What Happens To Quantum Information Inside A Black Hole?

แชร์
ฝัง
  • เผยแพร่เมื่อ 30 เม.ย. 2024
  • Check out the Space Time Merch Store
    www.pbsspacetime.com/shop
    Sign Up on Patreon to get access to the Space Time Discord!
    / pbsspacetime
    Meet Alice and Bob, famous explorers of the abstract landscape of theoretical physics. Heroes of the gerdankenexperiment-the thought experiment-whose life mission is to find contradictions in the deepest layers of our theories. Today our intrepid pair are jumping into a black hole. Again. Why? Well, to determine the fundamental structure of spacetime and its connection to quantum entanglement of course.
    PBS Member Stations rely on viewers like you. To support your local station, go to:to.pbs.org/DonateSPACE
    Sign up for the mailing list to get episode notifications and hear special announcements!
    mailchi.mp/1a6eb8f2717d/space...
    Search the Entire Space Time Library Here: search.pbsspacetime.com/
    Hosted by Matt O'Dowd
    Written by Matt O'Dowd
    Post Production by Leonardo Scholzer, Yago Ballarini & Stephanie Faria
    Directed by Andrew Kornhaber
    Associate Producer: Bahar Gholipour
    Executive Producers: Eric Brown & Andrew Kornhaber
    Executive in Charge for PBS: Maribel Lopez
    Director of Programming for PBS: Gabrielle Ewing
    Assistant Director of Programming for PBS: John Campbell
    Spacetime is a production of Kornhaber Brown for PBS Digital Studios.
    This program is produced by Kornhaber Brown, which is solely responsible for its content.
    © 2024 PBS. All rights reserved.
    End Credits Music by J.R.S. Schattenberg: / multidroideka
    Space Time Was Made Possible In Part By:
    Big Bang Sponsors
    First Principles Foundation
    John Sronce
    Bryce Fort
    Peter Barrett
    David Neumann
    Alexander Tamas
    Morgan Hough
    Juan Benet
    Vinnie Falco
    Mark Rosenthal
    Quasar Sponsors
    Grace Biaelcki
    Glenn Sugden
    Ethan Cohen
    Stephen Wilcox
    Mark Heising
    Hypernova Sponsors
    Daniel Muzquiz
    Michael Tidwell
    Frank Plessers
    Chris Webb
    David Giltinan
    Ivari Tölp
    Kenneth See
    Gregory Forfa
    Alex Kern
    Bradley Voorhees
    Scott Gorlick
    Paul Stehr-Green
    Ben Delo
    Scott Gray
    Антон Кочков
    Robert Ilardi
    John R. Slavik
    Donal Botkin
    Edmund Fokschaner
    Chuck Zegar
    Jordan Young
    Gamma Ray Burst Sponsors
    Arko Provo Mukherjee
    Mike Purvis
    Christopher Wade
    Anthony Crossland
    treborg777
    Grace Seraph
    Parliament
    Stephen Saslow
    Robert DeChellis
    Tomaz Lovsin
    Anthony Leon
    Leonardo Schulthais Senna
    Lori Ferris
    Dennis Van Hoof
    Koen Wilde
    Nicolas Katsantonis
    Joe Pavlovic
    Justin Lloyd
    Chuck Lukaszewski
    Cole B Combs
    Andrea Galvagni
    Jerry Thomas
    Nikhil Sharma
    John Anderson
    Bradley Ulis
    Craig Falls
    Kane Holbrook
    Ross Story
    teng guo
    Harsh Khandhadia
    Matt Quinn
    Michael Lev
    Rad Antonov
    Terje Vold
    James Trimmier
    Jeremy Soller
    Paul Wood
    Joe Moreira
    Kent Durham
    jim bartosh
    Ramon Nogueira
    John H. Austin, Jr.
    Diana S
    Faraz Khan
    Almog Cohen
    Daniel Jennings
    Russ Creech
    Jeremy Reed
    David Johnston
    Michael Barton
    Isaac Suttell
    Oliver Flanagan
    Bleys Goodson
    Mark Delagasse
    Mark Daniel Cohen
    Shane Calimlim
    Tybie Fitzhugh
    Eric Kiebler
    Craig Stonaha
    Frederic Simon
    Tonyface
    John Robinson
    Jim Hudson
    Alex Gan
    John Funai
    Adrien Molyneux
    Bradley Jenkins
    Amy Hickman
    Vlad Shipulin
    Thomas Dougherty
    King Zeckendorff
    Dan Warren
    Joseph Salomone
    Patrick Sutton
    Julien Dubois

ความคิดเห็น • 1.6K

  • @Orillion123456
    @Orillion123456 หลายเดือนก่อน +458

    I love the idea that a future mind-uploading device requires you to breakdance on top of it while it uploads you.

    • @richardconway6425
      @richardconway6425 หลายเดือนก่อน +5

      I think you'll find that you put the device on your head. For convenience, of course.
      Remember, there is no up or down in space, just round and round ...
      ratt 😜

    • @John-jc3ty
      @John-jc3ty หลายเดือนก่อน +28

      its part of the physic process. he breaks his neck to avoid having 2 bobs at the same time and breaking unitarity

    • @gage11769
      @gage11769 หลายเดือนก่อน +14

      I loved that part so much lol. Just do a headspin on this device while it WHARGARBLS your brain into a digital copy and then just let your deceased body flop onto the ground.

    • @bmxerkrantz
      @bmxerkrantz หลายเดือนก่อน +3

      ​​@@richardconway6425your comment spins me right round baby right round
      - dead or alive

    • @richardconway6425
      @richardconway6425 หลายเดือนก่อน

      @@bmxerkrantz yes, that too !! 🐸

  • @THE-X-Force
    @THE-X-Force หลายเดือนก่อน +820

    It's comforting to know that ancient PBS Space Time videos will still be around even when Sag A* meets its end.

    • @LuisSierra42
      @LuisSierra42 หลายเดือนก่อน +12

      As quantum information

    • @THE-X-Force
      @THE-X-Force หลายเดือนก่อน +22

      @@LuisSierra42 I dunno .. sounds like Bob was watching the vintage originals lol

    • @uggoldos
      @uggoldos หลายเดือนก่อน

      Hopelessly scrambled

    • @BrianOSheaPlus
      @BrianOSheaPlus หลายเดือนก่อน +6

      ​@@uggoldosBob's star-sized Matrioshka brain computers can unscramble them.

    • @uggoldos
      @uggoldos หลายเดือนก่อน +3

      But can the Matrioshka overcome uncertainty? Seems like the same problem Star Trek's transporter technology would have.

  • @AricBlunk
    @AricBlunk หลายเดือนก่อน +252

    Veritasium feels like a layman successfully reaching into the depths of science and bringing it back to us. PBS spacetime feels like a lifelong deep scientist successfully reaching out to the layman to explain things.

    • @fragly
      @fragly หลายเดือนก่อน +9

      😂 very accurate

    • @marcomoon6062
      @marcomoon6062 หลายเดือนก่อน +6

      Both of them go over my head sometimes 😅

    • @cereal-killer4455
      @cereal-killer4455 หลายเดือนก่อน +33

      @@marcomoon6062Spacetime is at a much higher level of science than veritasium although both are brilliant

    • @marfmarfalot5193
      @marfmarfalot5193 หลายเดือนก่อน

      It is!

