The Edge of an Infinite Universe

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Have you ever asked “what is beyond the edge of the universe?” And have you ever been told that an infinite universe that has no edge? You were told wrong. In a sense. We can define a boundary to an infinite universe, at least mathematically. And it turns out that boundary may be as real or even more real than the universe it contains.
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Hosted by Matt O'Dowd
Written by Matt O'Dowd
Graphics by Aaron Halevy
Directing by Andrew Kornhaber
Our universe may be infinite. In order to wrap our puny human minds around such a notion we like to come up with boundaries. For example we have the “observable universe” - that patch that we can see, and beyond which light has not yet had time to reach us. It’s boundary is called the particle horizon. Beyond it there exists at a minimum of thousands and possibly infinitely more regions just as large. Our observable universe is like a tiny patch of land in a vast plain. We define its horizon like we might build a little picket fence around our little patch - meaningless from the point of view of the plain, but it makes our patch feel more homey and us less crushingly insignificant.
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سلطان الخليفي

[@betterrobots]

"And Here's the really crazy thing" - mate, you just had like 8 really crazy things in a row and you're doubling down now?! I literally cant brain any harder.

[@liquidminds]

Our brains are inherently too small for this. We need to break it several times to create the space to fit all that stuff in. If you haven't broken your brain once, you haven't even attempted to understand physics.

[@stapler942]

If you've heard 8 really crazy things in a row, why not round it out with breakfast at Milliways?

[@bruhe8895]

@@stapler942 alright, I'll go to the restaurant at the end of the universe

[@SaltandSnark]

[@SaltandSnark]

Kind of ("space-time") relevant. ^_^

[@ModernDayRenaissanceMan]

This channel is the only one that explains the hardest stuff in a way I can almost understand... if I watch it 74 times.

[@adeshpoz1167]

74 is a massive understated number, buddy. Or maybe you forgot millions. ;)

[@Feniso]

It took me two years to fully understand Veritasium's video about quantum entanglement. You can see how I actually answered my own comment.

[@nafrost2787]

Sometimes it takes infinitely many times, and then you use the edges of minkovski space to the total understanding.

[@whig3982]

Why? These are really basic and there's exactly 0 math There's literally nothing hard to understand here it's just remarkable

[@gordon6029]

Chris Heckert makes me feel not Alone.

[@phlosen7854]

Whenever I feel like a Smartboy, I just come here to calibrate myself back to mediocracy.

[@ChildOfGorb]

Heres another video to help with that kzbin.info/www/bejne/hamqpIhupK6KoLs

[@srivatsav9817]

Hope one day this video makes you more smarter

[@shawnconary6810]

Man... This is so perfectly phrased lol. Nothing like a solid ton of high-tier knowledge being dropped on your brain to reveal how much you don't know.

[@ThomasJr]

Yes, I agree, this is really really hard to follow, but I suspect he makes sense, whatever theories he's following. Some are easier to follow, but too abstract is a big problem. But I am happy I almost understood some things.

[@samirbassilios18]

Smartass 😀

[@justmoritz]

Somehow this feels like we're cartoon characters slowly catching on to the fact that they are 2D things in a 3D world

[@russellsimien7936]

@emmm lol, no we're just 3d physical objects in a physical universe inside of a multidimensional greater multiverse. Not Marvel's interpretation but scientifically and Biblically starting on a sub microscopic lvl and physically to plus macro lvl and spiritually

[@thegoodmanrot1460]

@@russellsimien7936 Chapter and verse please?

[@stylusapteryx1490]

@@thegoodmanrot1460 It's a fair possible interpretation of biblical sources and scientific data. 1 chronicles 2.6 speaks of heaven and the heaven of heavens (a universe of universes?), which vast as they are, still cannot contain God. That's the macro. Colossians 1.16-17 speaks of God as like the Higgs Boson (see what I did there!?) holding the visible and the invisible together. Hebrews 11.2 is a good one, taking us down to the atomic level: "By faith we understand that the worlds (plural) were framed by the word of God, so that the things which are seen were not made of things which are visible." More speculatively Ephesians 3:18 possibly references four dimensions, "may be able to comprehend with all the saints what is the width and the length and the depth and height, to know the love of Christ which passes knowledge." In all of these verses, the writers are intelligently and humbly recognizing that there are realities currently beyond our current ability to understand, and yet they are striving to understand them anyway. Faith feeds understanding, and understanding feeds faith.

[@SPGHTTFRT]

@@stylusapteryx1490 I forget where I heard this but I always loved the comparison of biblical descriptions of angels to instances of a higher dimensional object intersecting our 3D space. Are you a Christian?

[@stylusapteryx1490]

@@SPGHTTFRT hi. Yes the old 'how many angels can you fit on the head of a pin' question. Yes I am a Christian. So many Bible verses have prefigured our scientific knowledge. "He stretches out the heavens like a cloak" ... Expanding universe. Psalm 8 the fish "pass through the paths of the seas". On the basis of that a man went looking for - and found - the ocean currents. And what about Job. "He binds up the Pleiades and looses the belt of Orion". We now know that from earth's perspective the stars of the pleiades are in fact moving closer together, and the three in orion's belt are moving apart. The supernatural is whatever transcends our current knowledge of nature. Whether as far back in time as the big bang or as small as a quantum theory of gravity, there will always be new levels of understanding to attain to, and, in the hearts of the humble, more wonder and reverence for the First Cause that holds it all together.

