Will the Universe Expand Forever?

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  • Опубликовано: 25 авг 2024
  • Will the Universe continue to expand outward or will it succumb to gravity and collapse upon itself? Find out in this episode of Space Time. Help us win a Webby Award by voting here: pv.webbyawards...
    Get your own Space Time t-shirt at bit.ly/1QlzoBi
    Tweet at us! @pbsspacetime
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    Help translate our videos! www.youtube.com...
    Throughout history, there has been much speculation about what the fate of the universe would be. Many theorized that the universe would eventually succumb to the pull of gravity, and reverse its expansion in what was being called ‘The Big Crunch.’ However, with the help of mathematical equations from Newton, Einstein, and Alexander Friedmann, we now have an answer.
    Special thanks to NAOJ and the European Southern Observatory for allowing usage of their photo of M83: apod.nasa.gov/a...
    Flourine production in lower mass stars: phys.org/news/2...
    _____________________
    Correction:
    escape velocity = square root of (2GM/r)
    - we accidentally left out the 2
    _____________________
    COMMENTS:
    Henrique Rigitano
    • We Are Star Stuff
    ReVenGe TheRedFireFox
    [deleted]
    Richard van der Linden
    • We Are Star Stuff
    Mason Glaves
    • We Are Star Stuff
    Rod Landaeta
    • We Are Star Stuff
    ______________________
    Written and hosted by Matt O’Dowd
    Made by Kornhaber Brown (www.kornhaberbrown.com)

Комментарии • 1,7 тыс.

  • @DeathsOnTheYAxis
    @DeathsOnTheYAxis 7 лет назад +339

    I think it's so cool that you guys came out with a series that challenges people to get into a bit of the math involved in this. Most of these shows assume that the public knows nothing and will get bored if they see any math, which means you have to create something extremely shallow. I think a large fraction of the public has some interest in the details behind science, and I found this video really exciting.

    • @xeno4162
      @xeno4162 4 года назад +6

      indeed

    • @stauffap
      @stauffap 4 года назад +8

      Exactly. Also it's important to display science realistically, which means that we have to stress the importance and power of math. A lot of things in physics make a lot more sense when you understand the math.

    • @hektor6766
      @hektor6766 2 года назад +4

      I think the dismissal of popular intellectual curiosity and capacity is the most odious, crippling and pervasive bigotry. American employers constantly decry the lack of an educated workforce, using that myth to alienate the populace from academia and to generate labor competition and thus drive down wages, even as they entice and distract society away from that education with cynically visceral commercialism.

  • @markovcd
    @markovcd 8 лет назад +43

    PBS Space Time fucking deserves this award. It's the only show which presents physics in understandable form but they don't dumb it down so much that it creates misconceptions.

  • @nygeek6471
    @nygeek6471 8 лет назад +251

    "You'll look out and only see darkness" can you imagine the future civilization that tries to make sense of their cold surroundings?

    • @pbsspacetime
      @pbsspacetime  8 лет назад +66

      +nygeek64 Before Vesto Slipher's measurement of galaxy redshifts in 1912, the notion of a universe beyond the Milky Way was just an idea. Future denizens of the "Great Space Egg" (the official name of the elliptical galaxy that results from our collision with Andromeda) will presumably assume that this island of stars IS the entire universe. But this is very, very, very far in the future. Even after the distant galaxies have escaped our cosmic event horizon their light will leak down to us for many, many billions of years.

    • @TheMPScott
      @TheMPScott 8 лет назад +19

      +PBS Space Time this is a very interesting idea which I personnaly first heard mentioned by Brian Greene, I can only imagine how unrealistic our current description of a universe teeming with stars and galaxies would sound to a civilization with no evidence other then that we and other potential ancestors would leave behind. Would they believe that our universe was once truly as it appears right now or would the seemingly damning evidence apparent to them be too much to believe the universe truly is more than just their island? Maybe someone or something will find out in a really, really distant future episode of spacetime. ;)

    • @Cythil
      @Cythil 8 лет назад +21

      +nygeek64 You got to wonder what we might be missing hidden from us due to the vastness of time.

