Infinite Universe?

Explains the difference between an Open Universe, Closed Universe, and Flat Universe. Also discusses the expansion of space-time.

[@EugeneKhutoryansky]

To see subtitles in other languages: Click on the gear symbol under the video, then click on "subtitles." Then select the language (You may need to scroll up and down to see all the languages available). --To change subtitle appearance: Scroll to the top of the language selection window and click "options." In the options window you can, for example, choose a different font color and background color, and set the "background opacity" to 100% to help make the subtitles more readable. --To turn the subtitles "on" or "off" altogether: Click the "CC" button under the video. --If you believe that the translation in the subtitles can be improved, please send me an email.

[@plasmaballin]

I like the space travelers' reaction when they find that they live in a closed Universe.

[@Mysoi123]

You deserve the title of Richard Feynman for an online educational channel. The perfect combination of animation, physics, philosophy, and excellent illustration has made you one of my favorite channels on KZbin, EugeneKhutoryansky.

[@EugeneKhutoryansky]

Thanks for the compliments!!!

[@luisabramson4957]

Awesome explanation!!! That lady's voice is sooo soft and mellow, that you can almost chew and taste her words. Very elocuent and easy to understand. Congrats!!!

[@EugeneKhutoryansky]

Thanks.

[@mikefallopian3191]

Those space chicks were bored shitless with each other after 300 years but they know they have to keep cruising around the universe together... f o r e v e r . . . .

[@jorjiang1]

don't worry, forever is a time loooooog enough to allow the particles in side the spaceship come together and form a dildo just by their stochastic movement

[@rustybolts8953]

Those women don't look flat to me!

[@KsenIzNN]

I love how you explain difficult substances in simple terms. It is truly a talent! Great job, keep going!

[@EugeneKhutoryansky]

Thanks for the compliment. Yes, I plan to keep going and make lots more videos.

[@mraccident]

Where can I join this space mission crew?

[@ashutoshpandey7965]

kutta

[@5Dmaxx]

You missed the take off.

[@matejhromin2925]

Hey, whats the name of thr cartoon character on your profile?

[@TheACG22]

This is such a cool channel!

[@er.sumeshghatane7158]

I guess the man making these video is Albert Einstien himself. I mean look at the imagination put in these videos. I am the big fan of this channel.

[@CuteSceneChic]

Love this channel. Seriously, the visuals are good. The voice over is easy to listen to, and I also like having the subtitles on the screen. However, that music is extremely distracting. Maybe lowering it or putting on a different track such as a gamma wave binaural beat, something that helps the viewer stay focused. Other than that, i love this channel, keep up the fantastic work. :)

[@EugeneKhutoryansky]

You can help translate this video by adding subtitles in other languages. To add a translation, click on the following link: kzbin.info_video?ref=share&v=IFdfrtzo4SY You will then be able to add translations for all the subtitles. You will also be able to provide a translation for the title of the video. Please remember to hit the submit button for both the title and for the subtitles, as they are submitted separately. Details about adding translations is available at support.google.com/youtube/answer/6054623?hl=en Thanks.

[@Trollimo]

I was having a group project, and my computer automatically started playing this part loud volume lol 2:18. I didn't notice it until everyone was just staring at me, since I was wearing noise cancel headphones lmao. But I love your videos though, this is one of my favorite videos, and I've probably watched this atleast 4 times already?

[@EugeneKhutoryansky]

I am glad you like my videos. Thanks. Sorry about sudden increase in the volume of the music.

[@mrbreakybee]

Don't be shy Eugene, and go further. Please try to make a video explaining how the decoherence on quantum level occurs. Something about quantum vacuum fluctuations would be great as well. I'm sure you understand it pretty well. Definitely one of the best explainers here on youtube. Everything is so clear. Just a pure scientific essence of our reality.

[@alfonshomac]

very good videos. thank you for your effort.

[@EugeneKhutoryansky]

Thanks. I am glad that you like my videos.

