Physicist Brian Greene Breaks Down Famous Time Travel Movies

[@spridle]

Brian, as someone who struggles a lot with learning, you have no idea how grateful I am of you. You give me hope that I can tackle the challenge of me learning. You make me less embarrassed about my level of intelligence. Thank you.

[@UNUSUALUSERNAME220]

That's cool. It's really a matter of how YOU learn. We all learn at different "speeds". Some people understand concepts quicker than some, other people understand slower and need to have things explained differently. That is the main problem teachers have. They have a classroom filled with people who all learn things differently, and at different speeds. You are limited by the amount of time that you can spend working with those people that understand things differently. Teachers also have to be able to spot when and where they "lose" someone, where someone stops being able to understand the concept being taught and move forward. Remote learning is difficult for some, but I love it. You can start and stop and learn at your pace.

[@jacklambert1521]

Struggling with learning does NOT mean you're not intelligent. Learning and thinking are two completely separate things. Don't be embarrassed or look down on yourself. You're way more intelligent than you think. You said it yourself: You want to learn. That is a sign of intelligence in itself. Dumb people are the ones who want to stay ignorant.

[@UNUSUALUSERNAME220]

@Davy Anthonissen Wow! THUMBS! Don't forget about your thumbs! You have thumbs! Thumbs make life alot easier. You took care of emotional intelligence, all I got left is thumbs.

[@ShawsOwn]

Curiosity will always outpace quick learning in the human race. The fact that you're even watching these videos is grand. If you're curious, you're living. If you're living, you're good.

[@leeanneb7178]

@@jacklambert1521 well said.

[@DesertRat332]

What "Back to the Future", "The Time Machine" and other movies get wrong is if you try to go back in time and are on the earth you will not end up in the same place on earth. The earth is not where it was 10 minutes ago, it has rotated, it has revolved around the sun, and the sun has moved around the Milky Way. Try to go back 100 years and you're going to find yourself out in empty space. If you went to a far away star (thousands of light years) at near the speed of light and then wanted to return you would have to allow for the solar system revolving around the Milky Way. It would not be in the same location it was when you left it.

[@_Opal_Miner_]

Every subatomic particle (wave) and the space between them will have expanded at your destination, as well. Physical time-travel requires compensation for both locational change due to movement but also for dimensional change due to universal expansion. That 1st one is simple enough math, no harder than a ship or a plane plotting a course on a spinning sphere. Solving for the second requires something as yet unknown, like a particle suspended in a red solution.

[@callmepotato]

There is a book that tackles this issue, albeit rather strangely, called "Ghost" by Piers Anthony. In it, the characters use a time vessel to travel, not just through time, but through space. When the ship travels in time, it stays in the same physical location while the Universe continues to move. In this way, they DO travel through space...or rather, space travels around them.

[@SykoticBanana]

I remember in the 70's a comic that came out called "2000 AD". Judge Dredd featured in it. Another character that feature in this comic magazine was a character called "Strontium Dog" whom if I remember correctly was some sort of mercenary. Now this character has a weapon called a "time grenade" a particularly nasty weapon that when it exploded it would take everything within a certain radius of itself back in time by an hour or so .... but as the planet earth had moved the victim was effectively transported in outer space.

[@blackholeentry3489]

@@callmepotato Just because "there is a book", while it may be the basis of a good story, it in no way means it has any bearing on reality.

[@iammattc1]

@@SykoticBanana He was a bounty hunter. He and his partner would occasionally use carefully calibrated time bombs as a means of escape, sometimes appearing in mid air and saying things like "the calculations were off!". Dredd also used a time machine to travel forwards in time in the "City of the Damned" storyline. At the end, they change the timeline and prevent a future disaster from happening, but the effects that have already happened (future Dredd's body is brought back to the present, Anderson gets a scar on her leg, Dredd loses his eyes and has bionics implanted) stay in place. This is queried, and the only answer given is that they don't know.

[@chrisdiner7170]

Brian Greene is an amazing physicist. I could listen to him all day!

[@steveswangler6373]

to be honest, i dont know how amazing Brian Greene is as a physicist, but i do know he is an amazing science educator. :)

[@eurbanautotech]

One of the things that never ceases to blow me away about Brian Greene is how fast he thinks. The man can talk for hours about deep and complex topics without a single "um" or "uh". Try it yourself. Sit down in front of a camera and see how long you can go without saying "um". It's hard. But not for Brian Greene. Always a pleasure listening to him talk!