    • @kylelochlann5053
      @kylelochlann5053 หลายเดือนก่อน +5

      Absolutely not. PBS is explaining one line of speculative reasoning.

  • @JBonzo12
    @JBonzo12 หลายเดือนก่อน +198

    "Bob waited 10^87 years, so a week isn't so bad. "
    I'm now dead in this timeline. 🤣

  • @_Mute_
    @_Mute_ หลายเดือนก่อน +599

    "Digital Ghosts in a Dead Universe" would make a great metal album name

    • @Annathroy
      @Annathroy หลายเดือนก่อน +20

      Band name too

    • @unocoltrane2804
      @unocoltrane2804 หลายเดือนก่อน +14

      DGIDU!

    • @b.s.7693
      @b.s.7693 หลายเดือนก่อน +4

      ​@@Annathroyand the first single

    • @WackoMcGoose
      @WackoMcGoose หลายเดือนก่อน +3

      I think it's also within the allowed length limit of a Dot Tumblr Dot Com, too...

    • @whoshotashleybabbitt4924
      @whoshotashleybabbitt4924 หลายเดือนก่อน +14

      @@b.s.7693 nah, Unitarity is the first single.

  • @purplenanite
    @purplenanite หลายเดือนก่อน +342

    10:36 "(Bob) is looking for signs of the experimental qubit. But if we're being honest, he's also looking for signs of Alice."
    awwww, that's so cute

    • @AM-gf7zv
      @AM-gf7zv หลายเดือนก่อน

      Staring at the last piece of ass he'll ever see... and desperately looking to reconstruct it for 10^74 years and more.

    • @davestrider2045
      @davestrider2045 หลายเดือนก่อน +16

      11:22 He knows that quantum mechanics and, perhaps, his own heart. Why did this slowly become a romance?

    • @alazarbisrat1978
      @alazarbisrat1978 หลายเดือนก่อน +15

      @@davestrider2045 Alice and Bob have been together since the start, of course someone had to ship them. So why not on a spaceship?

    • @Andrew30645
      @Andrew30645 หลายเดือนก่อน +10

      She jumped into a black hole to get away from him. That puts things in a different light!

    • @dayegilharno4988
      @dayegilharno4988 14 วันที่ผ่านมา +1

      :) Forget about "Seven days too long"... THIS is true dedication!

  • @GetterRay
    @GetterRay หลายเดือนก่อน +28

    People saying that Veritasium beat Space Time to the punch when literally everything in Derek's video had been covered by Space Time years ago.

    • @nomansbrand4417
      @nomansbrand4417 14 วันที่ผ่านมา

      And then there is kurzgesagt having addressed some topics months-years ahead.
      But don't see it as a competition - since scope and presentation style are so different for those three.

    • @maciejbala477
      @maciejbala477 11 วันที่ผ่านมา

      @@nomansbrand4417 yeah, and different style. Veritasium is really more on the pop sci side. PBS tries to go a bit deeper and be a sort of middle ground

  • @louisfriend1
    @louisfriend1 หลายเดือนก่อน +17

    This is without doubt the most engrossing and informative description of both the information paradox and equivalence for the layperson I've ever watched. Thank you Dr O'Dowd, and a special thanks to Alice and Bob for their committment to science.

  • @mlee9734
    @mlee9734 หลายเดือนก่อน +317

    Alice and Bob are 2 unsung heroes of our time. They have been involved in so many experiments I can't ever count. The have been thrown into black holes, left drifting on space for years, put into the heart of a supernova, they have even been shot through the universe at the speed of light and left to experience all the negative affects from it. And they never ever complain.

    • @sharpsheep4148
      @sharpsheep4148 หลายเดือนก่อน +56

      They also exchange MANY messages that they would like to keep private. Presumably about their grand adventures. 😅

    • @apmcx
      @apmcx หลายเดือนก่อน +9

      Spherical Bob best bob

    • @w01dnick
      @w01dnick หลายเดือนก่อน +28

      Don't forget they are also experts in cryptography, network protocols.

    • @Ein_Kunde_
      @Ein_Kunde_ หลายเดือนก่อน

      They are invincible.

    • @TheSaneHatter
      @TheSaneHatter หลายเดือนก่อน +1

      But where are Carol and Ted . . .?

  • @GwEClanGaming
    @GwEClanGaming หลายเดือนก่อน +202

    In the three body problem series (book 2) some guy fell into a black hole accidentally and they refused to pay out his life insurance because he wasn‘t dead yet from their point of reference 😂

    • @astrocoastalprocessor
      @astrocoastalprocessor หลายเดือนก่อน +30

      that sounds so plausible

    • @allanhernandez6692
      @allanhernandez6692 หลายเดือนก่อน +16

      I mean, they're right technically speaking! He hasn't fallen in yet! And even after a millennia has passed for everyone else, from his perspective hardly any time has passed at all!
      That's the thing I don't fully get with these videos too. I fully understand that the person falling never experiences time slowing down (rather they would see the rest of the universe speeding up), but that doesn't mean that they actually cross the event horizon. That could only be true if black holes are actually eternal.
      From their perspective, the hawking radiation taking place must speed up as well and the black hole would evaporate. The event horizon would shrink as they approach it and they would evaporate themselves before they ever cross.

    • @WhyneedanAlias
      @WhyneedanAlias หลายเดือนก่อน +13

      @@allanhernandez6692 As far as I understood it, the person falling in would experience the universe speeding up to some degree, but not the entirety of the universes future would play out while crossing the event horizon. So for an outside observer it would take infinite time to see something cross the event horizon, but for a person falling the event horizon is no special location (if we keep the equivalence principle) so for them it would only take a finite amount of the outside universes time. So even for an evaporating black hole, stuff could fall in (from their own pov but not from an outside pov)

    • @Deletirium
      @Deletirium หลายเดือนก่อน +3

      ​​@@WhyneedanAliasRelativity is so incredibly weird.

    • @viliml2763
      @viliml2763 หลายเดือนก่อน +3

      @@WhyneedanAlias That is not the reason why Alice would not experience the universe speeding up to infinity. It is simply because the photons from the dying universe would not have time to catch up with her until she's practically at the singularity, at which point she'll be dead.

  • @demeurecorentin
    @demeurecorentin หลายเดือนก่อน +7

    The animations are of impressive quality for a free educational video on TH-cam, thank you PBS.

  • @PaintballVideosNet
    @PaintballVideosNet หลายเดือนก่อน +14

    Me: I'm smart!
    *Watches video*
    Me: I'm dumb!

    • @jessstuart7495
      @jessstuart7495 24 วันที่ผ่านมา +1

      I'm in a superposition of smart and dumb at the same time.

  • @StormbringerMM
    @StormbringerMM หลายเดือนก่อน +471

    Veritasium Entered the chat.
    PBS Spacetime: “I was camping your respawn a few days ago”.

    • @ZoonCrypticon
      @ZoonCrypticon หลายเดือนก่อน +28

      Veritasium lost his credibility after the Gates connection. In veritasio veritas non iam est.

    • @User-jr7vf
      @User-jr7vf หลายเดือนก่อน +56

      @@ZoonCrypticon wooosh how does that invalidates what he says about science?

    • @mheermance
      @mheermance หลายเดือนก่อน +8

      ​@@User-jr7vfI don't even understand what that means.

