Why Going Faster-Than-Light Leads to Time Paradoxes

2024 ж. 27 Нау.
6 441 386 Рет қаралды

Is faster-than-light (FTL) travel possible? In most discussions of this, we get hung up on the physics of particular ideas, such as wormholes or warp drives. But today, we take a more zoomed out approach that addresses all FTL propulsion - as well as FTL messaging. Because it turns out that they all allow for time travel. Join us today as we explore why this is so and the profound consequences that ensue.
Written & presented by Prof David Kipping. Special thanks to Prof Matt Buckley for fact checking and his great blog article that inspired this video (www.physicsmatt.com/blog/2016/....
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::References::
► Alcubierre, M., 1994, The warp drive: hyper-fast travel within general relativity, Classical and Quantum Gravity, 11 L73: arxiv.org/abs/gr-qc/0009013
► Alcubierre & Lobo (2021), Warp drive basics, arxiv.org/abs/2103.05610
► Pfenning, M. & Ford, L., 1997, The unphysical nature of Warp Drive, Classical and Quantum Gravity, 14, 1743: arxiv.org/abs/gr-qc/9702026
► Finazzi, S., Liberati, S., Barceló, C., 2009, Semiclassical instability of dynamical warp drives, Physical Review D., 79, 124017: arxiv.org/abs/0904.0141
► McMonigal, B., Lewis, G., O'Byrne, P., 2012, Alcubierre warp drive: On the matter of matter, Physical Review D., 85, 064024: arxiv.org/abs/1202.5708
► Everett, A., 1996, Warp drive and causality, Physical Review D, 53, 7365: journals.aps.org/prd/abstract...
► For a more rigorous breakdown of the axis flipping in Minkowski spacetime, see Chapter 3 of "Special Relativity" by Valerio Faraoni (williamsgj.people.cofc.edu/Mi...)
::Music::
Music licensed by SoundStripe.com (SS) [shorturl.at/ptBHI], or via Creative Commons (CC) Attribution License (creativecommons.org/licenses/..., or with permission from the artist
► Hill - An Interesting Retirement [open.spotify.com/album/3S2hu2...]
► Joachim Heinrich - Stjärna
► Falls - Life In Binary
► Chris Zabriskie - Cylinder Two
► Chris Zabriskie - Cylinder Five
► Chris Zabriskie - Cylinder Four
► Falls - Ripley
► Caleb Etheridge - Always Dreaming
► Joachim Heinrich - Y
► Indive - Trace Correction
::Film/TV clips used::
► Interstellar (2014) Paramount Pictures
► Contact (1997) Warnes Bros.
► The Imitation Game (2014) The Weinstein Company
► Star Trek: Generations (1994) Paramount Pictures
► Cosmos: Possible Worlds (2020) National Geographic Fox
► Stephen Hawking's Favorite Places (2016) Curiosity Stream
► Star Wars: The Empire Strikes Back (1980) 20th Century Fox
► Star Trek: Deep Space Nine (1993-1999) Paramount Television
► The Day The Earth Stood Still (2008) 20th Century Fox
► Stargate (1994) MGM/UA Distribution Co.
► Star Trek: Beyond (2016) Paramount Pictures
► Star Trek IV: The Voyage Home (1986) Paramount Pictures
► The Expanse (2015-2022) Legendary Television Distribution
► Star Trek: The Next Generation (1987-1994) Paramount Television
► Avengers: Endgame (2019) Walt Disney Studios Motion Pictures
► Star Trek: Enterprise (2001-2005) Paramount Television
► Back To The Future (1985) Universal Pictures
► Passengers (2016) Sony Pictures Releasing
► The Time Machine (Dreamworks)
► Alien: Covenant (2017) 20th Century Fox
► Star Trek (1966-1969) Paramount Television
► Tenet (2020) Warner Bros. Pictures
► Loki (2021-) Marvel Studios
► Somewhere In Time (1980) Universal Pictures
► The Assassination of Jesse James by the Coward Robert Ford (2007) Warner Bros. Pictures
► Star Trek: Into Darkness (2013) Paramount Pictures
► Logan (2017) 20th Century Fox
► Star Trek: First Contact (1996) Paramount Pictures
::Subtitles::
► German by Frischholz Christian
::Chapters::
00:00 Introduction
06:52 Space Time Diagrams
12:51 Causality Violations
17:01 Paradoxes in Time
24:28 Outro and Credits
#FasterThanLight #Alcubierre #CoolWorlds

Пікірлер
  • I like to imagine that as soon as we discover FTL and break spacetime, the simulation crashes and the higher beings are annoyed they have another bug to fix

    @realbrickbread@realbrickbread Жыл бұрын
    • "God damn it i didnt think they would actually get to it! Now i gotta program a whole new enviorment and items"

      @MarcyTheKindaCoolWizard@MarcyTheKindaCoolWizard Жыл бұрын
    • “There is a theory which states that if ever anyone discovers exactly what the Universe is for and why it is here, it will instantly disappear and be replaced by something even more bizarre and inexplicable. There is another theory which states that this has already happened.” ― Douglas Adams, The Restaurant at the End of the Universe

      @lucasmoers@lucasmoers Жыл бұрын
    • Na no crashes (But i like the thought) I'm thinking just level 2 of the sim. It does not crash until 999,980 like the old arcade defender game.

      @insidejob8309@insidejob8309 Жыл бұрын
    • @@lucasmoers Can confirm. Same thing happened with my father.

      @MetalFan10101@MetalFan10101 Жыл бұрын
    • human scientists are the higher beings who put a sim into effect at a higher speed than their own reality to see the future, then when paradoxes occur, they have to wind back to when it happens, and figure out what's meant to happen then, and to do that they have to study the sciences which the sim people developed, but they can't figure it out, so one frustrated technician just removes the people who did the faster than light stuff, and resumes the sim.

      @noti7510@noti7510 Жыл бұрын
  • "The universe is not required to be in perfect harmony with human ambition." -Carl Sagan

    @bachelorchownowwithflavor3712@bachelorchownowwithflavor37122 жыл бұрын
    • Our physical bodies live in physical dimension out of many. ⚡️⚡️⚡️In multi-dimensions existence, causality wouldn’t be violated. Abrahamic secret texts of Jews, Christians & Muslims have hinted that “instantaneous” travel is indeed possible if we live within multiple dimensions. Each dimension has its own speed limit. When u reach certain speed, u jump into a deferent dimension & u loose direct connection to ur initial one until u slow down to within its speed limit. 🤔

      @duran9664@duran96642 жыл бұрын
    • Thats kind of a Captain Obvious thing for Carl to say..🤣🤣

      @letsbehonest4221@letsbehonest4221 Жыл бұрын
    • @@letsbehonest4221 You'll be surprised how many there are who don't understand something so obvious.

      @tylerdurden3722@tylerdurden3722 Жыл бұрын
    • Then for who is it

      @user-uu9vl2qx9r@user-uu9vl2qx9r Жыл бұрын
    • @ΝΙΚΟΛΑΟΣ ΗΛΙΑΚΟΠΟΥΛΟΣ not who..what .. For its self ...

      @letsbehonest4221@letsbehonest4221 Жыл бұрын
  • If FTL does exist, the universe might have some way of blocking any information/matter from interacting with the ship/crew travelling FTL. Similar to how the event horizon of a black hole stops any information from escaping it where time and space flip beyond it ( which would also break causality if information could escape ).

    @MechDragon108@MechDragon1086 ай бұрын
    • Why would it break casuality?

      @sentientglitch@sentientglitch5 ай бұрын
    • @@sentientglitch Because space and time flip past the event horizon of a black hole, the only way to escape the event horizon after previously entering it would be to use Backwards Time Travel which by nature would create time paradoxes just by its existence. This video explains why time and space flip inside a black hole if you want to know. kzhead.info/sun/erWTY7ZwaJuveGg/bejne.html&ab_channel=ScienceClicEnglish

      @MechDragon108@MechDragon1085 ай бұрын
    • But why are we perceiving things from the perspective of the STL ship when things happened at FTL ships pace. The STL didn't know about anything. When they finally visit vega everything would had already happened. So how is causality broken? And anyways the FTL ship will anyways break the space time laws so how can people even think of explaining it with our known knowledge?

      @GAURAV_RANA_@GAURAV_RANA_5 ай бұрын
    • @@sentientglitchwatch the video

      @odinson4184@odinson41845 ай бұрын
    • @Mech...you mean the universe may find some way of blocking messages to the crew of the STL ship..am I right here ?

      @robinfrost5439@robinfrost54395 ай бұрын
  • It's very rare and special when someone can explain such a complicated topic in an easy to understand and follow way. Thank you.

    @nativesugarshack9328@nativesugarshack9328Ай бұрын
    • favorite channel on 'tube. needs to have as many subscribers as real academically estimated by columbia star count

      @jgunther3398@jgunther3398Ай бұрын
    • In a way thats easy to understand and follow*

      @user-kb6mj7zq8t@user-kb6mj7zq8tАй бұрын
    • ​@@jgunther3398whatever

      @user-kb6mj7zq8t@user-kb6mj7zq8tАй бұрын
    • Except you can find a good explanation for just about anything on KZhead.

      @prestonwaters1088@prestonwaters1088Ай бұрын
    • Alcubierre drive Krasnikov tube Worm hole

      @nathanwhitmore3980@nathanwhitmore398027 күн бұрын
  • Does anyone realize how crazy it is that we can even theorize something like this

    @krishp1104@krishp11042 жыл бұрын
    • Thanks to Einstein

      @randomcubing7106@randomcubing7106 Жыл бұрын
    • I mean, on a certain level it's completely intuitive. You can't shine a light at something and then arrive before the light hits it, or conversely the light we see from stars has been traveling X light years to reach us, so to travel faster than light we would travel to the source before it was sent. But I will agree that it's crazy that we have actual equations and models for it, thanks to the work of giants (upon whose shoulders we stand).

      @Vort_tm@Vort_tm Жыл бұрын
    • If you think about it, maybe it is just a breach of the time line where earth after the ship send the reply to turn off the ftl transmitter, so you have a time line where the crew reply and a other where the don't receive any message because earth did not send it. So in the end 2 time line exist and no loop or paradox.

      @masteur@masteur Жыл бұрын
    • It's just the brain being brain lol, so smart it had to name himself

      @AboveEmAllProduction@AboveEmAllProduction Жыл бұрын
    • We usually dream bigger as humans with the knowledge we have. Just think about Egyptians about death.

      @eddycolon1986@eddycolon1986 Жыл бұрын
  • The speed of light should really be taught as the speed of causality. The speed of light is an incidental stenographer of the speed of causality.

    @tayzonday@tayzonday2 жыл бұрын
    • Yes! It’s not the right name but sadly we’re sort of stuck with it

      @CoolWorldsLab@CoolWorldsLab2 жыл бұрын
    • Let's adopt Asimov's interpretation and say that light, gravity, and causality all travel at "Celeritas", a special speed that is an innate property of the universe.

      @alecdacyczyn@alecdacyczyn2 жыл бұрын
    • Tay wtf you got some varied interests. Taught me economics and now you're prepping a physics song?

      @apainting4537@apainting45372 жыл бұрын
    • And the speed of light is a top limit in the Lorentz transformation of spacetime diagrams that cannot be exceeded ! Using FTL info transmission breaks the maths of the spacetime diagrams (square roots of negative numbers), so the conclusions of this videos do not stand :)

      @w0tch@w0tch2 жыл бұрын
    • @@CoolWorldsLab light travels faster than sound and doesn't break casuality for a blind man. Light travelling faster than light doesn't break casuality either. The universe operates on universal time, not local time. If you want to do a video about casuality, do one on the two different speeds of sound on Mars.

      @stewiesaidthat@stewiesaidthat2 жыл бұрын
  • The greatest explanation so far. I've been trying for months to understand this by reading forums and watching youtube videos. None were able to explain this. I still need to understand it more intuitively instead of through looking at lines, but this definitely opened my eyes. This is by far the best and most simply explained video so far on this. Thank you

    @AlmightyDude420@AlmightyDude4203 ай бұрын
    • Imagine a yellow star 10 light years away If you were to travel at the speed of light, it would take 10 years to get there right? lets say your friend is watching it in a telescope, 24/7 [LIGHT SPEED] - fly to star at light speed (10 years) - turn star purple - fly back home - (10 years later) you and your friend see in the telescope that the star turned purple [FTL] - instantly travel to star - arrive at star 10 years in the past - turn star purple - you might say, well the friend would see it instantly change - think about if instead of instant-travel, you travel with the speed of light back. toearth.. shouldnt it be purple the moment you land since you were traveling with the purple light? - also.. what happened to all the light that was traveling to earth? think about a middle-planet only 5 light years away from. the star instead..what do they see? -- at least how I understand it I think haha, but. who knows maybe there is infinite universes and you just jump to some alt dimension that is 99.9999999% the same except that the star turned purple at one moment instead of the other

      @kenny.speaks@kenny.speaks2 ай бұрын
  • Only my second time seeing a video from you and only a few minutes in and just wow dude. I really like your style as a creator. Great editing and writing and narration. Subjects that reawaken the part of me that used to dream. New information I didn’t know about subjects I’ve learned about multiple times before. Really loving this channel. Probably my favorite I’ve come across in awhile.