    • @LeadHase
      @LeadHase 8 лет назад +2

      +Cythil ie before the big bang

    • @Cythil
      @Cythil 8 лет назад +10

      LeadHase
      Actually you do not have to go even that far. (if there is even such a before time...)
      The earliest time with visible light, the time where the cosmic microwave background was created was 380,000 years after the big bang event. Now we can tell something about the eras before that but it gets harder.
      But beyond that we come to a era where our physics breaks down. The era where we need quantum gravity to make predictions.
      There early eras might actually hide things that we might never know anything about. Though I hope it not beyond our ability to figure out.
      But the tricky thing is... We might never know if there something hiding from us. There might be no trace that it was ever there.

  • @planclops
    @planclops 8 лет назад +402

    With each video, I always feel like my understanding decreases while my interest increases!

    • @AlcyonEldara
      @AlcyonEldara 8 лет назад +13

      +planclops : which is an amazing thing ;) I would find the Universe pretty boring if we could understand it so quickly ;)

    • @freewheeler8924
      @freewheeler8924 5 лет назад +2

      That's because science makes us stoopid.

    • @janniszimbalski6652
      @janniszimbalski6652 5 лет назад +9

      This means your understanding is increasing. :) You are more aware of how much more there is to know.

    • @audience7264
      @audience7264 5 лет назад +7

      The more we know, we realize how little we know, and we must know more.

    • @abstractrussian5562
      @abstractrussian5562 5 лет назад +5

      This is because uncertainty increases throughout your life. Your own heat death is soon.

  • @sithsmasher7685
    @sithsmasher7685 8 лет назад +186

    Wow, I'm not schooled in academic math, but you really dissected that equation for us layman people. Awesome job, Matt. I can't understand the deeper math behind it but at least I can still understand the general mechanics behind the thing. If you keep using effective analogies (since you mentioned Newton can no longer be used then something else?) and break down the math for us like this, I'm sure not many people will get lost. I'm looking forward to the next video.
    I told you before I wanted to understand the general mechanics behind dark energy how it's slowing down the universe doing negative work actually speeds it up. Because questions pop up for me like: "how is that negative work converted into dark energy?" and "doesn't this violate the law of conservation of energy?" and "can this mechanic keep going on forever or will it eventually get 'depleted' since energy should not be infinite?"
    I hope you can keep your creativity going to make it clear. Again keep up the awesome work.

    • @pbsspacetime
      @pbsspacetime  8 лет назад +43

      +Sith Smasher Thanks for the props! Over the next few episodes we're going to do our best to lay out the mechanics of dark energy, and hopefully to do that with the right balance meaningful analogy with the real mathematics. If we get this right it'll be pretty cool.

    • @alexandrugheorghe5610
      @alexandrugheorghe5610 8 лет назад +1

      +PBS Space Time Nice! Voted :-)
      I think when we're at frontiers, all educators should struggle to make the concepts as clear as possible from the point of view of how much we understand, what we do not, and what would be the general ideas in solving these problems. I think it's worth trying to inseminate into the listeners brains that they could start tackling this by questioning at least :-) It'd be pretty amazing.

    • @sithsmasher7685
      @sithsmasher7685 8 лет назад +9

      Alexandru Gheorghe
      The achievement of the 'pbs spacetime' team and its host Matt is that they can bring content that is hard to grasp, closer to the masses. That is something not to be underestimated as it brings about more interest in science from a bigger group of people. We all know if you don't understand something, you don't like it. I hope more people will take physics classes because of this channel. Personally I'd love to study physics and god knows I tried. I have igg3 deficiency which is a chronic shortage of antibodies in the immune system, and also a muscle disease. With that diagnose you know its 'game over' for academic studies. But this channel still brings me knowledge I'm dying to learn. I love it.

    • @drewdavis2392
      @drewdavis2392 8 лет назад +18

      +PBS Space Time Let me add my thanks as well. Let's face it: there are a zillion pop-sci TV programs about cosmology, black holes, etc, and they all stop at the same level of superficial detail. We don't need another one of those. But this channel trusts the viewers enough to go at least one step deeper, and so brings some new and interesting information to the subject, as well as a better understanding of what the more commonly seen qualitative handwaving is actually about. Even with just 10-15 minute segments, you're moving the level of education upward. Please keep it up.

    • @Futch22
      @Futch22 8 лет назад +3

      I agree, I find it very interesting when you break down the math and explain it in depth. would love to see it future episodes!