[@brettturner5299]

That was absolutely fascinating and explained a lot in a way even I could understand. Great video, thanks!

[@edo4867]

I really enjoy listening to Brian Greene. Like no other scientific communicator.

[@amberhoward7807]

This is already a very deep subject matter, but that ending man.... deep and honestly a perfect way to end this! Like icing on a cake or the strawberry added on top! Time is so precious to us bc the simple fact it is so mysterious. Awesome video!

[@samfordja]

The interesting thing about traveling through time is that not only would you end up at a different time, but a completely different location in space relative to the motion of the planets and stars. Let's say that you made a time travel device on earth where you step in and out on the same location on earth, you would have to account for the position that the exit point is in relative to the entrance. Even 1 year will most likely land you in the middle of space if you went in at one point and exited at that same point.

[@TouchBrian]

Yeah, I think about this all the time when thinking about time travel and was expecting him to talk about it.

[@clairepettie]

At the very least, you should attempt it with arm floaties on, in case you end up in a body of water.

[@momom6197]

No, that assumes you have a reference frame that is not locked to the movement of the Earth but rather the movement of the Milky Way's center, or another astral body. There is just no objective concept of "the same point" without a reference frame. The best you can do is find "the point with the same coordinates in that specific reference frame", and in that case, it makes sense to choose the terrestrial reference frame, since it is the most convenient, or more logically, choose the reference frame of the time machine. In that case, you don't end up in space, though it does beg the question of what happens to the reference frame if the landmarks you use or the components of the time machine are dispersed as you travel back in the past.

[@jeantetreault132]

Thank you Brian! You’re very interesting, eloquent and well spoken. You’re also easy to follow and as a scientist, you sure know how to define things in such a simplistic way. Thank you for all your teachings and also for this marvelous presentation. Johnny, Montréal, Canada 🇨🇦

[@ulalaFrugilega]

Thank you! What a lovely breakfast I had this time with you and all those thoughts.

[@slipperysloper3721]

Is that 3 feet of snow piled up against his windows?? Good lord. That place looks like heaven.

[@pkingo1]

Arrival is a great movie and for me it's about the primacy of consciousness, and that by changing our consciousness we have the capacity to liberate us from what feels like hard limitations of linear time and material reality, as it's an effect of our consciousness not what causes our consciousness.

[@BillZebubproductions]

I love the concept of moments being the atoms of time. Brian and Michio are exceptionally skilled at relaying information to laymen. Their books read like stories, which makes learning much easier.

[@MarkNism]

I always assumed that the Flux Capacitor in BTTF was the thing that prevented events in the past from having an immediate impact. Flux means change and in electronics a capacitor is a temporary store, so the Flux Capacitor temporarily stores the changes to give the time traveller chance to correct their course.

[@C2112-s7y]

Thats really cool! I assumed Hollywood chose two random science words and stuck them together without any thought whatsoever. It would be impressive if they did came up with the flux capacitor as you say.

[@Zoroasterisk]

I am absolutely certain you gave more thought to those two words than Zimeckis and Gale did to the entire script.

[@monkeytennis8861]

​​@@C2112-s7y they did; the OP is retro-defining the terms and it's tenuous bollocks

[@tacticalpossum7090]

The scariest thing about Interstellar is the person who was left on the water planet assumed dead. If he did die, technically he could have been minutes away from hundreds of years of rescue effort.

[@chitranshutomarjatt8788]

The thing I love about Physics is that it doesn't hesitate to ask serious and complicated questions.

[@Fractured-Exe]

I appreciate how easy it is for them to say “I don’t know” or “We don’t know”. Instead of acting like they know everything.

[@josephfoote3276]

We are all, already, traveling forward in time. Accelerating that is quite conceivable. Traveling back in time is a whole 'nother matter. As far as we know, time is a bell that cannot be un-rung.

[@Travasco]

It's the way he articulates things that does it for me

[@braddsn]

Brian is such an inspiration. An amazing human being.

[@particularbored6072]

I never thought of language in that sense. Considering my love for words, I'm grateful for that new perspective. Thank you.

[@richarddeese1991]

Thanks. I'm glad I took the *_time_* to watch this video. tavi.