[@namelessnick9791]

Me before watching a PBS space time video: “Aight lets learn some cool space stuff” 20min later: “... what just happened??”

[@ekothesilent9456]

@@vv2516 i wouldn't call much of this information "basic"

[@Kaytee-ct5yz]

🎼 I could only write a sentence from everything I learnt 😂😂😂

[@Kaytee-ct5yz]

@@vv2516 🎼 I wouldn't use the word "Basic"

[@paulmouatib9999]

I have quite a solid scientific background....studied quantum mechnics, physics and math in a very good school... and i was lost after 5min.... what just happened!

[@LuisSierra42]

@@paulmouatib9999 Minkwsky and ADS space happened bro

[@durstwurst]

So this is how the dog feels when I tell him stories about my life

[@iamcedricpowell8051]

LOLLL

[@altareggo]

lol good one. I salute you..now sit, roll over and tell me what the top of a house is called (hint: roof, roof!!)

[@karencarney7595]

I saw a dog food commerical before this video too..is that where u got ur idea for ur comment/joke?

[@tjsanmo]

LOL, dude. I have the same feeling. Some body tell me what I'm interesting, but I just cannot understand, sooooo sad.

[@Dexduzdiz]

😂😭😅

[@Tryingtomakeit390]

This how it used to feel when you came back to school after being sick for a week. 🧐🧐🧐

[@rianakanthi6752]

😂😂😂

[@candygarden5029]

especially with the "as we've discussed in previous videos" like nope sorry i missed that class

[@jeremyphelps5140]

I’ll understand this one of these days. I have to rewatch these videos several times before I start to understand what’s being said. The fact that I can even grasp some of these concepts is a credit to you guys at PBS SpaceTime for being such awesome science communicators :)

[@kingj.master1202]

yah i got a bit lost on this caz i thought he was just theorizing on what is beyond the boundary of space but then he gets a bit off topic with holographic principal n i didn't really get the analogy or care to since its not really something that is applicable, so the most i got out of it was pretty much, you can mathematically define an infinite boundary on paper or that the universe might not be truly infinite. n i suppose there is little point wondering whats on the outside of space (if anything at all). kinda hard to get there when we can't even rly go.. anywhere. space is kind of boring to me now. its like just there n doesn't support life for humans becaz it is not for them =p n it is most likely something other than what we think it is.

[@pboytrif1]

I love how much I convince myself I understand this stuff

[@nosuchthing8]

This topic is off the chain

[@timsullivan4566]

I know! I love how I manage to get the wool fully pulled over MY eyes too! (although, I confess that the other day, I DID have a bit of an "Oopsy!" issue with with my "Self-image vs Reality" balancing - I foolishly tried to convince someone OTHER THAN myself that I had a reasonable grasp of quantum mechanics, but the wheels started popping off THAT wagon pretty quickly, beginning with when I was interrupted by a correction to my pronunciation of the word physics, itself - apparently "fiss -iggs" is NOT commonly heard - who knew?)

[@stevesoldwedel]

I just enjoy listening to it, even just as background noise. This stuff is beyond me, although I'd like to understand it.

[@frankcrawford416]

I think these are interesting, but kinda of gibberish at this point.

[@johnknab9600]

Yes the earth is flat like your head mate

[@ernstkristianstlen4369]

Of all the channels that makes stuff I don't understand, this is my favourite

[@ikaeksen]

another good is open your reality channel..and cool worlds channel.

[@nancyhernandez2271]

I also like star talk with Neil Degrasse Tyson💜

[@bubblezovlove7213]

Some things are so awesome, you only understand a bit at a time as you go. The nature of understanding changes. You are here, that qualifies you plenty... 🤓🤓🤓

[@ashutoshmishra2439]

@@nancyhernandez2271 ❤❤❤

[@jaybyvan]

Agreed.

[@guyincognito1985]

Him: "Here is an ordinary square" 🔳 Me: "Woah, woah, slow down, egghead!" 🤓

[@19pens]

I love the way Matt O'Dowd so casually speaks of these heavy, complicated concepts. I also love those graphics! I thought for sure he would mention Mandelbrot's fractals when he spoke of tessellation. Then again, I'm no astrophysicist.

[@ZugZugz]

12:50 I thought there was hope of understanding something when I heard 2+1

[@shaggyfeng9110]

hahahahaha

[@toluadebesin8854]

😂😂😂😂

[@thirstfast1025]

When I die, I hope my afterlife is just this guy explaining everything forever, never saying "but that's for another video", just pouring knowledge into my mind to infinity.....

[@melanphilia]

Oh damn... bless you good sir! You just described my perfect afterlife

[@hermitcard4494]

And beyond!

[@greyraininthemimbrain3581]

I had a dream like that

[@thirstfast1025]

@@greyraininthemimbrain3581 I'm glad you remember that dream.

[@jzblue345]

Same here it would take an eternity and it's more interesting than the bible

[@Highbudget]

I ask myself 'how can the universe be infinite?' and I struggle to grasp it, how can it go on forever and ever? It seems impossible to me and then I ask myself "how could it not be infinite?" and I struggle to grasp that as well, how could the universe just stop? How could there be an ending and then nothing beyond that point? That seems just as impossible as an infinite universe

[@jacobjones5269]

This is why everyone who has ever contemplated infinity has gone mad..

