How Much Of The Universe Can Humanity Ever See?

Mr FakePřed 2 měsíci

Props to the camera man for going that far just to get the footage.

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  LoulyPřed měsícem

  Incredible, dedication..

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  Fredrick TalbotPřed 23 dny

  Hope he got enough per diem.

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  Sami SyedPřed 22 dny

  Outdated joke

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  Mr FakePřed 22 dny

  @Sami Syed Can a joke truly be outdated? 🤔

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  Sami SyedPřed 21 dnem

  @Mr Fake its irritating after so much of use

KossPřed 2 měsíci

Kudos for the team involved in doing this animations. They REALLY help understanding these advanced topics

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  vk vkPřed 2 měsíci

  Speak for yourself. I don't understand anything after "Space" and "Time"

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  norton manPřed 12 dny

  Is it the and part

Pete MPřed 2 měsíci

This was the BEST explanation of the subject I've ever seen! I understand the principles but had difficulty conceptualizing the 'edges' of the universe. It will take a few rewatches and lots of pausing, but I'm certain I will finally wrap my head around this. Thank you!

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  Paul HopkinsPřed 2 měsíci

  Definitely gonna be watched a few more times by me.

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  Pearly DhingraPřed 2 měsíci

  I agree.

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  FUG Slayer NomineePřed 2 měsíci

  @Paul Hopkins yeah I too had to re-watch the episode to properly conceptualize the space-time diagrams and to better understand how those later started to curve.

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  alf beemPřed 2 měsíci

  and then forgetting it 🙁

Oskar SkalskiPřed 2 měsíci

PBS Space Time is the best! I always struggled to grasp the idea behind diagrams for each of this horizons and hoped that someone will make a video explaining it and there is no surprise that Matt did it. I will still need to watch this episode again to be able to understand it fully but it is great to have this video.

Samael 11Před 2 měsíci

This is one of the best episodes, describing the basic concepts and definitions leading to a better understanding of time and expansion and the CMB that I've seen in a while. Good Job.

William MogeyPřed 2 měsíci

Great episode! Very well explained, and a spacetime diagram that Georgia O'Keeffe would be proud of. Thank you, Matt.

deathzitoPřed 2 měsíci

What a magnificent episode. And that's saying a lot, all of your videos are incredibly good.

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  m4s0ok4Před 2 měsíci

  Up for this

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  ZesPřed měsícem

  no such thing as magnifix or lot or etc or not, bix s 1uferiox bloat, doesnt matter, cepuxuax, outx, can outx any nmw s perfx

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  Jos van der SpekPřed měsícem

  I subscribe to this completely. I wanted to praise it in a comment too, but there is actually nothing to add.

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  bob ZombiePřed měsícem

  @Zes adverb verb noun adjective, noun verb noun adjective adverb noun adjective!

CapoJachuPřed 2 měsíci

Not only I am impressed by how much new information on a topic I thought I grasped I learned from this episode, the way it was presented was absolutely beautiful. I greatly appreciate the effort spent on making this episode. Give the person responsible for the graphs a raise!

Shane ZanathPřed 2 měsíci

This is one of my favorite episodes.I have never fully understood how we can map the CMB but there are objects whose light has not yet had time to reach us. 🤩 This makes so much sense now. Thanks!

I would like to remain anonymousPřed 2 měsíci

I loved this episode!!! So beautiful and eloquently explained to someone familiar with some of the concepts here (space-time diagram for example) but then going further and expanding on those concepts to explore some of the largest meta-questions in cosmology; How much of the Universe will we ever see? When will the Universe past the Local Group start to recede away? and many other questions on the same topic. So excited to watch the next episode of Space Time!

Nathan WilsonPřed 2 měsíci

This one wound up being a lot more complicated than I was expecting 😅. I'm very much looking forward to the next episode! Thank you for another informative episode and the super helpful charts! God be with you out there everybody. ✝️ :)

SauceGPTPřed 2 měsíci

I love that you're wearing a shirt that says, "Heat Death is Coming" while talking about the expansion of the observable universe. We appreciate the little things as well

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  CrowyPřed měsícem

  Nice detail.

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  Deepak NandaPřed měsícem

  So cool...

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  TonePilotPřed měsícem

  Typo at 2:18 wrt plasma years.