  • @mouzaalmualla3084
    @mouzaalmualla3084 8 лет назад +41

    I remember when I first started watching your videos, it would take me maybe 30 minutes of pausing and rewinding so I could have an obscure view of what you were talking about-- the concepts were so hard for me to understand. I truly believe your videos have increased my brain's ability to make sense of things, and have kind of been a workout for my mind. I love that you guys don't treat your audience like most of the documentaries out there do, like we don't even have a basic knowledge of physics. It makes your videos that much more fun to watch!

  • @EugeneKhutoryansky
    @EugeneKhutoryansky 8 лет назад +74

    For the annotation you added at 3:10, you may also want to mention this in the video description, as RUclips annotations don't necessarily appear for everyone, or on all devices.

    • @pbsspacetime
      @pbsspacetime  8 лет назад +32

      +Physics Videos by Eugene Khutoryansky Good idea. Done.

    • @feynstein1004
      @feynstein1004 8 лет назад +1

      +Physics Videos by Eugene Khutoryansky Hey Eugene. Looking forward to your next video.

    • @uhbayhue
      @uhbayhue 8 лет назад +1

      thank u for commenting. I immediately went to the comment section to see if anyone else had noticed that the escape velocity formula was wrong, but it makes sense thx to u :)

    • @omsingharjit
      @omsingharjit 6 лет назад

      I heard that the expention rate or speed of Galactic clusters by darkenergy acceleration is extremely faster then lightS , and we know anything that traveling faster then light can travel back in time , so M very curious to know what if I apply this effect with Darkenergy !!!!! mean I think if space between two clusters are expanding by such speed so in this way both galaxys can also creat Time Difference Potential relativity eachother !! or not ??

    • @theminutemenreport8822
      @theminutemenreport8822 2 года назад

      @@pbsspacetime unless expansion rates show the universe is a fibonacci sequence; never begining never ending. Never heard the fibonacci theory anywhere else mabey something to look into??

  • @crater7
    @crater7 8 лет назад +120

    Please continue showing the math behind the ideas you talk about, when possible. It's highly enjoyable!

  • @redimp2028
    @redimp2028 8 лет назад +314

    This is the most frustrating cliffhanger I've every seen since the the end of Half Life 2.

    • @Scrungge
      @Scrungge 8 лет назад +3

      lol

    • @deathpony698
      @deathpony698 8 лет назад +4

      +Arth Freeman play ep1 & most of ep2 bruh

    • @ilaughalot99
      @ilaughalot99 8 лет назад +3

      +deathpony698 why would you do this?

    • @deathpony698
      @deathpony698 8 лет назад

      Mhairi McLaughlin because those snot antlions things

    • @GodOnStrike
      @GodOnStrike 8 лет назад

      +Arth Freeman Walking dead season 6 finale my friend, walking dead season 6.

  • @David_Last_Name
    @David_Last_Name 8 лет назад +73

    When he started talking about the possibility of future generations not being able to see other galaxies, and how that would effect their view of the universe, I couldn't help but be reminded of this: As our sun orbits the Milky Way it will gradually drift through various nebula and gas clouds in the galaxy. It's been estimated that this has happened probably a dozen or so times through Earths history, and it would take the sun millions of years to drift back through the cloud.
    While inside the nebula the gas cloud would block out ALL starlight in the night sky completely. Only the moon and planets in our solar system would still be visible. Now, just picture what this would have done to our civilization had humans appeared during one of these transits. Imagine if for the entirety of human history the night sky had been nothing but blackness with 5 points of light only. Humanity would have thought that our solar system was the entire universe right up until the invention of radio telescopes when we would have gotten our first indication of something outside our own solar system.
    Imagine if one of the most startling discoveries of the 20th century was not the discovery of dark matter or the expansion of the universe, but rather just the discovery that other stars exist!! Human history would have been VASTLY different. Just some food for thought!! :)

    • @extendoduck
      @extendoduck 5 лет назад +17

      David, you should check out the classic novel Nightfall by Isaac Asimov. Not quite the same premise, but the same effect: it describes a planet in a close-multiple star system so that full night only occurs once in several thousand years. One plotline deals with someone trying to figure out an explanation for this, and the effects when he discovers that there are other planets via their gravitational effects.

    • @someguy3766
      @someguy3766 5 лет назад +12

      Also consider this - humanity could go extinct within the next century. Trillions of years into the future, our cosmic horizon will prevent us from seeing other galaxies and even cosmic background microwaves. An alien civilisation could arise during this time, and could become significantly more advanced than us if they manage to avoid extinction and colonise the galaxy. And yet, because of the expansion of spacetime, they would know significantly less about the universe than we do now. Even as a K3 civilisation their understanding of the universe and physics would be inferior to 21st century humanity.

