paper was only one day away. Now, when 2015 Biff goes back in time to give his 1955 counterpart the Almanac, that is literally 60 years worth of history that has to be rewritten. He had ample time to return to his future in 2015, because the overwriting timeline hadn't reached _that far yet._ But it had reached 1985 by the time Doc, Marty, Jennifer and Einstein went back. In fact, this is proven thanks to _deleted scenes_ from the movie. See when Old Biff gets back to 2015, he starts acting weak and collapses behind a dumpster in pain. Most people assume this is because he accidentally broke off the top of his cane in the Delorean, and then struck himself in the stomach with it. But a deleted scene proves otherwise; Biff is in-pain, _because he's being erased from existence,_ like Marty was in the first movie. As the Delorean flies back to 1985, the scene shows 2015 Biff _fading away._ He disappears because, despite his future where he is wealthy and corrupt, _he never makes it to 2015 in the new timeline._ This would later be revealed why, as it was originally planned that in the Alternate 1985, when Biff corners Marty on the roof, Lorraine was supposed to appear and _shoot Biff,_ killing him, to protect her son. (I honestly kind of wish they'd kept that.) But you see my point - in Back to the Future, the timeline doesn't get "deleted" nor does it get rewritten backwards. Time can only move in one-direction, so therefore, it gradually writes over itself whenever a sequence of events is changed. It explains everything in how Back to the Future works... I'm not saying that this is perfect, because the movie has to take some licenses with it. For example, the book of matches that Marty took from Biff's Tower, the Newspapers both Marty and Doc had from the Alternate 1985, and the Fax that Jennifer took from 2015. In these instances, whenever the timeline is changed, the aforementioned objects change instantly - Biff Co becomes Biff Auto Detailing; George McFly's Murder changed to his Honorarium, Doc being Committed to him being Commended, and Marty's firing being _completely erased._ We'll have to chalk that up to the movie wanting to have a visual confirmation that the future had been changed. But as for everything else, the logic is sound.

The writers deserved a award for this scene alone

This is why Temporal Mechanics has it's own separate course at Starfleet Academy.

Raj confidently being the next smartest guy after Sheldon.

There is actually a deleted scene in part II where old Biff dissappears upon his return to 2015.

This is more about proper grammar than understanding Back To The Future part 2. 😂😂😂😂😂😂😂😂🤣

"He's right " 😂😂

"He is right", me nod with no clue wtf they are saying...

It’s called the ripple effect , it takes time for the continuum to update .. it’s why there’s a week for Marty before he vanishes in part one. In part two there’s two Marty’s at the same time, it’s why the doc is rushing to fix things . It’s not instant

This is the group that truly needed to see the deleted scene of old Biff disappearing after arriving back in 2015, fading to nothing.

And if you think about it, at one point there are 4 Time Machines present in 1955. The one from the original film, the one old Biff comes back in, the one Doc and Marty come back in, and the one buried in the mine.

I always felt it was because it takes a while for the time lines to sort themselves out.

“That’s not how time works!!!” Bruce Banner

I’m more curious why there is an older version of Marty when Marty traveled to the future

James Gunn explaining the new DCU.

in a deleted scene, old Bif dies when he returns to 2015.

Actually, I loved that the first film showed that there changes to the timeline could be altered in two types of ripple effects. When Marty accidentally broke up his parents, the effects on him and the photograph of his siblings took almost a week of "Marty's" relative time in 1955 to change because events in 1955 that were going to decide Marty's future were in flux. But the second his parents fell in love, the effect on Marty was instantaneous because the future was no longer in flux. In other words, changes to the past didn't immediately change everything that followed after it, which would be seen by making the time travelers and their future items disappear instantly due to the paradox. For the sequel film, it makes sense that Old Biff could make it back to 2015 because the changes he had made in the past were causing HUGE fluxal changes over the course of six decades, and took 'time' to catch up from 1955 to 2015. I don't know if it makes sense on any quantum level in reality, but for scriptwriting, I thought the films gave a nice justification for why changing the future depended on what was being changed and how 'firm' that change could be.

I love how Sheldon starts off analysing grammar before science.

I would love to see the bloopers for this scene. Must’ve taken forever to film

The way Raj always memorizes his lines. Simply Amazing!

All stories involving time travel set their own time travel rules. For example, the first film establishes that changes that are made in the past affect the future as though the past was the present, meaning that the future only changes completely when it becomes the present. Then, the second film essentially establishes the idea of the multiverse because they travel to two separate 2015s, but still never leave Hill Valley.

The audience rightly gave the actors applause after Jim Parsons said all of those hard lines.