JS 2KPřed 2 měsíci

I absolutely love these videos deep diving on conformal mappings! It's such a powerful tool in GR.

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  James Driscoll_tmpPřed 2 měsíci

  You ain't mapping It ain't happening

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  John GagonPřed 2 měsíci

  GR seems to be one of the most reliable theories besides QM and it's CC, one of the few constants we can count on. I wonder if dark energy can be explained by expansion alone or if properties of empty space taken for granted might play a role, for example, space that has never seen certain waves in the layers of std model particles like neutrinos. Don't forget comoving space!

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  The ProgramPřed 2 měsíci

  I normally keep up, but this one will require multiple re-watches. And for something I thought I already understood! Bravo for helping me see deeper into the subtleties of the idea. Though... it's also an illustration of something I heard said, that a professor's job is to make complicated things simple... and simple things complicated. 😜

NightscapePřed 2 měsíci

I loved that shell analogy and spacetime diagram; it was very intuitive. I am happy I got to live at a time where there are still stars and galaxies in the sky.

Sebastian DierksPřed 2 měsíci

Completely awesome episode. I was actually waiting for something like that for quite some time, even commented a couple of times here or at Sabine Hossenfelder's channel. Physics Girl also has a nice episode on it where she explains it with stones on a beach^^ Anyway, the animations were really well done and helpful and the video contains everything I ever hoped for.. And the best thing is: There is a second part!

Roli RivelinoPřed 2 měsíci

As you told me to imagine being a photon spat out by a star near the beginning of time, racing towards the Milky Way against expanding spacetime, I could feel myself red shifting across the decelerating horizon. Thank you for that superb imagery!

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  Miles LundgrenPřed 2 měsíci

  That was genius

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  Michael ChuiPřed 2 měsíci

  So are you a particle or a wave.

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  Женя ЧерноваPřed 2 měsíci

  i'll have what he's having

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  James Driscoll_tmpPřed 2 měsíci

  @Michael Chui probably

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  Eye PatchPřed 2 měsíci

  @Michael Chui 😂

Jake AllenPřed 2 měsíci

I've always struggled to visualize how the light from the CMB reaches us, this is an amazing video. Thank you for making these

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  panner11Před měsícem

  My thoughts exactly. Tbh, they didn't explain very much how exactly we are able to see it. But the video gave enough visualization tools to work it out ourselves intuitively. Especially the non-conformal chart showing how in the early universe, the things beyond the hubble horizon, has space expanding much faster than the speed of light despite the small size of the universe, then slowing down, and speeding up. It really made it click why we can see the cmb 14 billion light years in every direction. And yet, at the time the cmb occupied a small space(relative to the current hubble horizon).

Jason FragaPřed 2 měsíci

I've always been confused about how space time diagrams and light cones worked until now. Phenomenal animation and explanation. 🤓

fiskfisk33Před 2 měsíci

Douglas Adams quotes will win my heart every time ❤️

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  Ms Zee ZedPřed 2 měsíci

  This quote is subject to a copyright dispute filed from a time machine whose own existence is being debated in the next courtroom.

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  Pope Vimto Ripkeef Happysack XVIIIPřed 2 měsíci

  NORMAL SERVICE WILL BE RESUMED AS SOON AS POSSIBLE……

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  Kommer Jan AllartPřed 2 měsíci

  I had the 42nd like 😅

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  PatrickPřed 2 měsíci

  How many of us continued the quote in our head? "I mean, you may think it's a long way down the road to the chemist's, but that's just peanuts to space."

EJ BertPřed 2 měsíci

I'll be re-watching this one a few times to understand all of the nuances. Great episode!

Brian & SylviaPřed 2 měsíci

I don't think I've ever actually heard a clear description of the particle horizon until now. Awesome!

CashFlowTVPřed 2 měsíci

Amazing episode. It's insane to think about far far future milky way life having no way to know the things we know now, such as proving thr big bang via the CMB. I wonder how a last billion year observation of light outside our local bubble would look like. Probably safe to imagine a starry sky with all stars slowly dissapearing?

lypse14Před 2 měsíci

What an amazing video, the visuals really clarified a lot of things that I was foggy on when it came to this topic, thanks a lot!

ajdeem90Před 2 měsíci

Fantastic episode, the animation and graphics helped me understand the material. Thanks PBS Space Time!

DroneBot WorkshopPřed 2 měsíci

Always a great day when a new Space Time episode is released!

