The Edge of the Universe

The Universe is immense. Does it have an edge out beyond the Cosmological Event Horizon? Or in time, before the Big Bang? Or in higher dimensions like Hyperspace?
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Credits:
The Edge of the Universe
Science & Futurism with Isaac Arthur
Episode 305, August 26, 2021
Written, Produced & Narrated by Isaac Arthur
Editors:
A.T. Long
Keith Blockus
Cover Art:
Jakub Grygier www.artstation...
Music Courtesy of Epidemic Sound epidemicsound.c...

[@garyuntermeyer7976]

"...,at least until we discover how to walk at right angles to reality." Superbly original way of putting that notion forth.

[@MarkusAldawn]

I believe "perpendicular to reality" was a line from Hitchhiker's Guide. Potentially intentional.

[@ekkekrosing8454]

Had an interesting idea for a scifi novel on how to access that. How about streching space out alot and hoping that some fluctuation makes wave like things that ate right angle dimensioon

[@kassendek4777]

This episode has a retro Isaac Arthur feel. Like I've travelled a few years back in time.

[@liusam651]

Maybe it’s the audiob

[@isaacarthurSFIA]

Semi-intentional, the FTL series is one of our first and this is technically episode #6 of it, and I used some of the same visuals and music themes, though mostly without thinking about it :)

[@askani21]

Or maybe it was sent from the past...!

[@andrewgraziani4331]

You sure you haven't?

[@petermcconnell9622]

I prefer the old IA videos more of a storyteller feel to them

[@MeesterG]

I'm a primary school teacher in the Netherlands and currently teach ~8 yr olds. I've brought my pc to run SpaceEngine a couple times and show them around. They come with a million questions and even after answering them for over an hour, they want more. It's thanks to you that I have a lot to share as well. Thank you so much for this!

[@yoshikhurazi1769]

You're an awesome teacher. I knew I would have killed to have something like SpaceEngine to see back in the day

[@lancerhalsey4816]

A fucking big rain hit our camp so nobody wants to leave the barrack, even the guys who are already on leave right now, what a good time for some SFIA!

[@isaacarthurSFIA]

Nothing worse than marching in the rain :)

[@SpecialEDy]

The first rule of Warfare: Stay dry and always carry a towel.

[@EgoEroTergum]

@@SpecialEDy First Rule of Hitchhiking: Always know where your towel is.

[@roadkillanonymous4807]

Watching this with my 2 and 4 year old sons. They love watching your videos, the visuals are captivating for them and they ask me lots of questions about what you’re talking about. Thanks Isaac…I hope we can all maintain our sense of wonder like my kids have right now.

[@ohmatron8360]

I bet your 2 and 4 year olds would actually prefer Peppa Pig !

[@roadkillanonymous4807]

@@ohmatron8360 haha nope. They’re familiar with that show. They ask to see “space videos”

[@ohmatron8360]

@@roadkillanonymous4807 I was only pulling your leg...I think it's great you open your children's minds with vids like this.

[@tite93]

Isn't the vocabulary a bit too much for children? Anyway, it's great if they enjoy it!

[@roadkillanonymous4807]

@@tite93 of course it is. They like the pictures of space and ask me what he’s talking about. I do my best to explain it to them, no doubt they don’t really get it yet.

[@DanielGenis5000]

This is exactly the type of show that made me fall in love back when I found this program!

[@kingali1606]

The edge of the universe is where we can find Isaac's video about atmosphere mining

[@road2apples]

♥✞♥Jesus Christ is Lord. Hallelujah We are God's creations. He spent time and energy making us each unique and are all beautiful in His eyes. Choose what to do with your body wisely, because the Lord expended effort on it. Do not throw it away. Cherish the beautiful gifts that you have been given. Thanks be to God.♥✞♥✞♥

[@cryptopunkz]

An absolutely wonderful channel with such astoundingly mind stimulating content. Thank you Issac, keep up the great work.

[@N0TYALC]

So excited for this. I remember being 4 years old, and trying to wrestle with the concept of “the end of space”. How does it end? A wall? Then what’s on the other side. I think that kickstarted my fascination with space

[@gigastrike2]

My current running possibilities are that either you hit a wall, you leave the universe and enter nothing, or it turns you like the inside of a black hole would.

[@N0TYALC]

@@gigastrike2 It’s still so incomprehensible to me. There’s no theory that doesn’t sound utterly insane.