[@alfonshomac]

Physics Videos by Eugene Khutoryansky no, no, Thank You, *High Five

[@kennyliljegren2667]

Very good infornation miss.Greetings from sweden

[@aghaanantyab]

i think our universe is "close universe" like a balloon, there are other universes out there. we can travel to another universe through 4th dimension of space. imagine an ant live on a balloon, he thinks that he can only move forward, backward, right, left. but he can jump to the other balloon through 3rd dimension (up and down)

[@juangreen8194]

aghaanantyab the latest measurements by cosmologists indicate that we live in a flat universe with a 96.4% certainty if I remember correctly. But as stated in the video we could be looking at a very small portion that looks flat to us.

[@alexlawrence1337]

aghaanantyab The 4th dimension is time. If moving through time means that you can move between universes, then we are constantly travelling through universes.

[@abhishekchourasia3945]

Eugene your videos are eye opening and leave the mind thinking about the subject for days...Thanks for educating so many people with such wonderful illustrations and easy to understand language and analogies.

[@rthorarensen]

Best video I have seen explaining the shape and size of the Universe.

[@EugeneKhutoryansky]

Ragnar Thorarensen Thanks. I am glad you liked it.

[@tfwoods3]

Who are these space chicks?

[@ronaldderooij1774]

Pixels.

[@communitycollegegenius9684]

Horrible feminist misandrists. I don't see myself being represented. I'm triggered and I'm suing.

[@ishworshrestha3559]

Uii

[@joeyjojojnr58]

please keep making more videos!! I am really enjoying them :D i like how sometimes you pause which lets me think about what you have said and visualise it.

[@EugeneKhutoryansky]

joey jojo jnr Yes, lots more videos are coming. I am glad you enjoy them. And I am glad to hear that you like the pauses, as this is something that some people sometimes complain about.

[@bartkwezelstaart9306]

Great video once more. You're always able to take out the essence but still be quitte educational (at least, for me as a high school student ^^ ). Awesome visualisation!

[@EugeneKhutoryansky]

Thanks. I am glad you liked it.

[@vitakyo982]

One of the girls seems so bored of space travel

[@pronounjow]

When you see nothing but empty space for practically an eternity...

[@ArtWorld006]

@@pronounjow But how can anyone bored🤔😑😑😑

[@MrHappy3feet]

I love your videos so much, great combination of physics and animation. Thank you!

[@EugeneKhutoryansky]

Thanks for the compliment. I am glad you like them.

[@Alishan_Usmani]

Hi I've seen your comments today 7years after you've commented . I'm from future. Writing this to you not of present you but you 7 yrs ago. 😂😂

[@HakonSkjold]

Mindblowing work as always! I can tell your animation skills are improving for each upload as well. Keep them coming, Eugene :)

[@EugeneKhutoryansky]

Thanks for the compliment. Though, I thought that my most complicated animations were in the video on Thermodynamics, with all the moving particles that had to interact with one another. Making the animations for the video up above was much simpler by comparison. But, I am glad you liked it, and yes more videos are coming. Thanks.

[@HakonSkjold]

Eugene Khutoryansky This might not be as complicated, but I really like the details of the starship and the people :) You state that "If the density of the universe is high enough, space-time can completely curve into itself to form a closed universe." As the "sphere" is expanding, the energy density decreases, right? Would that imply that a closed universe eventually will become an open one? (provided it does expand obviously) In that case, since a finite number of stars and galaxies existed within the closed universe, the number of stars/galaxies in an open one must be finite as well. And since the stars/galaxies in our own flat expanding universe is finite, the energy density must also decrease and turn it into an open one. Is that inevitable or am I completely wrong?

[@EugeneKhutoryansky]

Håkon Skjold Whether the Universe is open, closed, or flat depends on the ratio of the density of the universe to a parameter called the “critical density”. Although the density of the Universe is decreasing with the expansion of the Universe, the “critical density” is also decreasing with time. As a result, a closed Universe can never turn into an open Universe, even though its density decreases with time.