Cole CoughlinPřed 2 měsíci

This video was made for me! I have been drawing these things I called light leaves with the same teardrop shape and then someone pointed me to the Davis and Lineweaver paper and it explained everything but I understand it a lot better after watching this video!

Paul DeckPřed 2 měsíci

This is an excellent video, absolutely love the topic and presentation! Thank you!

Bert PasqualePřed 2 měsíci

This really helped explain the comoving diagram, thanks! One flaw in the photon traveling video; I couldn’t figure out what I was confused by until I held a pencil in front of my screen and moved my phone so the photon stayed in place while the rest of the diagram moved. The Milky Way moves away from the photon at first, but starts moving back towards the photon after the pause at the 2X sphere. I know you care about accurate representation! For next week’s video, I would like to see this video redone without the pause and nail the expansion accurately. Also please be consistent with the photon being represented at the center of the wave packet. Then show a split screen, top, middle and bottom, where in each, the Milky Way is held in place, the photon is held in place, and the original galaxy is held in place, respectively. Thanks!

Anthony NarozniakPřed 2 měsíci

I'm kind of curious to know if it would be possible for the CMB to fit in with with one of the latest theories that our universe is in a black hole...

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  Brian & SylviaPřed 2 měsíci

  By definition, the universe is, as long as it meets or exceeds critical density. It'd be a time-like black hole.

Allan BurnsPřed 2 měsíci

you do such a good job please never quit making these

GaladoninPřed 2 měsíci

How many time can we rediscover the spacetime diagram ? It'll always blow my mind ! Quick edit : this is how to science vulgarization works. I'm not a fan of math, never been easy. Yet, from particules interaction, to the physics of black holes, expansion, dark matter/energy, geodesics ... We've learned a lot of complicated ways to represent GR to quantum mechanics, it's awesome ! Thanks Matt and your team

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  Михаил МищенкоPřed 2 měsíci

  The left path at 5:48 looks suspiciously fast though.

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  DPřed 2 měsíci

  Spacetime is strangely arousing...

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  mvmlego1212Před 2 měsíci

  @Михаил Мищенко -- Yes. They've made the same mistake in at least one previous video. I thought the visuals were great overall, though.

Bryan HydePřed 2 měsíci

Fantastic episode, your diagrams and instruction really helped we non Astro PhD types. Thank You !

John GagonPřed 2 měsíci

Always enlightening and elucidating, and fortunately with such light whose photons are reassuringly within the Hubble Horizon. Thanks for a great presentation of the cosmos!

Keith CooperPřed 2 měsíci

Great mind-expanding video, Matt!

superhawk20002Před 2 měsíci

I always feel like there's some fundamental flaw in the way space/time expands. It would seem we would be limited to what we can see of the observable universe, with every second being a more narrow cone of vision. Further, so much should have already passed us, leaving a big blank abyss.

Jed GouldPřed 2 měsíci

Loved the animation as well. As for your question about our limits…how much does it matter? Old light from a young universe? Well put.

amir tambePřed 2 měsíci

Really unique way of representation through layers. 👍

Lana Marie ASMRPřed 2 měsíci

I actually thoroughly enjoyed the explanation of it all and I understood nearly all of it and it amazes me how us Bipedal apes that somehow are aware of our own existence is able to witness and understand things like this in some form. No matter if it's how things work or don't. It's still amazing that life exists as it does. ❤️🐦🥚🐣🐥🐤🐦❤️

Ary WahyudiPřed 2 měsíci

Matt always finds a creative & unique phrase to end each video with “Space Time” ☺️👍

Chuck TalbottPřed 2 měsíci

This stuff is great. Can't express how much I love this.

Daniel MPřed 2 měsíci

What a fantastic mind bending episode! Thank you!

Kumquat LordPřed 2 měsíci

I still find it rad that we only need around 50 digits of pi to calculate the circumference of the currently observable universe to within the accuracy of a single proton.

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  DKFX1Před 2 měsíci

  Not true. There's a lot of uncertainty in the measurements of the age of the universe and its radius. The hubble constant if famously difficult to pin down. EDIT: Misinterpreted the comment. Kumquat is right about his statement.

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  PlatPřed 2 měsíci

  @DKFX1 Requiring more certainty in measurements that aren't pi doesn't mean you need more than fifty digits of pi. Do youtube commenters have to hold their breath when they type because they can't do two things at once I wonder?