[@krumuvecis]

It could also be round, just in 4th dimension. Similarly like on Earth - surface seems 2-dimensionally flat, but there is no wall at the horizon - it just keeps on going until you go around and reach your starting point

[@lancerkind4055]

@@krumuvecis like a game of asteroids.

[@diouranke]

Pretty impressive for 4

[@Bhoddisatva]

This reminds me of a throw away sentence in Arthur C Clarke's novel "Against the Fall of Night" where its casually mentioned that the ancients had taken a starship and raced around the rim of the universe in a single day.

[@azmanabdula]

Everyone only went to the universe to see them him the edge

[@ColdHawk]

Wow! Early enough to see the edge of the universe from here! Cheers Isaac! Another great topic

[@road2apples]

♥✞♥Jesus Christ is Lord. Hallelujah We are God's creations. He spent time and energy making us each unique and are all beautiful in His eyes. Choose what to do with your body wisely, because the Lord expended effort on it. Do not throw it away. Cherish the beautiful gifts that you have been given. Thanks be to God.♥✞♥✞♥

[@maxkronader5225]

Most physicists: It can't be explained in words, you need to know the math. Isaac Arthur: Grab a snack and a drink; we're talking physics.

[@patgray5402]

I find it humbling that we laugh at people in the past who thought they would fall off the edge of the world, and yet here we are wondering the same kinds of questions.

[@surfside75]

Gold.

[@kebabinii7577]

13:24 I, for one, welcome our new hyper dimensional cat overlords

[@johannageisel5390]

You know all those yet unexplained phenomena in the universe? These are all caused by the Hyperkitten pawing at our universe while playing with it.

[@HistoryTime]

KZbin - There's a new Isaac Arthur video. Me - Immediately stop what I'm doing to watch

[@shadsalah3346]

your channel is great too.

[@HistoryTime]

Fun fact - Isaac was a massive inspiration for me to start my own channel

[@shadsalah3346]

@@HistoryTime great to hear that. always nice to see an domino effect of great stuff.

[@AboveEmAllProduction]

Sad to hear about your surgery patient that died because he posted a new vid 😢

[@deathsyth8888]

We all know there's a brick wall with a tourist view finder at the edge of the universe where you can look at the other side & find a universe where everyone wears cowboy clothes & hats. That's what Futurama taught me at least.

[@erideimos1207]

"We're not bothered by kicking the can down the road in science so long as the can arrives where it's supposed to be, which for a lot of theories is apparently a recycling center." 🤣🤣 And lots of episodes in September. See you Sunday!

[@pineapplepenumbra]

The Edge of the Universe has a wall, and on the wall there is a legend, it reads: *SLOW, Spaced Out Hippies Ahead!*

[@dermittelfinger5903]

There are 3 ways to watch SFIA. 1: With 100% attention, to learn something and to get thinking about the universe and our place in it. 2: As background noise, so one doesn't feel alone. 3: As relaxing podcast to fall asleep. All 3 of them are wonderful and I enjoy every second of it. Your videos are running around 4 - 6 hours on my screens every day and I love it.

[@planetoftheatheists6858]

The last time I was this early, the temperature of the universe was 10 billion Kelvins

[@katie-ampersand]

There is something different about the vibe of this video. There's a strange outburst of confidence and witty... humor? humor-adjacent thing that isn't present in the older ones. Especially at the beginning I like this video

[@AaronAlso]

2:25 .......that deep sigh..... yeah.... that is pretty much how I feel all the time. The best I have ever heard it put into words is Bill Hicks.... "...bear with me while I plaster on a fake smile and plough through this shit one more time."

[@mcnormally]

We will hopefully never reach the end of your videos! Thanks for your hard work!

[@road2apples]

♥✞♥Jesus Christ is Lord. Hallelujah We are God's creations. He spent time and energy making us each unique and are all beautiful in His eyes. Choose what to do with your body wisely, because the Lord expended effort on it. Do not throw it away. Cherish the beautiful gifts that you have been given. Thanks be to God.♥✞♥✞♥

[@mikeellery3336]

I have to wonder sometimes if we don't have the whole idea wrong? Kind of like a puzzle where the pieces mostly fit, but the picture makes no sense.