    • @jdkhare
      @jdkhare 4 года назад +1

      Look up the planet Krikkit in the Hitchhiker's Guide. Pretty much the same premise.

    • @garyliu6589
      @garyliu6589 4 года назад +1

      1. If light from a distant big bang is reaching earth observer, then the earth observer is not travelling away at light speed, otherwise the emitted light will not be able to catch up with the observer. (observer moving away from light source due to the proposed universe expansion after big bang)
      Thus, the universe is not expanding at light speed, &/or earth is not coming from the big bang that is being observed. The universe is not expanding or collapsing as a whole, may be some part is expanding, some is collapsing, some is neither. Like a collection of bubbles, some burst, some expanding, some don.
      Actually the mathematical model of the universe suggested this 3 possibilities are possible.
      2. Is ALL superclusters moving away from each other? We should not deduce the expansion if only SOME are observed moving away. May be we should look for the possibilities of superclusters closing in to each other.
      The golden rule of energy is, what goes up must come back down. Natural process is always work in a circle. Since energy cannot be created nor destroyed, it must always cycle in a circle.

    • @AliceHearthrow
      @AliceHearthrow 4 года назад +2

      @@garyliu6589 1. You can observe objects that you know are moving away at a faster than light speed, so long as its light which is now reaching you was emitted when it was not superluminal. And since the big bang happened everywhere and the light from that period is scattered everywhere, you will always be able to see it no matter its current speed (well actually at some point in the far it will be redshifted too much to be detected, but I digress)
      2. Some are indeed closing in on each other, but only those close enough to each other for their common gravitational attraction to counteract the expansion of spacetime, and it is completely expected.
      Also to that last golden rule bit: dark energy cheats a little bit, because it does actually create energy from its supposed field. Matt talked about in a semi-recent video though I don't remember which one. It was something to do with the fact that the conservation of energy must be preserved in a closed system, but that the universe wasn't really a closed system in that way, iirc.

  • @andrewtataj497
    @andrewtataj497 8 лет назад +10

    I'll vote for ya. Honestly, I watch a lot of these science-y type channels and yours really does stand out because you tend to go into more depth of the mathematics and physics of the scenarios you're describing. Yes, you still give just an overview, but even in this one, showing the form of the equation is enough to gain an appreciation for all the forces involved. It's always very well done, so please don't shy away from the details, it's the thing I love most about your channel!

    • @DiegoLopez-eo7xn
      @DiegoLopez-eo7xn 8 лет назад +1

      +Andrew Tataj You're absolutely right. They don't get too deep into the maths but they do try to make you at least understand the concept of it, or what it means. I love this channel because unlike others they have some really interesting topics.

    • @frankschneider6156
      @frankschneider6156 8 лет назад +2

      +Andrew Tataj
      Absolutely agree, i guess that's their USP

  • @garyfoster1020
    @garyfoster1020 4 года назад +7

    first episode I've seen with math.... as an engineering person, I would really LOVE to see more explanations with the equations. I can fathom a decent amount of the concepts but I've never been introduced to the math behind it and I'm very curious! It would probably help me understand some of the harder concepts

  • @trader025
    @trader025 8 лет назад +33

    Hands down ... best show there is in this field.

    • @winter32842
      @winter32842 8 лет назад +2

      +trader025 Go Vote. We are in second place.

  • @frankschneider6156
    @frankschneider6156 8 лет назад +8

    +PBS Space Time
    Hi, I just wanted to give you credit for actually getting into formulas and not shying away from them. I'm pretty sure that that's an issue you have intensively discussed internally, and it will cost you views, so kudos to you for sticking to it (albeit in an obviously easily digestible form).

  • @Fsilone
    @Fsilone 5 лет назад +11

    Darn, I was a big fan of the idea of the entire universe collapsing into one final singularity.

  • @hamedabidi36
    @hamedabidi36 8 лет назад +8

    "the universe will expand forever" is a bold statement but it certainly looks to be the most likely outcome. I'm not sad , in fact i find it amazing that we're sitting here trying to predict how the future would look like in a quadrillion trillion years .That is what's so great about humanity.