    • @rogaldorn4759
      @rogaldorn4759 หลายเดือนก่อน +11

      ​@@User-jr7vf
      Agreed.
      Now. If he had been shilling for the pharma, automobile or any other industry, tightly connected to systemic and abusive tendencies, I'd say:
      It's time to raise yer pitchforks, and pass some judgement.

    • @JJean64
      @JJean64 หลายเดือนก่อน +85

      ​@@ZoonCrypticon
      Bro's acting like as if Bill Gates have the ability to somehow change the laws of general relativity or something 💀

  • @ReformationRamblings
    @ReformationRamblings หลายเดือนก่อน +147

    Thanks for the video. I’m currently falling past the event horizon of a black hole and I can confirm that it really do be like this.

    • @donnyjepp
      @donnyjepp หลายเดือนก่อน +6

      You about to turn into pasta 😂

    • @TheWebsOfCorruptionNeverFail
      @TheWebsOfCorruptionNeverFail หลายเดือนก่อน +2

      Bro must have seen every Vsauce, Veratasium, John Micheal Godier, Vlog Bros, Smarter every day and PBS episode ever by now...

    • @chitlitlah
      @chitlitlah หลายเดือนก่อน +1

      My observations indicate that your approach to the event horizon has caused you to lose your grasp of the English language. Luckily, you should have crossed it by now so we won't have to hear it get worse.

    • @LuisSierra42
      @LuisSierra42 หลายเดือนก่อน +2

      I am the guy right in front of you, near the singularity

    • @aididdat1749
      @aididdat1749 หลายเดือนก่อน +5

      I might be in the black hole because I can see what you wrote.

  • @TripleOmega
    @TripleOmega หลายเดือนก่อน +10

    My first thought here was: Wouldn't Alice witness the end of the universe due to time dilation before crossing the event horizon?

    • @mrsaturn1102
      @mrsaturn1102 19 วันที่ผ่านมา +9

      If time dilation is so intense that Alice can witness the end of the universe, wouldn’t the black hole have evaporated by the time she crosses the event horizon?

    • @rombaft
      @rombaft 13 วันที่ผ่านมา

      I am not ro on the matter, but all the stuff in the black hole past the event horizon over time, not witnessing all time until the end

  • @boringturtle
    @boringturtle หลายเดือนก่อน +5

    For what it's worth, Alice and Bob are also the heroes of every computer security diagram. Their adventures are not limited to the textbooks of physics, computer science uses them too.

    • @garethdean6382
      @garethdean6382 หลายเดือนก่อน

      Where they do battle with their nemesis, Carol.

    • @drdca8263
      @drdca8263 หลายเดือนก่อน

      @@garethdean6382as well as Evelyn and Malaroy

    • @gendbh5652
      @gendbh5652 6 วันที่ผ่านมา

      And TV Tropes!

  • @JuanEstrella-Martinez
    @JuanEstrella-Martinez หลายเดือนก่อน +962

    Oh man, you got Dereked!

    • @TreesPlease42
      @TreesPlease42 หลายเดือนก่อน +38

      with wind chimes to boot

    • @juanfromthecosmos
      @juanfromthecosmos หลายเดือนก่อน +64

      I love this internet thing of getting "Dereked"

    • @borttorbbq2556
      @borttorbbq2556 หลายเดือนก่อน +15

      Thats so Derrick

    • @victorbrueggemann8934
      @victorbrueggemann8934 หลายเดือนก่อน +21

      Maximum Derek!!!

    • @thebogsofmordor7356
      @thebogsofmordor7356 หลายเดือนก่อน +31

      I fell asleep listening to that video last night. I thought I was having a weird dream dejavu until I read this comment.

  • @MarijnvdSterre
    @MarijnvdSterre หลายเดือนก่อน +60

    I know! You either die or end up behind some bookshelves.

    • @brothermine2292
      @brothermine2292 หลายเดือนก่อน +3

      Or both. The blue-shifted rain of X-rays hitting you from above would be fatal.

    • @badbadrobotrobot959
      @badbadrobotrobot959 หลายเดือนก่อน +6

      Thank God that at least you can't come out of the black hole by moving faster than the speed of light because of "the power of love".

    • @duprie37
      @duprie37 หลายเดือนก่อน

      ​@@badbadrobotrobot959 Jennifer Rush just entered the chat...

    • @Soupy_loopy
      @Soupy_loopy หลายเดือนก่อน

      Finally, someone else remembered the bookshelves. What's the point of jumping into a black hole if you're not going to check out the back of the bookshelves?

    • @cosmicraysshotsintothelight
      @cosmicraysshotsintothelight 25 วันที่ผ่านมา

      @@brothermine2292 How would they be moving faster than you to be "hitting" you? Or just make sure the helmet is lined with Brass. Gives a whole new meaning to "on the hat".

  • @gabor6259
    @gabor6259 หลายเดือนก่อน +8

    This is by far the best love story I've ever witnessed on this channel.

    • @AntonAdelson
      @AntonAdelson 17 วันที่ผ่านมา

      Yep, I came for science. Stayed for the love story!

    • @YogiMcCaw
      @YogiMcCaw วันที่ผ่านมา

      Can't wait for the episode where Alice and Bob become entangled!

  • @simoncoweII
    @simoncoweII หลายเดือนก่อน +12

    Jumping into a black hole is the secret recipe to making the best spaghetti in the universe.

    • @evangonzalez2245
      @evangonzalez2245 หลายเดือนก่อน +1

      Nuclear pasta always comes out a bit dense 😉

  • @_haze__5684
    @_haze__5684 หลายเดือนก่อน +78

    Pancakification will be a whole new section in our text books before long and you heard it here first, from one Matt O'Dowd.

    • @RichWoods23
      @RichWoods23 หลายเดือนก่อน +5

      At least we won't go hungry.

    • @Anonymous-ow6jz
      @Anonymous-ow6jz หลายเดือนก่อน +6

      @@RichWoods23 yes, we have pancakes and spaghetti!

    • @bmxerkrantz
      @bmxerkrantz หลายเดือนก่อน

      ​@@Anonymous-ow6jz sooooo, what's for lunch?

    • @ArawnOfAnnwn
      @ArawnOfAnnwn หลายเดือนก่อน +2

      @@Anonymous-ow6jz Human pancakes. So is that how Soylent Green is made?

    • @cosmicraysshotsintothelight
      @cosmicraysshotsintothelight 25 วันที่ผ่านมา +2

      Yeah but their skillets are convex instead of flat like ours. So the pancakes would look like Quisp cereal.

  • @stanmanlyman4550
    @stanmanlyman4550 หลายเดือนก่อน +112

    Alice saw the tesseract and taught bob how to decipher all the qbits

    • @LuisSierra42
      @LuisSierra42 หลายเดือนก่อน +15

      And then she saw her daughter and started screaming her name: MUUUUUURPH!!

    • @stanmanlyman4550
      @stanmanlyman4550 หลายเดือนก่อน +8

      beautiful movie though

    • @Deletirium
      @Deletirium หลายเดือนก่อน +4

      Lamest twist EVER, for an otherwise very well-made film.😖

  • @bentationfunkiloglio
    @bentationfunkiloglio หลายเดือนก่อน +9

    This video demonstrates why PBS Space Time is the best science podcast in the known multiverse!
    Super clear presentation and analysis that makes the most difficult concepts accessible to even us non-Phd mortals!