[@martinisreb9502]

@@EugeneKhutoryansky You appear to be the only content creator that makes educational videos and supplement your material by answering insightful questions in the comment section. God bless you, Eugene. Never stop doing you. 💯

[@babakvelamkon]

I need to take a month off work and sit at home watch your vids . You r just simply amazing. any time i watch any of your vids i feel chill . Thanks

[@EugeneKhutoryansky]

+babak plus, Thanks. I am glad that you like my videos.

[@shaminoranger8588]

Something I've always wondered is why do we assume that the universe is expanding when we observe red-shifted galaxies in general? If two galaxies are in separate regions of contracting space then observers in each would observe the other as red-shifted. Relatively, they could conclude that the space between their own galaxy and the distant galaxy is expanding and that this appears true for the universe in general. But rather than one big expansion caused by a yet unclear force, why could it not instead be many points of contraction associated with a less mysterious force: gravity? Wouldn't both options produce the same observation of red-shift bias?

[@KhantNPi]

Shamino Ranger because, let's say you have a box. there is something in it. you can't open it. but it smells like an apple. You see no sign that it cannot be an apple. so, instead of assuming that it is some kind of mysterious object, you assume it is an apple for now, even thought you are not perfectly sure. you are still skeptical about it and keep searching for better evidence.

[@KhantNPi]

Shamino Ranger because, let's say you have a box. there is something in it. you can't open it. but it smells like an apple. You see no sign that it cannot be an apple. so, instead of assuming that it is some kind of mysterious object, you assume it is an apple for now, even thought you are not perfectly sure. you are still skeptical about it and keep searching for better evidence.

[@scottgastauerjr4445]

I love the reaction at 2:08 🤣 detail deserves a sub 🤙🏼

[@Zeneeka0405]

I absolutely love your videos! I'm so much looking forward to more!

[@EugeneKhutoryansky]

Thanks. More physics videos are coming soon.

[@NICEFINENEWROBOT]

To fear (not: to shun) God is the beginning of wisdom.

[@tabamal]

Thanks for your effort.. I like the music, the animation and also the accompanying text

[@jamesbentonticer4706]

Living in a finite universe poses paradoxes like, what happened before it or what's beyond the edge? But a universe spacially and temporally infinite takes care of these problems. We probably live in an infinite universe.

[@chuckles6886]

I know how this comment is apparent but this video simplifies the theory down yet keeps the information well done

[@DanielKrogh]

So the theory of a closed universe, the only way that could be possible is if you were to travel in a slight angle, like going around the world. it feels like you are going straight, when in the reality you are actually going in a slight curve, meaning that you would eventually return to the same area you started. but then again if the universe is like a planet (a sphere) what would be outside of that sphere?

[@rodrigoappendino]

Maybe doesn't exist an "outside"

[@mrboni5]

Just take a look at the atoms, they are circular, cells are circular, and the earth is circular taking that into account and that can lead to the belief in a circular universe or the thory of the orange shaped universe with continous expansion and contraction

[@samuelmarak6062]

What the progeny of man,animal & plant look like ? It's obvious.So also we can understand the shape of the universe assuming the atoms,planets &stars to be it's progeny!

[@creemyice]

We don't live in a universe, we live in a society

[@grufgoinHAHAHA]

also nice comment. It implyfies that vast majority of people will never have to deal with such problems in their short lives.... But still it is fascinating and captivating isnt it?

[@mannouriscy]

Great Great Great!!! Thanks Eugene! Another perfect video from you! I look forward to your other science videos! Also your animations have improved A LOT!!! Thanks again!

[@EugeneKhutoryansky]

Thanks for the compliment. New physics videos are coming soon.

[@edwinjones1000]

A closed universe would make this observable universe a mere quark in the overall size of existence.

[@PiznesPiznes]

Thank you Eugene! It is a pleasure to watch your videos!