    • @jettmthebluedragon
      @jettmthebluedragon 2 года назад +1

      That may be but forever means forever 😐 so how are we living right now ?🤔 if the universe were to expand forever you might as well say earth would have never formed in the first place 😐and what was before the expansion 🤔? What caused the expansion in the first place 🤔and why are we not dead in the first place 😑

  • @terrencecoccoli524
    @terrencecoccoli524 8 лет назад +4

    It's amazing how you and your team can explain this in a language that we science plebes can understand. Thanks for making science more accessible.

  • @booJay
    @booJay 8 лет назад +44

    Quit being amazing, Science, or I will learn the crap out of you. Don't think I won't!

  • @JSKiZZinQflat
    @JSKiZZinQflat 8 лет назад +14

    Voyager's cameo at 8:46- 9:40

  • @MeatPops
    @MeatPops 8 лет назад +3

    Thanks again for an amazing video! I'm so glad you guys are bringing actual equations out and explaining them for us. I'm a total layman when it comes to physics but I really enjoy trying to wrap my head around this stuff!

  • @CarrotSurvivor
    @CarrotSurvivor 8 лет назад +16

    You don't understand how much I love this channel

    • @cortster12
      @cortster12 8 лет назад

      +Carrot Survivor I think I do.

  • @piplupsingularity
    @piplupsingularity 5 лет назад +6

    "If the kinetic energy of expansion and the potential energy of collapse are perfectly balanced"
    As all things should be.

  • @MrKandelion
    @MrKandelion 8 лет назад

    this channel is truly something special. no joke, I often sit down and watch like 5-6 videos from this channel. I've watched all the videos about black holes like 100 times. You guys do a great job conceptualizing these complicated topics and I will have my mind blown over and over again when I watch this channel. THANK YOU

  • @JackChappers
    @JackChappers 8 лет назад +1

    Please never stop making these videos they're what the world needs

  • @RaimarLunardi
    @RaimarLunardi 8 лет назад +60

    Best Channel in the Whole internet!!!!

    • @alderleyva1755
      @alderleyva1755 8 лет назад +3

      +Raimar Lunardi dont forget Veritasium and all of the Vsauce channels

    • @EnkeEnkhtsogt
      @EnkeEnkhtsogt 8 лет назад +2

      +Raimar Lunardi Sixty Symbols is nice too

    • @alexandrugheorghe5610
      @alexandrugheorghe5610 8 лет назад +1

      None come close to this one :D Maybe Eugene's videos on physics.

    • @RaimarLunardi
      @RaimarLunardi 8 лет назад +2

      I love Veritasium, Sixty Symbols, Numberphile, Vsauce, It's Okey to be Smart, Kursgesagt and many others!
      But Space Time is The Best, hands down!!!!

    • @jingchaoye
      @jingchaoye 6 лет назад

      if we are the only species in the universe, then it's the best channel in the whole universe.

  • @silicalnz3008
    @silicalnz3008 8 лет назад +54

    For some reason I was expecting a "yes" or "no" answer

    • @garethdean6382
      @garethdean6382 8 лет назад +3

      +SilicalNZ It was a yes, just a long-winded one.

    • @silicalnz3008
      @silicalnz3008 8 лет назад

      spoilers

    • @oonmm
      @oonmm 8 лет назад +1

      That would be to limit yourself to only two answears, when you could have infinitely many!

    • @silicalnz3008
      @silicalnz3008 8 лет назад

      Oh jeez, don't remind me of shakees video

    • @studtistics2448
      @studtistics2448 6 лет назад

      So the universe will expand forever but it will eternally slow down?

  • @shahaed
    @shahaed 5 лет назад +2

    Nice video! Explaining the math without too much handwaving was cool

  • @buya3671
    @buya3671 5 лет назад +1

    I have noticed that the episodes in this series average between 12 and 13 minutes. Just long enough to watch without you head exploding.

  • @andreguimaraes9347
    @andreguimaraes9347 8 лет назад +39

    8:52 is that the Voyager probe in the background?

    • @pbsspacetime
      @pbsspacetime  8 лет назад +4

      +André Reis Good eye, André!

    • @andreguimaraes9347
      @andreguimaraes9347 8 лет назад

      Thanks! :D

    • @ryonhovey4450
      @ryonhovey4450 8 лет назад

      +PBS Space Time I noticed that, at first I thought it wasn't intentional for some reason...

    • @Grzyb032
      @Grzyb032 8 лет назад

      +André Reis Damm it! I was about to comment on that!