[@AreEia]

Indeed. First off, there might be some event or interaction, that has passed by our possbility to ever detect it. Like how in billions of years, there wil only be "island galaxies" left, and whatever intelligence arises then, will not be able to find all the pieces of the puzzle so to speak. Our minds have certainly not evolved to understand the intricasies of the universe, and I dont mean intelligence here, but rather how we are experiencing and viewing the world thorugh the lense of a specific homonid species. With all that entails concerning limited capabilities, brain unable to think in a way that could give us an understanding, our conecpts of sensors and measuring being limited, etc. And ofc the most important issue; "is math discovered or created?". Because there is a possibility that math and our understanding of the unvierse is just a really well functioning framwork/lense to view the world though, without actually being an intrinsic part of the universe as our current understanding/hope is. Personally I have hope that we might someday be able to understand what this existence really is, if it even is a "concept"/"occuring event" that CAN be understood. But my best guess is that we as a species will have become something entirely different looong before we will ever get close to this point. In the meantime I love learning about this stuff, and hope us strange little apes can argue, discuss and intensely try to figure out what this all really is about :) For that part about math, Roger Penrose has some interesting videos and interviews about this subject, if you did not know about it or want to check it out :)

[@carbonice-dragon74]

Traveling to an older, bigger, colder universe might be an interesting plot point for a sci-fi story beyond just hiding there the way you briefly mention. If you can travel back and forth between universes, you can look for evidence of dead mega-structures and such in the older universe, return to your universe or an even younger one to travel quickly to those locations, and then search for advanced technology that there literally hasn't been enough time for anyone to have developed yet in your own universe. It could make for an interesting take on the "future explorers find ancient ruins with super-powerful alien artifacts" trope.

[@road2apples]

♥✞♥Jesus Christ is Lord. Hallelujah We are God's creations. He spent time and energy making us each unique and are all beautiful in His eyes. Choose what to do with your body wisely, because the Lord expended effort on it. Do not throw it away. Cherish the beautiful gifts that you have been given. Thanks be to God.♥✞♥✞♥

[@StalinMcRally]

That's a lot of talk about edging. Interesting talk as always, Isaac!

[@Sauce....]

lmfao

[@agalah408]

His videos are always edgy

[@AboveEmAllProduction]

I'm edging as I'm reading your comment. And now I have arrived all over the place.

[@zackcook5123]

I'm relatively new to this channel but id like to say your content is really awesome

[@ThePherras]

love the futurology but I also love just learning about space and I think we should have more of thee sprinkled in.. also literally can never have enough fermi paradox vids!

[@road2apples]

♥✞♥Jesus Christ is Lord. Hallelujah We are God's creations. He spent time and energy making us each unique and are all beautiful in His eyes. Choose what to do with your body wisely, because the Lord expended effort on it. Do not throw it away. Cherish the beautiful gifts that you have been given. Thanks be to God.♥✞♥✞♥

[@IPilotheHATREDCopter]

Can you revisit active support structures again and go into more details about how they can be achieved? Your original video is one of the only few web sources on this. And as active support appears to be the basis for all mega structures and major space construction concepts I feel like this deserves a remake. Thank you for all you do. Please upvote so Isaac reads this! Ty all!

[@atk05003]

You might find more sources by searching the names "space fountain" and "orbital ring". "Active support structure" might be too vague to get good search results. en.m.wikipedia.org/wiki/Space_fountain en.m.wikipedia.org/wiki/Orbital_ring

[@Compnerd1]

Nothing like waking up to a new video by Isaac!👍

[@SpecialEDy]

Happy Arthursday fellow sapient intelligences! Greetings from the Quantum Chimichanga Reality!

[@poodytanx8611]

Yum

[@tanin34]

Hello from the Quantum Cheeseburger Reality!

[@jimmynutrition7858]

Hello from the quantum cigarette reality

[@askani21]

*Teleports in* Greetings, fellow multiversal voyager! *Rubs tentacles against your thigh* A happy Arthursday indeed! *Farts cinamon tasting cloud of joy*

[@jimmynutrition7858]

@@askani21 wtf bro

[@complex314i]

I have always been fascinated by the notion of a universe having multiple temporal dimensions. Unfortunately, I have only seen multiple dimensions of time discussed a handful of times. Of particular annoyance is that all of the times any detail is given, it is actually a multi-component formulation of 1D time, not true multidimensional time. I want to hear about time = , multiple independent temporal variables. What I get is time = . Multiple components, but a basis . It is described as there being a basic unit of time "t" events are measured in. Component 1: the amount of time intervals Component 2 The rate of progressing through these time intervals

[@ineednochannelyoutube5384]

Additional temporal dimensions would probably have to do with the different collapse of quantum superpositions.