[@asherkime5910]

Ok buddy

[@schakiarligonde1736]

The universe can be finite and have no edge

[@duetopersonalreasonsaaaaaa]

The only way I could comprehend a finite universe visually would be if it looped back around to itself, sort of like how planets do. But that might just be because I have no reference for any other object that you could go in one direction 'infinitely' but really is a finite space.

[@Eagle3302PL]

@@duetopersonalreasonsaaaaaa Klein bottle, doughnut etc. plenty objects out there that have an infinite path on their surface. Basically any object that has no edge.

[@The_Crazy_Monkey75]

I'm fascinated by space, even though I don't understand 99% of what he's saying and yet I keep on watching it!

[@timsullivan4566]

Wow - I actually understood EVERYTHING he said this time! ... except for the stuff that came after he said, "In today;s episode..."

[@alifatemi6511]

I come here whenever I feel too smug and within 5 minutes I'm as humble as humble pie.That and it's always fun to learn how much you really dont know.

[@SaltandSnark]

I know right. I thought the equation was a B.S. cover-derived but time-streams have to work the same way. Had to report F.E. haters. ;/

[@mr.battle20]

The best part about all this is that it's all guesswork. They "know" about as much as we do concerning the fabric of spacetime and black holes. They're just better at guessing about it.

[@halweilbrenner9926]

You know the def Of humble. Most don't

[@PierreH1968]

I popped more neurons in 20 minutes than while I was writing my master's thesis.... I will watch it over again for sanity....or giggles

[@obrtre2]

I am sorry I ever asked "what is the universe expanding in-to." I'll never ask again...I promise.

[@ruatsangawhite7261]

Universe is flat Flat Earthers: breathing intensifies

[@PreezyBaby420]

ruatsanga white hahaha!

[@bryanx0317]

I'm holding out for this "saddle universe" theory. It would justify my belief that the Earth, as well as the universe, rides on the back of a giant turtle. ...my only concern is whose ass is on top off us?? 🤯

[@majamystic256]

@@bryanx0317 an Otter, why do think they call it Otter Space

[@deathmetal11111]

Plot twist: They find out that in the TRUE nature of the universe, the Earth IS flat. We just experience it as a sphere because we're missing like 13 dimensions.

[@shambosaha9727]

@@deathmetal11111 Weird

[@andrewmitchell9796]

I love how this channel doesn't dumb anything down. I'd rather have to smarten myself up to follow than have it dumbed down for me. That being said, this got very complicated very fast!

[@damonsasser8129]

if you can not explain it to a child, than you truly do not understand it as well as you would want to believe!

[@Adityarm.08]

@@damonsasser8129 most concepts at the advanced level build on top of thousands of foundational ideas. So no, you can be the "ideal" teacher & still require 2+ decades to explain something to a child.

[@TheButterMinecart1]

I mean, they do simplify things a lot by omitting the gigatons of maths behind all the theories.

[@botezsimp5808]

@@TheButterMinecart1 It'd be cool if they had a separate math section on their channel explaining the math of all these videos.

[@frankdimeglio8216]

This channel is political. It is maximum money making agenda "physics". It is dumbed down "physics". It's plainly not honest. TRUTH, reality, AND nature/natural experience go hand in hand. They are knowingly lying about physics. Here's the proof. Here are the facts. THE THEORETICAL, TOP DOWN, CLEAR, SIMPLE, AND BALANCED MATHEMATICAL PROOF OF THE FACT THAT E=MC2 IS F=MA OF NECESSITY: Gravity AND ELECTROMAGNETISM/energy are linked AND BALANCED opposites, AS E=MC2 IS F=ma; AS ELECTROMAGNETISM/energy is gravity. Gravity IS ELECTROMAGNETISM/energy. Very importantly, outer “space” involves full inertia; AND it is fully invisible AND black. NOW, carefully consider what is THE SUN; AS it does (and it must) exist in both time AND SPACE. The stars AND PLANETS are POINTS in the night sky !!! E=MC2 is CLEARLY F=ma ON BALANCE. Gravity IS ELECTROMAGNETISM/energy. ELECTROMAGNETISM/energy is gravity. "Mass"/ENERGY IS GRAVITY. E=MC2 IS F=ma. This NECESSARILY represents, INVOLVES, AND DESCRIBES what is possible/potential AND actual IN BALANCE, AS gravity IS ELECTROMAGNETISM/energy !!!! Gravity/acceleration involves BALANCED inertia/INERTIAL RESISTANCE, AS E=MC2 IS F=ma ON BALANCE; AS ELECTROMAGNETISM/ENERGY IS GRAVITY. "Mass"/ENERGY involves BALANCED inertia/INERTIAL RESISTANCE consistent WITH/AS what is BALANCED electromagnetic/gravitational force/ENERGY, AS E=MC2 IS F=ma; AS ELECTROMAGNETISM/energy is gravity !!! It all CLEARLY makes perfect sense. Carefully consider what is THE MAN who IS standing on what is THE EARTH/ground. Touch AND feeling BLEND, AS ELECTROMAGNETISM/energy is gravity; AS E=MC2 IS F=MA ON BALANCE !!! (Energy has/involves GRAVITY, AND ENERGY has/involves inertia/INERTIAL RESISTANCE.) Objects fall at the SAME RATE (neglecting air resistance, of course), AS ELECTROMAGNETISM/energy is gravity; AS E=MC2 IS F=MA ON BALANCE !!! ACCORDINGLY, the rotation of WHAT IS THE MOON matches it's revolution. The stars AND PLANETS are POINTS in the night sky. The sky is blue, AND THE EARTH is ALSO BLUE !!! Carefully consider what is THE EYE. GREAT. GRAVITATIONAL force/ENERGY IS proportional to (or BALANCED with/as) inertia/INERTIAL RESISTANCE, AS E=MC2 IS F=ma IN BALANCE; AS ELECTROMAGNETISM/energy is gravity. TIME is NECESSARILY possible/potential AND actual IN BALANCE, AS E=MC2 IS F=ma IN BALANCE; AS ELECTROMAGNETISM/energy is gravity. Gravity IS ELECTROMAGNETISM/energy. BALANCE AND completeness go hand in hand. TIME DILATION ULTIMATELY proves ON BALANCE that E=MC2 IS F=ma, AS ELECTROMAGNETISM/energy is gravity. This CLEARLY explains the cosmological redshift AND the "black hole(s)" !!! AGAIN, gravity IS ELECTROMAGNETISM/energy. E=MC2 is CLEARLY F=ma IN BALANCE !!!! Think QUANTUM GRAVITY !!! It all CLEARLY makes perfect sense ON BALANCE !!!! Great. By Frank DiMeglio