There's actually a deleted scene that shows what happens to Old Biff soon after he returns with the Delorian to 2015. He starts having a heart attack but then disappears because of the timeline change due to him giving the sports almanac to his younger self.

Back To The Future, things fade gradually instead of disappearing immediately. Therefore, Biff went back to Timeline A BEFORE the universe was altered. So when Doc and Marty went back, they skipped the memory barrier, which is why they remember Timeline A when they're in timeline B. Also, Marty B was at a boarding school, which was why we never see him. Doc B was in an insane place, which is why Doc A never ran into him.

I am surprised that it didn't cause a paradox and destroy the universe. Sheldon and Leonard and Howard talking about time travel not the time travel itself lol.

Unfortunately the scene that addresses this got deleted. Old Biff actually gets erased from history (like Marty's siblings in the first movie) shortly after giving himself the almanac. As in the first movie he disappears slowly, indicating the ripple effect that changes the timeline is slow, not instantaneous, which is probably why he's able to go back to his own 2015 before vanishing. The 2015 of the future probably DID alter itself around Marty and Doc; they just didn't stick around to see it fully change.

I wish i had friends like these where you can talk for hours only to massage your brain

a normal conversation with my friends tbh

Doc implies alternate timelines shift around time travelers. Assumably because they were the ones to CAUSE the shift therefore they and their actions had to have happened. You can see this when jennifer is left in the alternate 1985 but Doc says she'll wake up in the real 1985 when they fix things. So that explains why they retain their memories and nobody else does.

Give that writer a raise

Essentially, it’s a paradox Because 2015 Biff went back in time, he created a timeline where the Time Machine was never made, meaning he couldn’t go back in time to alter the timeline to begin with. To address Howard’s point, it’s possible that the timelines branched to prevent the paradox and allow the Time Machine to exist. Only flaw with the movie is that went Doc & Marty went back to 1985, it should have been their 1985 instead of the alternate one. Essentially, what 2015 Biff did shouldn’t have affected their timeline

The point of this scene is the grammar. That is what makes it funny!

The "He's right" from Raj is what gets me the most 😂

In order to begin to understand time travel you have to understand that in Back to the Future, time flows in a single set line and any changes in that timeline are deviations from what “should” happen. This would mean that the original timeline would always exist and that by changing things in the past, a deviation is created and now there are two timelines based on action(s) done in the past. Doc comes to understand this once He travels to the future for the first time and why he desires to destroy the Time Machine once and for all in order for all deviations to be eliminated. That is, until the end of the 3rd film where he makes a new Time Machine and then says that the future isn’t predestined, after he says that everything gets thrown out…

I have several issues with bttf. One... at teh end of 2, the delorian is struck and goes back in time. It was not going at a speed of 88 mph. Also... at the end of 1, if marty goes into the future, the present is effectively changed and the future. So... the family sees that marty and his girl friend are missing, they put in flyers for their return, the cops are called to investigate... and there is no pizza night, no car crash, no firing in the future. It is a terrible flaw that no one ever speaks of.

Wait until they watch all the Terminators

“He’s right. Also what kind of a name is Biff? It sounds like the sound you get when you open a can on pillsbury dough. *Biff* “

The fact that I followed and understood about 90% of what they were saying during the first viewing suggest I am a nerd. Not sure if that's a good thing or not 😂

Future Biff made it back to Doc and Marty but he faded away so what he did did alter the timeline. Based off the first movie, it takes a while for changes to be complete, remember Marty looking at the family photo and how people in it were slowly fading away? So Future Biff made it back cuz the changes didn’t hit him yet. But this is not how it should work, if you alter the past which will alter the future, a completely different time, then it wouldn’t take time for changes to hit you cuz you do one thing in one time period, another time period you’re not in gets hit, the changes should be super quick like in other movies

So playing by dr who rules: can't interfere with your own personal timeliness, which includes events which have an effect on your timeliness, unless that effect had already taken place in your personal timeline.

This is peak nerd comedy 1 of the best sitcoms ever

My head hurts

It's these types of subjects that I personally debate over. On a daily basis with my best friends lol.

Actually its time directional precision biff the old biff “stole” the almanac didnt buy it which is years again precisely to change his life is when he realized he will wake up in a green dome with a hot tub in it

To break this down in a way that you can understand, we see in the alternate 1985 that the Marty from that timeline isn’t around, and the Doc from that timeline has been committed, so there is no way they could go to 2015 in the DeLorean and therefore given older Biff a chance to use it to go back in time. So by giving himself the almanac, Biff creates a timeline where he can’t go back in time to give himself the almanac. This is briefly acknowledged in the graphic novel Back to the Future Untold Tales and Alternate Timelines. Doc visits himself in A1985 at the asylum and works out this version of him never built the time machine so they have created a paradox. He explains that he and Marty were safe for the moment but eventually, the space-time continuum would correct itself.