[@jijilr]

Economists: "There is no free lunch" Non-Economists: The whole universe is a free lunch. Physics: "Matter can't be created or destroyed." Non-Physicist: "Tell me this again after teaching me about big-bang theory."

[@kedrednael]

Wouldn't physics say: Matter is energy?

[@InventiveHarvest]

The Universe is a free lunch that requires effort to gather. This effort is the cost of lunch.

[@johannageisel5390]

@@kedrednael Yeah, that's weird. Every physicist knows that matter can very well be destroyed into energy or created from it.

[@johannageisel5390]

@@InventiveHarvest The effort will also increase entropy.

[@Lusa_Iceheart]

@@johannageisel5390 Hmm, I suppose you could say Entropy is like a tax; you get nothing for paying it, you can't avoid paying it, and the asshole who set the rate doesn't listen to his constituents but swears it'll be better in the next term.

[@randomuser778]

"Compactified" is now my new favorite word. Great stuff as always, Isaac.

[@JohnDlugosz]

You should look it up to grasp its real meaning, in mathematics first, and then how physics uses it. His usage isn't exactly _wrong_ but it gives the wrong idea of what the term is actually referring to.

[@randomuser778]

@@JohnDlugosz Not sure what you're on about, mate. At NO POINT did I say the usage was wrong, nor did I say I did not know its meaning.

[@dfgdfg_]

Liked the tone and cadence with this one. Felt more personal, like listening to a friend

[@ultrahd3388]

Seeing more often less than 30min vids on SFIA is super worrying for me.

[@surfside75]

10-20min videos on KZbin will become the normal.

[@runningman5871]

Lee Smolin had a theory that black holes formed new universes with slightly different physics. As such, one prediction is that universes should be tuned to making more black holes.

[@AreEia]

Yeah, and it seems like a really interesting theory(especially considering our universe in particular, has attributes that makes it an almost ideal blak hole "spawner") but it is part of the many worlds theory. Ofc, both could be true. And if our universe has other variants/temporal states we can cross into/use as a medium, and there is a hyperspace above that again. I would say then that the possibilities of many worlds is almost 100%. The really cool thing I think, if any of these cases are true. Is that with our universe being such a damn good black hole creator, we might end up being like the central travel point/nexus for travel across both our other temporal variants and the multiverse, sometime waaaaay off in the distant future. That would be neat :)

[@sirgog]

Great to see the Matt O'Dowd shoutout at the end. PBS Spacetime is up there with 3blue1brown and Michael Penn as my favorite science content creators (the latter two being math oriented, PBS physics)

[@George4943]

Origins are such difficulties. Each personal universe -- the universe as seen from a given point -- expands in radius at 1 light-second/second. Expansion is in spacetime.

[@cryptolicious3738]

great video and amazing upcoming ones, wow! thorium, human machine teaming, stealth spaceships, very delicious topics :D

[@Chad_Thundercock]

Last time I was this early, there was one unified force.

[@TheAdeybob]

I tend to subscribe to the idea that time-space is plotted out on the inside or outside of a spherical shape. This allows for a foundation of infinity, being as there are infinite coordination points on a sphere. Of course, this might mean we're all trapped on an event horizon...

[@TheElijahMuhammad]

Beyond the edge of the universe is endless darkness with no wall or limit to it

[@ilejovcevski79]

The opening phrase of this video is my favorite quote to all those that like to play smart by parroting "nothing moves faster then light"! =))

[@ineednochannelyoutube5384]

@@fantasyEXX No they did not.

[@jeffrutledge4824]

That dark energy is coming from somewhere.

[@jamesbrownlie]

Hey Isaac, another great episode. Thanks! I was wondering if you could explain what it would take to divert very cold air from the troposphere to ocean level, for example in the Arctic? How difficult would this be? Would it actually have a significant cooling and reflect effect to mitigate some of climate changes effects in at least that region? Thanks

[@ravenkeefer3143]

I do think I've seen that compacted universe hung on a collar a cat was wearing and it's slightly bigger brother in the work locker you "don't open unless emergency"....🤫😉 ✌️ Favour ALL, Isaac Sarah

[@davidfinley1214]

A cat in a morgue??