[@emyjones2270]

I personally don't understand nothing of this .... but... I sincerely love to listening to this ... and challenge myself to be smarter and to try to be independently thinker ...

[@morrisdonte7064]

Hi Emy how are you?

[@morrisdonte7064]

@@emyjones2270 good to know. So where do you live and how is the weather conditions over there today?

[@morrisdonte7064]

@@emyjones2270 good to know. I live in Austin Texas USA. I am a single parent to my daughter her name is Emmanuella

[@morrisdonte7064]

@@emyjones2270 so tell me about your self do you have a kid? What’s your marital status?

[@artexatrayu8930]

@@morrisdonte7064 Ironically this video is about something you clearly don't understand. Boundaries dude. Go find a dating app and stay within them.

[@tbxvividos]

i love your sense of humor and how you interject it periodically throughout these videos in seemingly innocent ways.

[@HQ4575]

this makes me feel like an ape trying to understand the universe wait a minute....

[@soumyabratahazra7723]

🤣🤣🤣🤣🤣

[@sharpshooter740]

Yeah about that...

[@RealtyWebDesigners]

This is way advanced on this topic. Start with 'Black Hole theory' In fact, there's a book that is fascinating and awesome; it gives you an overview of advanced theoretical physics REAL FAST; Gosh I forget it off hand..

[@RealtyWebDesigners]

What he's saying 'compactified' is this: Newtonian physics don't totally make sense with new knowledge/data.

[@RealtyWebDesigners]

He's also showing how "Unification" is happening in Math and in 'space' (spit; space is a 'placeholder' for "Time, Energy, Mass (information) and Gravity"

[@mayaburroughs1715]

pbs space time giving me another existential crisis. brilliant

[@chrissandoval9459]

Here I was thinking: "the edge of the universe, how mind blowing could that possibly be? Maybe I'll understand this episode". HAHA

[@Harry351ify]

*nodding understandingly* hmmm Yes, yes. I have heard some of these words before.

[@danthemansmail]

"And here's the crazy thing....." Dude, my mind was blown way before we ever got to that.

[@quahntasy]

I am just happy there are people in this world thinking about this stuff and understanding it. Actually gives me hope for humanity when this channel's video goes on trending.

[@americalost5100]

Good luck with that. Trump supporters outnumber us all...

[@VarietyGamerChannel]

Cry harder snowflake. @@americalost5100

[@gonzomuse]

@@americalost5100 And as if by magic! It's almost like you asked one to pop up and say something stupid, just to make your point. ^^

[@americalost5100]

Hey racists, just wondering; do you think we'll be able to see the wall from space?

[@UltimateFeudEnterprise]

America Lost Define racism and then explain how anyone you have replied to in this comment section is racist. I guarantee you won’t be able to.

[@blackthorne-rose]

I haven't had a clue what he's talking about in years but I mb love listening to him anyhow. I suppose it's great that there's a platform for physics geeks to play on... and the rest of us can just feel happy we're being subconsciously trained for future lives as Interstellar travellers! lol...

[@ForestWoodworks]

I cannot believe Dr Matt convinced me to sit through this whole video. This isn't another, "I feel less smart after watching this," or a "I did my smart for the day" comment. I just happen to like his shirt. Is that merch I can buy?

[@Kj16V]

*PBS Space Time:* [Talks unfathomable physics at me] *Me:* "Ooh, pretty pictures!"

[@iamcedricpowell8051]

LOLLL

[@shilohauraable]

🤣🤣🤣

[@darknez09240]

very true i could not understand most of what he talks

[@MrLeSa95]

@@darknez09240 he doesn"t really know how to simplify it so most people can understand

[@christopherbabb7065]

@@MrLeSa95 he just needs to compactify it it onto a conformal disk so we can get it.

[@KudaFamily]

You lost me at 0:01, I made a full recovery at “shaped like a Pringles chip” and then my brained crashed again.