[@EugeneKhutoryansky]

Thanks. I am glad you like them.

[@jjbipod4355]

Okay. I dont typically comment. However, in my efforts at finding lucidly explained videos over physical concepts finding fruition here, I can recommend these videos by this uploader to perhaps be as good as they may come anywhere else. I gained a lot in that you repeat concepts often, that help with reinforcement.

[@EugeneKhutoryansky]

+Jj Bipod, thanks for the compliment about my videos. I am glad that you like them.

[@Reivivus]

That brings some questions to my mind: It would seem that even in an open or closed universe, if the universe is expanding, then what is it expanding into, and furthermore, what is beyond this universe? You illustrated the universe as a sphere and the blackness around it was to illustrate the position of the universe in relation to space, hmm, so what is that blackness? If we live in a flat universe, then what would happen if it were possible to flip this universe upside down, would all the laws be inverse functions? Then, it appears as though, there is another possibility, the universe is all there is, and drawing anything outside of the sphere or plane of the universe is just pretentious. Still, what is the volume beyond the universe that the universe is expanding into? Though, I suppose we could negate this possibility if we assumed that an outside volume just does not exist until the universe creates it!

[@roner61]

There is another view, that is: Space itself is appearing (being "created") between particles...the cause?: Dark energy...dark matter...? Nobody knows what is out there creating space...from "nothing".

[@midnight.light_]

I think Universe is infinite and there is no start. That big bang was just a part of creation, everything was there before big bang...some kind of consciousness, you can call it god, i dont know. I think universe dont have start and end, its so hard to imagine.

[@rayantahir]

Midnight Light If the big bang was the part of the creation THEN THERE WILL ALSO BE A PART OF DESTRUCTION OF WHOLE UNIVERSE AND LIFE. WE MAY FIND THE PART OF DESTRUCTION AT TIME OF "DESTRUCTION".WHAT DO YOU THINK +Eugene Khutoryansky

[@roner61]

rayan tahir Of course, the Universe going die out, that itsnt any secret, any physicist knows it. The Universe is expanding but at the same time its getting "colder",and diing.

[@midnight.light_]

rayan tahir Of course, everything should get back to the Source . This is just my world view

[@gorkemvids4839]

Maybe universe-sphere is expanding because density drops while galaxies draw away and galaxies draw away because universe is expanding which explains exponential expantion

[@noem1977]

Perfect. Voted and subscribed.

[@EugeneKhutoryansky]

Thanks.

[@americanscholarsoftruthand5940]

If the universe was an infinite, open system, the universe would have no shape. But all shapes would be contained in it because having a shape would imply that it's bounded when in fact its infinite from all directions at every point in space.

[@KennethRothey]

All kingdoms have a law given; 37 And there are many kingdoms; for there is no space in the which there is no kingdom; and there is no kingdom in which there is no space, either a greater or a lesser kingdom.

[@teslathejolteon8007]

I love these videos, it goes from scary existential music to party music from 2002!

[@KutadguB]

Brilliant, easy to understand and not boring also (that is hard to find these 3 come together in one). Eugene you can build a website and start a community. Im sure there are lot of people who want to help and make it bigger. I am one of them too :)

[@dougdouglas3945]

Love your videos and the way you explain things so I can wrap my head around some wild and crazy stuff. Mucho appreciado. But I have to say the choice of music sometimes is...kinda grates my last good nerve. For real, tune it back and tone it down maybe a notch or two. Not trying to be a d**k but had to say it. Anyway, again, for real thanks for all the work and all the videos, for real!

[@raj_jm]

if u say that universe is infinite than lets say that it is not infiniti but there should be something beyond that if we draw a circle on apaper and say that its the universe than there is the paper in which we have drawn the circle and there is a surrounding atmosphere around the paper and the atmosphere,is say a table than there is a surface on which the table has been placed. it never ends!

[@iBOXRIVER]

I agree. The question of what the universe is contained in, is never awnsered.