  • @cilvrado
    @cilvrado 8 лет назад +5

    Guys, don't forget to vote for the Webby nomination. Go Spacetime!!

  • @AngeloBrillante
    @AngeloBrillante 8 лет назад +8

    At 3:09 you're missing a 2 in the Escape Velocity formula :)

    • @pbsspacetime
      @pbsspacetime  8 лет назад +3

      +Angelo Brillante Oops, thanks for catching that. Annotation added!

    • @AngeloBrillante
      @AngeloBrillante 8 лет назад

      My pleasure!

    • @SRNF
      @SRNF 8 лет назад

      +Angelo Brillante

  • @markfudge5642
    @markfudge5642 8 лет назад +1

    I would like to thank you, lets just say that my education was limited and now in my 40's I am trying to educate myself. Though watching is like emptying a sinking ship with a spoon, I always understand the points made, even if I don't understand the maths. I love watching these and until today had thought that the universe would end in the big crunch, leading to another big bang. kinda like an extra life in a video game. So thank you, you have enriched a subject I have always been interested in.

  • @Keysforjourney
    @Keysforjourney 8 лет назад +8

    if the answer is the big crunch, then we will meet here again after death to prepare for our birth.

  • @nicosmind3
    @nicosmind3 8 лет назад +6

    4 views and 25 thumbs up. Thats how amazing this channel is. It breaks RUclips!! And with the spirit we can break GR and the speed of light barrier. Well done rule breakers. One rule at a time :)

    • @maj.peppers3332
      @maj.peppers3332 8 лет назад +1

      +nicosmind3 now looking at 342 likes and 4 views :P

    • @studtistics2448
      @studtistics2448 6 лет назад

      But the speed of light is a law. :)

  • @sigmagx8956
    @sigmagx8956 8 лет назад +1

    I've never been so happy to have an explaination of the GR equations . Everyone thinks everyone else is stupid. But you take us seriously and say we will get through this trust me ... That's why I watch this show , aside from loving physics

  • @daclarooftw
    @daclarooftw 8 лет назад +1

    no words the editing the amazing narrator. everything is perfect. I'm currently studying physics and this is wonderful

  • @VoyagesIntoImagination
    @VoyagesIntoImagination 8 лет назад +4

    I would like to see more of this kind of exploration of the math in future episodes.

  • @Memoonk
    @Memoonk 8 лет назад +3

    I must say you guys are getting better at explaining things. Great work 👍

    • @sithsmasher7685
      @sithsmasher7685 8 лет назад

      +Memoon Khan Yeah and then some. The very first video on relativity with Gabe really freaked me out. He didn't explain the spacetime interval equation and I quickly got lost when he started about that minus sign. Above video shows how it should be done.

  • @Azombiebaby
    @Azombiebaby 8 лет назад +1

    I don't understand the calculations or technical side of this stuff but I do enjoy watching the videos :) I've put in my vote for you guys.

  • @VisualBRON
    @VisualBRON 6 лет назад +1

    I've got so many questions about the expansion .... If space is expanding, does that mean that the density of space is reducing? If the galaxies are separating ... are the individual atoms separating too? How about subatomic distances? ... is the plank length expanding? What about causality ... if the plank length is expanding, does causality take the same amount of time to leap a unit of length? Is the radius of the earth expanding? Is the earth bigger now then when it was first formed? If we're expanding with them, does this mean that the first cells (though containing the same number of atoms) were smaller than their current day equivalent? So which measurements DO change with this expansion?

  • @NATESOR
    @NATESOR 8 лет назад +26

    that pocket is incredibly distracting

  • @6Twisted
    @6Twisted 8 лет назад +3

    I wish I could come back in 1000 years to know the answers to these questions, provided we're still around at that point. Interesting t-shirt design by the way...

  • @airplayn
    @airplayn 8 лет назад

    Voyager coasting across the galaxy in the background was a nice super nerdy touch.

  • @MaryAnnNytowl
    @MaryAnnNytowl 3 года назад

    I hope I'm not the only one that appreciates the Star Trek sound effects you guys sneak in to these videos! 😁 And I DO appreciate them! My ears always perk up when I hear one!
    Also, though I don't _quite_ always understand the maths involved in these videos (okay, TBH, I seldom understand all of it, LOL!), I enjoy them tremendously, anyway! Thank you for what you do!

  • @MrMakae90
    @MrMakae90 8 лет назад +4

    Can't wait for the other videos of this series.