[@zaxxx1975]

haha you crashed! uh hold on?,,, "what was i watchin?!!"

[@marv5078]

Lmao

[@ive_y]

Mmmm could do with a pepreeka

[@rissarose781]

Lmao

[@MsMorgasm79]

@Bertrand de Born Speaking of clowns...

[@umarshamsi8550]

Amazing channel. Spent the last few months going through all the videos. Liked and subscribed. It's humbling to run head long into the limits of ones intelligence, but still enjoyable.

[@sharplessguy]

Usually this type of science documentary/show leaves a lot to be desired. This particular one is pretty good. I've been studying quantum physics for a while now and I was surprised at the host/narrator's ability to simplify/teach complex concepts

[@khodahh]

Hmmm that Penrose Diagram seems to be a recurring character. Hope to see it in the next season... Lovely personality.

[@SaltandSnark]

Thank you. How much mod work do we need here?

[@sachi20ful]

Very versatile

[@monkieassasin]

I am convinced that Penrose will go down in history as one of, if not the, greatest scientist to have ever lived.

[@BeckBeckGo]

I loved the use of Escher to help solidify this concept.

[@gamingpriests]

At one point my mind just wandered off and started thinking about random stuff

[@juliusnebulus702]

At one point my brain forgot how to understand English

[@mdu2112]

@@juliusnebulus702 LMAO

[@ChantHareKrishnaAndBeHappy]

LOL, yall

[@justmoritz]

The funny thing is when it tunes back in I am at exactly the same level of comprehension.

[@opium42069]

Dogs, cars, women

[@maryannryan9423]

I understand almost none of this but I love this channel and it is very helpful when I watch Jeopardy!.

[@morrisdonte7064]

Hi Mary how are you??

[@wildbob8650]

THIS RIGHT HERE is what I've been waiting for. It puts it all together beautifully!

[@joshuacole8284]

This video turned my brain into a Minkowski space.

[@limiv5272]

Your brain is now infinite?!

[@harshitrautela6585]

@@limiv5272 He can now use 100% of his brain.

[@mmoviefan7]

flat

[@ricardodelzealandia6290]

When this guy left Australia, the IQ of the country halved.

[@mmhoss]

Australia is in the denominator though so it doubled

[@ok-kk3ic]

The country can’t have an IQ. What?

[@morgengabe1]

@@ok-kk3ic Actually it's about 1/ln(2) of the gross domestic intelligence quotient

[@jonas-ke4qz]

o k are you joking, or are you just stupid.

[@jonas-ke4qz]

herobrine854035 max Australia is dumb except for this guy. you guys lost a war to emu's.

[@ARS1508]

3D analog of the 2d surface of a sphere... What does this even mean? Help!!

[@louisconstant8214]

A sphere, which is a 3D shape, has a 2D surface. A hypersphere, which is a 4D shape, has a 3D surface. A 4D hypersphere with a 3D surface is impossible for us to visualise, but in the deSitter space example, it would just mean that the 3D universe that we live in is actually the 3D surface of a hypersphere where if you keep going forwards you'll end up where you started, just like on the surface of a regular sphere.

[@nahreallytho6583]

Coming back to this after watching every episode in the series and i still feel like im kidding myself

[@mannyverse6158]

I'm just happy that there are people in the world thinking about this stuff and understanding it

[@samdell5593]

Im not sure about the understanding part... 😂

[@sebastianelytron8450]

Yeah, feels good to see others succeed in life amirite?

[@neurofire]

#metoo

[@antiisocial]

I am not one of them...my head hurts.

[@guytheincognito4186]

It's a great feeling

[@someguy3766]

I'm usually ok at following these videos, but I'm really struggling with this one...

[@My_NameJeff]

Ikr..this is too scientific for me to understand

[@purplemonkeydishwasher9818]

I feel like a lot of these are very mathematically heavy and can’t really be understood without digesting the physical math behind them.

[@EmpireRamzes]

same here, i was hoping i wasn't the only one

[@SimplifiedFinanceSiFi]

You can summarize the video with "what happens when you warp through space (so infinite speed)" 1. You end up where you started 2. You hit a wall 3. You go on forever For 1.) the universe would have to be a big 4d "ball" and we should be able to detect it or its so big that we can't measure precise enough. Its therefore possible We always ruled out 2.) because i think that would result in weird stuff and its probably not how expansion works. I wanted to add it though. And for 3.) the universe was always infinite. What happend at the big bang was just decreasing density and expansion of a point in an already infinite universe. so what would happen if you go on forever is, at some point you would just stop seeing matter and particles, just empty space. And the stuff with the diagrams was just about measuring and mapping and preparation for the video of the holographic principle. This video is more philosophical than scientific since it has no real applications. It's still fun and interesting though

[@jmitterii2]

It's his bouncing around with different space types and transformations... transformations even in linear algebra make me think okay wait, that term does this and that term makes the it go that way... nope... opposite...

[@AnthonyArya]

oh boy, what did i just get myself into.

[@morrisdonte7064]

Hi Anthony how are you?

[@VividBoricua]

Watching the end of this episode from 2020, just laughing about 2012. Ah, simpler times.

[@drunkenramble4120]

This channel makes "How The Universe Works" look like Barney's Sing-A-Long.