[@iBOXRIVER]

+Valdemar Højlund But the universe is not open. It started from the big bang, which itself was contained inside something, and then expanded into what we NOW call the " universe". The question is what was there BEFORE the big bang?

[@nicolasmoonlit8109]

@@iBOXRIVER (I know, I'm too late, but.. ) "Before Big Bang" isn't correct. Not because of "There were no time 'before big bang'". Big Bang was the birth moment for causality. Every event happend before Big Bang doesn't influence on any event after Big Bang. It's just no matter. But hell, it is interesting to know what was before, but... We can only make our guesses. Even if we are Laplaces Demons. [₽] _[₽] Everything I just said is just a theory. Very sad, but unproved theory. It is one of the 'guesses' of scientists, I previously mentioned. (Sorry for my clumsy English)

[@garamiglm2026]

Thanks Mr Eugene. Wonderful set of videos. Awesome.

[@ELBMohdKaifuddinKhan]

Loved your channel

[@sohamzemse]

Wow. I appreciate your work. this was much awesome as your past videos too.

[@concretecubes]

great illustrations! really lets me get a better concept and understanding of a possibly infinite universe.

[@johnstevens8720]

More videos please! I share all of yours on my fb

[@EugeneKhutoryansky]

More videos are on the way. And thanks for sharing my videos.

[@blake301987]

Awesome video as always. You should be featured on Vsauce, that way you'd get the number of view these videos deserve!

[@EugeneKhutoryansky]

If you know anything about how to get featured there, please let me know. Thanks.

[@homhable]

The words expand my brain while that cheep music narrows it.

[@Wherrimy]

But the rate of expansion grows faster than the rate of narrowing

[@monicanagaraj1828]

😕😕😕

[@thekalevar]

How dare you. soundtracks are awesome

[@radar0412]

"Cheep?" Like the Automobile The Cheep Cherokee?

[@z00t3d]

Deaf? Or bad taste in music..

[@Lytv333]

This videos are just amazing. Eugene, earth needs more people like you! I love your channel. I however, would love to be able to show it to my parents and other people that do not speak English. Is there anyway I can add subtitles here in youtube so that other people that speak only Spanish would understand? Regards

[@David_four_twenty]

Top 10 You Tube channel of all time right here :)

[@EugeneKhutoryansky]

Thanks for the compliment.

[@shubhanshukaroliya]

You are King of animation..... None of the animations on KZbin can describe better than you... Please make video on general relativity....

[@EugeneKhutoryansky]

Thanks for the compliment. I already have many videos on General Relativity. Below are just two examples: My main video on Relativity: kzbin.info/www/bejne/m6ecq6WqlMSfm8U My video on Einstein's Field Equations: kzbin.info/www/bejne/i5e3mYmsd7yNrq8

[@mikebe41]

it just amazes me that there is something, instead of nothing. where did all this something come from? what caused the universe to exist, and what caused the pre universe to exist. Pitty we will never know

[@mikebe41]

+FrancOdelic Music site GOD burped and presto, here we are. what really blows my mind, what if the universe is Infinite! that is mind blowing

[@somabhisek4165]

@mikebe41 It also amazes that something was created out of nothing;how's it even possible??????

[@Jpear5000]

@@somabhisek4165 What's interesting is that classical causality cannot apply at the beginning of the universe, as it is inherently non classical. Thus the notion of a cause always preceding an effect doesn't necessarily hold. We know this from experiments in quantum systems (entanglement). It a grander theory of the universe can be verified, it may give us insight into these questions.

[@ominous-omnipresent-they]

There has always been something.

[@mahipalyadav6053]

Well may be matter, energy, space, time combined together is equal to nothing just as 100 combined with -100 is equal to zero(nothing).

[@mageshg1938]

Thanks for your effort. Even though I am not able to contribute financially, I feel gratitude and immense sense of appreciation and love and respect to you :)

[@LendriMujina]

Could you please put together a playlist for the music your videos use, or just list them somewhere? I like the songs, but don't know where to find them on their own.