[@andykod77]

Just the thought of Time Travel is absolutely fascinating

[@freqeist]

the Statue of liberty scene is and was still mind blowing

[@obeymulder5912]

That was absolutely beautiful what he said at the end.

[@synthwolfe8906]

"You can change whatever you want, but is a good idea to know how these ideas actually work". There's a saying in writing that goes "know the actual rules before you butcher them". Basically what he said. Its best to know how things actually work before you change them to suit your needs, that way you can keep at least a semi-coherent thought process. Thats the main reason I watch these: so I know the basic ideas of how things work. And I've come up with a few ideas for my own writing. Partly from hawking and Einstein, but largely from Brian Greene here.

[@synthwolfe8906]

So when he mentioned that moments in time just are, it got me thinking about Futurama, and how fry became his own grandpa. He never became his own grandpa. How things "became" is how they always were. You cannot change the past because whatever you do to change it is how things were always meant to play out. Interesting to consider that an animated comedy series could be more accurate than what many consider to be "plausibly accurate" sci-fi.

[@thomashonjr]

The Spanish film Timecrimes is an underappreciated gem of the time travel genre.

[@galvorniii]

This is why I like agents of shield. They has time travel and it was always immutable time. Everything was solidly built without paradox that I can recall. Good narrative.

[@woooster17]

There was a story in Stargate SG1 called ‘A Matter of Time’ that involved a black hole and the effects of its extreme gravity..with the associated time distortion effects. The entire series is also based on the use of wormholes. Enjoyable Sci-fi 👍🏼

[@ZesPak]

Yes, I was thinking that as well. In the eyes of SGC they were basically "stuck" there.

[@birgitmelchior8248]

Yes but Sam says in this that the gravity effect coming through the wormhole is completely in violation with general relativity. And it is. Dr Becky (an english astrophysicist) reviewed that episode on her youtube page)

[@rsr789]

@@birgitmelchior8248 Link please.

[@mattglass9782]

Would of loved them to ask him about Primer! from what i understand that is the best time travel movie scientifically sounding like the most possible

[@adamkolendorski9953]

Brian is awesome TED talks all of it dumbing it down for us thank you

[@Geraint3000]

This is all fantastic, as is the view from his drawing room window!

[@Cabochon1360]

Great video. Obviously, one could talk about this for hours. (I'd love to hear your take on the movies "Primer," "Timecrimes," and "Slaughterhouse Five".)

[@humbertosanchez5734]

Primer deserves to be talked about, it's such a great movie

[@xanderg1957]

I like to think slaughter house five isn't time travel. It feels like it's about ptsd to me and the time travelling is flash backs and all the wierd space zoo stuff (its been years since i read it) is actually a coping mechanism/fantasy world.

[@mattcernjavic9999]

There is a episode of Doctor Who where he and Donna Noble land in Pompeii on the day before it erupts and he finds out that he was the cause of the eruption. If he was not there it would not have erupted but as it did, he always had to be there.

[@alistairbain6149]

Perhaps you could add TIMELINE to a future edition: “While excavating a site in France, Professor Johnston finds some discrepancies and travels to USA to consult with his sponsor. Shortly his team members find his bifocals and a note begging for help; both of which date back to fourteenth century. When contacted, the sponsor tells them that to find Johnson they too must travel back in time. All but one agree.” Great film despite its problems. Thanks for your vid. Explains the issues in an understandable way.

[@Globovoyeur]

A very interesting presentation, Dr. Greene. Perhaps you can someday find the time to analyze another set of movies.

[@frankmisiti8836]

I always took the Back to the Future pictures fading thing to mean that the more events that transpired differently than the way they really did the odds or likelihood of them being born were continuously decreasing but not yet impossible which is why they had not blinked out of existence entirely

[@harpo345]

The chances of the exact same sperm fertilizing the exact same ova at the exact same moment are so remote that even the slightest change in circumstances between the two parents would mean the chances of your birth would be, to all extents and purposes, zero.