    • @koponstanley4
      @koponstanley4 หลายเดือนก่อน

      Big ask,
      Could you ask for me about the background music playlist?

    • @Soupy_loopy
      @Soupy_loopy หลายเดือนก่อน

      Hey, would you please ask if they could change the name of black holes to dark meatballs? Speghettification and dark meatballs just go together.

  • @gunsmithcat7542
    @gunsmithcat7542 หลายเดือนก่อน +7

    TL;DR if you fall into a black hole, the government will have to pay your pension for all eternity.

    • @SinKimishima
      @SinKimishima 18 วันที่ผ่านมา

      Dunno man, feels like the lawyer will say that since it is outside the boundary of the government, the contract obligation pauses until you return

  • @Subbestionix
    @Subbestionix หลายเดือนก่อน +142

    Degankenexperiment 😂
    For the non-germans: he pronounced the first two syllables of Gedankenexperiment (imaginary experiment, thought experiment) backwards - honestly not that noticeable or relevant, but had me smirk, so had to say it

    • @aaronhammond7297
      @aaronhammond7297 หลายเดือนก่อน +13

      I noticed and I don't even speak German

    • @Subbestionix
      @Subbestionix หลายเดือนก่อน +7

      ​yeah xD
      But I can see how non native speakers could mix up de and ge without having practice in German or knowledge of how German words are assembled
      For the ones interested:
      ge- is a common prefix of words that have some punctuality.
      "Someone thought X" for example translates to "Jemand hat X gedacht", where "denken" is the stem of "to think".
      In this case however "Gedanken" is not the past tense of "to think" but rather like "thoughts" or "in my mind".
      It can also be more of a result of the thinking itself. It's like the entity of a thought or thoughts.

    • @dembro27
      @dembro27 หลายเดือนก่อน +3

      I heard him say it the right way, but maybe my grasp of German pronunciation is just that bad.

    • @pierreabbat6157
      @pierreabbat6157 หลายเดือนก่อน +4

      I heard "degunken" (middle syllable /gəŋk/ like "gunk").

    • @charlesrockafellor4200
      @charlesrockafellor4200 หลายเดือนก่อน +1

      I have little German, but mostly I come at it from an OCD and AS/HFA perspective, and being a geek means that I know that word intimately, so it leapt right out at me when he said it (though I was so surprised that I had to replay it a couple of times, and I still don't know how it got past the filming and editing crew).

  • @JonCofer
    @JonCofer หลายเดือนก่อน +19

    I don’t really know what you’re talking about in most of this episode, but I do like the way you say it

  • @deepdrag8131
    @deepdrag8131 หลายเดือนก่อน +3

    Thanks for this. I’m planning to jump into a black hole for my birthday and I’m wondering what to expect.

  • @MrChipMC
    @MrChipMC หลายเดือนก่อน +6

    Please make a episode about colliding blackholes and time dilation!
    You are saying object is like "freasing" at the event horizon. So will we see how those blackholes approach each other and eventually collide or not?
    Please explain! 🙏

    • @Zeeraha
      @Zeeraha หลายเดือนก่อน

      Merger of two black holes has already been registered by LIGO. The black holes would collide in a way, that when close enough to each other, a new event horizon would appear because their masses are combined into the even stronger gravitational field. What is on the edge of event horizon is, by my view, frozen in time. What happens below it is another mystery. Example, towards the center of bodies, the gravity weakens, but the pressures are immense, thus time may pass within the black hole.

    • @MrChipMC
      @MrChipMC หลายเดือนก่อน +1

      @Zeeraha exactly! I want to see the video like they did before about the monkey and observer near the blackhole , but this time about two blackholes

  • @kwokhardy2512
    @kwokhardy2512 หลายเดือนก่อน +62

    - Being up at 4am for no reason
    - Sees new spacetime video notification

    • @Graycy808
      @Graycy808 หลายเดือนก่อน +1

      Feel it too lol

    • @a_mediocre_meerkat
      @a_mediocre_meerkat หลายเดือนก่อน +3

      - see bob breakdance to upload his mind to a computer at 4:07am

    • @null-0x
      @null-0x หลายเดือนก่อน +1

      Same

    • @the_algo_rhythm
      @the_algo_rhythm หลายเดือนก่อน

      Gang.

    • @fraserwilliams2414
      @fraserwilliams2414 หลายเดือนก่อน

      - Sparks blunt

  • @CortanaCH
    @CortanaCH หลายเดือนก่อน +21

    I just can't watch enough videos about black holes. The most fascinating thing in space.

  • @willo7734
    @willo7734 หลายเดือนก่อน +2

    I’ve watched most of the PBS spacetime episodes over the years and I can say this is my favorite one. Well done PBS spacetime!

  • @mattwilcox8134
    @mattwilcox8134 หลายเดือนก่อน +3

    As another merch idea, that black hole pin design would make an awesome phone case.

    • @cosmicraysshotsintothelight
      @cosmicraysshotsintothelight 25 วันที่ผ่านมา

      Only if the black part gets painted with Vanta Black and actually appears like a hole.

  • @theplanetrepairman9945
    @theplanetrepairman9945 หลายเดือนก่อน +26

    "What Happens If You Jump Into A Black Hole?" ....To shreds you say?

  • @mgancarzjr
    @mgancarzjr หลายเดือนก่อน +44

    I predict that we won't be able to decrypt the messages sent between Alice and Bob.

    • @thezipcreator
      @thezipcreator หลายเดือนก่อน +4

      they're using that qubit to generate their encryption key

    • @JdeBP
      @JdeBP หลายเดือนก่อน +3

      Bob's dual computer science achievements of developing a true artificial intelligence _and_ a method of reading consciousness are somewhat underrated, too. (-:

    • @cosmicraysshotsintothelight
      @cosmicraysshotsintothelight 25 วันที่ผ่านมา +1

      The bits might be arriving at a very slow baud rate...

  • @jamesdouglas5055
    @jamesdouglas5055 หลายเดือนก่อน +7

    I propose after the geDunkin experiment is finished we all go out for geDonuts.
    If we had completed a gedanken experiment instead we would all go out for fries because die gedanken sind frei.

    • @badroad1000
      @badroad1000 27 วันที่ผ่านมา

      If we eat all that we'll end up with a huge gedankedank.

  • @cherryspades3440
    @cherryspades3440 หลายเดือนก่อน +2

    LOVING the editing and overall production on the newest episodes

  • @hereticpariah6_66
    @hereticpariah6_66 หลายเดือนก่อน +19

    _"Spinning, whirling_
    _Still descending.._
    _Like a spiral sea_
    *_UNENDING!!!"_*
    ..
    Rush, _Cygnus X-1_

    • @brothermine2292
      @brothermine2292 หลายเดือนก่อน

      "Twirling, twirling, twirling into the future." -- Citizen Kang (Or was it Kodos?)