[@sadkritx6200]

@Nibogen Cupcake I said a bang bang bangity - bang 🎶🎶

[@numista]

Seem to be a very clever explanation, but my brain couldn't follow...

[@calvinsylveste8474]

Think of it like a Niagara dolomite brick wall surrounding the entire universe.

[@rastrisfrustreslosgomez544]

Don't feel bad this is not trivial. Basically, physicist realized that you can perfectly describe all the information hold within a blackhole in a 2D array instead of the expected 3D. A black hole basically strips a full spatial dimention out of anything that crosses the horizon and as black holes are the physical boundaries of our universe, physicists theorized that the edge of the universe ALSO should be described as a 2D array with 3Dness behaving more like an illusion, a hologram.

[@malcolmt7883]

The colors were nice though.

[@ericmacleod1904]

Listen, I am very very high right now and this video has put my mind in an indescribable state of confusion and overwhelming wokeness

[@Va5e1er]

I watch these episodes every time they are released. I get about 50% before my brain says "no your never gonna understand this" and shuts down.

[@przemyslawwawrzynczak2348]

Sometimes I’m amazed at myself for understanding so much. Thank you space time

[@luckylunaloops]

"Time symmetric" NOW we're getting somewhere.

[@abheekgulati8551]

My God, this was one hell of a video. I've never felt so lost while watching a video before!

[@howardbaxter2514]

I haven't felt this lost since my Differential Geometry of Curves and Surfaces class last semester.

[@MrCrownUK]

"Got it, cool, we're done here..." Closes laptop, and goes to sleep feeling rejected.

[@Empinada]

I've never considered myself stupid before, but I keep having to pause to think things over to understand them, and the second I hit play again and he moves on to something new I lose every bit of understanding I had before. I feel like a dog with my head tilted to the side in confusion.

[@kourosh234]

This is the most interesting and best channel on KZbin. Well done Dr. O'Dowd. Bravo guys :)

[@IainMcClatchie]

WOW! Among other things, hats off to the graphics people who somehow managed to keep up with Matt on this episode. That feeling when the roller coaster is about to start down the first slope, and you realize that it's so much taller than you expected... I swear if you guys can get me to understand the holographic principle, I'm going to double my contribution.

[@mjburger7881]

It will take me infinitely long to understand this episode. He lost me approximately 25 times. I wonder the percentage of people who saw this, who are actually able to explain it to a layperson.....

[@ThePastelAssassin]

Just watch this lecture by Leonard Susskind. Search "Leonard Susskind on The World As Hologram" or click YT link kzbin.info/www/bejne/aHWsnWZ-m81sqrs . He was close friends with Richard Feynman and teaches at Stanford. Him and Gerard't Hooft both collaborated together in developing the holographic principle. So it's best to get your layman explanation of it from one of the sources. It's really insightful and easier to follow IMO.

[@carloguerrero6583]

Just replying to be there when it happens. Scroll along.

[@tacticalnuke3805]

So, here's basically what i figured from this vid... Our flat space-time (the world we live in) is literally just the surface of some higher dimension construct. The reason our universe is infinite is because the edge is not on our space, but on a higher dimension. The hologram thingy, basically means all of this reality, means we are just shadows from a much, much more complex stuff. Edit: After watching the latest video though, I think i have to make some adjustments to my personal "take". We aren't just shadows. We're are also casting something of our own on a higher dimension. That's what we call gravity. And that solves the information paradox on black holes too, apparently. This getting more confusing for me. My brain is overloaded. Mind=blown.

[@jonathanmatthews4774]

I had a good day at work today. A senior analyst gave me a job well done on a task he assigned to me. I was feeling good. But I didn't want to get too high on my britches, so I made sure to watch the latest PBS SpaceTime and knock me back down to reality. That is. I know nothing. I have no idea half of what you said. And the more I watch, the more I realize how much I don't know. And the more I realize how much I don't know, the more I love this channel. Yes, today is a good day. Both a compliment at work and a new PBS SpaceTime. I am happy.

[@ThierryTiramisu]

3:33 the universe 🌌 is a Pringle! You just can't stop 🛑. It's infinite 😂

[@bubblezovlove7213]

Oooooh lots of new stuff to think about! That is deliciously new and complex and sits neatly on top of my current knowledge and understanding levels... nice! I love you P.B.S. space time!

[@koenvandamme6901]

I think I may have watched too much Spacetime. This actually made sense to me.

[@sebastianelytron8450]

Please write a paper and have it published explaining this simply. You'll make millions.

[@sebastianelytron8450]

@Joe Chang Proof you understood nothing

[@septitais]

@Joe Chang What are you smoking man, I want that stuff too

[@QazRiyami]

Ray Pass it on once you’re done smoking it. I want it too

[@raybod1775]

U know, none of this stuff really means anything to our daily lives. Too much Spacetime might be detrimental to your social life and social skills. Personal experience.

[@heckyes]

This channel needs to be renamed to PBS - Existential Crisis Weekly.

[@cholten99]

Nah, Kurzgesagt would sue :-)

[@spenat28]

Agreed.