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  DKFX1Před 2 měsíci

  ​@Plat Nice one. I recognize the difference upon considering your classy comment, but digits of pi mean very little theoretically in terms of accuracy measurements if your constants are not equally precise or more so.

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  PlatPřed 2 měsíci

  @DKFX1 No problem. Maybe after one more classy comment you'll finally understand what people mean when they say you only need 50 digits of pi for this. They're saying IF you had perfect measurements you would only need 50 digits of pi to get that level of accuracy. I shouldn't have to explain this to someone who can write complete sentences but hey I guess my expectations are too high for people who seem otherwise intelligent and articulate.

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  BatmanPřed 2 měsíci

  @Plat The comment can easily be misinterpreted. A more correct way to phrase it according to your interpretation would be "you would need only 50 digits of pi" as opposed to "you only need 50 digits of pi". But one thing that cannot be misinterpreted is your terrible personality and attitude.

Neal DanielPřed 2 měsíci

Thanks for this. I had been thinking about it. The transforming diagrams were incredible.

arbinoypogiPřed 2 měsíci

The animation makes it so much easier to grasp the concepts and ideas! Thank you!!!

Gonzalo Luis BorderollePřed 2 měsíci

Beautiful video Matt; in my opinion one of the best of your great channel. I had to watch it twice.

Zoltan VaciPřed 2 měsíci

Thank you for FINALLY providing an explanation of where the CMB comes from and how it relates to the size and geometry of the universe. I have seen the CMB invoked so many times without a real explanation other than "it comes from the big bang"

success meditationsPřed 2 měsíci

Loved the hitchhiker reference. Well explained as always.

Werner HoffmansPřed 2 měsíci

This seems to be the clearest explanation I've ever seen. Would have liked a summary at the end of the sizes of all horizons defined, though.

George BurdellPřed 2 měsíci

Thanx to Dr. Dowd for these videos... I know they are difficult to put together but they are excellent!

Gem IndigoPřed 2 měsíci

I can't say I understood everything said in this video but it was fascinating all the same!! I hope that one day,when my mind has expanded along with my consciousness, I'll be able to intuitively comprehend every aspect of the world around me.

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  C2H5OHPřed 2 měsíci

  THIS clearly reflects that the mind does not produce consciousness on its own. It is an evolution with the environment.

Pablo GonzálezPřed 2 měsíci

Outstanding job, as usual. Many thanks

Matthew WatsonPřed 2 měsíci

While watching this video, I realized that space and time really are the same thing. When we look into the sky, we are looking into the past just as much, if not more than, we are looking at a far-off object. It just never truly occured to me that at night we are looking into the distant past I knew the light we were seeing was old but it still felt like I was looking at an object that was far away. But that's actually a weird way to think about light that is depicting phenomena that may not even exist anymore, especially as the space continuously changes. I was just so used to "oh, the far off stars! Maybe someday we will explore them, like distant mountains!" But no, they are so unfathomably far away that we cannot experience them as we are now. And it seemed like the past was just a concept, an artifact of memory, and the only thing that really existed was the present. But my whole life I could physically look into the past from the light of other stars as soon as my planet shielded the light of the star nearby. Every dozen hours we have the chance to look into far distant times. Wild.

Scott HammondPřed 2 měsíci

Thanks, Ive been waiting for this. It made sense that the cmb was both super far away yet fairly close depending on how you look at it.

zombiemosesPřed 2 měsíci

Question! Do to the red shift/blue shift of light in the universe(or some other method), can we tell where the center of the universe is roughly? And if so, where are we in relation to it?

mossyfriendsPřed 2 měsíci

it’s tragic yet strangely beautiful at the same time, that we can never discover everything. There will always be places to see and new things to discover. We will never get to see them all, but we will also never run out of new discoveries. We will always be explorers to the very end.

Joel PinballPřed 2 měsíci

I like the background sound/effect/music that comes in when Matt starts the epic explanations.

Ugo NunesPřed 2 měsíci

Idk if it’s my headache, but this is the first video in a while that I struggle to understand the material. That is GREAT NEWS, I love learning new stuff! Great video!!

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  Mark FreemanPřed 2 měsíci

  I was literally the opposite, mostly dont get it, but these diagrams, makes it sense.