    • @nessiecz2006
      @nessiecz2006 หลายเดือนก่อน

      I'm confused but I like it

  • @jonathanl8538
    @jonathanl8538 หลายเดือนก่อน +9

    3:55 Thank you! For years I've wondered how to reconcile time freezing at the event horizon with actually crossing the horizon. How could anything cross if time slows down and ultimately "stops"? Wouldn't Alice see the whole future history of the Universe flash by, including seeing the black hole evaporate before she actually falls into it?
    But I think this video's explanation did a good job putting these concerns to rest :)

    • @robertmolldius8643
      @robertmolldius8643 16 วันที่ผ่านมา

      You are correct that Alice sees all the stars go out as she falls through the event horizon. 4:43 Each second that passes for Alice is hundreds of thousands of times longer than the current age of the universe. Mind exploding

  • @kobayashimaru8114
    @kobayashimaru8114 หลายเดือนก่อน +3

    I really appreciate all of the clever visuals

  • @davidf5609
    @davidf5609 หลายเดือนก่อน +5

    This episode smells of Leonard Susskind.

    • @Yltimate_
      @Yltimate_ 23 วันที่ผ่านมา +1

      It's in the name. Suss

  • @MrLeafeater
    @MrLeafeater หลายเดือนก่อน +7

    I'm gonna compress all the videos I've watched, that explain this "experience", into a single video from which none of the constituent videos can escape or be decoded. I love black holes. (This is the most thorough of them all; I even learned a few things.)

  • @Moon_Metty
    @Moon_Metty หลายเดือนก่อน +7

    Alright, we know about Alice and Bob.
    But this still doesn't answer the most important question of all:
    Where is Waldo?

    • @Soupy_loopy
      @Soupy_loopy หลายเดือนก่อน +1

      No way, you're not dragging me into this. I spent way too much time searching.

  • @IceFire9yt
    @IceFire9yt 18 วันที่ผ่านมา +1

    I'm unreasonably glad that you gave Alice and Bob a 'happy' ending.

  • @RedDuke42
    @RedDuke42 หลายเดือนก่อน +2

    Fantastic video once more. This channel perfectly fills the niche between more layman-oriented science shows like Veritasium, and full-blown physics lectures. ❤

  • @kyleespinoza7201
    @kyleespinoza7201 หลายเดือนก่อน +5

    My intuition tells me that the quantum bit (and Alice, for that matter) isn't duplicated or deleted, but it being in the blackhole and emitted in Hawking radiation are different moments in time. I'm sure it's a gross oversimplification and me not fully understanding the math and physics, but i can't shake the feeling either.
    Guess I'm waiting like Bob lol
    Now that i think about it some time later, i wonder what digitized Alice would remember once Bob is done reassembling her. What was her subjective experience of it all? Would she remember falling past the event horizon? I wonder why or why not...

  • @Vastin
    @Vastin หลายเดือนก่อน +23

    There is a reasonably straightforward resolution to this paradox, but it requires that we treat the horizon as a true horizon, not a coordinate horizon - and this seems logical if we consider the effect of length contraction on Alice's perspective of her own fall. She is after all, *approaching the speed of light* as she approaches the horizon, and her perspective of the black hole (if she could see through it) is that its depth is very rapidly diminishing, and as she gets even closer its width should likewise begin to contract rapidly until the entire horizon becomes a POINT OBJECT towards which she is falling.
    By the time she 'reaches' the horizon, the diameter of the entire event horizon should only be a single Plank Length - the outer horizon has now *become* a singularity from Alice's perspective. All black holes have the same diameter of one Plank Length, regardless of their mass, though from a more distant perspective their Area and apparent diameter reflects their mass. Their density does NOT drop as they grow - they achieve Plank Density as the Beckenstein Bound is saturated, and their Area expands in lockstep with their mass to maintain Plank Density no matter how large or small they are. Whether a black hole is one angstrom wide, or a LY across, it has the same density, because it is now effectively a 2D sphere and its 'density' as a 2D object does not change as you add mass.
    Unfortunately the implication this has for the tidal forces of the black hole are somewhat dire for Alice. She will be spaghettified because she is not approaching a black hole with a diameter of billions of km - she's approaching a black hole with a diameter of one plank length. She will then be pancaked as well, but she will NOT fall through a causal barrier where Bob can no longer observe her at all because she perceives no horizon at all, nor any space to fall 'into'. Alas Bob will receive very little information about her due to the time dilation she's experiencing in this 2-dimensional pseudo-singularity, which presumably will evaporate gradually via thermodynamic processes similar to how hawking radiation is currently described. He'll still have to go through the process of recording the Black Hole's entire evaporation process and reconstruct Alice's data, because she's been scrambled about as thoroughly as anything CAN be scrambled - reflecting the maximal entropy of the black hole.
    Some interpretation similar to this is necessary to prevent violation of the Beckenstein Bound and prevent the formation of a true physical singularity of infinite density. In this case the surface of the black hole consists of a plank density shell of mass, with each element of it probabilistically 'smeared' across the entire horizon, as from the perspective of each particle they are in fact falling towards a singularity - though more accurately, they will see that singularity explode in their faces as they fall due to the fact that their perspective of the approach to the horizon now extends into the unimaginably distant future all the way to the point where they are re-emitted in very little pieces, their 'fall' concludes with them being blasted out into space and the infalling observer's experience would be far more akin to taking a nose-dive into a supernova than falling into a placid void.
    Why do I think this is the case? I mean, quite frankly it's because I don't believe that beckenstein bound violation is acceptable, nor are physical infinities, and EVERY model of a black hole interior I've ever seen postulated clearly violates the Beckenstein Bound and describes a physical infinity - while this model prevents that. That's the entire reason. Make of it what you will.

    • @axle.student
      @axle.student หลายเดือนก่อน +1

      Thank you. I am not a physicist but did follow most of what you said accept for a couple of labels. I currently have a deep fascination with the intersect of singularities and event horizons. Looking at the common Minkowski spacetime geometry with fore and aft light cones we have an intersect of the 3D event horizons at a singularity in the "Now" time event horizon. That illustration of the 2D plane that intersect the diagram appears to hold all of the infinite number of intersects in the 3D universe "across: that "Now moment. No singularity on that plane can be aware of any other singularity until some time later when the light cones of each singularity cross. Alternatively some of those singularities may be close enough to be touching in the time event horizon of "Now" and have a direct awareness of the other singularity .
      So I am left with this mix of both local and non local singularities in every plank length in time. In some sense for me the entire universe feels like a kind of progression of infinite singularities in each "now" moment.
      >
      My focus is on this singularity intersect of all event horizons in each moment.
      >
      Sorry if I didn't explain my view well. It's complex in my mind and difficult to put into words in a short statement :)

    • @allanhernandez6692
      @allanhernandez6692 หลายเดือนก่อน +7

      This makes much more sense to me. I have always been frustrated by the black hole explanations which posit a crossing of the event horizon which makes no real sense given that black holes are not immortal, and even if the rest of the universe has an infinite amount of time to watch, the person falling will never cross.
      Given that black holes evaporate, and the universe sees the black hole evaporate before the faller ever crossed the horizon, it can only make sense that the person falling must experience the corresponding rate increase of hawking radiation (from their perspective) as they approach the horizon until they themselves are emitted as hawking radiation.