[@EugeneKhutoryansky]

The music for this video was made by Nekoprism. You can find his website by typing "Nekoprism" into Google. Thanks.

[@cortespravida0]

Dar atenção aos brasileiros é incrivel, não pare

[@wiscokiddd]

I think that the big bag theory depends on the red shift theory. What if over long distance, the faster, blue light fraction of visible light tends to disburse in all directions while the red fraction remains more linear so there is no time space shift? What if the energy of the greater universe that exists beyond the speed of light condensed into time space energy and matter as we know it? Something certainly existed before the big bang if their was one. Also if there was in fact one big bang there certainly were and will be more. What's more is if an equilateral triangle is bent, it is no loner an equilateral triangle. Space, just as numbers containing no biggest number, contains no limit; there is no limit to the length of an imaginary line. So if there is some sort of supposed saddle or sphere shape of a finite universe in theory, the observers of the imaginary straight line can compensate for such things and the line will continue infinitely. I have said for several decades that space being infinite is still just space and space is not everything. Thank you for making this video Eugene and Kira.

[@TheAnantaSesa]

I don't know why blue light would disperse like it does in the atmosphere. There's no gas to spread it.

[@wiscokiddd]

+Ananta Sesa das Well the average or background temperature of the universe is 2.7 degrees above absolute zero so it is not a perfect vacuum for one. So to travel from the edge of out atmosphere for several billion light years would mean passing through quite a bit of mass. For two there is some reason that it is easier to make a red laser that a blue laser. You don't have to know the answer exactly to come to the conclusion that there are no all inclusive theories in an infinite universe. Thank you for asking, most people do not bother and if they do they just parrot what they have been told without even a thought or mind experiment.

[@PacRimJim]

Since distant parts of the universe are moving away from us at greater than the speed of light, there's no way to determine if the universe is finite or infinite.

[@de0509]

and that it feels a bit lonely that after a certain distance away, you totally will never be able to even see the other parts of this universe

[@tabamal]

does anyone know the name of the accompanying music?

[@EugeneKhutoryansky]

The music was made by Nekoprism, and you can download this music for free from his website. The names of these songs are "Angel's Mercy" and "Death Trance." This second song is a remix of music from the 1990 video game "Phantasy Star II."

[@tabamal]

Thank you

[@lucianocastillo694]

Physics videos out here spitin facts

[@decadence6418]

Hey,awesome animation video helped me alot!

[@EugeneKhutoryansky]

Thanks. I am glad you liked it.

[@fidrewe99]

What speaks against a flat universe containing a finite volume and a finite number of galaxies? A cube may be closed into a torus in six dimensions with its intrinsic geometry remaining flat. It is often argued that no fourth spatial dimension needed to close space into a hypersphere as its topology is just an intrinsic property. In the same way one could argue that a flat universe could be closed into itself intrinsically.

[@Luisitococinero]

+Fid Rewe Interesting observations.

[@irlserver42]

The universe's curvature has never been observed to be flat - the ideological fixation on the idea that this is true has caused all small positive curvatures to be 'rounded down' to flatness. We have no observations showing us that we live in a flat universe.

[@mekingtiger9095]

No mention about the "Critical Mass" thing and how it might affect the expansion of the universe in the future according to its shape, though?

[@MatthewGraham027]

Question: Since we do not know now if the universe is flat, how will we ever know? Since the only way (it seems from the video) to know if the universe if flat or not, is to observe it from a larger perspective; aren't we limited? Even if we could move at the speed of light, we would still need an incredibly massive distance to observe the universe; maybe so large that it isn't feasible. And with space expanding, won't even our ability to see be diminished over time?