David KennyPřed 2 měsíci

I like to think I know something about the universe. I like it more when Space Time proves me wrong, and I have to watch again to try figure it all out. Definatly something new and mind bending.

robopsychologyPřed 2 měsíci

A nature article titled "Double-slit time diffraction at optical frequencies" was published on 3/4... I am very curious on your opinion on this! :)

Help Me Change The WorldPřed 2 měsíci

Very interesting! Thank you for the lesson! :)

JoshuaPřed 2 měsíci

Great episode as always and just mindboggling. But less mindboggling after I watched it. The spherical shells concept was great at explaining this.

EPřed 2 měsíci

Can you please do a video on if there is any relationship between the Bekenstein Bound and Shannon Entropy? Like if I throw a 1kg book into a black hole, does the bound grow more than if I threw a 1kg chunk of iron?

Jim GriffithsPřed 2 měsíci

06:36 - I think you're right when saying DE "took over" at a certain point, billions of years ago. I think it likely started right at the beginning, but its effects only started to 'dominate' later on. If it didn't exist at the beginning, the Universe would've collapsed back in on itself and we wouldn't be here. You can see how the rate of change of the curve starts from right at the beginning - Dark Energy (expansion) must've therefore been having an effect, albeit a weaker effect earlier on. My hypothesis is that spacetime (whatever it's made out of) is a substance, and that substance is entering our universe at all locations simultaneously. The more spacetime we have in our universe, the more "space" and "time" there is for new spacetime to enter from outside, so it gradually accelerates in expansion. Probably wrong, though! Just some thoughts about the multidimensional realm in which we exist. I'd love to see someone with expertise to try to figure out my hypothesis on a mathematical level, though. Perhaps someone already has. I mean, every other idea I've had, I've found out some great mind had the idea decades/centuries ago! Ideas are timeless.

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  Gordon Freeman's associatePřed 2 měsíci

  The idea is called Emergent gravity. Spacetime is a condensed matter/many-body system. There are a lot of papers on the subject.

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  Gordon Freeman's associatePřed 2 měsíci

  I could tell you more if you were interested.

John GagonPřed 2 měsíci

I'm curious if AI will ever extrapolate new insights about our universe. Cosmology seems like one area where the I in AI, required would be too demanding for it but I'd like to know your thoughts and the collective reasoning out there on it.

dmkPřed 2 měsíci

thank you so much, i've been thinking about exactly this for years and you answered all my questions :)

Peter PanPřed 2 měsíci

I’d like to think we will be able to one day see all of the universe just based off of the statistical algorithms that we are able to figure out in the future that we can use to simulate universes :)

Steven SchilizziPřed 2 měsíci

Matt, your episodes are always… brilliant! And I always come away from them, or out of them, feeling smarter, a good-feeling illusion! But this time, this once, I must say I lost my footing! My head went spinning and I went reeling. Boy, I’ll need to read up on the (new to me) concepts you introduce here, and then re-watch and re-re-watch this video until the moving coordinates and shifting and stretching spacetime eventually sink into my kilogram and a half of wet slushy mush that neuroscientists call the brain. You’re right: I had never seen those diagrams before. They’re fascinating. Thanks again for all the effort you put in making these videos a piece of art. Have you thought of getting GPT4 etc. to help you with them? 😉

Test RabbitPřed 2 měsíci

Could we in principle create a pair of probes that use direct counterfactual quantum Zeno effect principles and maintain the entanglement such that we put one probe outside the black hole horizon or event horizon and put the other one in and measure what's inside of it?

radkersonPřed 2 měsíci

If light is quantized, why doesn't it begin to stutter as it reaches the edge of where we can see it?

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  somanayrPřed 2 měsíci

  Light is quantized at a given wavelength, so if you stretch out the waves the quanta becomes smaller

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  XtreeM FaiLPřed 2 měsíci

  What edge? There is no edge from the light's perspective.

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  Chris ParisPřed 2 měsíci

  Redshifting is based on the wave-like tendencies of light, and so while the total energy of light will be the same, the energy will be spread across a larger time, appearing as a lower frequency/higher wavelength or redder.

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  Mike RehermanPřed 2 měsíci

  Light took speech lessons as not to stutter

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  Julia VixenPřed 2 měsíci

  The interaction of light with fermions is quantized... photons are a useful mathematical abstraction for calculating the interaction, but photons are not actually a "thing" that exists. It's just a way to talk about a very small part of the continuous electromagnetic field.