    • @axle.student
      @axle.student หลายเดือนก่อน +1

      @@allanhernandez6692 I am sitting here (again) struggling with the idea of red shift at the event horizon and light traveling away at 'c' from just above the event horizon. There is this frame of reference issue that keeps coming up for a photon suddenly shifting from a velocity of 'c' outward to zero velocity and then to a velocity of 'c' inward beyond the event horizon. I know different geometry explains this away by moving the direction of the photon sideways in time, but that zero velocity moment still weirds me out lol
      >
      [edit] The photon travels at 'c' in space and at 'c' in time and exist along the event horizon of the light cone already. I have to ask where we find the extra velocity or loose the velocity if 'c' is constant.. We can explain it a way with warped space, but then physics says space doesn't actually exist to warp in the first place. It's contradiction that I can't get past no matter what way physics explains it :(

    • @Vastin
      @Vastin หลายเดือนก่อน +5

      @@axle.student There are a number of issues with the standard explanations of the event horizon. The problem seems to arise from an incomplete formulation of GR that postulates a crossable horizon in the first place - accepting that premise inevitably creates a host of paradoxical behaviors and contradictions. Because that's what our best math describes, that's the description most physicists accept for the time being - but looking at it in terms of logic and the fact that all our OTHER physics and math are violated once you take that step, it just seems like the least likely solution.
      It really seems like in order to understand gravity and relativity better, they should be looking for ways to close off the horizon like this that maintain the logical consistency of the rest of physics, rather than playing with mathematical artefacts 'beyond' the horizon. While I see the appeal of that as a theoretician, it eventually loses its shine after the 'nth' iteration or so which fails to resolve any of these paradoxes.

    • @axle.student
      @axle.student หลายเดือนก่อน +1

      @@Vastin Thank you. I appreciate your comments. Again not a physicist but well studied (non indentured) across a number of disciplines. It is the singularity and event horizon problem that has bugged me for as long as I can remember. I thew all the std constraints of physics out the window a few months back to jail break my mind and run some thought experiments. I focused upon the issues around the singularity and event horizon issues and gained myself some better insight by thinking outside of the box. I have nailed down some interesting perspectives around the 4D space-time geometry. I can see an entire working 4D universe abstractly in my head accept for the non locality link. Even gravity appears to become nothing more than an emergent expression or illusion of quantum and GR.
      >
      Lot of work to translate that from my head into words and graphics ahead. I have seen/encountered a number of physicists that appear to have been or are down a similar rabbit hole so I will look toward there work for some guidance. Maybe they have already tested it and no point my looking any deeper :)

  • @Vastin
    @Vastin หลายเดือนก่อน

    I do love these sorts of thought experiments and your presentation on this one was a lot of fun to follow.

  • @jo_crespo11235
    @jo_crespo11235 หลายเดือนก่อน

    Excellent video Matt, keep the hard work.

  • @567secret
    @567secret หลายเดือนก่อน +5

    Why can't Alice's perspective of falling into the singularity be equivalent to Bob's perspective of the hawking radiation emitted? Ie. the singularity is a projection of the inevitable future of the evaporation of the black hole by Alice's perspective? As I understand it this would make sense with what the spacetime diagram interior to the blackhole tells us?

    • @tonywells6990
      @tonywells6990 หลายเดือนก่อน +1

      Alice contains a lot more energy than that radiated as Hawking radiation which is why he has to wait a long time (10^100 years or so) for all of her information to come back out.

  • @TooTRUEtoBeG00D
    @TooTRUEtoBeG00D หลายเดือนก่อน +4

    I just watched new Veritasium video about black/white holes.
    What a time to be alive.

    • @AricBlunk
      @AricBlunk หลายเดือนก่อน +1

      I just saw your comment and saw the video last night and agree with you.

    • @mkk3a
      @mkk3a หลายเดือนก่อน +1

      A "Two Minute Papers" easter egg?

    • @TooTRUEtoBeG00D
      @TooTRUEtoBeG00D หลายเดือนก่อน

      @@mkk3a It seemed appropriate. Shout out to Karol.

    • @TooTRUEtoBeG00D
      @TooTRUEtoBeG00D หลายเดือนก่อน +1

      @@AricBlunk LETS GOOOOOOOOOO!

  • @d4mdcykey
    @d4mdcykey หลายเดือนก่อน

    This was a brilliant presentation and quite thorough, very impressive job.

  • @abhisheksingh1143
    @abhisheksingh1143 หลายเดือนก่อน +1

    Fantastic video. Thank you. Congrats!

  • @SayAhh
    @SayAhh หลายเดือนก่อน +13

    Cool! Another black hole video!

  • @linecraftman3907
    @linecraftman3907 หลายเดือนก่อน +3

    I was worried about Bob until the very end, glad it worked out in the end

  • @BytebroUK
    @BytebroUK หลายเดือนก่อน

    I just want to say that although the channel is a joy anyway, I completely love these deep dive sequences. Good work, people.

  • @jordonleigh174
    @jordonleigh174 24 วันที่ผ่านมา

    Fantastic episode, Matt! Thank you!!

  • @victorpilgrim
    @victorpilgrim หลายเดือนก่อน +5

    i think Alice never got pass the event horizon, falling down she starts to experience such a huge time dilation, that on her time scale the black hole starts to evaporate. I also think because of a such curved space the black hole (or is it the stuff that fell in? i feel like there's no difference, black hole is the stuff that fell into it) will start to glow. in that case black holes are frozen in time (for the outside observers) collapse, and that huge collapse is hidden by Einstein's squeezing of space to very thin slice of what we perceive as the event horizon. The crossable event horizon doesn't exist, instead it's a place where collapse of the black hole is happening, while the singularity is the moment in time to there they fall/when the black hole evaporates. This is the intuition i got from watching these wonderful videos for years

    • @Xanaden
      @Xanaden หลายเดือนก่อน

      I thought the same thing. If it takes infinite time to reach the event horizon, then dark energy (expansion of universe) should make the distance to the event horizon infinite as well. and hawking radiation would cause the blackhole to vaporize before you pass the event horizon for the same reason.

    • @JCDAMV
      @JCDAMV หลายเดือนก่อน +1

      This is only true when using Schwarzschild coordinates. Schwarzschild coordinates are very convenient for describing weak gravity fields, but they fail to describe a black hole event horizon.
      There are alternative coordinate systems en.wikipedia.org/wiki/Schwarzschild_metric#Alternative_coordinates you can use to describe an event horizon without time becoming zero/infinite.
      I think that is going to be explained in future videos!

  • @buttonsjr
    @buttonsjr หลายเดือนก่อน +4

    Now do one about what an infinite universe with infinite mass and infinite energy would look like. PBS infinite series mentioned it in one of their last videos. The Mandelbrot set or another fractal pattern seems like it would immerge is such a situation due to infinite mass and energy requiring infinite black holes. I think the we could be inside of a black hole that is a part of a russian nesting dolls of black holes that is also part of a fractal of black holes and parallel universes and black holes could be the pathway to other universes.
    It certainly makes more sense that "dark energy"

  • @Kronzik
    @Kronzik หลายเดือนก่อน

    Starting to see the vision for this arc of content, excited to see it all come together.

  • @tomorowsnobodys
    @tomorowsnobodys หลายเดือนก่อน

    I’ve ordered the black hole pin from your store! I happened to be shopping for pins today and wouldn’t you know it, one of my favorite channels uploaded an excellent new video and they happen to have a new pin depicting one of my favorite objects! How serendipitous for us both!

  • @Gandalf-The-Green
    @Gandalf-The-Green หลายเดือนก่อน +4

    Six stars of the Northern Cross
    In mourning for their sister's loss
    In a final flash of glory
    Nevermore to grace the night
    - Rush

    • @gabor6259
      @gabor6259 หลายเดือนก่อน

      Firework!