[@adeshpoz1167]

@@Nihilova Holy cows. I missed on that video... now I'm bound to watch it soon!!! 😱😱😱

[@MoonRegolith]

I like to personalize the info to deepen the inner crisis. And to force growth. Grab a regular old 3d flashlight, and point it at the wall. Slowly move it toward where it meets the other wall (any perpendicular one). Watch as the flat projection of light changes shape as the light moves from one surface to another. Try describing to yourself what you're seeing. Everything from the floodlight beam to the changing circular-to-ovoid light geometry on the wall. A creature living solely within that circle of light... would never dream of you and your flashlight. Sitting there and slowly moving it across surfaces. You literally change it from being upon two "dimensions" in this simple exercise to being on one common dimension + a new one. Geometrically, there are also a few deep mysteries happening with the precise shapes involved. The questions there occur on multiple levels... but, one existential helplessness at a time. (treat it like meditation if that helps, doing one careful thought exercise at a time... then adding in each day some of the info you've learned here). We're the first generation who stands a chance at understanding this new view of the universe on an intuitive level. Physicists of old would have killed to watch well-produced supercomputer simulations or video descriptions of all the subjects they weren't specialized in. In 30 years, when we're on brain-download episode 47,689... You'll finally be ready for that SpaceX journey to Sagitarius A*. See you there!

[@ryanvess6162]

@@MoonRegolith does this mean you are a nondissiter-earther?

[@physicswithshahab]

Pbs space time is great makes physics as fun. Most of the physics I was confused about cleared by pbs .thanks Shahab with physics is fun

[@Saritabanana]

You had me until about the 4 min mark when my brain began to vibrate and turn inside out and all I could remember was 'compactification'

[@morrisdonte7064]

Hi Gogo how are you?

[@kevincleary5982]

This episode made me feel like an idiot, but at least I laughed my ass off for an hour reading the comments.

[@noudvangemert297]

Same here. The comment section of this video is gold, it's also the only thing I understand about this video..

[@vedantsridhar8378]

I actually enjoy not understanding anything about it. It fascinates me how difficult physics can be and how smart scientists can be.

[@dustofyth4433]

Him: (mentions names, whole new nouns, verbs and terms I haven't heard in my life) Me: exACTLY

[@joshmercer8980]

How wonderful it must be to understand any of this.

[@KrnelPanc]

This is like Jazz, full blasting, horns a blowing, drums a singing, boddaaap tazzz

[@kjthompson6513]

I define a nanosecond as the moment of clarity of understanding after watching an episode.

[@jhuger]

Wouldn't Anti De Sitter space be De Stander space?

[@caduceus68]

I prefer the "Pringle Universe". Mmmmm....Pringles

[@sebastianelytron8450]

How is this not top comment? Give him likes people!

[@sasshole8121]

De Dad Joke

[@aarona6420]

Christopher De Walken space

[@jasonhoffman6642]

Yeah, dad joke if your dad was Kip Thorne...

[@rogersledz6793]

Thank you so much for uploading this video. It is helping me get through the pandemic!

[@sidewinder814u]

LMAO at the title and then you said in the intro "Our Univers May be an infinite" or it might have an edge? LOVE YOU MAN! :)

[@nevermind-he8ni]

I finally smoked enough weed to understand this.

[@ryanvess6162]

About to undertake that right at this moment

[@claymaxon]

Please share. I don’t think mine is good enough.

[@unyieldingvortex2081]

Your a man of culture I see

[@michaelsmith9556]

I’m doing that right now

[@dmfitzsim]

never mind brillian 😂😂😂😂

[@MrOvipare]

I really want to thank you for making this extremely abstract subject very "accessible" and interesting. Also, the recap of Penrose diagram and Hawking Radiation was gold! WELL DONE!

[@DaDaviesCL]

Ewe we we, is the sound of 2 realities colliding.

[@simeonparvanov6852]

Why no ads for such a good production? You should apply them , dude, we respect you, so respect yourself!

[@szalaierik]

This was the first time I did not understand the topic :D (but I am confident I will on multiple watches) I love this channel. Cheers!

[@GamersPlayerUnion]

It amazes me how one person can know so much about a subject.

[@ianmoffet5080]

The titles always grab me and I always think I can grasp what he’s talking about. I never can.

[@CosmicBarrilet]

As Argentinian, I've seen dozens of videos of Juan Maldacena, even L. Susskind or Joe Polchinsky without catching it, I`m only accountant with poor background in Mathematics and Geometry. This video, helps me a lot for example with the explanations of Mikonski, De Sitter and Anti-De Sitter spaces and so on....gonna watch it a couple of times more. Thank you.!

[@yoyovlogs7755]

The Whole of Space is truly infinite in both size and time and in every directions, it has no beginning and no end.

[@Kiamoko]

This is on a whole other level than where I'm at. I'll have to revisit when I've gained enough knowledge to understand. Now backtracking...

[@adamwilson2427]

Even he talks in Layman's terms it still beats me. I have to start right from the beginning. A clear genius

[@ThomasJr]

He doesn't, he always talks physicist speak, this is a not a channel for laypeople

[@ThomasJr]

@@paressh really, u sure? you don't even know proper grammar in English.

[@jezer8325]

For sure, he must be really smart to grasp this stuff to the point that he can confidently explain it to a layman. Huge props to the whole team behind this channel on that front. But what really intimidates me though is the whole community of clear geniuses who not only comprehend but even contribute to the field. There are so many ridiculously smart people out there, it's wild.

[@jezer8325]

@@ThomasJr I'm not too sure about that. Maybe 'laypeople' is a relative term. The way I see it, teaching cosmology to the non-layperson would involve a lot more math and formalism; and I'm sure the team behind this channel would agree that the point of these videos is not to serve as a cosmology course for physics students but to educate a general audience.