    @markjames1908@markjames19087 ай бұрын
    • Then kiss him

      @twerktospec@twerktospec6 ай бұрын
    • @@twerktospec maybe I’ll just kiss you 😘

      @markjames1908@markjames19086 ай бұрын
    • @@markjames1908 sick ass foo 😘😘😘

      @twerktospec@twerktospec6 ай бұрын
    • Chill bro Mr kipping doesn't wanna bang you

      @colbyr7811@colbyr78112 ай бұрын
    • AYO

      @DON-cg8kp@DON-cg8kp2 ай бұрын
  • There once was a young lad named Mike. Who could run faster than the speed of light. He took off one day, In a relative way, And returned on the previous night!

    @JACK_TheAllSeeingEye@JACK_TheAllSeeingEye Жыл бұрын
    • 6.67 out of 10

      @dudew.5272@dudew.5272 Жыл бұрын
    • @@dudew.5272 How about "11/10" because a score greater than 10 is impossible.

      @EbbandFro@EbbandFro Жыл бұрын
    • @@EbbandFro ackchtaly 🤓🤓☝️☝️☝️☝️

      @ophysic2861@ophysic2861 Жыл бұрын
    • what we gotta do is rip open a hole into hell itself and travel through in these giant bubbled ships so we aren't eaten by demons

      @vanillaicecream2385@vanillaicecream2385 Жыл бұрын
    • @@EbbandFro Spinal Tap says otherwise

      @BPJJohn@BPJJohn Жыл бұрын
  • Well, I don't know about time travel, but a fascinating thing to think about is that if you could travel FTL and have a way to look at earth from any distance, you could go far enough away from earth to see the past.

    @mw2zorzest@mw2zorzest9 ай бұрын
    • ​@@rodrigues.iVery easy point to understand. We're here on Earth looking out into space. If we look at the sun we're all seeing the sun in the past, as it was 8 minutes ago because that's how long light from the sun takes to reach our eyes. So likewise, if we could instantly transport to a point next to the sun and then looked at Earth we'd be seeing Earth as it was 8 minutes ago in the past. If we could instantly transport to Alpha Centauri and stare back at Earth we'd be seeing Earth as it was over 4 years ago because that's how long it takes light to reach our eyes from that star system. Get it?

      @jakecutter1487@jakecutter14878 ай бұрын
    • Not only that, if you then turned around and went back, you would BE in the past, and that is a simpler way to show the FTL violated causality, right?

      @paulshlasko3608@paulshlasko36087 ай бұрын
    • No... Wrong

      @davidkatzenbach7189@davidkatzenbach71897 ай бұрын
    • @@davidkatzenbach7189 If you mean me, how exactly is it wrong? If you move at FTL speeds you would see 'old' light once you stopped, therefore you would see the 'past' of the planet, which is why we see stars not as they are, but as they were many years ago, some stars already died, but we still see them because they're so far away that light from the time of their death has yet to reach us, same way we see planets, which reflect the light from stars. Light speed isn't instant, it's just really really fast. Thats what Lightyears are, we see a star 1 lightyear away as what it was like 1 year ago, because that's how long it takes for light to travel to our visible space. If I'm wrong, feel free to correct me, I am not omniscient, I can make mistakes, but I don't think I did here.

      @mw2zorzest@mw2zorzest7 ай бұрын
    • @@paulshlasko3608 No, because as you would get closer to earth you would see less and less into the past, @philgiffin1487 explained it perfectly, the closer you are to a planet the less the time difference would become. I explained it in my other reply more thoroughly.

      @mw2zorzest@mw2zorzest7 ай бұрын
  • What if the solution is a combination of two rules? 1. Anything that is going FTL cannot physically interact with anything going STL. 2. When exiting FTL, your world line is also precisely what it was before you engaged FTL. For example, an FTL ship cannot instantly travel to an STL ship, and exit out of FTL with zero relative velocity to the STL ship. This would make the STL ship intercepting an FTL message impossible. The only way to send messages FTL is by way of literally sending a physical ship that exits out of FTL at the destination. A message that simply travels through space and can be arbitrarily intercepted by any observer is just not possible. The FTL ship could also fly out to the STL ship at FTL, but in order for it to ever get back to Earth earlier than it left, it would have to accelerate to have a zero relative velocity to the STL ship from this example. But then that acceleration would take time, preventing it from getting to Earth before it left. I dunno, I’m no physicist, so I feel like I have to be missing something here, because that type of restriction doesn’t feel too arbitrary to me. This could just be me not yet picturing some other diagram following those two rules that still break causality. Seems like the isolation within FTL, and your relative velocity from your departure being conserved in the jump, both feel like they might be more of like natural consequences of how an FTL drive might actually work.

    @thebladerunner744@thebladerunner7446 ай бұрын
    • I agree with you and just said something similar in response to another. I think we collectively miss the fact that radio messages are transmitted absurdly slower than any speeds we are trying to achieve physically. So we wouldn’t “know” what happened to a vessel on the other side of successfully achieving FTL speeds unless that vessel signaled back. And how long would that take? “God only knows” as they say. That’s assuming we couldn’t return the vessel home with its findings. All wild thoughts. But science and logic tells us it’s possible. Still solving the “how”

      @this_dood_right_here@this_dood_right_here2 ай бұрын
    • Was just thinking about this concept of world line alterations as I was (re)watching this video. The notion of intercepting an STL message while in FTL somehow confused me/didn't seem like it should be possible in that reference point.

      @thejoshuahatcher@thejoshuahatcherАй бұрын
  • "It almost seems like a cruel cosmic joke that the universe be arranged such a way that we are able to look out and glimpse its wonders and yet are trapped here by the speed of light." So well said

    @shinysheepy6311@shinysheepy6311 Жыл бұрын
    • Like God said "You can look but you can't touch".

      @foxtayle683@foxtayle683 Жыл бұрын
    • Blind people have eyes yet they can not see. Be grateful for what you have.

      @AKa-qi2ov@AKa-qi2ov Жыл бұрын
    • It is only a cruel joke, due to human avarice. The concept of continuing to climb stairs to silver level, gold level, platinum level, diamond level luxury and status ...and be temtped by yet another staircase. The fire door locks behind you and you're trapped on a dirty roof with a noisy AC compressor.

      @STho205@STho205 Жыл бұрын
    • @@AKa-qi2ov Some don't have eyes.

      @chemplay866@chemplay866 Жыл бұрын
    • @@chemplay866 some don’t have brains and like their own comments 😂

      @AKa-qi2ov@AKa-qi2ov Жыл бұрын
  • I like how Terry Pratchett said it better than the way Hawking did: Everything that happens, stays happened.

    @zadrik1337@zadrik1337 Жыл бұрын
    • I wouldn’t even bet my lunch on that smug assumption.

      @JROD082384@JROD082384 Жыл бұрын
    • I like Jim Butcher's version Law For the Conservation of History. Postulating that there is a force similar to inertia for temporal events. Essentially after an event has occurred a strong force will ensure that it remains unchanged

      @mkohlhorst@mkohlhorst Жыл бұрын
    • Yeah it might be a bit naive or misunderstanding some implications of our current understanding of quantum mechanics, but it always seemed more intuitive to me that the future is set and that "change" is just a matter of viewing the universe from a different position within the spacetime and there is no need to "invent" a force preventing causality to break when the universe was already set (though this being true would probably make closed causal loops impossible).

      @Itherageli@Itherageli Жыл бұрын
    • ​@@mkohlhorst The "Good Doctor" Isaac Asimov described the inertia of the time stream in "The End of Eternity", an interesting read even today.

      @elmoteroloco@elmoteroloco Жыл бұрын
    • So... "Everything that happens, try to stays happened"

      @elmoteroloco@elmoteroloco Жыл бұрын
  • I'm no expert, but, it seems that the ultimate paradox of sending the messages back in time before the event happened only appears if you switch between the two frames of reference. Which you do (we are talking about material around 19 min of video). To explain, you mark the signal of supernova travelling from earth to the stl ship instantaneously as observed from the earth and then mark how the signal to switch the FTL transmitter travels from the stl ship to earth as observed by the stl ship. If you were to draw the signal lines corresponding to single observer only, they will almost overlap and be parallel. Given a slight time delay in the machine that receives and interprets the signal and sends the signal back (a computer constrained by the speed of light for example) the signal to switch off will be always slightly later. Causality violation will never occur from a point of view of a single observer and no-one would ever be able to experience it, including the machine that sends out the supernova signal and receives the switch off signal, unless they can be in two places at the same time and be able to switch between the two frames of reference freely.

    @thevaticanbikers1535@thevaticanbikers15356 ай бұрын
    • This is exactly what I 100% believe. The line at 18:12 drawn down-left is impossible even if you send message at 1 million x speed of c. The lowest it can go is horizontal (right to left). Thanks for sharing!

      @naveedrehman6083@naveedrehman6083Ай бұрын
    • Yeah this confused me as the message back from the ship from earths perspective should be traveling upward and left instead of downward and left. In which case no paradox happens. Earth will always send the message before the ship sends the reply.

      @Amehdion@Amehdion29 күн бұрын
    • It's because this is all wrong and your velocity has nothing to do with altering space time. Relativity proves this but everyone likes to misinterpret Einsteins findings. The epxlanation with the clock moving slower the faster you go to lightspeed was not an example of altering time. It was just an example of how the light behind you would react if you approached light speed.

      @jordancook8511@jordancook851128 күн бұрын
    • THHHIIIIIIISSSS

      @SpaceCitizenFaye@SpaceCitizenFaye27 күн бұрын
    • ​@@naveedrehman6083the horizontal line is earth's reference frame, not the universal one (there isn't a universal one). That line is possible given the space line and the null line of the STL ship.

      @xkinsey3831@xkinsey383114 күн бұрын
  • There's a great scifi series on a subreddit where humans are using C+ canons that send projectiles using something akin to "slipspace" to travel faster than light to target, and in universe from the target's perspective they get hit before the canons are even fired.

    @Alex-dh2cx@Alex-dh2cx5 ай бұрын
    • Cannons, not canons.

      @wehrewulf@wehrewulfАй бұрын
    • @@wehrewulf bud, im typing on a phone, v relax

      @Alex-dh2cx@Alex-dh2cxАй бұрын
    • ​@Alex-dh2cx what is the series called? On the hfy subreddit i assume?

      @elliotvanhijfte@elliotvanhijfteАй бұрын
    • @@elliotvanhijfte HFY, First Contact by Ralts Bloodthorne. That particular bit is a good ways into the story, which is over 2 million words. I THINK it was in one of the historical flashback chapters, but I'm currently in the Nova Wars series set far in the future from that part, i can't quite remember where in the story that came up, was just a small thing mentioned. They use some sort of special temporal tech to even be able to target things at great distances. It's probably the best long running series on the subreddit. The story of how it all got started is pretty amazing as well, the first few chapters are part of an introductory anthology, and the first chapter he wrote while serving in desert storm back in the 90s.

      @Alex-dh2cx@Alex-dh2cxАй бұрын
  • In the Halo extended lore (books and etc), their use of slipspace creates time paradoxes like, constantly. It's not uncommon for a ship to arrive at it's destination hours, days, or WEEKS before it left. And everyone's collective reaction to the existence of these paradoxes is just to kinda shrug, say "hey man, don't worry about it too much," and move on

    @gabe9125@gabe9125 Жыл бұрын
    • That's great, i fucking love it

      @deephorizon1365@deephorizon1365 Жыл бұрын
    • “Hey if we keep doing this the universe might break” “Cool”

      @brandenmarcum430@brandenmarcum430 Жыл бұрын
    • Every time I learn something about Halo lore it sounds completely tonally dissonant from the games I played. "John Halo is a brainwashed child soldier alongside every other Spartan, and the people who commissioned the Spartan Project belong in the Hague." "The use of slipspace at all is an existential threat to all the universe." "the UN created the Spartans to suppress rebellions with legitimate grievances" this is a space marine game about fighting aliens and being badass, what the fuck is all this genuinely horrifying secondary lore?

      @nickmalachai2227@nickmalachai2227 Жыл бұрын
    • @@nickmalachai2227 I'm glad to see someone else say this, I feel basically the same way. The deep lore fans irk me bad, it just sucks all the wind out of the sails for one of the most fun series of games I played as a kid. Like, I actually used to enjoy wiki diving and reading some of that lore- some of it was cool- but then every time I see people get up on a pedestal about how the UNSC are some evil Nazi-equivalent authoritarian regime, "the real baddies" (Compared to the Covenant? Those genocidal maniacs? Seriously?) and the spartan child soldier stuff, it makes it feel like none of it was worth it. Like, way to ruin a series; not only are the games after Bungie moved on arguably kind of mediocre, but then the books and other secondary lore retroactively hurt the Bungie games too. There's just nothing left to enjoy. It makes me so sad.

      @HorseDe-luxe@HorseDe-luxe Жыл бұрын
    • @@HorseDe-luxe I actually like the secondary lore, for the most part, I just wish the games were tonally consistent with it. Granted, I'm a Star Wars and Transformers fan. I'm used to worse bullshit than this.