[@charlietuba]

One of the major problems encountered in time travel is not that of accidentally becoming your own father or mother. There is no problem involved in becoming your own father or mother that a broadminded and well-adjusted family can't cope with. There is also no problem about changing the course of history- the course of history does not change because it all fits together like a jigsaw. All the important changes have happened before the things they were supposed to change and it all sorts itself out in the end. The major problem is quite simply one of grammar, and the main work to consult in this matter is Dr Dan Streetmentioner's Time Traveller's Handbook of 1001 Tense Formations. It will tell you for instance how to describe something that was about to happen to you in the past before you avoided it by time-jumping forward two days in order to avoid it. The event will be described differently according to whether you are talking about it from the standpoint of your own natural time, from a time in the further future, or a time in the further past and is further complicated by the possibility of conducting conversations whilst you are actually travelling from one time to another with the intention of becoming your own father or mother.

[@amberhoward7807]

Love this! Also love your views as people think I'm weird for not believing in the possibility for time travel....

[@TheXetrius]

Love it, thank you detailing your perspective.

[@rabbitandcrow]

I love Frequency. Thanks for your service on it!

[@MrDaddynomates]

I recommend watching a series of short films called "calls". It's on apple TV. It's a similar idea to the movie "frequency". In "calls" something weird starts happening with mobile phone signals. It becomes possible to make calls to the past or future. People start giving information to people in the past, to prevent accidents or just change things. It causes all kinds of problems. The films are all audio with weird graphics. You don't see any actors. It's all voice acting. I really enjoyed it.

[@3DJapan]

I've seen the folded paper in so many movies but I usually see them folding it then the punching a pencil through both sides.

[@chris432t6]

Super cool. Thank you BG!

[@cmarkn]

I'd like to see your ideas on Twelve Monkeys. In the movie and the TV series, the characters did things that could have changed history, but the results of their actions were always what they remembered as having happened. There were no transitions, no memories of another timeline. It sounds like what you describe as the way time travel would work.

[@aaronseet2738]

"don't have to time travel naked." T-800: Why didn't you say so sooner?

[@SalvableRuin]

I agree with the "It's a black and white thing," but I like how they did it in the film, because Marty's existence in reality and in the photograph were a reflection of the probably that he would be born. A faded Marty was a probable but not guaranteed Marty, affected in real time by the choices of his future parents. A fun idea!

[@sirlawrence9161]

But if Marty ceased to exist, he couldn't go back in time and separate his parents, thereby reaffirming his existence. So there is no scenario in which Marty will not exist, because his parents will get together whether he goes back in time or not.

[@macmcleod1188]

Yes. Like Schrodinger's cat. Marty both existed and didn't exist.

[@kumaridesilva3992]

I love this - thanks for the upload!

[@DanHarkless_Halloween_YTPs_etc]

Good stuff, though the fact that Greene isn't a biologist was illustrated when he definitively stated that most animals experience the world moment-to-moment - that they aren't able to mentally time travel. Maybe true if you define "most animals" as "most species in kingdom Animalia". I suspect, though, that _most vertebrates_ (along with some mollusks, and possibly other invertebrates) possess some degree of episodic memory, and can make decisions with reference to it. Mental time-travel into the _future,_ rather than just the past, might be a lot more limited (e.g. corvids, elephants, and great apes), but it's possible that, say, _all_ mammal species (and additional birds like parrots) have such an ability. We probably need better-designed experiments to prove this, though, and need to avoid limiting them to a tool-use paradigm like variations of Tulving's "spoon test".

[@aristideslourdas8478]

Animals see the future all the time. When they're hungry they look for locations that are likely to have food, when the sun begins to set they look for safe places to rest. Past experiences give us future expectations, such as we expect the ground will hold us when we stand on it. Their brains might be smaller, but its the same model. All the same features to varying effectiveness.

[@DanHarkless_Halloween_YTPs_etc]

@@aristideslourdas8478 I guess the argument would be that some or all of those instances are demonstrating simple operant conditioning, rather than actual mental time-travel. I suspect that's hogwash, though.

[@CyberSystemOverload]

21:40 is where it really hits. A lesson to us all.

[@kaemincha]

so cool to see him just talk and the conversation flows, but he's still weaving in explanations for the theories behind this stuff.

[@JohnSmith-vm8rx]

I’d be curious to get your thoughts on the series continuum. Great segment BTW.

[@neogeo1670]

this channel is a hidden gem

[@BobBilheimer]

When Dr. Green discusses the idea of travel to the past, any modifications then would result in future events always incorporating that interaction. What is, always was. And the scene that I am thinking of that illustrates this is the final portion of Bill and Ted are battling Chuck De Nomolos towards the end of Bogus Journey. Also, I would have liked to hear Dr. Green‘s take on the ending of Contact.