[@cdfgh1111]

The narration reminds me of the old USA Network show NIGHTFIGHT that came on late Saturday night and early Sunday mornings...wayback in the 80's

[@sixpooI]

sick music

[@TheMrMxyspptlk]

those classical representations are so misleading, thanks for your efforts but they just add confusion. Just represent the curvature of spacetime as it is, i.e. a 3D space sucked by masses, so easy and clarifying. Thanks Eugene, you do a really good job

[@craig2493]

The fallacy of spherical and saddle-shaped models is based on the unquestioned assumption that where baryonic or "normal" matter is located is where the Universe "is", and that any space beyond that is not part of the Universe. The fabric of the Universe is both matter and space, the two of which are everywhere conterminous, inseparable, and the elementary components of this fabric.

[@Noneyettocome]

If the universe has no end it has no shape.

[@relentlessmadman]

great video, BUT were you aware that looped music was in vented to drive us all insane??????????

[@m77dfk]

Nice eclectic background music.

[@semyuelshekhovtsov]

+EugeneKhutoryansky there are too important things to consider, which are missing in the video however these are strongly relate to the subject. The only way to approximate infinite space we know so far is closed space, for example - surface of a ball or surface of a torus. Stephen Hawking suggests that if you could live eternally and travel at relativistic speed, you could fly in a straight line till you came back to where you started. According to the latest researches our universe do has boundaries - the redshifted light waves or gravitational field boundaries. Can't explain it here in details, thats too much to write in the comment, but you could research on it if you are interested.

[@aaronodom8946]

If BOB was traveling at half the speed of light and SUE was also traveling at half the speed of light, but in exactly the oposite direction, would they experience the same observations as if BOB was stationary and sue was traveling at the full speed of light?

[@HaroWorld1]

interesting how the condition of a "closed universe" is that the density of the universe is high enough that the space closes in on itself... much like a black hole.

[@mikkel715]

Found here another piece of gold in your video collection. What is the correct explanation of a Relativity viewpoint Seems-to-paradox: (Not classic twin “Paradox” I hope - Since there is no Paradox in the classic Twins’) One accelerating toward a distant planet with the exact momentum to match the expansion of the universe? Now the two twins will be at rest relative to each other. Even though one twin is accelerating and not traveling as much through time as her distant twin plus her close neighbors, now left behind? What am I missing here? Thanks for these amazing videos. This channel is my first and for now, the only Patreon channel here.

[@EugeneKhutoryansky]

I have a video titled "Twin Paradox in General Relativity" at kzbin.info/www/bejne/mJurfZWlgJeAZ8k Thanks again for your support!!!

[@mikkel715]

​@@EugeneKhutoryansky Thanks for answer. I have watched your Twin "Paradox" video a couple of times. It's good. I'm thinking, that what I'm missing so my thought situation is not a paradox is: Only from one of the distant two observers, they are at rest to each other. One person accelerating away towards a distant galaxy (Let's say) to only be at rest to this galaxy, due to expansion of the universe, doesn't mean she is at rest from the point of view of the observer in the distant galaxy. Edit: My first can't hold up.. Can it be explained by General Theory of Relativity? By considering the accelerating one in accelerated orbit around another, then look at the gravitational waves?

[@EugeneKhutoryansky]

I am not sure I understand your question. If you are asking about what happens if their acceleration is only due to the expansion of space, then they will never meet again to compare clocks. Two observers don't need to agree on which of them has aged more, until they meet again to compare their clocks.

[@mikkel715]

@@EugeneKhutoryansky Oh, I fell into this kind of universal time comparison again! Once upon a time I understood Einstein’s Theory of Relativity. Now I have studied it more. Thanks for your answers! Need to watch the last part of your video about Bell’s inequality again I think.

[@eduamart11]

What I don't understand is that initially (after the Big Bang), why does the idea of gravity (pull due to density) seem to be ignored when talking about the expansion of the universe? The vid states that only the area in between the universes are expanding but don't the universes themselves have enough density (at least initially) to keep the expansion from happening?