      @nickmalachai2227@nickmalachai2227 Жыл бұрын
  • "The cosmic speed limit, the speed of light is so diminutive compared to a galaxy. It almost seems like a cruel cosmic joke that the universe be arranged in such a way that we are able to look out and glimpse its wonders and yet are trapped here by the speed of light. Fated to only ever peer through the bars of our cosmic prison and dream." -- This is so beautifully spoken...

    @yufansa@yufansa Жыл бұрын
    • That's a carl sagan quote right?

      @obothehobo173@obothehobo1737 ай бұрын
    • But isn't true. You don't need FTL to visit the Galaxy, as long as your speed is very close to the speed of light, your proper time slows down a lot. For example, at 299,792,456 m/sec (just 2m/sec less than c) you can reach a destination 720 Light years away in just one month at your clock. But for the rest of mankind, so your family, relatives and friends you are disappeared forever and no communication is possible. This is the real problem.

      @buioso@buioso7 ай бұрын
    • @@buiosoyeah that’s why it’s basically useless. The few people on board the ship or w/e is traveling would get to experience it, but upon returning the civilization probably wouldn’t even exist

      @ProfShibe@ProfShibe7 ай бұрын
    • I'm sorry but I.dont see a paradox here for the ftl ship. There's so much trickery and perspective here. Imagine you are on the other side of earth and you discover the country you're in has learned of an atomic bomb strike coming at them, then you see the atomic.bomb on its way, it doesn't mean the warning came first. It's just the order of information you received that's changed, not the ORDER of ACTUAL events. Why do physicists put MORE emphasis and make EM WAVES the MOST fundamental aspect of the universe but not the ACTUAL mass and energy aka atoms which emit them in the first place? Think of em waves as Carrier waves. They don't matter at all. So what if i travel faster than light and I arrive at another planet, stop, and then someone using a telescope sees the light from my body arriving later starting from near the end (where light is closest) and appearing to go back. We would know the light is just an illusion. The ACTUAL FUNDAMENTAL ATOMIC MATTER AND MASS MATTERS MORE THAN ITS EM RADIATION IT OUTPUTS. But we instead only focus on the atomic OUTPUT aka em waves and base ENTIRE THEORIES AND PHYSICAL LAWS around THE EM WAVE. Who cares about light? We've seen that atoms can "communicate" at "infinite speed" via the double split experiments. If particles can communicate faster than light they are MORE fundamental than light. Now sure information can only travel faster than light but why focus on information as if it's more fundamental than the MASS energy? Particles can communicate instantly at infinite distance, and while the information is limited at light speed, so what. Light is just em waves with no mass. Could we make life out of em waves? No. So who cares. If we did travel faster than light THEN saw the light of our travel arrive, I'm sure NO ONE would say "wait how come you're here but yet I see you still on the way?". Everyone would know that it's just an illusion. So I don't see any paradox

      @davidt8087@davidt80877 ай бұрын
  • Thank you Professor, very interesting. I myself think that the only reason we even discuss FTL travel is because SF writers had to 'invent' it in order to write space travel stories. One thing: I believe you pronounced the word *albeit* as 'al-bite'. Actually albeit is simply a contraction of 'although be it' or 'although it be', and so is correctly pronounced *all-be-it*.

    @BenjWarrant@BenjWarrant3 ай бұрын
  • Omg this diagram finally explained why and how space and time are connected. Thank you so much. I always thought I understood this concept but I was just repeating info not fully grasping it.

    @caitlyn9972@caitlyn99722 жыл бұрын
    • You need to look at curved spacetime diagrams (this one is flat) to understand the link between space and time :)

      @w0tch@w0tch2 жыл бұрын
    • @@w0tch thanks, I will.

      @caitlyn9972@caitlyn99722 жыл бұрын
    • @@N3KRoM3KHANIKaL Yes, I completely agree. We do not have enough information and may never get it. And relying only on math is most likely not the answer. It's a very "human" way of trying to solve things.

      @caitlyn9972@caitlyn99722 жыл бұрын
    • Even then it's still a massive stretch, we don't even know it time is linear, parallel, or circular, we can observe evidence of what we experience as the passing of time, but quantum physics seems to be bending our undersanding of the rules of time, energy and matter. Remember 3rd law of thermodynamics, entropy "TENDS", why the word tend? Because at this point it is outside the realm of our current paradigm of awareness as well as the technological capabilities as it relates to se sensory data acquisition to be able to define that theory with a more resolute likely useful definition. Aka our current level of understanding is the first black and white television. Imagine, give it colour and increase its resolution to 8k, I'll bet its a picture you can draw a more detailed understanding from. Crude metaphore I know, but there is no such thing as the best answer, only the "currently knowable" best answer. Don't act like it's a doorway to a new world of understanding, but all the knowledge you learn is simple a small stepping stone for you to leap from into the universe of the unknown, for the purpose of stumbling upon new unseen, unknown, and untouched wonders. Big and small. Seen and currently unseeable. The final frontier is not the beginning of the last mission, but the beginning of the first mission, that never ends.

      @dlayman101@dlayman1012 жыл бұрын
    • @@N3KRoM3KHANIKaL maybe so.. but that doesn’t mean we give up trying. Ever. The only real failure that exists is in not trying at all. Otherwise every attempt to find FTL or unlock the mysteries of the universe bears fruit in the end, even if ultimately that fruit is just another way in which we learned how not to make a lightbulb.

      @SkywalkerSamadhi@SkywalkerSamadhi2 жыл бұрын
  • I landed at the same "strict rules" conclusion back in 2007 when designing a sci-fi setting with FTL. I borrowed a bit from Douglas Adams and ended up with a version similar to one you hinted at. That any attempts to perform an action which would result in a paradox would be met with increasingly unlikely events to prevent it from occurring in the first place. Thus, before sending any FTL comms, or engaging in certain kinds of travel, you have to draw the light cones and think through the implications as shown in your video. Thanks for putting this together. It was nice to see someone think through the same things and tie it into a neat package.

    @Icedragon256@Icedragon256 Жыл бұрын
    • I am doing a copy and paste from a quick thought I had. "Just spitballing here, because I am not a physicist nor time traveler, but perhaps it needs to be viewed in other dimensions rather than with a 2d graph. Say for example someone makes a device that in theory can send an FTL message. They turn it on and send a message, but nothing happens so they think it didn't work. However thinking in the infinite universes model the senders universe continued on it's time line, but the message was received in a multitude of parallel universes. They have zero clue as to where the message came from, but they received it none the less. Or perhaps the universes have a way of keeping things tidy, so too speak. So when the FTL message is sent, how do I say this, the entire universe is sent and is no longer where it was in time. Thinking in terms of infinite universes perhaps there are as many, call them anti universes (empty spaces) in the big empty. So the universe itself where the FTL message originated instantly fills the space where the message is received thus avoiding some weird entanglement of timelines. Sure there might be some side effects such as the Mandela effect, but that is price we pay in order to have FTL."

      @just_me2797@just_me2797 Жыл бұрын
    • This is why I only travel on Bad News. 😉

      @W0NK042@W0NK042 Жыл бұрын
    • I have proven that even if you ignore all paradoxes with time travel it still violates the 1st law if thermodynamics.

      @RoyalPomegranate@RoyalPomegranate10 ай бұрын
    • This is what I was thinking. I'm glad to see somebody else thought the same. I even hypothesized that that causing a paradox, that section of time is broken off and takes that space with it, like ALL of that universe at that exact time, essentially causing what would be parallel universe. Sting Theory mathematically checked out, and postulates that a multiverse exists, along with at least 11 dimensions. I think something like this videos scenario paradox happened in the Mark Wahlberg Planet of the Apes. I remember there being a video transmission they received in the beginning of the movie that was actually sent years later...

      @raymondturner6784@raymondturner67849 ай бұрын
    • But I don’t understand, the problem seems to be STL not FTL but STL are totally possible

      @gatekeeping8528@gatekeeping85289 ай бұрын
  • I'm 30+ sitting here at 3:28am and have just learned through that graph, how their theories come about. I could listen you talk all day and will definitely sub to your channel ❤

    @orbisunum766@orbisunum7666 ай бұрын
  • What a fantastic misunderstanding of the subject. Glorious video, classic KZhead.

    @user-sm4ms8cx1m@user-sm4ms8cx1mКүн бұрын
  • I enjoy that you are actually including the possibility of breaking the universe in this video. That is why we stopped increasing speed, in my warp engine space ship.

    @CalamitousJonathan@CalamitousJonathan2 ай бұрын
  • Always a GREAT day when KZhead dings you because there is a new Cool Worlds!! 🛎 👍

    @marilynkozak7915@marilynkozak79152 жыл бұрын
    • Absolutely 💯

      @MrJuxone@MrJuxone2 жыл бұрын
    • Yesss

      @stevenclark7453@stevenclark74532 жыл бұрын
  • Yet again you combine scientific explanation with a thoughtful and beautiful message. Thanks for one day deciding to start doing these videos, they mean a lot to me.

    @Heretbg@Heretbg2 жыл бұрын
    • Same。

      @miaokuancha2447@miaokuancha24472 жыл бұрын
    • Why not also mix it with spiritual & religious thoughts?! ⚡️⚡️⚡️In multi-dimensions existence, causality wouldn’t be violated. Abrahamic secret texts of Jews, Christians & Muslims have hinted that “instantaneous” travel is indeed possible if we live within multiple dimensions. Each dimension has its own speed limit. When u reach certain speed, u jump into a deferent dimension & u loose direct connection to ur initial one until u slow down to within its speed limit. 🤔

      @duran9664@duran96642 жыл бұрын
    • I see what you did there. Or maybe what you will do there

      @the-guy-on-your-moms-couch@the-guy-on-your-moms-couch2 жыл бұрын
    • @@the-guy-on-your-moms-couch Well played!

      @miaokuancha2447@miaokuancha24472 жыл бұрын
    • I like Carl Sagans son too

      @onlyonewhyphy@onlyonewhyphy2 жыл бұрын
  • This video is amazing. Thank you for this simple explanation of such complex issues. I have discussed your diagrams with a couple of colleagues last night and we had an amazing time 😊

    @matzefly@matzefly22 күн бұрын
  • Great video. Speed of “thought” as form of FTL travel? Perhaps currently the only way. Also, love Hawkings ideas that time paradox’s are impossible.

    @user-ml8oq5dh9n@user-ml8oq5dh9n3 ай бұрын
  • Congratulations, you had my complete attention to the entire 25 minutes. Very well done video and explanation. Super interesting

    @victorcurysimionato6412@victorcurysimionato6412 Жыл бұрын
    • He's an interesting man, I'm the same way. I can get deep into my own thoughts while listening to a video but like you, listened to it in its fullness.

      @daMillenialTrucker@daMillenialTrucker10 ай бұрын
    • I use this video to sleep

      @KhaiGK@KhaiGK9 ай бұрын
  • What is most beautiful about this video - is actually what it has done to the comments section. Look at all the wonder, the questions, the curiosity, the debate. All these wonderful human beings trying to discover - this is what I love most about humanity, we're all in this thing together :)

    @madzangels@madzangels2 жыл бұрын
    • Have a look at the comments on some conspiracy videos. The moon landing deniers, or the flat earthers for instance.

      @pansepot1490@pansepot14902 жыл бұрын
    • @@pansepot1490 no don't your brain will hurt badly

      @gamingcreatesworlddd2425@gamingcreatesworlddd2425 Жыл бұрын
  • Sorry to double-post; but this is one of the best videos on this subject. I often discuss why FTL communication alone can create paradoxes; but it is a tough concept to internalize so I have to go back and re-think it through. (Either by watching a video like this or drawing my own space-time diagram.) Speaking or spacetime diagrams, maybe you can siimplify it. Perhaps you can consider just "earth" and the sub-light ship communicating instantaneously (FTL.) Instead of a message and response becoming flipped, consider a continuous "open channel" (like a real-time phone call with both the home planet and the ship without ever hanging up.) Since time goes slower for the ship right from the beginning anything said from one will be heard from the other in opposite order, with the difference between the two getting greater and greater. (As an aside, I suppose on Earth the voice from the ship should sound in slow motion, while the vocals from earth should sound speeded up on the ship.. this is incidental, but it demonstrates since the vocals coming from the earth will be super fast containing much more information why it will appear to be from the *future* from the ship's perspective. Perhaps have the earth to ship channel constantly reading the news....the crew of the ship will hear the news more and more from the "future." I put that in quotes since it's cool from the ship's perspective. It's only the "future" if the ship then instantaneously relays that information back to Earth. ) Thus the time difference between call and response will continually increase as the distance/time between the two increases.