Dr. Ricco LindnerPřed 2 měsíci

Love it that you also use These cool tranforming graphics on this topic, not seen like this before 😎

stephen whittakerPřed 26 dny

I always wondered if we were to discover a stable wormhole even a smallish one in the future and it was connected to an area of spacetime much closer to where the observable universe lies, If we were to look through with a radio telescope what would we see?

Shrimply Pibbles Jr.Před 2 měsíci

Question: if a particle is TRULY a point… wouldn’t it be the same at all scales no matter what? Could the same photon be affecting hidden small scales?

Scott J. WaldronPřed 2 měsíci

As always I struggle to understand these topics but they are fascinating! If FTL travel is ever a real technology and assuming it can achieve distances faster than the current rate of expansion, then I'm thinking we'd be able to see more and bring that information back to Earth, right? (or wherever humans are living at the time). The idea of recording points in space with a FTL ship, putting that data in a storage medium on the ship, and then returning it to Earth is a really cool concept in itself.

It'sGoodPřed 2 měsíci

Is it possible that we will one day discover some kind of quantum entanglement between the particles in the milky way and those of galaxies on other side of the universe? Could that not be used to then gather information of those regions outside our event horizon?

Ketracel WhitePřed 2 měsíci

Really hard for me to follow and grasp.. but I trust you know what you're talking about Matt! :D I'm glad it makes sense to you lol

Mayank BhaisoraPřed 2 měsíci

If theoretically given enough time (assuming a that a person lives forever) will our body expand so much with the space that signals from our brain won’t be able to reach our feet? Will we perceive things differently at that time or everything will seem normal as relatively everything is expanded exactly same?

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  DeipatrousPřed 2 měsíci

  no

CarolinePřed 2 měsíci

Technically, you could see longer if you had strategically placed gravitational lenses station around the outermost parts. Some light that would not be possible might still go in a parabolic orbit around a black hole near the edge and then reflect to earth though it might not be possible to tell where it came from it.

Censored CensoredPřed 2 měsíci

Matt, what can you tell us about the war between time and space/time, as described in that other science documentary, Doctor Who?

SunRey EPřed měsícem

I could feel my mind expand and contract with the shape of that space-time diagram 😶‍🌫️🤯 Seriously, thank you for providing some amazing visual representation and narration.

m4s0ok4Před 2 měsíci

One of the most interesting video you did! Really loved it

Matthias "Koschi" KoschnitzkePřed 2 měsíci

At 2:20 there is a typo: I says the CMB was emitted after 380,00 years, instead of 380,000. 🙂

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  Sherlock HolmesPřed 2 měsíci

  I came to the comments to see if the observant viewers saw the typo, too. I was not disappointed.

funny manPřed 2 měsíci

Finally, it's the best PBS Spacetime episode of all time. You've really outdone yourself this time!

beatsntoonsPřed 2 měsíci

Is the series on the brain's creation of time over? I was hoping for a few more episodes on that one :)

Laurens van ZuijlenPřed 2 měsíci

Dear PBS, this video is one I've been waiting for for 5-6 years. The question that I've been pondering all this time is this: How do you differentiate between the photons from the CMB and photons from distant galaxies that have undergone an enormous redshift? After seeing this video I think of 2 options; whether it is a different type of wavelength than light from another galaxy; or you get a different prism spectrum if you compare the light from cmb with light from a distant galaxy. Maybe a good subject for a new video??

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  DeipatrousPřed 2 měsíci

  it is the spectroscopic equivalent of "these sheep are really tiny, and those sheep are far away"

mitchblahman13Před 2 měsíci

I love the universe spheres. What are the little artifacts at the bottom of them?

Vineet KansotiaPřed 2 měsíci

So jealous of the people who can comprehend all or most of the intricacies involved in this episode.

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  Michael SommersPřed 2 měsíci

  You can too, if you put in the work.

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  MonOptiquePřed 2 měsíci

  It is not necessary. The understanding of things will change again in future centuries. 😉

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  Michael SommersPřed 2 měsíci

  @MonOptique Sure, if you remain ignorant now, you won't have to update your knowledge in the future.