[@Maazzzo]

More, please! Have him do TV next. I liked Brian.

[@karlhenderson1908]

Thoroughly enjoyed this refreshing talk. GREAT to hear his take on slices of time just being what they are (therefore unchangeable). YES!!

[@danielmarkleblanc1800]

Read your book Until the End of Time. Love it ; except, I have not been sleeping to well since. It just keeps me thinking of things that I wouldn't have considered before. New Perpectives! I love your take on nature and the way you express it. FANTASTIC STUFF Brian Green.

[@divyamacsuedon3899]

Dr Greene, Mesmerising, sir! How close you are to the timeless truth.

[@tonytrilex2555]

such a great video but how come such little views

[@AllDayBikes]

11:26 Man I would've too, nothing to be ashamed of, that would be a rather unsettling feeling.

[@HomespunWisdom]

5:53 Interesting comment. I too watched the original "Planet of The Apes" as a child (around six years of age), but I had been to a museum several times by then, so I already understood that if things had changed drastically 'since the past up to the present', then nothing was ever 'unchanging' or certain. The scene still had an impact on me (upsetting me greatly) considering that of all the possibilities that could happen in the future, destruction of all that which was familiar as a result of wanton violence was deeply lamentable, whether in historical reality or in fiction.

[@achtsekundenfurz7876]

Whenever there are two movies by the same name, I get the feeling that "the original (________)" and "the good (________)" always refer to the same movie. With songs, it's more like 95%, but with movies, I couldn't name a single exception.

[@HomespunWisdom]

@@achtsekundenfurz7876 Agreed! With song 'covers' sometimes, there's a pertinent nuance that the inspired singer brings forth with greater (albeit subtle) tonality and cadence, drawing attention to aspects that are essential to initial appreciation, or else which may have been overlooked in their original expression, but filmatically, it does seem to be a different matter. :)

[@achtsekundenfurz7876]

And THEN there are others who don't even try (esp. with music) and just use the name of a good song. Every singer just has to have a song called "Always" or "Everybody" no matter how bad they are...

[@HomespunWisdom]

@@achtsekundenfurz7876 By odd coincidence, I just happened to come across 22 well established composers (Beethoven, Tchaikovsky, Chopin, Brahms, Gorecki... to name a few) who all have a piece of work referred to as: "Opus 36". Sharing a name is hardly a modern conundrum, is it..? :D

[@matthill263]

In BttF I assumed Marty 'fading out' was to do with the probability of him being born decreasing rather than it taking time for things to ripple through time.

[@antoniusblock7193]

In the movie Event Horizon, from 1997, a character played by Sam Neill already described the wormhole tunnel with a piece of paper like this.

[@LiaGoldie]

It was described with a piece of paper like this in the children's book A Wrinkle in Time written in 1962 as well

[@beastmode7988]

I have never enjoyed being so confused before. Thank you.

[@Ltulrich]

We are time traveling right now. 60 seconds per minute, 60 minutes per hour, etc. This is the best way to understand it.

[@spornge]

What bugs me is the photo does not disappear as well .

[@leok7193]

Hope he'll do an episode about Futurama with the same topic. They did a number of takes on time travel including a time machine that only goes forward in time and suggests that time is a cycle that ends with the decay of the last particle and reignites with another big bang creating an identical universe where the same effects occur (the entire history of time is pre-determined). The also did a number of time travels to the past where events in the past were revealed to have always been meant to happen and shape the present, like Fry accidentally becoming his own grandfather. They had a number of writers with advanced science degrees, so it's not total mumbo jumbo like Back to the Future...

[@clairepettie]

This has given me an all new perspective on Peggy Sue Got Married. The end of that movie may have gotten more right than I realized as a kid.

[@carriefix7096]

So interesting, all of it! I have so many questions! BUT, you look much better in real life than your older face in the movie!

[@ssmmkc]

One of the best Time Travels I know is from an Anime called Zetsuen no Tempest, despite all its flaws, the Timetraveling in it is amazingly done

[@DaveVelo1]

The way I visualize it, time is universal. It progresses the same no matter where you are located in the universe. The image we see from any object out in space, regardless whether by naked eye or a scope is light that emanated from that object in the past. In other words, we can't see the object as it is in the present.