  • @MrCristie1
    @MrCristie1 8 лет назад +9

    can you do more videos like this. It was enjoyable with the little bit of math

  • @vikramvirulkar4616
    @vikramvirulkar4616 8 лет назад +1

    Amazing episode! Best explanation for the expanding universe so far! Keep doing what you are doing, you are making a lot of people really happy!

  • @harrygreenaway8003
    @harrygreenaway8003 8 лет назад +1

    I don't understand 80% of the things you say, but I love it and hope I can be like this one day, (seriously) keep up the good work ☺

  • @winter32842
    @winter32842 8 лет назад +5

    I voted. This is my favorite science channel because I learn so much (other channels usually repeat same interesting facts). Go vote, we are in second place.

  • @cbremer83
    @cbremer83 8 лет назад +4

    Cliffhanger ending on The Walking Dead. Cliffhanger ending on Spacetime. At least I only have to wait a week to wrap up this one.

  • @AlexanderDockham
    @AlexanderDockham 8 лет назад +1

    i may not understand most of what is said, but i finally understand escape velocity... so that's a start

  • @RedJonathon719
    @RedJonathon719 8 лет назад

    You explain things so well
    1. Khan Academy
    2. PBS Spacetime
    3. Crash Course
    4. Physics Videos By Eugene
    5. Scishow
    Yes, I do think that Scishow (especially Hank Green) could make an improvement in their -"How confusing their videos are (just a little bit, no offence),"

  • @sueken22able
    @sueken22able 8 лет назад +4

    8:46 - 9:12 was that Voyager 2 Cruising by, in the cosmic background? Haha.

  • @JTCGiantz56
    @JTCGiantz56 8 лет назад +8

    Damn you got a hell of an arm

  • @Piffsnow
    @Piffsnow 8 лет назад +1

    I didn't understand everything, but I enjoyed the formulas' explanations.
    We don't see that often on RUclips, so thank you. :)

  • @pedroassis2777
    @pedroassis2777 8 лет назад

    I just realized I miss your episodes much more than I do for Walking Dead or other TV shows.
    Awesome work.

  • @gerrimcdonnell6333
    @gerrimcdonnell6333 8 лет назад +53

    4 views but 220 likes lol

    • @Chrisallengallery
      @Chrisallengallery 8 лет назад +36

      They've broken the space-time continuum.

    • @ozdergekko
      @ozdergekko 8 лет назад +1

      +Gerri Mcdonnell -- early access for patreons?

  • @n1ira
    @n1ira 8 лет назад +4

    plot twist, the equations are wrong and there is no dark energy

  • @anissnoussi8991
    @anissnoussi8991 7 лет назад

    I'm barely understanding these videos! yet they are very well made that I can't stop watching!

  • @too-hot-to-handle01
    @too-hot-to-handle01 8 лет назад

    Also, just because, you have the most mind blowing RUclips channel of which I could think of. Thank you for letting me have something to definitely look forward to every week.

  • @dschonsie
    @dschonsie 8 лет назад +159

    My belly does, so why not the universe?

    • @muuundotarde7914
      @muuundotarde7914 6 лет назад +7

      dschonsie beacuse the american goverment does not funnel macdonalds into space,
      Lets pray they never do.

    • @howaboutno5569
      @howaboutno5569 6 лет назад +2

      There will come a point of a heart attack

    • @manit77
      @manit77 5 лет назад +1

      Do you de-gas in the morning

    • @kadavropodden
      @kadavropodden 5 лет назад +2

      Ass above, so belly.

  • @megasupergames
    @megasupergames 7 лет назад +5

    Red shifting: So the space expansion is somehow extending the photon's wavelength to the point they actually become less energetic than they were at the start of their journey. Question: Where's all that energy going to?

    • @tararat
      @tararat 5 лет назад

      Photons getting DARK. Where goes the ENERGY?

    • @scienceguy6918
      @scienceguy6918 3 года назад +1

      Good question. I was actually thinking about this today. My thought is that the energy doesn’t go anywhere. It’s more the idea that the energy is spread out, instead of concentrated.

  • @RafaelSoaresTorres
    @RafaelSoaresTorres 8 лет назад

    I just saw a ten-minute video on complicated Physical Mathematics, and it seemed so short and simple! Dudes, I really love spending my productive time watching you! Thanks and thanks again!