[@digitalnomad9985]

@@davidfinley1214 Not in our version of the collapse of the wave function.

[@donhodgkinson6233]

Hi this is one of your best videos yet and I have really enjoyed your work over the past few years. I would like ask you about the no real images of the earth from satellites in high orbit.

[@MarcoLandin]

This one was an absolute mindbender. Thanks for keeping me up at night Isaac!

[@thetruth45678]

What if the real edges of the universe were the friends we made along the way?

[@lancerkind4055]

Explain please.

[@reporeport]

love this episode so much

[@mlr6530]

Isaac- If a galaxy is outside of our event horizon- photons from that galaxy can never reach us. But from the photons perspective no time elapses and it arrives to us instantly.....

[@bobologic6849]

...we’re not bothered by kicking cans down the road in science so long as the can arrives where it is supposed to be. Which for a lot of theories is apparently the recycling center... - Isaac Arthur

[@murasakinebula4772]

PBS SpaceTime is THE channel from which I came to SFIA in 2016 and I became ~10000th subscriber. There was a video about black hole ships here and I remember being impressed. And a similar video also came on Spacetime at the same time, so youtube recommended me SFIA channel's video.

[@fiiral5870]

The question is it that edge has drinks and snacks.

[@sgu00dir]

Isaac please do a show on the existential dread of a civilisation that develops on a planet in the late universe that is passed all cosmological event horizons. Imagine an intelligent species develops in a solar system but never has the ability to see the universe. Kind of sad to think that might happen

[@dermittelfinger5903]

I think they wouldnt feel dread. Quite the contrary. Look back at our civilization, we thought we were gods creation on our own world. Only when we recognized how big and ancient the universe is we slowly stopped thinking we are creatures made by god with a divine plan. A species born to late to see anything but it's own galaxy or even it's own star might feel super special.

[@virutech32]

they would still see a cosmos just a smaller one. barring the obvious modification we'll get up to, our decendants will one day be chillin in a local group-sized galaxy too & i don't see why that would bum them out. even less reason to be bummed if you evolved in that dying supergalaxy since u would never know anything different & would still have the option of colonizing whats left to meter out the available fuel as long as you could but nothing in life is guaranteed except death sure you could've been born in better times or humanity could have evolved earlier but you & we are here now i don't see how the what-ifs change anything

[@sgu00dir]

@@virutech32 no I mean a civilization that saw no cosmos as everything was outside its event horizon. Its unlikely but technically possible. No matter if they invented 'interstella' spaceships, they would never find or see anything. Though would they eventually compute that they don't see anything because of expansion I wonder. Otherwise what a sad existence and shows that truth is not really so important a quality since that civilization would never be allowed to know the truth

[@sgu00dir]

@@dermittelfinger5903 yes very true. Might be very happy thinking they are unique and alone. But if they develop past religion, they would have a difficult and painful question as to why they are in this empty expanse of nothing. Horrible!

[@virutech32]

@@sgu00dir well the only way that would happen under our current understanding is if life evolved on a rogue extragalactic exosystem somewhere in the cosmic voids. which i guess is as likely as any other place so it's not that far fetched, but again they would never know anything else so it would only be sad for you. i mean for the majority of human existence earth was all we ever knew. sure we saw stars & the moon, but that was the realm of the gods & all that was empty anyways so it's not like this civ would be anymore "alone" than we are. it's not like there are any ET lining up to say hi so if being alone doesn't make us sad i don't see why a civ that wouldn't have ever even contemplated there being any other option would be saddened by it. plus they aren't alone anymore than u or i am. there's billions of other people around & not meeting ET doesn't diminish that or really matter at all until you actually do meet an ET. that's like being sad about never having met the gods. until or unless we actually do it wont matter to the majority of people.

[@pinoyhssf]

Another great concept development video in science, from a brilliant content creator

[@sgu00dir]

There is a strange irony in the fact that us humans have a difficult time conceiving of 'the edge' of the universe, whilst simultaneously living on it and experiencing it constantly. The edge of the universe is in fact the only thing we really know. This is because we live on the edge of the time dimension, the future is outside the universe. The edge of the universe is today, and beyond the edge is tomorrow. And the expansion of the universe is not an expansion of space, but an expansion of space-time. It is actually time that we see expanding.