[@drunkinmaster1]

Awesome video! Where did you source your music from, particularly around the 4:00 mark?

[@EugeneKhutoryansky]

drunkinmaster1 The music at about 4 minutes into the video is a remix of background music from the video game Phantasy Star II. The remix was made by NekoPrism. The other song in this video (the one at the beginning at the end) is another remix made by NekoPrism from a different video game.

[@drunkinmaster1]

I thought that sounded familiar. Seemed to fit the theme nicely. Your quantum mechanics video rocks as well. I've seen the Dr. Quantum videos already, but enjoyed how yours went deeper into detail about the particle rotation. Too bad we never had these illustrations in school.

[@playerscience]

Hey, nice video Eugene. I've something to say... Since the space is expanding, the density of the universe is decreasing, hence even if our UNIVERSE is a sphere, it will eventually become flat and then hyperbolic(saddle shape). Am I right?!?🤔🤔🤔

[@EugeneKhutoryansky]

No, if we live in a universe shaped like a sphere, then it will stay shaped like a sphere, and will not later become flat or like a saddle. This is because a finite universe can't suddenly be transformed into an infinite universe. I am glad you liked my video. Thanks.

[@joost1453]

This video deserves more views

[@EugeneKhutoryansky]

Thanks.

[@VinciSciTech]

Your efforts sees in your video. i loved it. thanks for this beautiful presentation !!

[@DriesduPreez]

Mind-blowing stuff.

[@Matthew00049]

would like an explanation as to why a high density universe causes it to be closed and spherical and a low density universe causes an open, saddle shaped universe

[@ergbudster3333]

The flat plane analogy is absurd. We keep seeing it because it's easy to picture.

[@ominous-omnipresent-they]

Light is electromagnetic radiation, therefore, lightspeed represents the finite speed at which information can travel. It is the cosmic speed limit as far as we can tell.

[@quadrant2012]

Dope music

[@asavvysimpleguy6433]

Since all we can see is "flat"( note the quote marks😊), i.e. solar systems, galaxies, the visable universe, it's not unreasonable to assume the same goes for the infinite universe making a disc shape. (❓) 🤔

[@phoebedemontefalcon1423]

Matter occupies space. Space without matter is like a blank of nothingness. So its really possible that space is either infinit or just round or a loop. Same with our old idea of earth. We never thought that the earth is round

[@alezzanik8166]

Hello,awesome video!! nice job :) I need to ask something though,how is it possible to violate the euclidian geometry with a sphere when the euclidian geometry apply only on flat surfaces?

[@EugeneKhutoryansky]

alez zanik A two dimensional being living on the surface of the sphere wouldn't necessarily start out knowing that the surface is not flat. Therefore, if he started applying Euclidean geometry, he may eventually run into problems.

[@PeterMsk2023]

The infinity of the Universe is supposed to mean the energy (in both life force and inanimate forms), time and space (of these three fundamental elements) infinitely, in all directions. Otherwise, it will create never-ending questions and issues involved, like what the other side will be; what makes them different from each other.

[@nicholasgonzalez]

Good work!

[@EugeneKhutoryansky]

Thanks.

[@Komati]

Awesome video! Dat music though.

[@dougjohnson5033]

The universe expands in space and time. With regard to time, we exist only on the boundary between what existed what does not yet exist. So essentially, we live on the edge of the universe, now.

[@tielojongmans3826]

Distant galaxies recede, a single galaxy stays together because of gravity. Has anyone researched the distance where separation begins? I mean in clusters. Will the Local Cluster stay together forever? And will other clusters? How big can a cluster be to remain together?

[@anom3778]

If you could shrink each star to atom size, how big an object would it make?

[@joseantonioghz4324]

I have a question. you say that the expansion sped is greater than the speed of ligth, but you can't compare velocitys in diferent tangent spaces since two different points posses a different tangent space in which the corresponding velocity live. why you say that? or am I getting wrong something?

[@dd-vz7wy]

Thank you 👍🏻