  • @cesaraugusto6083
    @cesaraugusto6083 หลายเดือนก่อน +3

    Great video as always. But there's something that I've been wondering for a while and still haven't been able to find an answer.
    Time dilation gets more and more extreme the closer you get to the event horizon as you mentioned, so in this case if Alice were to "hang around" close to the EH for a minute in her own relative time and then managed to get back to Bob far from it a way longer time would have elapsed for him and the "universe outside". That I understand.
    But the problem is about her perspective as she goes through the event horizon. Wouldn't time dilation tend to infinite as she gets closer and closer?
    If so, as soon as she were to cross it, her relative time dilation would be so extreme that any amount time she experienced inside the EH would be equivalent to a tremendous amount of time "outside"(maybe infinite?). And if so any time she spent there would mean that enough time outside had passed that the black hole would've evaporated, so she wouldn't ever be able to actually experience what it's like to be inside one, as all the space inside would get instantly smaller and she'd be crushed against the singularity before just "popping out of existence".
    This has been leading to so many sleepless nights for me 😅. Please tell me what I've been doing wrong or missing. Thanks!

    • @thedeemon
      @thedeemon หลายเดือนก่อน +3

      Time dilation is not just a function of position, it depends a lot on how you move. If you stay put, hover, then yes, time dilation near the horizon is very strong, and exactly at the horizon it's infinite, your clocks don't tick at all. But for that you need to stay put there, which is impossible for massive bodies. Very similar to moving at light speed - if you could go at speed of light, your clocks also wouldn't tick, infinite time dilation. But massive bodies can't do that. Event horizon is a "null hypersurface" - just like a light cone, staying there is equivalent to moving at light speed, crossing it outwards is equivalent to moving faster than light.
      For a falling Alice things look differently, and her clocks keep ticking. She doesn't even see the outer universe sped up, unlike the staying put scenario. See how "proper time" is defined using the metric tensor, it's all about vectors in 4D spacetime, how you move there.

  • @jacksawyer3626
    @jacksawyer3626 หลายเดือนก่อน

    Outstanding Dr. Matt.

  • @GeneticFreak
    @GeneticFreak หลายเดือนก่อน

    This video came out just days after Derek's video and such perfect timing! A whole week of black hole pondering!

  • @Quzga
    @Quzga หลายเดือนก่อน +8

    MUUUURPH

  • @claudiaarjangi4914
    @claudiaarjangi4914 หลายเดือนก่อน +6

    How freaky-cool is it , that the event horizon is a "border" between now & the literal Far far far future.
    😁🌏☮️

  • @mastercontrolprogram82
    @mastercontrolprogram82 หลายเดือนก่อน +1

    Massively interesting episode!

  • @grasshopper-ln9us
    @grasshopper-ln9us หลายเดือนก่อน

    This was the 1st TH-cam channel I subscribed to and it's still going strong

  • @WeRemainFaceless
    @WeRemainFaceless หลายเดือนก่อน +16

    Love that you’re covering this topic. For most of my adult life I’ve pondered what would happen if you we’re to dive into a black hole (and survive the tidal forces/radiation etc).
    I came to the conclusion that, theoretically, you’d never reach the “singularity”. By the time you reached the point in space that could be considered a singularity, the black hole would have dissipated and you’d find yourself back in normal space, albeit a few thousand billion years in the future.

    • @breezyx976
      @breezyx976 หลายเดือนก่อน +4

      Hence why the singularity itself cannot exist. Nice catch!

    • @anywallsocket
      @anywallsocket หลายเดือนก่อน +1

      “A few thousand billion years” lmao ok

    • @juliavixen176
      @juliavixen176 หลายเดือนก่อน +5

      Using Gullstrand-Painlevé Coordinates (following the proper time of an observer in free-fall) you *will* actually reach the physical singularity at the black hole's center of mass in a finite amount of time. Pretty quickly too, from your point of view. (From seconds to days depending on the size of the black hole.)

    • @Andromedon777
      @Andromedon777 หลายเดือนก่อน +2

      ​@@juliavixen176but would the universe behind you age much faster to the point of seeing its "death", including that of the BH?

    • @david21686
      @david21686 หลายเดือนก่อน

      @@juliavixen176 What does that coordinate system say about how long it would take to reach the singularity in the reference frame of a distant observer? Would it be longer than the time it takes for the black hole to evaporate?

  • @KoZeroSM
    @KoZeroSM หลายเดือนก่อน +4

    0:11 It's "Gedanken," not deganken or whatever that was

  • @Rooftopaccessorizer
    @Rooftopaccessorizer 4 วันที่ผ่านมา

    i have watched probable 40 videos on this topic and i just keep going

  • @hcesarcastro
    @hcesarcastro หลายเดือนก่อน +1

    From Bob's persepective, which would have happened first: Alice crossing the event horizon or the black hole evaporating?

  • @binbots
    @binbots หลายเดือนก่อน +19

    General relativity and quantum mechanics will never be combined until we realize that each individual observer is observing them both at different moments in time. Because causality has a speed limit (c) every point in space where one observes it from will be the closest to the present moment. When one looks out into the universe they see the past which is made of particles (GR). When one tries to look at smaller and smaller sizes and distances, they are actually looking closer and closer to the present moment (QM). The wave property of particles appears when we start trying to predict the future of that particle. It is a probability wave because the future is probabilistic. Wave function collapse is what we perceive as the present moment and is what divides the past from the future. GR is making measurements in the observed past and therefore, predictable. It can predict the future but only from information collected from the past. QM is attempting to make measurements of the unobserved future and therefore, unpredictable. Only once a particle interacts with the present moment does it become predictable. This is an observational interpretation of the mathematics we currently use based on the limited perspective we have with the experiments we choose to observe the universe with.

    • @andreaswiescher7196
      @andreaswiescher7196 หลายเดือนก่อน +6

      That's an interesting point of view

    • @andreaswiescher7196
      @andreaswiescher7196 หลายเดือนก่อน +3

      Can we get that covered in the next episode please?

    • @ab8jeh
      @ab8jeh หลายเดือนก่อน +3

      Isn't that the premise of loop quantum gravity?

    • @Corvaire
      @Corvaire หลายเดือนก่อน +1

      Please don't disturb the delicate balance of book sales. ;O)-

    • @timhaldane7588
      @timhaldane7588 หลายเดือนก่อน +2

      How do you reconcile this with experiments (and the entire field of quantum computation) that depend on keeping a system in superposition? What would it even mean for a system to be in superposition? Also, how would such a metaphysical explanation help to resolve mathematical infinities when attempting to combine the physics of GR and QM?

  • @doggedout
    @doggedout หลายเดือนก่อน +4

    "....Bob can do this, because he has nothing but time on his hands."
    Bob should have thought of that before he dropped Alice into an infinitely endless expanse of black nothing with a singularity at its center.

  • @danillorippel
    @danillorippel หลายเดือนก่อน +1

    This video is amazing!❤

  • @quentinbricard
    @quentinbricard 16 วันที่ผ่านมา

    Thank you for this video!

  • @indinaut
    @indinaut หลายเดือนก่อน +4

    it's spaghetti time!

    • @evgenijdenisov
      @evgenijdenisov หลายเดือนก่อน +3

      Or pancakes.