    @yurkdawg@yurkdawgКүн бұрын
    • I alluded to this in my post, but here's an even simpler slight variant. Let's not even consider reversing cause and effect. Instead think of instant FTL to and from a sub-light ship allowing Earth to see the future. So we still have an open instantaneous FTL channel from Earth and a normal sub-light ship (going a decent fraction of light speed.) Over this channel we just send a 24-hour constant headline news feed. Since time slows down from the perspective of the ship, this news feed will seem to be moving in fast speed. This is simply because time is slowing down from the ship's perspective. Heck you dont even really need FTL for this! Anything "realtime" will appear speeded up from the ship's crew perspective. But this time let's have the ship now with its instantaneous FTL transmitter continuously send that signal right back to Earth. Eureka! A watcher back at Earth will now be watching TV from the future! (Albeit speeded-up, so they better be paying attention! 😂)

      @yurkdawg@yurkdawgКүн бұрын
  • Great video and it really got me thinking! There is one thing I don't understand though, and would love to hear an explanation from a physics student or a professor. Which is this: how can the STL ship send an FTL message to Earth's past? This is how my non-physics brain perceives the situation and what I (think I) understand: 1) Time is relative for both the Earth and the STL ship 2) Time on STL ship ticks slower since they're moving closer to the speed of light. They are moving towards Vega and away from Earth and the supernova. Hence it makes sense why the first thing they see is "Vega receives message" in the previous diagram. 3) While time has slowed down for the FTL ship, time ticks forward for those on Earth. 4) Now let's assume that 1000 years have passed since STL ship has left Earth and that's when the supernova explosion was detected by Earthlings. This means when Earth sends the FTL message and STL ship receives it instantly, 1000 years might have passed on earth while only 1 year might have passed for the STL ship's crew, depending on their speed. So far so good. (5) And this is the bit that messes with my head. When STL crew responds to that message with another instantaneous FTL message to Earth - how is that going in the past exactly? 1000+ years have already passed on Earth when the STL ship responds instantaneously, meaning Earthlings should've received the response AFTER they sent the message in the first place. While Earth might looks like it's stuck in the past to the STL ship, in reality time has progressed a lot further than it did on the ship. The Earth itself is not in the past. Thanks in advance for your help. I hope someone can clearly explain how STL's FTL message ends up in Earth's past (with examples if possible). Thanks for your patience with my limited knowledge of physics!

    @utubedarko@utubedarko4 ай бұрын
    • Based on the way you described it I don't think causality is broken, because you didn't send the message through time into the past. I think of it like this, data/matter could be transferred faster than the speed of light, but the moment it arrives at its destination it is subject to that space's flow of time. So in your example when the message is received and then the crew processes it and sends their reply, far more time has passed on earth than in the ship. This would mean that the message couldn't travel back in time, because even if it arrives instantly, it is not processed instantly. Essentially FTL travel and communication would affect time and space differently. So you can send messages to points in space faster than light but not time. If you could communicate faster than light through space-time then you would break causality. Essentially the FTL ship is more accurately isolating your flow of time to increase your moment through space. So you move through time slowly but through space faster. By the time you arrive at your location the time warping breaks and you enter the normal flow of time at a different point in space. In essence, you don't move through time and space equally. This would prevent time travel to the past but allow for FTL communication and Travel. I think, Damm this is taxing on the brain.

      @haydenscholze7452@haydenscholze74524 ай бұрын
    • That’s a nice try. I applaud your brain work. But the physics you grapple with are well known and understood, mostly in Einsteins Theory of Special Relativity. If you have a basic, non mathematical, grasp of that it is much more clear.

      @stanjohns348@stanjohns3483 ай бұрын
    • Thank you. I know it's well established, I just don't understand it. If you do understand it, I'd appreciate an explanation.

      @utubedarko@utubedarko3 ай бұрын
    • @@stanjohns348 ☝️

      @utubedarko@utubedarko3 ай бұрын
    • Hi darko, if a message beam were to travel faster than the speed of light, time would reverse due to Time Dilation (Google or GPT Einstein’s Special Theory of Relativity)

      @stanjohns348@stanjohns348Ай бұрын
  • I'm having a lot of difficulty wrapping my head around some things here. For example, why is the space axis a mirror-flip across the null line of the world line? For the "stationary" earth I get that it would look like a mirror-flip, but why is it? Also, when the transmission is sent from the STL ship after receiving the earth transmission, why is the slope negative? I feel like having this side-by-side with a similar diagram for the STL ship's perspective (with its world line being vertical, and the others being angled) would help clear things up... Like, I get that there's some consideration here for time dilatation, but wouldn't that be bypassed too, as using something like the Alcubierre drive, the object is not actually moving FTL, just the space it resides in is, so it wouldn't suffer time dilatation... I'm just getting confused.

    @Calvinxc1@Calvinxc12 жыл бұрын
    • This is where I'm stuck as well. I feel like the mirror line is the most critical aspect of the problem, but is also the least explained. He says, "Now, adding the null line back on we can note the relationship that the space axis is really just a flip of the time axis around the null." This statement is just kinda thrown out there like it might as well just be a coincidence rather than a requirement. But he's a smart guy, so I'm sure there is more to it that gets lost in the explanation. Here is what I really don't understand. FTL travel is obviously impossible if what he's saying is true. So then why are people spending years of their lives working on possible FTL ship designs? Is it not a complete waste of time?

      @jdshi6693@jdshi66932 жыл бұрын
    • yep, the 'obvious' mirror flip across the null line was just thrown in there without any real explanation. I'm confused.

      @rhorho2@rhorho22 жыл бұрын
    • Whole this explanation is a little bit wrong, straight lines are from special relativity theory, but relativistic slower than light ship need to have curved lines from general relativity, so space lines of the ship is only local oriented, and not apply to the whole universe, but(to be fair) the general relativity theory allows close temporal lines that breaks causality.

      @theOrionsarms@theOrionsarms2 жыл бұрын
    • If you want to a deeper explanation, check out Section 3.3 of williamsgj.people.cofc.edu/Minkowski%20Spacetime.pdf. It really comes down to Lorentz transforms. That the FTL ship is isolated during its trip doesn’t really matter, it departs and arrives in regular space time and is able to reach its destination faster than a beam of light (a beam of “causality”) can.

      @CoolWorldsLab@CoolWorldsLab2 жыл бұрын
    • @@CoolWorldsLab Beam of causality ... Those are words to conjure with.

      @miaokuancha2447@miaokuancha24472 жыл бұрын
  • Your written script and voice work is top class, man. Documentary level for me, especially for a subject matter that I find intriguing.

    @Iron-Bridge@Iron-Bridge Жыл бұрын
  • What if for the reply signal that gets sent back (for the Supernova FTL Warning example), could we potentially just calculate the point in time/space where Earth would be, and send a signal with a specified frequency to travel the exact speed needed to meet that calculated point?

    @adalwulfsnow201@adalwulfsnow2016 ай бұрын
  • so my question here is at around 18:10 you're demonstrating what happens if the STL ship intercepts the FTL transmission, then sends a transmission back saying to "turn off FTL Transmission", what rule applying says that the returned transmission must move backwards in time? Why would it not move to upper position of the diagram of which case Earth would receive that transmission before Vega see's the Supernova keeping the order of causalities in line? Why must the returned transmission from the STL ship back to Earth be moving backwards in time?

    @silentvigil1911@silentvigil19116 ай бұрын
  • Cosmological and chronological paradoxes are so interesting, rather enjoyed listening to this more than I'd expected.

    @terra2965@terra2965 Жыл бұрын
    • the hack is to listen to it like your life depends on it.

      @fullercrane1795@fullercrane17957 ай бұрын
  • If FTL is impossible, the upside is that the possibility of aliens attacking would be quite low.

    @curiousgemini@curiousgemini Жыл бұрын
    • That also includes the possibility of meeting them :( The world could be littered with civilizations, just they might be far apart, or some might even be next to each other, and we’d never know.

      @ProfShibe@ProfShibe8 ай бұрын
    • If hostile aliens became aware of us through telescopes much more advanced than ours and wished, for instance, to take over this wonderful piece of "real estate", they could possibly, with their advanced technology, attack us with a virus. The virus is so small that it could be accelerated to near the speed of light without breaking any rules. Said virus could be designed to make us really smart, smart enough to change our ecosystem in their favor, and so aggressive as to cause our own downfall through constant conflict. They could then send their STL vessels with colonizers to eventually clean up the mess and take over the place. Its not really far-fetched, in my opinion!

      @paulshlasko3608@paulshlasko36087 ай бұрын
    • Alien 👽 of some types can bring souls witches % for the record player ✨!? Lol it's not of today because Mars&darWtfts planet a moon to Mars!

      @200fpsASH@200fpsASH7 ай бұрын
    • if aliens existed the first thing i would show them is a baja blast from taco bell

      @tobencoombs5750@tobencoombs57507 ай бұрын
    • @@200fpsASH Take your meds

      @pierreo33@pierreo337 ай бұрын
  • At 18:09, why is it that the ftl message from Earth still goes up at an angle on the diagram (seeming to go forward in time), while the ftl message from the ship goes down (seeming to go backward in time)? Does it change from one ref frame to another, whether a ftl path goes forward or backward in time?

    @flexico64@flexico643 ай бұрын
  • I watched the entire video, and I get the sense you broke the rules of your own diagram. You drew two diagonal lines at the start, indicating the speed of light. You set the premise that any line between the time axis and this diagonal line is something moving slower than light (STL). Any line between the diagonal line and the space axis are faster than light (FTL). You then start speculating about FTL transmitters able to send a message instantaneously, meaning horizontally to the right. I'm with you so far. This is where you break every rule that has been set. You draw a line that goes downward. We've not established any reason why a line would do that. Your made up transmitter can only go up to a limit of a horizontal line (instantaneous messaging). These paradoxes start popping up because you've suddenly decided this message is being sent to the past. The FTL transmitter is now a time machine for no reason. Like I said there might be some physics I don't understand. However in the diagram you've been using, there has been zero explanation of why any line would ever go down. The established rules were that lines could only be in the STL or FTL directions. Once you start going downward you break your own rule set.

    @MHGFTW@MHGFTW3 ай бұрын
    • Indeed, why is the first message drawn according to earth's POV but the second one is drawn according to the ship's POV? There's no explanation for that

      @digammaf7060@digammaf70602 ай бұрын
    • ​@@digammaf7060it's sent from the ships pov because that's where that particular message was coming from. However the original comment is correct that it doesn't make sense on this graph as if you map out time/ space for the the ships pov the line going downward would indicate that the message is sent faster than instantly from the ship back to earth. However if you send the message ftl but not faster than instantly than I don't think any causality is broken

      @tb3099@tb30992 ай бұрын
    • @@tb3099 Take 3 points, the first one being the emission of signal, the second one being the relay of the signal on the ship, and the last one being the reception of the signal on earth. Place those three points in a similar configuration as in the video. From earth's POV there is a downward worldline, but if you apply the Lorentz' transform on all three points to obtain the ship's POV there is no downward worldline anymore. In fact, the downward worldline becomes an horizontal worldline, relevant with the idea that the message is transmitted instantaneously from the ship's POV. I just checked that using a graphing calculator, the original comment is not correct about that, and you are not correct about that either. I would gladly share the Geogebra file but I don't know how.

      @digammaf7060@digammaf70602 ай бұрын
    • @@digammaf7060 interesting I was trying to figure out how to do it but I don't have a graphing calculator or know what app to use on my phone. On your graph is there a point at which the ships the ships transmitter can send something faster than light but not break causality.

      @tb3099@tb30992 ай бұрын
    • I will explain it to you so you can reproduce it exactly. It's not complicated. The Earth's worldline is the line defined by x = 0 (vertical line perpendicular with the x axis). The Ship's worldline is the line defined by y = 1.18x (arbitrary speed close to the speed of the light). The light's worldline is the line defined by y = x (45deg line). The Signal emission Ma is located at (0; 4), the Signal relay Mb is located at (3.38; 4), the Signal reception Mc is located at (0; 1.14). Now you have the world from Earth's POV. To get the Ship's POV, we will apply the Lorentz transform on Ma, Mb and Mc. First, the speed of the referential we are using is 1/1.18 (we are using the natural units in which c = 1). According to the wikipedia page of the Lorentz transform, we should first compute a factor called Gamma which in our case is about 1.884 (remember to take c = 1 and v = 1/1.18). Then, for each point Ma', Mb' and Mc' which are the equivalent of Ma, Mb and Mc from the Ship's POV, we can compute the coordinates like this: Mx' = Gamma * (Mx - v*My) My' = Gamma * (My - (v*Mx)) (I simplified the equations seen on the wikipedia page because c = 1) We are left with: Emission' = (-6.39; 7.54) Relay' = (0, 2.14) Reception' = (-1.82, 2.15) As you can see, Relay' to Reception' is not a downward worldline from the Ship's POV, the only downward worldline is Emission' to Relay', which is a direct consequence of breaking the speed of light and not relevant. This is not worth discussing because the real issue is not the shape of the worldline: that wouldn't be a problem for causality if both message worldlines were drawn from the same perspective, and that's why I'm telling you that you are not on the right path. The real issue here is that EVERYTHING on the diagram is drawn from Earth's POV, everything BUT that one message reply which is drawn from the Ship's POV, which doesn't make any sense at all. When you are drawing a spacetime diagram, you draw everything from the same POV. Imaging drawing the inside of a house, but for some reason that one couch is drawn as seen from the outside. This is non sensical. When drawn correctly, the diagram is Emission = (0; 4) Relay = (3.38; 4) Reception = (0; 4) As you can see, Emission-Relay and Relay-Reception are the same line segment, which is relevant with the idea that the communication is instantaneous. When switching to the Ship's POV, both Emission-Relay and Relay-Reception are downward worldlines (since we broke the rule of the light speed then it's not surprising to see other funky things happen) but both are the same line segment, breaking no causality at all.