[@Lusa_Iceheart]

Very astute point! We're looking for an XYZ three dimensional edge while simultaneously riding the edge of the Temporal dimension. We can't be thinking in three dimensional geometry when there's four dimensions at play. The human brain processes Time and XYZ space as two separate things, hell physics is based around them being two separate variables (speed for instants is spatial distance over time) but their really all the same concept. It almost begs the question that perhaps we have so many problems with the math in physics b/c we started on the core assumption that space and time were independent variable and not just different directions of the same variable. How would the math change if we threw out the separation and treated them as up-vs-down rather than separate entities?

[@sgu00dir]

@@Lusa_Iceheart well look no further than Einstein himself for the maths of space time! But I do sometime wonder if the expansion of the universe, of spacetime, is in the main the expansion of the time dimension. Its strangely intuitive if you think about it, every passing moment is that expansion.

[@Lusa_Iceheart]

@@sgu00dir Oh jeez, I like to think I can handle complicated topics, but Einstein was a whole different level! I'm not sure I could follow along with his math. I can however appreciate the work other people put into understanding it all. Yes, it does seem to be pretty intuitive, the answer right there, time is expanding so spacetime is expanding, it makes sense.

[@michaelwinter742]

Idea: the universe isn’t getting bigger. Everything within it is getting smaller. Gravity pulls local objects toward each other, making it less noticeable at short distances.

[@AppNasty]

Hey, Isaac. Have you written any books that are science fiction? I feel you'd be gangsta at it.

[@justsayjay]

How is it possible to make such stellar ( höhö ) content and drop it with this frequency? Does Arthur live next to a black hole to find the weeks of production time to drop these almost daily?

[@virutech32]

he has a decent backlog & writes these eps weeks or months in advance.

[@rhuiah]

So...internally, the travel time for a photon is 'zero' regardless of the distance (or how much time passes for some observer). What happens if the travel distance is literally infinite though, due to there being nothing to interact with? An infinite travel time from an external perspective, and yet still instantaneous internally?

[@springbloom5940]

We already jump dimensions. Your perception is the only thing in motion, through time. Reality is that stack of paper, or maybe slides, composed of parallel dimensions. Your perception moves from a fixed point on one slide, to an adjacent point, on the next slide, in what seems to be a single direction. Something in the structure of the mammalian brain, another sense perhaps, allows it to perceive this motion. This makes it possible to choose, the next point; or at least, present the illusion of choice.

[@TheShootist]

dude, your diction has improved markedly . . . huzzah!

[@oldered5663]

15:00 - I though that was how FTL worked in babylon 5...

[@terraneko8999]

i havnt watched your videos in some time and i regret it cause your videos are always so gooood

[@veejayroth]

SUCH a good episode! Thanks, Isaac.

[@JeromeBakerSmoke]

I am 10 days late but happy 7 year anniversary on your first video!

[@theatheistpaladin]

Traveling back near the big bang would not only be difficult due to high energy, but anything you do, even merely existing there, would affect the evolution of galaxies. All the smallest of changes would magnify as the universe evolves. You hull cutting through that plasma would change densities, and that would in turn create greater densities that probably wouldn't have occurred otherwise. Add Chaos theory on top of that and you changed everything in the end.

[@Impossiblah]

If you think about it, there is no contradiction between energy conservation and energy coming into existence at a beginning of time. Conservation of Energy is just an implication of time invariance. If there's no such thing as time, there's no time symmetry, and no such thing as energy conservation. It's not that energy goes from a zero to non zero quantity at the big bang. It's more like energy goes from a null, undefined quantity to some actual quantity.

[@JohnDlugosz]

Also, the total energy of the universe might be zero, so coming into existence did not cause a change to the total either.

[@rhuiah]

Great episode.

[@SebastianSipos]

00:00 technically, there is space generated between us and everything else... in a geometric progression in relation with the distance to... stuff

[@Roel922]

Super cool episode

[@altargull]

time runs slower where a lot is happening. It's the system lagging.

[@reinux]

Isaac's already lining up his dad jokes. I approve.

[@TheSkystrider]

Isn't it so cool how you can detect the end of the episode by some queue in Isaac's voice. It's sort of like it always ends in a bit of a joke/paradox and can detect the end by his tone of voice. I can't really describe how I know.