[@akavario]

Predestination is one of the craziest time travel movies ever.

[@manoo422]

Its not about time travel...

[@davidzam33]

Amazing video. Thank you! Subded

[@fionahaines882]

wow. Brian Greene is AMAZING

[@xwrn]

I would like to know Prof Greene's thoughts on Primer.

[@DarthBludgeon]

I like the way Heinlein approached the subject of "changing the past"... You just create a parallel alternate timeline that progresses theoretically from the moment you arrive (I'm including some Chaos Theory in my hypothesis). As soon as you appear on the planet you would change the balance, mass, and so many other things that the cumulative impact of your very existence on the new timeline would change things in a radical fashion. Heinlein treats time as just another Dimension... actually 3 more dimensions to correlate with the 3 spatial dimensions. Ever read any of his Multiverse novels? :)

[@PaulGirdlestone]

Also a point to note that in Back to the Future, why is it just Marty and his family in the photo that fade? If they didn't exist, no-one would have taken the photo at all as the person, presumably another family member, would have taken that photo of the kids. At a very big stretch, are they just taking a photo of a random wall with some trees behind it? The movies are legendary but damn the inconsistencies and issues it causes. I am still waiting for my hover board!

[@DVOS2686]

Another time travel movie that people don't talk about enough is Predestination! Love that movie

[@davidkirby9234]

If any of you are intrigued by the description of the film The Time Traveler's Wife, I urge you to pick up the novel. I really liked the film -- even if, IIRC, it left out the last scene in the novel, which was the scene that first popped into the author's mind and caused her to flesh out the novel. But I loved the novel -- although it includes the "naked time travel" trope that Prof. Greene isn't wild about.

[@rezadaneshi]

I think it's much simpler. It's never going to be a paradox. Time moves at the speed of light. That's why time stops if you travel at the speed of light. Even if you survive the round trip back to kill your grandfather and came back, the timeline you killed your grandfather is moving into its future at the same speed that your timeline you came back to is, and the two will never intercept. Wait 50 years and go back to that time line, you'll see you don't exist there and you had created an alternate timeline. If we ever discover anti graviton, the best we could do is visit either the past or the alternate timelines we have created

[@JRWatchman85]

I loved your input in a documentary I watched years ago about string theory. The way Brian explained being locked in time sounds like he is making the case for fate, whereby nothing we can do will change the outcome of our life which is predetermined. Maybe fate is determined at a higher level of reality but at the level we experience it, via our life on this planet, it gives the illusion of free will and choice?

[@RDSports5]

Thank you so much for commenting on this fascinating theoretical construct. As a huge Back to the Future fan, I have always enjoyed trying to make sense of it all (as though any of it could ever really make sense, but it's obviously fun to analyze and think about). With that in mind, although I have also been fascinated by String Theory and other theoretical approaches to time, dimensions, and how we may, in theory, be able to manipulate time and space, I do think it's important to keep in mind that our own ideas about this are only theoretical at this point in time (pun intended). While it's possible that time does not work in a 'Ripple Effect' manner that is shown in BTTF, we also can't say with any degree of certainty that it doesn't work that way, which I think is what makes the topic more enthralling to think about. Thanks again for continuing this dialogue on a captivating subject area.

[@wiegraffolles9822]

I think you might be misunderstanding what scientific theories are. Scientific theories explain why phenomena occur. They have been rigorously tested and/or scrutinized under the scientific method. They are not the same as the colloquial use of the word theory you may use with friends and family. An example of a scientific theory is evolution.

[@Goldslate73]

I know I'm late but please do an episode like this again with Professor Greene on TENET. Please... We deserve it. Please...

[@whoever6458]

I've been traveling through time for my entire lifetime. However, I only travel into the future and I only do so at a rate of one second per second.

[@ahriman935]

Wow, that's some high frequency, how do you do it? In Africa they do so at the pace of one minute every 60 seconds.

[@PhilORourke]

Absolutely fascinating Professor Greene and thank you.

[@shahan2963]

Brian Greene is phenomenal.

[@jayceewedmak9524]

Thank you very much.

[@arl6280]

I really enjoyed this. I just want to point out that, technically, every tunnel is a tunnel from one moment in time to another..