I agree with Howard's theory of the timeline.

You don't disappear immediately when you change the past. It takes a while for the things to fade in or out. Not to mention time travellers are essentially protected otherwise Marty wouldn't remember his history of the bad childhood.

.....I want to see their "Hot Tub Time Machine" discussion...

I would love to see the outtakes of this.

The reason old Biff returns to the same 2015 is simply just the ripple effect hadn’t caught up that far yet. By the time Marty and Doc tried to go back home, it had already reached 1985 landing them there in the new Biff alternative reality.

I watched this twice, just because I originally thought this scene was funny for the sheer absurdity of it, but on the second viewing I actually wound up understanding what Sheldon said, and sure enough his point makes sense.

That scene is fantastic😊

I'm surprised they didn't bring up the Star Trek: TNG episode Yesterday's Enterprise. In that episode, when the rift opened up and the Enterprise-C came through, the present immediately changed because the past had changed. That would have made more sense than the 2015 where Marty and Doc were not changing. Sheldon if anyone should have remembered that.

Omg ridiculousness so halarious and Shelfon gave credit lol

The writers for The Big Bang Theory were/are brilliant! 😊

As an aside, I love that Biff is too dumb to create a time paradox when meeting his older self.

I've always figured that it's due to the fact that the timelines are not instantly updated, ergo do not reflect the changes that have just been made instantaneously. It takes time for them to make it logically sound and congruent with one another.

He's right 😂

My poor head 🤣

love this scene

Four of my brain cells arguing with each other and why I'm tired all the time. 😵‍💫

I thought I heard every argument about how the time travel was handled in that movie, but this is one of the first time I hear it about the almanac. Good stuff.

Dude...that was so BRILLIANT!

This is why certain deleted scenes need to stay in.

Biff travelling back to 1955 makes it so the time machine is never built in 1985.

Ha ha ha ha ha ha!!! DISSECTING IS MISSPELLED.

The Hitchhikers Guide to the Galaxy did this joke. Hilarious...

Those wacky time travel paradoxes, y’all. 🤪

This is basically the same question about Marty still existing after he interrupted his parents meeting. As a Time Traveller with knowledge of future events, Biff is still able to affect the timeline so it isn't solidified. It's not until he returns the time machine, and it's taken away from him by Doc and Marty, that the new past is put in place. I think it works given the way time travel is shown to function in BttF1.

They would have had had funny scene with Groundhog Day too!

Hot tub Time Machine always getting the jabs

"I hate temporal mechanics."

Hey!! You cut the "What kind of name is Biff?" Part... That was also the best

This is exactly why I'm not a fan of time travel plots. There are ALWAYS so many plot holes that get created, no matter how careful the writers are to account for said changes

Someone call the hulk to clear this up.😂

Genius!

...And this is why I never wanna find myself in a time paradox.

Yeah, I had this argument too, but with Terminator 😂

Raj: he’s right 😂

Id like to see them explain the bill&Ted timeline

Me and my friends have these conversations but only after a few blunts

The Biff's first bet/birthday thing doesn't make sense, the moment he gave himself the book things are all ready in motion, like a domino effect.

The tragedy of BTTF that no one talks about is that in Timeline A, the original timeline, Marty just disappeared one night and was never seen again.

There's always the problem that space is also a factor. Earth in 2015 was in a totally different region of space from where Earth was in 1955. For a "time machine" to work properly, it has to also travel thru space back to the same star date coordinates...

1:37 - 2:19 they put Jim Parsons through the line memorization gauntlet on this one.

This will forever hurt my brain lmao.

This bit speaks to my life.

Sheldon's "x" on the board in the first time was corrected later 1:29 and 1:34

my brain hurts

Hail to the Prop Master of Big Bang. He produced all you see & provided all food appearing on the show as he was also a chef.

When he mentions a timeline where Biff never gets the Almanac delves into multiverse theory

Best scene ever!

I skipped so many temporal causality classes at the academy to pilot runabouts for extra latinum. I wish I had stayed in class now…

My brain hurts 🤕🤯

Time travel makes my head spin. but like in the 3rd one wouldn’t there be 2 time machines.

How does Biff know how to operate the time machine ? They should’ve saved uncle Joey

I’ve seen all three BTTF movies and I have to say this is making my brain hurt