      @digammaf7060@digammaf70602 ай бұрын
  • Attempting the impossible almost always brings great discoveries even if it's not the one that is being sought

    @allenhonaker4107@allenhonaker41072 жыл бұрын
    • Also leads you to fall off a cliff

      @MyKharli@MyKharli2 жыл бұрын
    • @@MyKharli As a former rock climber I can tell you that as long as you are properly belayed go for it

      @allenhonaker4107@allenhonaker41072 жыл бұрын
    • what even is an "impossibility?"

      @brokedolph@brokedolph2 жыл бұрын
    • well in this case there is nothing to attempt, speed of light is fundamental part of spacetime .. going faster follows same logic as lifting chair up while sitting on it

      @TechExpanse@TechExpanse2 жыл бұрын
    • 18:44 This paradox will never happen. Thats the point, it will always be a closed loop. Similar to Delayed Choise Quantum Eraser experiment. It is the same thing... I know it is hard to understand, but yeah, FTL is possible, time travel as well and it does not lead to paradoxes ! U can imagine it as those events are linked in time and they always happen (forming a closed loop), no matter what you will do between those events. Also on quantum level in very short times, the causality breaks down... You can apply this to whole universe. And yes, time paradoxes are not possible :-) as Steven Hawking said. Also, what do you think about the UAPs ? I would say they use FTL travel without a problem and some nonsence about causality does not bother them :D.

      @greenpumpkin172@greenpumpkin1722 жыл бұрын
  • respect to all the cameramen who time travelled into the past to bring us footage of all their FTL ships for use in this video

    @Cxntrxl@Cxntrxl Жыл бұрын
    • Disrespect to spam ty comments👎

      @daytradersanonymous9955@daytradersanonymous9955 Жыл бұрын
    • i love you

      @AashishK1993@AashishK1993 Жыл бұрын
    • Oh look an original joke...

      @MetalFan10101@MetalFan10101 Жыл бұрын
    • @@daytradersanonymous9955 Phd

      @durcheinanderme@durcheinanderme Жыл бұрын
    • @@MetalFan10101 phd

      @durcheinanderme@durcheinanderme Жыл бұрын
  • I don't understand why would the FTL message from the ship goes back in time? Why was the purple line drawn below and not above? Shouldnt it be pointing upwards since that's course of time? I'm very confused and it's very late.

    @non-blogger@non-bloggerАй бұрын
  • 14:54 Dont you have to start at the space line of the STL space axis like you did in your world time example? Vega wouldnt receive the warning from the ships perspective at this moment. It would know about the event, once the ship lands on vega. Wich makes sense since more time has passed in both systems. And why would the message travel backwards in time but forward in space once the STL ship responds?

    @radikarler1425@radikarler14256 ай бұрын
  • One problem I’m seeing with the Minkowski diagram @13:53 (unless there’s a component I’ve missed) is that the Earth timeline has the STL time/space axis to Vega occurring before the ‘Earth sees X’ event (in the diagram it diverges from the Earth time line at the base of the diagram) should it not be diverging from the ‘Earth sees X’ event? If I’m not mistaken, the STL ship left the Earth to Vega at the reception of the X supernova event?

    @samg8572@samg85724 ай бұрын
    • Finally a comment from someone that saw the same thing I saw. It seems wrong to me

      @dhfonz@dhfonz9 күн бұрын
  • I legitimately wish you could see my face the moment i notice there is a new Cool Worlds video in my subscriptions sitting there waiting for me, i love this channel so much, the work and effort that goes into every video does NOT go unnoticed, thank you for giving us such high quality brain food. oh, btw, I NEED MORE lol.

    @TheDisabledGamersChannel@TheDisabledGamersChannel2 жыл бұрын
  • I think as soon as something like FTL is achieved, we'll soon learn that there is some other, infinitely stranger arbitrary limitation way beyond our grasp that we could never have even conceived of before. I have dreams about it all the time, since I was a child in fact.

    @nellkellino-miller7673@nellkellino-miller7673 Жыл бұрын
    • Same! I think it's just a question of science. As much as i believe in science, we make a lot of hypothesis and assumptions, we are also able to calculate stuff precisely(think gravity) without actually understanding how it works exactly or at the quantum scale. We can measure stuff and make accurately predictions on things because they follow rules, even if we don't understand them at their core. With our understanding advancing we will eventually find out that there's much more hidden stuff in the universe, much more detail to the laws of physics as we know them. I'm pretty sure with time everything we deem impossible will eventually unravel itself with technology. Think about our understanding of gravity or molecules or whatever has evolved, from thinking that something doesn't allow you to leave the ground, to thinking there might be a force, to formulating an explanation to that force, to finding actual data on it and doing research. We will eventually end up finding that gravity is an illusion and happens for other reasons than we think 🤣

      @griseld@griseld Жыл бұрын
    • I like the way you think!

      @stefanschleps8758@stefanschleps8758 Жыл бұрын
    • @@griseld As much as I like your enthusiasm, and would love for FTL and other fancy tech to happen, wanting it to happen won't make it so. The reason science is so scientific is because of intrinsic scientific value; skepticism. Being skeptical is probably a key to being a scientist. So it isn't really healthy as a scientist to start thinking that everything you know now is completely wrong because something else that people thought was right turned out to be wrong. That kind of thinking can lead you to certain biases that can have a lot of effect on your research. Of course, pretty much all scientists and people want FTL to be possible and would love for it to be so, but also most of them know that as it stands right now, FTL is likely impossible, and, assuming they aren't researching something that could change that, they are probably working according to that. Scientific/technological progress could hit a wall tomorrow, and any advancement could freeze. Of course, that's unlikely to happen, but it is possible. It's good to be optimistic, and enthusiastic, but knowing where the potential limits are is good. I would love for FTL to be possible as I already said, but as far as we know it's either impossible or requires incredibly advanced technology that we won't have for hundreds, or maybe even thousands of years. And our current best theories suggest it's the former, but who knows? Maybe someone will create a theory of quantum gravity that will be proven, and that will allow for FTL.

      @optimuseprime7887@optimuseprime7887 Жыл бұрын
    • What would that be like?

      @procrastinathor4594@procrastinathor4594 Жыл бұрын
    • I wonder how much faster you would have to go to reach that barrier

      @JeffTheHippo@JeffTheHippo Жыл бұрын
  • I have an important question. If we are looking at the events from the Earths reference and the initial sending of the FTL message from earths reference, why would we view the response from the ship in the ships reference? From the perspective of the ship the response message would arrive on earth before the initial message but from the perspective of earth the messages would be sent and received in the order of Send, Response. It wouldn’t break causality it would just break the perception from the ship.

    @americankid7782@americankid778226 күн бұрын
  • I have one doubt with that if there was a dense material between VEGA and EARTH which slows the speed of light than the angle will be greater than 45 degree so it would be easier to go faster than the speed of light in that material (like a material in which speed of light becomes C/10 ) so than also will it build a paradox or it wont????

    @random_guy_Ash@random_guy_Ash9 күн бұрын
    • You’re describing God-Level technology. You’re suggesting converting 25 light years of space…… 6trillion X 25 = 150 trillion *Miles* of empty Vacuum space…. Into a different material that slows the speed of light itself. I feel like it would be easier for an advanced civilization to just figure out how to “teleport” by poking holes into a pocket dimension than it would to figure out how to bend 150 trillion miles of space into a new material, or even just simply changing the way the vacuum of space works within that pocket. The only way I could think to make that work would be covering that whole pocket inside some kind of container. Whether a physical container, or a barrier of energy. Either way, that’s God-Level technology. You’re literally changing reality itself at that point.

      @johnnyrocket1685@johnnyrocket16859 күн бұрын
    • @@johnnyrocket1685 Also like slowing down the speed of light is a pretty easy this ( like in the case of crowned glass) it's like a hypothetical situation which can also happen with a mere coincidence like a nebula burst in the middle of vega and earth which can result in that condition And also i wasn't concerned about the conditions existence rather than more concerned about what will the consequences of these conditions

      @random_guy_Ash@random_guy_Ash9 күн бұрын
  • I like how he predicted every point where I got confused or skeptical and delivered a good answer without me ever asking anything lol About the talk in the end about exploration without FTL, it was quite poetic, but individuals can actually experience it one day and travel to many stars, considering there is no barrier in the laws of physics that say living things can't last for billions of years. More than that, the way in which time is perceived can be drastically modified, where a million years travel can feel like a mere hour. Just imagining human-like consciousness in a digital substrate is enough to see how this things are possible

    @Luna-wt9oy@Luna-wt9oy2 жыл бұрын
    • Same. I'd have a question pop into my head, and two sentences later, he was explaining it!

      @cassandravonpohl942@cassandravonpohl942 Жыл бұрын
    • One problem. The Universe really doesn't like computers either.

      @toromontana8290@toromontana8290 Жыл бұрын
    • Even if we stay our squishy selves, we can cross our galaxy in under 25 years (traveler's time, because of time dilation) going at a comfortable 1g halfway and decelerating at the same rate the other half. Even going to the edge of the universe will take under 50 years in these conditions. Maintaining that acceleration that long will require insane amounts of fuel of course (i.e. the annihilation of 600 million tons of matter and antimatter as fuel for crossing the galaxy for a 100kg payload), but it's nice to think it's "possible" in some ways.

      @youtubeforcinghandlessucks@youtubeforcinghandlessucks Жыл бұрын
    • you must not have even tried to look at the "graphs"

      @pinnacleexpress420@pinnacleexpress420 Жыл бұрын
    • Looking at my cat, I cannot really fathom what she is truly thinking as she stares back at me. With this in mind, I truly have no way to imagine what a "human-like consciousness in a digital substrate" would ever feel like. I suppose it would be as alien as comparing my consciousness to that of an ant...

      @valkyriefrost5301@valkyriefrost5301 Жыл бұрын
  • Sir, I only found out about you less than a month ago but have almost instantly became obsessed with your content. Keep it up man, I love everything you put out.

    @colinharrington5303@colinharrington53032 жыл бұрын
  • But why is the msg from STL ship travells back in time instead it should flow with time and come in future to earth...as both STL ship and Earth are travelling forward in time...is there any explaination why we draw the msg form STL ship line backward in time

    @arushsharma5814@arushsharma581423 күн бұрын
  • It's amazing how slow you plan to go faster than light. I have other things to do. If I have time, when I'm finished goofing off, I might check in to see if you made it to light speed.

    @kurtisengle6256@kurtisengle62563 ай бұрын
  • I have an affinity for how this gentleman explain science jargon in elucidating terms to the lay person and makes it also both profoundly educational and entertaining. He's never ever boring.

    @calebkimm325@calebkimm325 Жыл бұрын
  • The whole time I'm watching this wonderful video, I'm thinking 'eh maybe it is good that life can't FTL' while being thankful it is a question we have the facilities to think about. I'm tickled by content that invokes healthy pluralistic thought. Please never stop.

    @nobiggeridiot@nobiggeridiot2 жыл бұрын
  • Question: If the world line tilts when an object moves why does it tilt only in one direction? If i understand the speed of light correctly it does not matter where you are, in which direction you move, or how fast, light will always move in all directions at the same speed, for all observers. So wouldn't the light cone for the STL ship still be a 90 degree angle pointing to the top? If so, shouldn't the world line of the ship have a bend and thus also go "up" on the left side?

    @tortenschachtel9498@tortenschachtel94985 ай бұрын
    • Yes, u r perceptive. It was drawn for simplicity. A cone would be more accurate. A mathematical equation would be more accurate still, but I wouldn’t understand it.

      @stanjohns348@stanjohns3483 ай бұрын
  • why is the STL ship's reply world line travels backwards in time?

    @amieldansapilan7783@amieldansapilan7783Ай бұрын
  • Best explanation of time travel paradoxes I've seen in a long time, thank you for this! I feel so amazed that on one hand we can theorize and explain stuff like this yet a lot of people will still doubt that we ever went to the moon.

    @becyk_du_quebec@becyk_du_quebec Жыл бұрын
    • For sure. It's like a hideo Kojima metal gear story lmao he'd right a story about some shit like this. Make a good one crew falls out time

      @kritizismmusics9737@kritizismmusics9737 Жыл бұрын
    • I don't think we went to the Moon, too many variables and orbit and where it's going to be and how do we get there if you look at Apollo 13 movie with Tom Hanks they talk about the 8-ball bubble how do you get orientation when you're not on Earth

      @joehopkins6724@joehopkins6724 Жыл бұрын
    • @@joehopkins6724 dude, there's a decent shout for never breaching LEO. but your argument is instantly null and void when you're bringing up hollywood movies lol.

      @mowvu5380@mowvu5380 Жыл бұрын
    • Yeah man. I love this guy

      @ayaankhan-vt5jy@ayaankhan-vt5jy Жыл бұрын
    • There are still people who think the earth is flat. Even though the first circumnavigation of the earth was completed 500 years ago. The problem with time travel is if it were conventionally possible we should already have had evidence of time travelers and it would be very easy for anyone from the future to prove it. From a theoretical standpoint, M-theory is the only possible solution to the paradox I can imagine but still seems impossible to prove regardless.