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  MonOptiquePřed 2 měsíci

  @Michael Sommers Yes. The difficulty lies in the fact of not having a global view of the entire "sky of the galaxies". In my cosmological model, the "sky of the galaxies" would be in rotary motion within the thickness of a titanic hollow sphere. The apparent inflation would be a temporary dilation.

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  Michael SommersPřed 2 měsíci

  @MonOptique Hahahahahaha!

QaosPřed 2 měsíci

Is there a way to calculate/estimate how much of the universe we won't ever be able to see?

darto gedaPřed 2 měsíci

Could someone explain to me why the top part of the graph is limited by an infinite? I've never seen this type of asymptote before.

Bill VinsonPřed 2 měsíci

The first time I heard of space being able to expand faster than light was from the children’s book series “Do you want to be a Wizard” by Diane Duane.

Chris BrownPřed 2 měsíci

Thanks, this episode answers a question I have had for a long time. How long before we start loosing the ability to see things.

Aric BlunkPřed 2 měsíci

This video was right on the edge of my event horizon of understanding, and expanded it, thank you.

Agent 8449Před 2 měsíci

"You could imagine the night sky as a set of shells" So the geocentrics and their heavenly spheres weren't entirely wrong, funky! I love when coincidences/connections like this happen

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  The ProgramPřed 2 měsíci

  I thought the same thing, with the pinprick stars thought to be windows into Eternity, which in a very loose sense some of them are. Great metaphorical echo!

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  y11971alexPřed 2 měsíci

  Geocentrism and heliocentrism describe the relative movement of bodies in the solar system. That is not relevant to the ideation of the night sky as a set of shells, which is relative only to the observer’s position and does not imply any movement.

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  The ProgramPřed 2 měsíci

  @y11971alex He's very obviously talking about the imagery, not claiming that it's a literal return to the Ptolemaic system.

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  DavidPřed 2 měsíci

  Any point in an infinite plane or sphere is legitimately "the middle" from its perspective. Hence, the Universe actually does revolve around us.

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  DeipatrousPřed 2 měsíci

  @The Program you can never quite tell though

Avaron VerdejoPřed 2 měsíci

Amazing episode, it is as much beautiful as it is soul-crushing x-x

Dark JaguarPřed 2 měsíci

What about setting up "relays" where one group after another only shifts "half out" of our contracting horizon, so that messages can be passed from one horizon to the next? I imagine we could do that until all these horizons fully contract.... right?

TuonraPřed 2 měsíci

Omg this is exactly the kind of question I have for physics! What if anything can humanity do to 'escape' the heat death and sustain ourselves through the multiverse. #BigDreams

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  Michael SommersPřed 2 měsíci

  What can we do? Nothing.

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  Joey PuentesPřed 2 měsíci

  Big Rip

Hossak 2014Před 2 měsíci

"Space is big. Really big. You just won't believe how vastly hugely mind-bogglingly big it is. I mean, you may think it's a long way down the road to the chemist, but that's just peanuts to space." Great video :)

za chromePřed 2 měsíci

What do you think about toroidal universe with the huge black/white hole in its centre?

Lüder MathwigPřed 2 měsíci

could single quarks exist in an undefined state?

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  Aaron PerelmuterPřed 2 měsíci

  How could anything exist in an undefined state? By definition, you’ve not defined if it exists.

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  zzasdfwasPřed 2 měsíci

  AFAWK, quarks can't be separated to large distances from each other because the color force increases with distance, so at some distance the binding energy between two distant quarks exceeds the rest energy of two more quarks, so quarks will be created in the vacuum.

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  Lüder MathwigPřed 2 měsíci

  @zzasdfwas by undefined, I mean a sort of super position. How should we know there arent quarks like that?

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  Lüder MathwigPřed 2 měsíci

  @Aaron Perelmuter same answer to you 👆

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  Aaron PerelmuterPřed 2 měsíci

  @Lüder Mathwig Well of course there are. Quarks are tiny particles, just like electrons and just like the neutrons and protons they are a part of. Therefore, as all quantum objects can exist in a superposition, the answer is of course. Moreover, a superposition is not an undefined state, it’s a combination of every state possible, we just have no idea which and in what proportions.

Tim HansenPřed 2 měsíci

Loved This Video! Can’t wait for the next one on this topic

Shuai GePřed 2 měsíci

Thanks! Interesting as alway. Looking forward the futures episodes.