    • @peteshively5552
      @peteshively5552 หลายเดือนก่อน

      I like pancakes

    • @Soupy_loopy
      @Soupy_loopy หลายเดือนก่อน

      It's peanut butter jelly time peanut butter jelly time peanut butter peanut butter peanut butter and a baseball bat!

  • @evilleagueofevil9049
    @evilleagueofevil9049 หลายเดือนก่อน +3

    I'm confused. It seems to me like there is a simpler contradiction driving this weirdness, present without anything quantum (except Hawking radiation):
    In Bob's frame of reference, Alice takes infinite time to cross the event horizon.
    Also in Bob's frame, the black hole Hawking evaporates in finite time.
    So, Alice never crosses the horizon in Bob's frame.
    If we then ASSUME Alice crossed in her own frame, then of course the frames contradict.
    I can't do the necessary math, but intuitively, Alice should never be able to cross, even in her own frame of reference. Time dilation would make it so the horizon shrinks away from her (via Hawking evaporation) before she reaches it.
    The outro (15:28) says Alice not crossing would break the equivalence principle, so my question is, how?
    (Is this the "firewall at the horizon?")

    • @tonywells6990
      @tonywells6990 หลายเดือนก่อน +1

      In Bob's frame Alice's photons that he receives do not take infinite time, since of course there are a finite number of photons emitted and Bob is of course at a finite distance. However, in Bob's frame Alice still passes the event horizon and actually increases the area of the event horizon and the radius of the black hole, which he can then measure a very short time later.

    • @drdca8263
      @drdca8263 หลายเดือนก่อน

      @@tonywells6990Must there be finitely many photons emitted? If they have smaller and smaller amounts of energy, couldn’t there be infinitely many?

    • @tonywells6990
      @tonywells6990 หลายเดือนก่อน

      @@drdca8263 No, the photons don't multiply in number. They are redshifted.

    • @drdca8263
      @drdca8263 หลายเดือนก่อน

      @@tonywells6990 Ah wait, we are only considering the periodic emissions of the gamma ones, and there is only a finite amount of Alice’s time that Bob sees (before she crosses horizon from her perspective) and it only flashes finitely many times,
      Ok, I retract my previous point then.
      (I was thinking about maybe possibly infinitely many infrared photons emitted from thermal radiation)

  • @BenjaminCronce
    @BenjaminCronce หลายเดือนก่อน

    Loved the animations

  • @JTheoryScience
    @JTheoryScience หลายเดือนก่อน

    3 Million subs! Congratz!

  • @ChobThomas
    @ChobThomas หลายเดือนก่อน +3

    You die, saved you 20 minutes

  • @bigjermboktown6976
    @bigjermboktown6976 หลายเดือนก่อน +2

    Am I first?!

    • @sully7593
      @sully7593 หลายเดือนก่อน

      Nan

  • @boneladders
    @boneladders หลายเดือนก่อน

    these black hole related episodes are my absolute favorite! 🖤

  • @vladus..
    @vladus.. หลายเดือนก่อน

    Nice explanation 💪🏻

  • @roop-a-loop
    @roop-a-loop หลายเดือนก่อน +3

    wheres the new video dog

  • @tonyr.6637
    @tonyr.6637 หลายเดือนก่อน +1

    Awesome! :D Great episode. I have 2 questions:
    1. I thought it was impossible to fly **directly** into a black hole? I was of the understanding that black holes are all “frame dragging” the space around itself in a sort of 3D whirlpool.
    2. The fact that photons have to “struggle” out of the gravitational well was covered. So, shouldn’t Alice’s image have been red-shifted until she disappeared as she crossed the event horizon?
    (**ASIDE:** BTW, not trying to nitpick! I just want to know if stuff I’ve learned elsewhere still holds. I know these _may_ have been omitted either by oversight or because it would needlessly overcomplicate the thought experiment.)

  • @corlisscrabtree3647
    @corlisscrabtree3647 หลายเดือนก่อน

    Thank you 🙏

  • @Infinite_Horizonsss
    @Infinite_Horizonsss หลายเดือนก่อน

    Thank for the video 🎉

  • @sleeeto
    @sleeeto หลายเดือนก่อน

    this was such a great video

  • @lindsayt.8214
    @lindsayt.8214 19 วันที่ผ่านมา

    Delighted by the addition of romance to the Alice and Bob thought experiment.

  • @caffedinator5584
    @caffedinator5584 หลายเดือนก่อน +2

    Love the breakdancing mind copier 👌

  • @The_Silver_Lurker
    @The_Silver_Lurker หลายเดือนก่อน

    Good follow-up to the episode of Star Talk from a couple weeks ago!

  • @ptiwari2392
    @ptiwari2392 หลายเดือนก่อน +1

    Wow, Matt ending on a cliffhanger for once, what a pleasant surprise. Super cool episode, this is exactly the kind of stuff I wonder about sometimes (on a way lower level than this obviously). Something about the event horizon is so final, it would be a miracle if physics could find a way to peer past it. Maybe in a couple hundred years! or a couple thousand...

  • @petepanteraman
    @petepanteraman หลายเดือนก่อน

    Great job 👍👍 makes sense why it's been a wait, but worth it

    • @petepanteraman
      @petepanteraman หลายเดือนก่อน

      Also TH-cam won't let me like the video

  • @Kohl293
    @Kohl293 หลายเดือนก่อน

    Off all the answers, the firewall is my favorite. Can’t wait to see how it breaks everything!

  • @user-or5ke5yn4w
    @user-or5ke5yn4w หลายเดือนก่อน +2

    Now I think I'm starting to get it. When they tell that singularity is not a point in space but a moment in time - it means that you never reach the 'central point' of the black hole because time speeds up so fast that before you fall there, the black hole already evaporates. Hmmm... In some sense the center of a black hole doesn't exist then, as nothing ever reaches it.
    Or even stricter idea - you can't actually pass through the horizon, because it starts shrinking right under your nose because of very fast time and Hawking radiation until it's just gone, and you find yourself at that same place without a black hole after it has evaporated, some 10^80 years later or so.

    • @thedeemon
      @thedeemon หลายเดือนก่อน

      nope, the idea of singularity acting like a moment in time comes from analyzing a static solution where black hole does not evaporate and doesn't grow either. It's just about coordinates and spacetime geometry. See recent Veritasium video for more info and animated charts.

  • @jamesleatherwood5125
    @jamesleatherwood5125 หลายเดือนก่อน

    Didnt realize the thought experiment about falling into black holes had so many variations and variables based on perspective. My mind engine bes starting up and my thoughts be rumblin to life! Love it when videos do that! :)

  • @joey_after_midnight
    @joey_after_midnight หลายเดือนก่อน +1

    an arrow on the surface of a torus pointed towards its empty center can travel endlessly around the circumference of the donut and always travel in a straight line that never reaches a singularlity, but forever travels towards it. It can appear a contradiction, but both situations can be true at the same time. To the rider of the arrow the Universe can seems to expand and contract while being static on the surface of the Torus.

  • @machevellian79
    @machevellian79 หลายเดือนก่อน

    Great episode, feels like I am waiting near the event horizon for next week an eternity from my perspective.

  • @VisMajorr
    @VisMajorr หลายเดือนก่อน

    Matt thankyou so much! I have been dying for this series for years now! You are spot on! Cant wait for Bob and Alice to have a couple of blackhole mass sized piles of bell pairs 😉 I am AMPS…I mean AMPED for the next one!