      @whichgodofthousandsmeansno5306@whichgodofthousandsmeansno5306 Жыл бұрын
  • 15:18 If we are looking at things from the ship's crews' perspective, how can you say that the first thing the crew perceives is Vega receiving the message from Earth? How did that information get from Vega to the ship? Was it instantaneous? Doesn't this information take time to travel to the ship from Vega? Yes, the time line has reached Vega, but it hasn't reached the ship yet. In fact, it appears that the ship learns about the message from Earth to Vega when the ship arrives at Vega (this might be an artifact of the speed of the ship, and might not be true for a different speed). More importantly, according to your timeline, the STL ship thinks Vega has received the message from Earth BEFORE THE SHIP HAS LAUNCHED. 18:11 Justify the world line for the return message from the ship. No matter how I look at it, the message from the ship back to Earth arrives later, not earlier. I don't see any way to get your reply world line from any of the other lines you've drawn.

    @tom4ivo@tom4ivo Жыл бұрын
    • I was feeling stupid for not understanding that part of the video, but my reasoning is the same as yours. I went back and forth in the video trying to understand why the STL ship would see that vega was warned before earth even sent the message. wouldn't that require that ship to see faster than light? on the other hand, I find it far more likely that I just don't understand the use case and I'm missing something that smarter people than me have thought of xD

      @jackie.p6891@jackie.p6891 Жыл бұрын
    • @@jackie.p6891 The time slice isn't about seeing events it's about them "happening" on that world line. The video is missing some crucial explanation of the STL ship and how it travels. The close to speed of light you are travelling (without FTL) time for you actually slows down and your observations of the world outside are also slowed down. Which seems paradoxical but it's what relativity tells us. So when we talk about what the ship experiences it's really just a question of it's perspective of the outside world. A transformation into the perspective of the ship would produce a diagram where the events happening on Eartth are slowed down.

      @salbrismind@salbrismind Жыл бұрын
    • @@salbrismind The STL ship's space line should be an S shaped curve to account for acceleration to relativistic speeds and deceleration. That would change it's position on the overall chart.

      @danielross7983@danielross7983 Жыл бұрын
    • If time is a constant in the equation, then no amount of space warping, special relativity, can make anything go back in time, or can make something happen before it starts. It can slow down subjective perception or slow down objective perception, but time proceeding forward, cannot go backward.

      @sirdeadlock@sirdeadlock Жыл бұрын
    • I am with you guys I am either too dumb or a message can never travel back in time

      @ozasco@ozasco Жыл бұрын
  • By far best explanation compared to all others. Great job. Could be perfect if at 14:30 (most frequently played viewer likely replying because it was a bit confusing) if you just explained more why the 45 degree flip dotted line for STL rather than mention to refer to a previous video for that understanding. Still good job.

    @ReynosoJD@ReynosoJDАй бұрын
  • 18:09 why would the STL ship's message answer go back that way on the diagram? I don't get it at all. It's very confusing because there were no example of someone answering back without FTL shenanigans.

    @DarkThomy@DarkThomy5 ай бұрын
  • You always sound so dramatic and yet extremely clear, scientific and well spoken in your explanations. Love watching and listening. Thanks professor Kipping, for the work and the stories.

    @jeromemanceau4263@jeromemanceau42632 жыл бұрын
  • It would've been useful to see that diagram from the STL ship's perspective, since it's not very clear why their reply travels at that angle

    @Zakini@Zakini Жыл бұрын
    • I also agree, although after a few times of piecing it together, I think this is what I came to. Under relativity, the speed of light is constant, therefore is that 45º line between the vertical of time and horizontal of space. Any observer is always going to have their own time line vertical and their own space line horizontal and the null line or speed of light line halfway between them at a 45º angle. So as someone else speeds up on your graph, their line will tip towards the right. This is their time line but their space line is also tipping up, both getting closer and closer to the null or speed of light line. I think it gets easier to comprehend once he switches over to instantaneous messages because those are parallel to the space line. So its easy to see why a line leaving the STL ship leaves parallel to what its space line is. I think the part that I don't understand is why one instantaneous or FTL message gets placed parallel to the earth's space line and yet the return message from the STL ship is parallel to its own space line. So I get the math of why the line is that angle, but I don't understand why 2 instantaneous messages don't have lines that are themselves parallel.

      @isavedtheuniverse@isavedtheuniverse Жыл бұрын
    • Indeed. Given the diagram, isn't their reply being sent backwards? Surely their message to earth would be in a diagonal going up and left. This is because time is going forward so the path of any action should always point upwards except the instantaneous lines which are flat ? (In an angle that mirrors the light speed line).

      @danielebowman@danielebowman Жыл бұрын
    • @@danielebowman this is exactly what I’m having trouble with. Their time line is going upward, so sending or receiving should be higher from where they started. I wish I understood this better, but the paradox didn’t make sense on that graph, or could have been drawn better. I don’t know why it’s angled down.

      @MagicScorpio@MagicScorpio Жыл бұрын
    • @@MagicScorpio Time should always go up on the context of the graph. The author made a bad mistake.

      @danielebowman@danielebowman Жыл бұрын
    • @@MagicScorpio I think it's easiest to see it when you actually tip the graph to the angle of the STL ship's space angle. The time access for the ship was shown moving up and to the left through the graph. The STL ship using FTL communication back to Earth sends on it's space angle, which intersects with Earth in the past.

      @dansmith4132@dansmith4132 Жыл бұрын
  • I wish every video was so capturing and beautifully made - just epic

    @erykbrzozowski2087@erykbrzozowski20873 ай бұрын
  • Shouldn't the message from STL ship back to earth be going forward in time (up and to the left in the diagram), not back? Can someone explain?

    @user-bz8sn1gj8h@user-bz8sn1gj8hАй бұрын
    • I don't get it either

      @homelessengineer5498@homelessengineer54989 күн бұрын
  • Outstanding! FTL was always a dream since watching Star Trek as a kid. The fact that we can glimpse these wonders of the universe as water filled meat sacks is truly amazing. Even if it isn’t possible, I appreciate that logic as to why is isn’t possible. Space is big. We’re living in an age of high definition discovery.

    @esbuenodun@esbuenodun Жыл бұрын
    • Water filled meat sacks, lol 😂

      @k.lisaswensen9877@k.lisaswensen9877 Жыл бұрын
    • Wouldn't call humans just water filled meat sacks. We are an outstanding species that just appeared shortly on earth. Our intelligence and consciousness is a God's given gift truly. In the future I believe we'll be able to change universe to our fit

      @mateonikolic6984@mateonikolic6984 Жыл бұрын
    • @micaiah middleton kzhead.info/sun/aNWYqpx6oZuPoZ8/bejne.html - Starship Congress 2017: Miguel Alcubierre, "Faster Than The Speed Of Light"

      @charleslong7815@charleslong7815 Жыл бұрын
  • The direction of the return ftl message from the stl ship is unexplained here. I would love to know the reason for that, seems like the most important part. Wonderful vid, very informative and easy to follow!

    @Jane-gq8xo@Jane-gq8xo7 ай бұрын
    • It had something to do with the local reference time line being tilted, which also felt unexplained. If the diagram is drawn based on Earth's perspective, or even some sort of objective third perspective, why would the timeline tilt at all?

      @ApostleO@ApostleO7 ай бұрын
    • It's because for the message to be ftl, it has to be under the yellow line, if the message went up, it would go over the yellow line and thus not be ftl

      @tbunreall@tbunreall6 ай бұрын
    • @tbunreall is correct. To elaborate, we’ve measured the speed of light to be the same no matter what your velocity is, i.e., the yellow line stays put for both Earth and the ship. The only way that can happen is by time slowing down as your velocity increases. So from Earth’s perspective, time has slowed down for the ship and vice versa. That is equivalent to saying that if two objects are traveling at different velocities, their time axes will be different. Now to get the space axis, you have to flip the time axis around the yellow line. So their space axes will also be different. An instantaneous message has to be parallel to the space axis of the sender. The instantaneous message from Earth to the ship is parallel to Earth’s space axis while the *_RETURN_* message is parallel to the _ship’s_ space axis. Anything slower that’s still FTL has to have an angle between the yellow line and the space axis of the sender. Please let me know if anything is unclear, it helps me learn too!

      @dennis-o@dennis-o5 ай бұрын
    • This video is incorrect and gives wrong conclusion. Draw a 45 degree from STL towards earth. You can still do FTL lower than 45 degrees but it will be above the moment when original transmission was made. Logic in this video is false

      @badrkhan@badrkhan5 ай бұрын
    • I agree it's the most important part of the video and yet it doesn't seem correct to me either. It really does need an explaination because the whole video depends on it ! xD And no offence but the replies you got don't convince me. Hoping for a better representation ;)

      @TonyVallad@TonyVallad5 ай бұрын
  • What I don't understand about the diagram is when the STL ship sends back the FTL message, don't you switch the frame of perspective from Earth to the ship? I understand that from the ship's perspective the message arrives on earth before it was sent. But from earth perspective it would arrive later? So, even if there are two realities when we look at them from the "outside" - from each perspective, there is no break of causality?

    @gschmeus1@gschmeus13 ай бұрын
    • No, it arrives back on earth before it was sent from EARTH’S perspective.

      @stanjohns348@stanjohns3483 ай бұрын
  • Revisting this. Professor, I just saw an article featuring your terrascope idea, featuring you, of course 😊. I was so excited for you

    @joshuagharis9017@joshuagharis9017Ай бұрын
  • Hiya, aerospace engineering grad student here! This seems really well-researched, and yes, this _is_ an effect that happens exactly as you say - and it's also not time travel. Not in the way we conventionally think of it, anyway. This model is actually referring to _information_ travel, which is surprisingly pretty different! And no, even if you switched the FTL signal to, say, a person traveling FTL to tell the Vegans (lol vegans XD), everything still holds up to how we understand relativity. This is because this thought experiment doesn't factor in the *quantum effects of information.* Take a pair of electrons, for example - let's make these two electrons quantum-entangled (something that can actually happen!), which is a fancy way of saying that their properties are connected and shared - when one electron does something, so does the other. We have experimentally proven that, when one electron's spin flips, so does the other - _instantaneously._ Which shouldn't be possible, so long as we assume everything is capped at the speed of light. AND this happens regardless of the electron pair's distance from one another. So in theory, if we separated these two entangled electrons across the entire Milky Way, then flipped one, the other would also flip at the exact same moment as the first. This is because with _information_ travel, there's no light-speed limit to be found - no speed limit at all, really. So when one electron flips, the information of that flip _instantly_ travels to the other electron, and so it flips at the exact same time. Crazy, right? All this just to say that, according to quantum physics, information is not bound to the rules of relativity, in regards to both space AND time. This is exactly what happens in this thought experiment - due to the nature of the different axes of space, the information onboard the STL ship comes in all jumbled and in the wrong order, but because information doesn't actually have a given speed limit (the entangled electrons are proof of this), nothing in relativity is broken! The rest of the universe follows the horizontal axis (mostly), and causality remains unbroken - since the space axis is relative to the observer, the *perspective of the order of events can change* because _information has no given speed limit,_ it's only limited by how it's perceived - so the events themselves still happen exactly in the order they happen. The line parallel with the space axis, traveling up and down, is really an _information perception line._ Think about it this way - forget the signal. What if you had a ship that traveled at exactly the speed of light? Both its time and space axis would be at 45 degrees, and thus its perception line would also be at 45 degrees. In that frame of reference, all three events - supernova X, Earth observation of X, and Vega observation of X - would happen at the exact same time. And what if we add back in the signal, and the ship was an FTL ship? Flip the STL ship line and the STL space axis line at 14:47, and we're FTL! The perceived (note: _perceived_ ) order gets _really_ janky with this example - first, the Vegans receive the warning from Earth; then the Vegans see X; then Earth sees X; then X happens. It's almost backwards! But that's okay, because *information - and thus our perception of that information - can arrive in whatever order it wants, or rather, in the order that the frame of reference allows.* No time travel, just information travel. Just thought I should mention that, to alleviate the confusion! Physics, sadly, just _really_ doesn't like actual, real time travel. (My inner Doctor Who fan is crying) Edit: Whoopsie, so I brought this post by my thesis advisor, aaand turns out I may be just a _wee_ bit absolutely incorrect about how transmission of information via quantum entanglement works. Say you have a pair of entangled electrons that you've measured to have a net spin of 0. If you measure one electron's spin to be some value x, due to quantum entanglement, the other electron's spin must be -x. Simple enough, right? All entanglement says is that mutually shared info is conserved. _Technically_ it means you also instantly know that the other electron's spin is some value -x once you measure the first electron to be spin x, but the pitfall for many people (including myself, sadly) is extending this logic to the _transmission_ of information. Just because an electron is entangled with another doesn't mean flipping that electron will have an instant effect on the other. Transmission of information is, much like everything else in the universe, bound to the speed of light. Physically flip an electron, and the other electron will flip after an appropriate amount of time, NOT instantly. (Note that this also is in an ideal setting, where spin only happens along a single axis - normal electrons can have spin along any axis they want, which has all sorts of brain-breaking issues that I will NOT try and summarize for both your and my sanity.) Having said that, though, the logic of the information perception line still holds true to a degree. Proper FTL travel doesn't yet exist, so we can't properly test the effects that FTL might have on causality. The thought experiment proposed in this video calls into question some of the issues FTL might have, but this post is more calling into question the claim that what's happening is time travel. An error I made was assuming the information in this setting was quantum information, which makes no sense since this isn't really a quantum system! You find quantum info in a quantum system, which this isn't, so the information perception line is really just the perception of normal, tangible information. (And again, quantum info like everything else is bound to the speed of light. Just pointing out another error I made.) And yes, it still looks like causality is being broken, but still only from an information standpoint. Events still carry on as they do, it's just the order of _detection_ of events that's getting weird. Which is totally fine! Harking back to the entangled electrons, if we separate the pair far enough and make enough observations in a second, communication via the speed of light would take longer than the interval between observations, meaning you can find out the other entangled electron's spin faster than the other side could tell you what that spin is. So in a bit of a backwards way to what I said earlier, information _still_ finds cheeky ways of "beating" the speed of light without actually beating the speed of light. If information can do that, then there's no reason why this doesn't extend further ie. to this thought experiment. Information gets wonky, but we already know that's okay. No time paradoxes here! To be fully honest here, I ain't an expert in this field - I'm a hands-on build stuff kinda guy, the stuff discussed in both what I've said as well as in this video are only tangentially related to what I study. Thanks so much to all the people who've (politely) criticized my errors - y'all were the reason why I brought this to my thesis advisor in the first place. Science is all about correcting incorrect assumptions, so thanks to all of y'all for setting me straight! And feel free to point out any other errors I've made in this edit - there's only so far proofreading will get you lol

    @adamhsu8247@adamhsu8247 Жыл бұрын
    • I wanted to write something similar, but you explained it much better than I ever could. TLDR: Paradoxons are always a human brain child. If they actually happen they are resolved on their own.