[@pancakes8670]

"We're not opposed to kicking cans in science, as long as that can arrives where it's supposed to be, which apparently to some theories is a recycling center." I like this

[@richardgreen7225]

Just because energy or entropy is out-of-sight does not mean that it does not exist. If either one passes over the boundary of the system we are observing, we simply need to update our bookkeeping. Both of these concepts, energy and entropy, are statistical (macro) metrics - they are emergent. That means we have to be careful about the bookkeeping.

[@bentuovila5296]

All i got from this is a word to describe what happens to a car in an accident. I gets compactified.

[@shouldb.studying4670]

The changing pixel size analogy blew my mind 🤯

[@Tepalus]

I would say if someone asked where the universe is expanding into, just let them imagine the surface of an inflating balloon with a stickfigure on it. The universe isn't expanding anywhere, it's expanding onitself. If you take it down a dimension with a stickfigure, people can grasp the theory better.

[@alexanderkozlowski1678]

Love your videos

[@ravenlord4]

So what happens during a possible Big Crunch? Would galaxies begin to wink into existence at the observable horizon, speeding towards us faster than the speed of light? As the universe got smaller, could we reach a place where we could go no father (some maximum distance from our starting point) and we would start heading back regardless of the direction we chose? Would black holes grow bigger as they merged and swallowed other converging matter, our would they get smaller as the space that they were embedded in contracted? It would be interesting to see if CPT symmetry really would be conserved in such a scenario ;)

[@muninrob]

Yes Kind of - we don't really know what happens in a singularity due to divide by zero errors. Black holes are weird, the singularity gets smaller as it adds mass, while the event horizon gets bigger.

[@frans8861]

OK that joke in the beginning was pretty safe.

[@polarisraven5613]

So the part I don't understand about the 'upscaling' universe stretch bit, if all matter takes up space, and that space is expanding, then either that space is leaving the matter that previously occupied it, or the matter is expanding alongside the space (as the space expands, so does the matter there)? I'd imagine it's the former, as in the latter case I fail to see how distances between objects would change.

[@procactus9109]

Never thought I'd see that Sudo scientist Kuku here

[@josephramirez3809]

You should add Perpetual Motion machines in the Clarcktech series. By the way, I watch your videos once in a way and keep doing what you love most!!

[@FirstLast-gk6lg]

Nothing can travel faster than light. Nothing, can travel faster than light. Both are true statements

[@yoka3975]

Does anyone know what happened to hades 9? I remember Isaac talking about it a few years ago but I haven’t been able to find anything on it since.

[@empireempire3545]

Afaik it fizzled out?

[@fluffysheap]

Isn't that the realm where Satan himself is chewing on Judas, Brutus, and... Uh a third guy who isn't as famous

[@JeromeBakerSmoke]

@2:17 - 2:24 Laughed out loud, that was great

[@willyreeves319]

objects that pass the event horizon of a black hole still affect other objects on this side of it in that the mass of those objects are still mass and are still gravitationally affecting other objects

[@soultrick7474]

Hello Isaac, great vids, great channel. What do you think about Sir Penrose CCC theory?

[@jeffreystewart9809]

The restaurant there is where I go to get my drinks and snacks.

[@CyFr]

What's going to be perplexing is when we get results back from the James Webb, is if the universe is still bigger, making the time from the big bang even longer.

[@sterlinsilver]

I always wondered that if you were to hypothetically travel faster than the universe was expanding, what exactly would you go into?

[@ryandoesstuffapparently1540]

I would guess just more universe, at least to a point. I’d say it’s doubtful that we are at the exact centre of the universe.

[@JohnDlugosz]

You mean like ordinary motion? The expansion is quite slow at short distances, and zero in gravitationally bound systems like our solar system. We travel from A to B faster than the expansion of the space between A and B all the time! It's a requirement of actually getting to B.

[@sterlinsilver]

@@JohnDlugosz assume for a moment that we have hypothetically teleported to the very furthest edge of the universe. It is expanding, but into what? Assume we cross the boundaries between what is the universe and what it is expanding into. Is it a wall preventing us from going further than what has already been defined as reality? Or is it as of yet unknown and/or incomprehensible area beyond what we know as our universe?

[@araterstepanian8196]

the universe is flat and when you sail to the edge, you fall into oblivion.

[@altha-rf1et]

"Is this the edge of the Universe or is it the beginning?"

[@sporovid5856]

Watching your channel makes me know how much we don’t know. I guess all we can do is have faith that our universe has some reason for existing.

[@OpreanMircea]

awesome episode!

[@archlich4489]

I do love a good paradox.