[@ThomasJr]

@@jezer8325 He's not accessible to laypeople, other channels are much easier to follow. Matt is a CUNY professor, of course he masters these themes, but he's not a good teacher at all for laypeople.

[@MG-er6dm]

How could I have missed this one. 😣

[@robertschlesinger1342]

Excellent video. Very interesting, informative and worthwhile video.

[@Fancy_PotHead]

Ads, desitting yes, curves, stuff quantum, yes ofc... Hmmm. *strokes beard with deep thinking look on face* Nupe, no idea wut's goin on here

[@qotda]

LOL!+!+!!!

[@gdolphy]

Ads Space. Did he mean KZbin monetized?

[@abhishekshah11]

I love how he said "got it? cool" yeah I totally got that except the compactified minkowski part.

[@alexandralenzinger8482]

Abhishek shah it’s like when u ask someone directions then when they’re done u realize u didn’t hear any of it but to save face you just say thanks and walk away hoping you look like u heard them

[@nerdwisdomyo9563]

Think you so much for confusing me so greatly, genuinely makes me so happy to see these maps of space and time, so cool, im just grinning right now

[@ericthompson3982]

I'm really curious why so many people here who don't 100% laser focus on specializing in this don't think they're big brains. You're here, which means you're curious, which is the smart move.

[@adantigus]

"This all got going in the early 60s when physicists discovered LSD."

[@SpiritualFox]

adantigus So he shrunk 3D space to 2D space using technobabble and optical illusions just so he could add time as the third dimension, bringing us right back to 3D space. Psilocybin trip confirmed.

[@bassangler73]

Lol...true open thinking achieved with LSD, but I think THC has the same effect

[@poshmark9807]

it's so great!

[@etralin3dream983]

1P LSD

[@ErinRaciell]

bassangler73 THC would NEVER have the same effect as LSD. It doesn’t even compare to the slightest. Let’s not confuse things

[@kevinmawlieh9526]

If a person could understand this, he should reward himself

[@mikeconrad1183]

Ok

[@ThomasJr]

this is extremely abstract math. I took a course in college called Topology and it's as abstract as it can get. I nearly failed.

[@RockMonkeyLV]

I don't know why I subscribe to this channel. I can only watch the first 2 mins of every video before my brain takes a crap.

[@febojarlock9469]

Matt: 13:32 ...but here is a crazy thing!!! Me: oh, really??? The craziness began since KZbin recommended me this video XD

[@charlierashi100]

He's speaking in English and yet I still didn't understand a word that was being said.

[@pranayp1950]

Yep

[@aprilgaudette7327]

Deaf people lmao

[@dermotmcdermott6890]

Malcolm X claimed to have read the entirety of Webster's Dictionary. A sizeable vocabulary properly exercised in the mind of a loquacious individual tends to ostracize them from the masses.

[@DrWhom]

don't worry, there are mistakes.

[@charlierashi100]

Deipatrous, good to know.

[@SunnyApples]

Is there anyone watching this without having any clue what he is talking about? I am here because of curiosity and pictures!

[@sergioortiz8219]

Matt may be great at teaching physics to graduate-level students, but he really is not a good science communicator. Every now and then I'll watch one of these videos to see if he's changed his style, but it seems he's stuck in his ways

[@arthurmario5996]

I don't have much trouble; it's very strange until I accept that my present view of the universe is very limited. Then I can begin to understand.

[@mikemondano3624]

It's like what John von Neumann said about mathematics. Nobody understands it; we just get used to it.

[@alexanderokak5112]

Sergio Ortiz I get where youre coming from, I am 3 years away from Uni too and do not understand many of the things he says, but I think that he is an excellent teacher and all I’m lacking is a bit more knowledge of physics to fully appreciate his videos. He does a good job at explaining it though, but remember that he cant spend all day trying to Kurzgesagt his videos because it would be too annoying for advanced viewers. Imagine if your maths teacher explained addition every time before teaching you maths? It would be a bit tedious.

[@xxDPKINGxx]

This one got too complex for me, usually I can understand after thinking for a while, but not with this one.

[@IAmNumber4000]

Find you a guy that appreciates you like this guy appreciates confusing science stuff

[@FredPlanatia]

This is such a precious site. Amazing insights achieved by some talented humans are brought a little closer to the masses (like me) while preserving much of the beauty in those achievements. This episode in particular stands out in that respect. The graphics accompanying the explanations are worthy of a prize for contributions to this internet corner of spacetime.

[@aidinnejad8059]

PBS SPACE Time team, I love you guys, You are amazingly awesome. Presenting the New Horizons of Knowledge about Universe in an artistic way with universal harmony, this is what you guys are doing. Ultimate respect from here to you guys.

[@jpmendozajp]

I’ll play this video to my date, and pretend to understand.

[@LuisSierra42]

Good luck

[@mwolkove]

You gonna tell us what happened?

[@butHomeisNowhere___]

she left him

[@taichiwinchester1102]

You'll end up with infinite space and time to regret.

[@gabrielbarrantes6946]

Fascinating, this kind of topics is why is great to take some graduate level complex analysis and maths in general

[@uncleweirdbeard86]

I miss this series. I still want to learn so much more