      @Bullshitvol2@Bullshitvol2 Жыл бұрын
    • This implies a device can be constructed to determine absolute speed of an object. The idea of an information order can be used to distinguish the angle of a given objects space axis and the information axis. Take two ships in space, they start off docked, moving through space at some unknown fraction of the speed of light. they exchange entangled electrons and set timers for an hour. both ships then accelerate away from one another so their separation speed is .5c after an hour of observed time on one ship they flip their electron, but the on the other ship they see the electron has already flipped. they can conclude that because the electron flipped on their ship, they must have been moving at a higher lower angle to the information plane. Assuming they can observe and be alerted to the flip as you suggest, they could even calculate their angle to the information plane. Now lets say after each ship observed an hour pass they turned around and reunited. After their rendezvous they will be on the same course and speed as before but now know what that speed is compared to the information plane. They can then decelerate together to be at zero absolute universal speed. At this point our duo can do all kinds of naughty things like shine around the emittance spectrum of helium at any other observers in the universe while transmitting a signal declaring their speed as zero absolute. Of course this would allow any observer to determine their absolute speed by comparing red shift of the helium spectrum. Or our stationary ships could observe the redshift of equidistant galaxies billions of light years away and determine were the center of the universe is. The ability to take such actions is highly cursed and Einstein would not approve. The fundamental problem here is the information axis. The universe does not actually suffer this problem or we would have declared Einstein's theory of relativity dead the moment QE electrons were observed. With accurate enough clocks we could have already determined the absolute speed of earth by using earth's rotation to generate the velocity difference. The flawed assumption here is that QE can relocate information. QE cannot do this. Yes, the changes in a particles are instant BUT you could not differentiate the change from random chance without observing BOTH particles and comparing the results. So far as we know this observation must happen at luminal speeds. Example: some process, call it radioactive decay, simultaneously generates two entangled electrons. these electrons have an a spin sum of zero but each one has an unknown spin. you then separate these electrons from each other. you take one electron and put it threw some spin flipping machine. Now you pass your electron through a filter that sends an electron with an up spin into detector A and a down spin electron into detector B. The moment the electron hits a detector it breaks its entanglement due to the act of observation. if your electron hits the up spin detector you can know with certainty the other electron would have hit the down spin detector but the observer of the other electron would have no clue your electron was passed through the flipping machine unless you told them. Fundamentally the information of the spin the electron does not exist until observed, changing the spin state before hand changes nothing and observing the electron breaks the connection. No FTL information. Its actually comical how far entangled pairs go to generally troll anyone trying to do FTL communication with them.

      @jadenwalker6713@jadenwalker6713 Жыл бұрын
    • @@jadenwalker6713 Neat - didn't know that! And now I do, thanks friend! I guess there's still plenty of gaps in my knowledge for now lol

      @adamhsu8247@adamhsu8247 Жыл бұрын
    • You literally wasted a mile of comment space being wrong.

      @JROD082384@JROD082384 Жыл бұрын
    • Physicist here, well done engineer. However, again, there is no "flow" of time as if it is a river. Einstein postulated that all matter has it's own time clock and that it can, and does, tick at different rates for different velocities.

      @jdove6883@jdove6883 Жыл бұрын
  • Excellent explanation in something only an expert would understand, to an audience who generally probably doesn’t understand. This has become one of my favorite channels

    @Therightisright@Therightisright2 жыл бұрын
    • To be clear though, there are no real experts on this subject because it's all entirely hypothetical in nature. For all we know ftl is accomplished a different way than we think, gateways, portals or some method we haven't even dreamt up yet. They might know more than we do on a surface level but are still in the realm of the most basic understanding themselves. There is always some unknown factor when dealing with these types of things, some variable that cannot be accurately predicted. It's best to take it all with a grain of salt.

      @DeathBYDesign666@DeathBYDesign6662 жыл бұрын
    • @@DeathBYDesign666 But none of that matters! The mechanism is irrelevant; assuming relativity is true, _no matter how_ you accomplish FTL, temporal paradoxes are possible.

      @garysturgess6757@garysturgess67572 жыл бұрын
    • @@garysturgess6757 That I would assume depends on how we define what space-time actually is. A bridge or portal still connects two points in space-time, but it's not actually moving though it. Like I said there's always some key component missing (like extra dimensions) that we just don't have enough awareness of to get past the basic logistics of it. The problem is that there is no way to actually prove any of this and plenty of physicists are still happy to work on the problem, even knowing the paradoxical nature of it. The theory of relativity vs quantum mechanics is also a paradox of sorts but most are certain there is a way to bridge the gap. At some point we're going to have to redefine how we interpret the word "paradox" because as of now it's simply means "no solution". I'm relatively certain that a KZhead video isn't going to have every conceivable answer either.

      @DeathBYDesign666@DeathBYDesign6662 жыл бұрын
    • @@DeathBYDesign666 The extra dimensions and lack of literal physical movenent in the portal type of FTL makes no difference, it still breaks causality because it allows information to get from point A to point B faster than it would take a photon to make that journey. That's literally all that matters

      @wildcardbitchesyeehaw8320@wildcardbitchesyeehaw8320 Жыл бұрын
    • @@wildcardbitchesyeehaw8320 And this matters why? There are so many paradoxical implications in just regular physics (the inside of black holes, the gap between quantum mechanics and general relativity, even just general existence itself) I don't think it necessarily means anything. That is what technology has always done, it makes things possible that nature can't easily do on it's own. Just because we don't understand a thing doesn't mean it cannot be done. Many much smarter people than you or I don't seem to think it's as impossible as it seems either. Paradox doesn't mean impossible, all it really means is beyond the known laws of physics or contemporary logic. There is no reason to think the laws of time are any more well understood than anything else, perhaps even far less so.

      @DeathBYDesign666@DeathBYDesign666 Жыл бұрын
  • I haven’t finished the video yet but idk if i have missed something because why at 18:21 does the message go back in time? Wouldn’t they have a STL transmitter aswell and send it back to earth in the future?

    @flimsy558@flimsy55819 күн бұрын
  • Isn't the STL line off? The slower it goes the more vertical it will be, right? But then, the mirroring at the speed of light would be more extreme, to a point where the angle becomes zero, if the STL ship does not move at all, hence the time slice would be horizontal too. The message back, seems to travel backward in time in any reference system. Why? Just because it is drawn this way? Shouldn't it be angled up, and everything is restored? Looks to me, that in addition like the space/time coordinates of the STL ship are confused with that of Earth and Vega. Or vice versa and this causes the paradox. Confused.

    @AJ-qv9yo@AJ-qv9yo6 ай бұрын
  • Let's start perhaps with a more modest goal: Alcubierre-style drive that targets STL flight instead of FTL. Even that would be a tremendous step forward for our civilization.

    @seattleitefpv@seattleitefpv2 жыл бұрын
    • .

      @galaxya40s95@galaxya40s952 жыл бұрын
    • That seems like it would be more difficult than actually achieving FTL. I would think that simply creating the warp bubble is going to be hard enough, and generating the energy levels and creating the exotic matter required is a monumental achievement in and of itself.

      @robertharvilla4881@robertharvilla48812 жыл бұрын
    • I disagree. What we should actually focus on is achieving relativistic STL flight directly. By my understanding, the closer the ship gets to c, the less time they experience throughout their trip (as the length between their origin and destination contracts, or as time dilation, depending on reference frame). Assuming STL travel close enough to c, one could get to almost any location within the cosmic event horizon, while only experiencing the amount of time it takes the ship to speed up and slow down from its own perspective. The only problem this results in is that all those who aren't also travelling relativistically will be left in the past by the crew of this ship by a number of years equal to the number of light years travelled (this is the effect that would be solved by FTL travel, for what it's worth). It seems to me that an STL Alcubierre drive would remove the length contraction / time dilation effects from the crew, since they aren't actually moving, which would paradoxically possibly make the trip longer for them than if they had travelled traditionally at the same rate as their warp bubble travelled.

      @rarebeeph1783@rarebeeph17832 жыл бұрын
    • @@rarebeeph1783 I don't think that relativistic speeds are going to be possible for humans due to the often overlooked relativistic effect of mass dilation, not time dilation. The faster you go, the heavier you become, and there's no telling what that is going to do to the ship itself, much less its crew.

      @robertharvilla4881@robertharvilla48812 жыл бұрын
    • But the possible negative effects of relativistic travel might only be dealt with by warping space itself rather than accelerating to higher and higher speeds. That makes warping the most likely of ways forward, or at least the least problematic. But then there's the question of what that's going to do to the universe itself when such a warp bubble is created. Seems to me it would result in a singularity or something even worse. ;)

      @robertharvilla4881@robertharvilla48812 жыл бұрын
  • My favourite page. New videos are such a highlight to my day

    @theatty@theatty2 жыл бұрын
  • I think you should explain point no. 2 (i.e. Space axis flips the time axis about the Null Line) clearly and why is the red line for the STL ship staring at the origin of thr graph ? Why not where the Earth is marked from with the blue star ?

    @riichobamin7612@riichobamin76123 ай бұрын
  • why did the STL timeline start from the origin? should not it have started from the same point from where FTL timeline started? We will send a msg using STL system only after Earth sees it, right? Not from the Time origin. Just like when we sent via FTL system. If someone knows the answer, please reply.

    @akshatagrawal15@akshatagrawal153 ай бұрын
  • I always love the very grounding and philosophical thoughts proposed in these videos along with the theory. Really helps to place the science and the importance of these studies in a broader sense and why or why not humanity should pursue them.

    @stealthyshiroean@stealthyshiroean Жыл бұрын
    • Well said.

      @johnnynitetrain32379@johnnynitetrain32379 Жыл бұрын
  • At 18:14, I have a couple questions about the diagram that confuse me. Earlier in the video you state that there are two null lines on either side as you can go in both directions in space. Where would the second bill line be for the STL ship? Would it basically be a reflection of the other bill line around the time graph of the STL ship? In that case, the space axis curves on the other side too. Which would mean that that message they sent was not only faster than light, but faster than instantaneous travel, and passes straight through the space axis, which does not match how the ftl transmitter worked on earth. From the STL ship's perspective, that ftl transmission would follow a similar angle as the one on earth, but that doesn't happen. Is there something I'm missing, or is the diagram wrong?

    @marinerusher5252@marinerusher52528 ай бұрын
    • Diagram seems wrong. Surprised nobody is asking this question

      @okaythisisfuckingrid@okaythisisfuckingrid6 ай бұрын
    • Have the same question. Earlier in the video it was stated, that null line (speed of light travel) is 45° and instant travel is 90°. So if we measure the angle between “STL ship line” and reply it is clearly greater than 90°. Which doesn’t make any sense. It also mentioned that everything is casted in the Earth’s frame of reference, but it is never explained how the casting between different frame of references really works.

      @stivvits1067@stivvits10676 ай бұрын
    • Same thoughts. The message should be going up and to the left, below the ship's null line, so the message would still be ftl as well as arrive after the original message. Frame of reference for the world lines should be the point of origin, as it is with the original message. So the reply would still come after the message

      @MartyrKomplx@MartyrKomplx5 ай бұрын
    • Yes for both observers an instantaneous message would seem as if it was received before it was sent. Also, from the STL ship's perspective, an instantaneous message from earth would pass through earth's space axis.

      @martbarnav1787@martbarnav17873 ай бұрын
    • Yes. The illustration was drawn to one side for simplicity. A 3d cone would be more accurate. A mathematical equation would be more accurate still. But would us bums understand that?