[@BD-yl5mh]

12:06 while I think yes, they could have done this where the burn was always there, with an establishing shot earlier that shows it’s then, and then we see the dad do it and the son looks at it and smiles maybe. Having said that, we already have a magic radio, so why not have a magic desk? I haven’t seen the film but maybe the conceit is that the desk itself, or perhaps the small region of space where the desk sits (assuming it hasn’t moved in 30 years) possesses the time warpy magic where cause and effect are a bit messed up

[@oobrocks]

The "only naked" concept is simple: James Cameron invented that so heroes or villains couldn't bring future weapons w them (i know u didn't meantion the Terminator)

[@carpetlayenful]

The game Final Fantasy X was the first interaction that peaked my interest. The connection between gravity and time. Yet the dissociation of space and time.

[@CherryFairy02]

Brian's rants about how changes in a timeline wouldn't be gradually noticeable to a time traveler made me feel so validated. Any time I watch a piece of media where changing the past is a plot point, I'm always immediately confused because- like he said- that would just be the way that events in the past happened, so the person from the future shouldn't have any memories of it being any other way. Though, his descriptions of what actually feasible time travel would look like makes me curious what the point of this time travel would actually be, since the people not time traveling would have to wait many years to collect the resulting data and the time traveler would be leaving behind everyone they know forever and wouldn't be able to relay anything they learned back to the people in their original life (so, I guess they would need to be really confident that a) they know exactly how many years they're going to skip and b) that there are still people waiting on the other side to collect data from them.) I guess that's where the realm of fiction steps in- to explore the human implications of these kinds of ideas.

[@SwissTanuki]

In the end it all comes down to math and physics. Fascinating

[@Sheevness]

Having dreams that coincidentally seem to play out the next day seems related to what he was talking about in the movie Arrival. I wonder if anyone else experiences this.

[@squamish4244]

I do, all the time. Is this a brain trick, fifth-dimensional stuff or precognition? Weirdly, Brian Greene and most physicists would rather accept a fifth-dimensional explanation and be horrified by precognition, because physics deals with all sorts of bizarre shit but is still kind of terrified of the idea of anything that implies nonlocal consciousness.

[@patavinity1262]

Disappointing he didn't call out the intense stupidity of the film 'Arrival'.

[@prisonersofspacetime6304]

Traveling through time naked is a basic thesis of the Terminator franchise. Their explanation is that the time machine only picks up on biological tissue even though the Terminators have a metal endoskeletal. The metal components are hidden beneath the biological layers and therefore not detected by the machine. Sound biological and physical premises here! 😜

[@MrAlv21]

cotton is a biological tissue :-)

[@MrAlv21]

@Vincent Verona not more dead than your hair or nails

[@frankbruder3097]

In _Terminator_ it was a restriction that prevented the conflict from being fought with futuristic weapons. That made it more interesting from a storytelling perspective and easier and cheaper in the props and special effects department. In the original, the time travel was a last-ditch attempt by Skynet before it was defeated in the future. It had Terminators as infiltrators but it never had a need to coat a plasma gun in lab-grown living tissue like it can do with the terminators, and it had no time to start developing that. In the sequels that aspect makes less sense, and just the existence of the sequels makes less sense with the original premise. In _The Time Traveler's Wife_ the character experiences time slips due to a fictional medical condition. The reason he ends up naked is that it's a biological thing, so his clothes aren't affected by it. Of course his cells would need to use some physical effect to travel through time. Depending on how it works it might be that his clothes should be dragged along or that tight clothes should be dragged along but loose clothes left behind. If he can not carry anything with him, then then he can never present any evidence which was also one of the narrative purposes of this rule in _Terminator._

[@leeanneb7178]

What about the issue of being naked would force the traveller to find clothing appropriate to the timeline in which they find themselves, so as not to draw attention to themselves by appearing so differently dressed?

[@MrAlv21]

@@leeanneb7178 being naked draw more attention than being dressed weird and you can always change your clothes at the first chance. By the way if you are so advance to create a time machine you should be able to dress the traveler with the appropriate clothes of the destination time.

[@pinduxa2020]

I'd love to hear his take on Doctor Who.

[@PeterManger]

Time Cop with Jean Claude Van Damme is the most correct time travel movie I've seen!

[@jamessullivan4391]

I like how Brian allows his kids to play drums in the basement while he is making a program.

[@flandornthesapphiremage9053]

PHEW! Thanked be the gods I can keep my clothes on, next trip.