      @stanjohns348@stanjohns3483 ай бұрын
  • Following your logic with the diagonal time slice at 15:19 the crew of the STL space ship suddenly moved back in time during the take off, they moved before the event X happened. How do you explain this?

    @eatmydragon@eatmydragonАй бұрын
  • Got a question: 14:25 - "2. Space axis flips the time axis about the 45 degree null line" Why?

    @dontbleedthadalo@dontbleedthadalo4 ай бұрын
    • It's how the Lorentz transformation works. You can derive this geometrical property from Einstein's equations of time and space dilation in special relativity, though in reality it was done the other around, with Einstein's equation being derived from those geometrical properties. Edit: it you want to get an idea how to do math with the Lorentz transform, I recommend this series: kzhead.info/sun/a9Nrn8-Og2uEnYk/bejne.html

      @user-pk9qo1gd6r@user-pk9qo1gd6r4 ай бұрын
    • Thanks! @@user-pk9qo1gd6r

      @dontbleedthadalo@dontbleedthadalo4 ай бұрын
  • Amazing video. To me everything about it was perfect. The structure, the atmosphere, the visual depiction, the music and most importantly the topic and conclusion of the video. I rarely discover such gems on here, so thank you a lot!

    @calacestar@calacestar Жыл бұрын
    • Life and death situation!!! 🖐👉The Connections (2021) [short documentary] 💖🙌

      @VeganSemihCyprus33@VeganSemihCyprus33 Жыл бұрын
  • Thank you for this lesson! I finally have a slightly better grasp of 'world line' diagrams. I did't realize, or remember, that all "C"/ Light Speed lines are 45degrees. That helps. Now, I'm gonna look at a nice sunset to rest my brain!!

    @cjc363636@cjc363636 Жыл бұрын
    • Spacetime itself can exceed this speed limit, by stretching and contracting space which itself is the concept behind the warp drive and the wormhole. This video is mostly hogwash that only deals in purely in physics currently testable by current means and not in theoretical physics. Here is a paper that deduces that FTL can be achieved: arxiv.org/pdf/2201.00652.pdf

      @housetheunstoppablessed4846@housetheunstoppablessed4846 Жыл бұрын
  • why would the "time-line" tilt in the stl spaceship, and even if it does, if we are considering the events outside the ship should we not consider the time from the global reference frame, I am not able to clearly explain it, and am not able to fully understand the part about flippling the time axis, this is not an objection or criticism as I do not understand this completely, if someone can explain it would be helpful

    @tk_kushal@tk_kushal5 ай бұрын
  • I'm confused. Why did the STL ship start at the bottom of the Earth's time axis instead of starting at the point when Earth saw X?

    @isaiahtimothylacaba5985@isaiahtimothylacaba59853 ай бұрын
    • Same.

      @riichobamin7612@riichobamin76123 ай бұрын
    • Because it left the planet before Earth observed the supernova. And probably to keep the visualization/graph relatively condensed for the sake of the video lol

      @iLikeMelk@iLikeMelk25 күн бұрын
  • To be honest, I've watched this video a dozen times, mostly with awe, but still trying to understand it. I'm getting there!

    @beyondthetech@beyondthetech10 ай бұрын
  • doesn’t this assume the FTL system functions within and is warped by spacetime? if it were to be outside it, like a wormhole, would it not be a line that moves up at 45 degrees for some time, jumps over, and then 45 degrees again until hitting the other stationary observer? it seems to me it would create a light cone that has multiple center points, but with some shift up to account for some non-zero distance to travel to get there. this seems like it would be much better behaved, but i’m not a theoretical physicist.

    @morgan0@morgan07 ай бұрын
  • Can you explain why the STL ship at 14:00 originates from the origin? Wouldn't you start the journey through space once earth sees Supernova X?? In this case, you would never get to Vega before they see Supernova X, rendering a warning useless. I seem miss why you originated that line where you did, and not when Earth saw supernova x

    @cm96yyc@cm96yycАй бұрын
  • I’m struggling to understand why you placed the space axis for the STL ship, if we created a new chart with just them line it would be well below the null line no? It was at a very acute angle

    @lyndon7221@lyndon72216 ай бұрын
  • Damn - these shows are amazing. I love the philosophy components and the human impact of cosmic questions.

    @passtheparcel360@passtheparcel360 Жыл бұрын
    • I bet you do you philosophical dummy

      @geigercourtier@geigercourtier Жыл бұрын
    • Ends at philosophy. The fact that we cant build anything outside of earth explains it all. It is all fiction. Fight for ypur groung, it is all you wiil ever get..

      @dominikjaremek3120@dominikjaremek3120 Жыл бұрын
  • Don’t take this wrong but the style of this video’s cover is really like 3b1b which is one of my favorite channel, and also thank you to make contribution to spread the knowledge and explaining everything to us😂

    @user-nc4rs5xm1u@user-nc4rs5xm1u2 ай бұрын
  • How would the stl ship receive/perceive info about Vega receiving a ftl message? Are they just receiving earths ftl message to Vega? because on the diagram the ftl message axis intersects with the stl ships axis after Vega receiving the message.

    @Wyatt-Barton@Wyatt-Barton6 ай бұрын
  • My brain is definitely too smooth for this. Awesome video.

    @hingewichsterfick@hingewichsterfick2 жыл бұрын
  • I would posit that it is possible it's just all about frames of reference. You would not be able to affect anything in your personal referential past. You could observe it, but not change it. I think the diagram is off in using the frame of reference for the STL ship as the "speed" of their FTL message would be significantly "faster" than the message from Earth. The correction for this means that their message would NOT arrive prior to that of the sent message. (On the graph their message would appear to them (could they see the graph) to curve upward past the message point. Using star trek terms if you fired off a message at warp 1 its not going to travel at (warp 1 + full impulse) simply because you were going at full impulse. Basically this graph "forgets" that for all of the pink FTL lines, the straight "space" line is not straight. For them it is a curve, so if you factor that in and the flatten it back out it shouldn't violate causality. I am probably wrong somewhere, it's 2 in the morning...

    @cptblood1981@cptblood1981 Жыл бұрын
    • Ah thank you. I was thinking that this seems very off but couldn't put it in words.

      @GAURAV_RANA_@GAURAV_RANA_ Жыл бұрын
    • It doesn't make sense to me that the stl ship exists on a line based on the space axis...

      @Johninatorful@Johninatorful Жыл бұрын
    • Saying that "the line is not straight" and implying it should be straight is basically equivalent to saying "relativity is incorrect." Now, you can have FTL travel AND causality if you scrap relativity, but unfortunately, relativity looks highly likely to be true based on our current assumptions. And relativity means those strange angled paths through spacetime, where by going really fast in a frame of reference time will pass differently (seems to be experimentally true for satellites with clocks in orbit!). (And yes, I know that the video seems to claim that relativity isn't the problem, but... it totally is, I disagree with the video on that.)

      @Snow_Fire_Flame@Snow_Fire_Flame Жыл бұрын
    • @Peter Ingraham no, what I am implying is that this graph is uses a straight line (thus treating it linearly) vis a vis space whereas the whole concept discussed involves bending or folding space. I do not think relativity presents a problem as I have discussed as I believe it sorts itself put if you discount momentum and the standard rules that apply to speed and motion as you would have to when folding space itself. Similarly to how the rules change when you approach a black hole they would change when you folded space. As such, this graph assumes that if they are traveling at (using star trek references just for ease of discussion) warp 1 and fire of a beacon at warp 1 it will be traveling at warp 2. It will not. I posit that folded space travel is a definite limiter such that you cannot increase the speed simply by initiating a launch from something going at speed. As such it would APPEAR to curve away from the perspective of the FTL ships view on the graph IN ACCORDANCE WITH RELATIVITY. Whereas it's not actually making a curve on the graph because the graph treats space as linear and FTL travel does not.

      @cptblood1981@cptblood1981 Жыл бұрын
    • It may be right or wrong but the fact that it is showing 4 dimensional space-time on a 2 dimensional graph, it's like trying to show a 3D cube in 1D, it's simply not doable or at least it seems to me. From what I learned we are able to show a cube on a 2d sheet just because we are able to visualize the depth of the image and draw a "line behind the lines" that how we create 3d in short we are able to circumvent one dimension by imagining it so 4d can be shown in 3d, 3D in 2D, 2D in 1D, jumping from 4D to 2D doesn't make much sense and many things may not match like they should. That I think is the main problem here that there is just no way that he could show what he wants on 2D sheet. Rather than FTL I am more convinced by Einstein-Rosen bridges theory beacuse from what I know they go through additional 4th dimension of space there for not creating this paradox if its true. (sorry for mistakes if any english isn't my first language)

      @garconek712@garconek712 Жыл бұрын
  • I don't understand a word of it, but I am spellbound.😊

    @stevenk-brooks6852@stevenk-brooks68526 ай бұрын
  • 15:38 Okay but how does that sequence of events actually manifest itself from the crew's perspective? They won't "know" that Vega received the warning before X even happens, and by the time they arrive at Vega it will be _after_ the warning was received, just as it is for Veg's timeline. And they are now _on_ Vega's timeline at that point so it shouldn't matter..?

    @___jd@___jd6 ай бұрын
    • I think it's because in that scenario at 15:38 the crew inside the STL ship is not interfering yet like he illustrates later on, so yeah if the crew doesn't interfere then nothing of consequence will happen, however in their reality the chronological timeline of events is already messed up even though they don't know it. Like if they continue their journey normally then nothing will seem out of order, however during their journey some things happened that they don't know of that broke causality

      @Enthai21@Enthai21Ай бұрын
  • That was awesome,, answered a question I've had a difficulty conceiving for so long.. it now makes sense and as always opens the door to more questions. Great video and thankyou very much..

    @jeffvincent4827@jeffvincent4827 Жыл бұрын
  • 18:56 just out of curiosity how is FTL instantaneous in one way and in the other way traveling back in time. In that sense it should be back traveling from the beginning or did i understand something wrong?

    @famalos_xd3730@famalos_xd3730 Жыл бұрын
    • Video lacks the crew diagram and explanation of lorentz transformation. Without it, its hard to understand why it goes back in time.

      @ProOkox@ProOkox Жыл бұрын
  • Phenomenal job of explanation & presenting in a minimalistic way 👏🏻👏🏻👏🏻👏🏻👏🏻

    @MK.__@MK.__6 ай бұрын
  • The diagram at 18:24 for the return FTL message from the ship should be above earths position in the time axis due to the fact that while the message is FTL, the time required for it to return is still moving in the upward direction or am I wrong

    @TurbulentFlow9220@TurbulentFlow92203 ай бұрын
  • 18:07 Can someone explain how the "bizzarly" part works? How fast is the STL ship's reply message? Doesn't a message traveling backward in space at light speed from the ship have to travel at about a 5 degree angle above the ship's space axis (or 175 degrees above the ship's forward space axis direction), meaning the reply message in the diagram is not FTL? If so, then couldn't a paradox be averted by sending the reply significantly below lightspeed?

    @highmolecularweightRDX@highmolecularweightRDX2 жыл бұрын
    • I'm guessing it would have to be negative speed, which isn't a thing

      @bossoholic@bossoholic2 жыл бұрын
    • I don't understand what you're describing there but a message at light speed always has a 45 degree angle, independent of the frame of reference. That's basically the whole thing with the speed of light.

      @unvergebeneid@unvergebeneid2 жыл бұрын
    • You are correct, but he used the frame of reference composed from straight time lines and space lines that are applying to whole universe from special relativity theory, but time dilation on a relativistic ship could be correctly explained only if you use general relativity, that orientation of lines is a local efect, do not apply to other far away objects that don't move exactly in the same ways like that ship, and yes general relativity allows close temporal lines that breaks causality but not require causality to be broken.

      @theOrionsarms@theOrionsarms2 жыл бұрын
    • @@theOrionsarms Thank you! so STL ships moving close to the speed of light have a smaller angle in which messages from them can be FTL when observing for a reference frame of a stationary observer, and the angles messages can be sent at sub-slight speed from an STL ship are not the same in the forwards or backwards spacial direction. I guess David Kipping didn't mention this because the ship's reply was within normal physics, though he should have mentioned how causality does not have to be broken, the way you described.

      @highmolecularweightRDX@highmolecularweightRDX2 жыл бұрын
    • @@bossoholic This graph only works if the ftl communication he is using is a magical ftl particle. If its a wormhole with one end on the earth and another on the spacecraft, or an entangled particle pair, one particle on earth and one on the spacecraft, from a mathematical standpoint, the space ship is on earth and in space simultaneously, there is no space between them and therefore, no negative space arrow. Im annoyed at his lack of imagination and lack of use of real world solutions, like quantum communication By this graph, he is using negative space, like negative speed, as you said, is not a thing. he also needs negative time to make his graph consistent, its a very unscientific graph based on analogy, he's breaking the laws of physics to prove them. look up Einstein's 2 lighting bolts on a train track thought experiment, the observers in the train and the observers at the train station see events happening in a different sequence of events, but they are both correct, hence simultaneity. No causality violations occur.

      @problemsolved3293@problemsolved32932 жыл бұрын
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