  • @Mcbeth700
    @Mcbeth700 8 лет назад

    PLEASE NEVER STOP MAKING THESE! I need my Space

  • @palniok
    @palniok 8 лет назад +9

    Dat Voyager. :)

  • @panshulpant2433
    @panshulpant2433 8 лет назад +11

    At 3:10 the formula for escape velocity should have a '2' inside the square root if I am not wrong...ie.., V=sq.root of 2*GM/R.

    • @pbsspacetime
      @pbsspacetime  8 лет назад +13

      +Panshul Pant You're absolutely right. Annotation added.

    • @panshulpant2433
      @panshulpant2433 8 лет назад +1

      +PBS Space Time Thanks for taking a note of it Sir . All your videos are Fantastic.! Greetings from India...:)

    • @lordgarion514
      @lordgarion514 6 лет назад

      aa
      First of all, he's not a pseudo anything.
      Secondly, they thanked him right after he posted it, 19 months before your dumbass posted your stupid shit.
      Try reading next time.

    • @ethanfranzen8684
      @ethanfranzen8684 5 лет назад

      Without the 2, it is circular orbital velocity.

  • @alstud1
    @alstud1 8 лет назад

    Gave ya an upvote on the webbyawards, everyone go cast a vote, take less than a minute, and get this awesome channel out in front where it belongs (though I do enjoy 2 of the other 4 shows on there as well).

  • @CosmicNous
    @CosmicNous 6 лет назад

    I love how the Voyager spacecraft just passes by in the background.

  • @Hecatonicosachoron
    @Hecatonicosachoron 8 лет назад +4

    I often hear it said that the Einstein equations (including a cosmological constant) are the *only* consistent generally covariant equations linking geometry with stress/energy and also contain only up to 2nd order derivatives of the metric tensor. Who was it that proved that and when was it proven?
    Is it the only one because stringing together the metric tensor with itself several times it will contract to a unit tensor?
    Also is it not the case that if physical spacetime is not Riemannian (but can be modelled very well as one on all length scales that can be readily probed) then some very surprising things may be possible?

  • @ozdergekko
    @ozdergekko 8 лет назад +7

    It was a hard decision between PBS and Veritasium. PBS got my vote because of Space Time and the versatility with nice shows like PhysicsGirl, Gross Science and more.

  • @friedelmajoor8469
    @friedelmajoor8469 8 лет назад

    Space, the final frontier. These are the episodes of pbs Space Time. It's mission: To explain strange new worlds and to boldly go were no one has gone before!

  • @MindCraft4You
    @MindCraft4You 8 лет назад

    Stuff like this makes me want to become a mathematician that just derives important formulas but I don't know if there will be that many cool ones left. Awesome video

  • @TSMK900
    @TSMK900 8 лет назад +4

    Will you also be releasing a blooper video of when you dropped that apple at 2:42? I know you dropped it :p

  • @lokynokey4822
    @lokynokey4822 7 лет назад +3

    8:48 Do you think we wouldn't notice?

  • @evanstone2015
    @evanstone2015 8 лет назад

    I don't usually subscribe to RUclips Channels, but when I do, I subscribe to PBS Space Time. You guys are awesome!

  • @ibrahimalsamak5268
    @ibrahimalsamak5268 8 лет назад

    I'm in my last year in high school and I going to study physics at university and this channel is why I choose physics, very big thanks to you

  • @emmacloud4739
    @emmacloud4739 8 лет назад +8

    The universe on its largest scale looks like a neuron...

    • @JoshuaGilmer
      @JoshuaGilmer 8 лет назад +6

      +Emma Cloud I remember learning that on a large enough scale, everything looks like a sponge.

  • @astroash2697
    @astroash2697 8 лет назад +3

    Expansion may slow down, stop, reverse, but the Universe will never end. Just in case, it comes with a reset button.

  • @NeonsStyleHD
    @NeonsStyleHD 8 лет назад

    The thing I love about his series, is I have this book called The Road to Reality by Roger Penrose, which is about the beauty in the physics by expaining the Maths. However it's incredibly complex, and you really need to know a lot about Maths to understand it. With whoever is the writer of this show is; he explains the math in such a succinct way, that I can read an understand the book. Thanks.

  • @stevehillier8480
    @stevehillier8480 8 лет назад +1

    Voted, good luck guys - favourite RUclips channel. Get on and vote people!!

  • @JasonOwlbright
    @JasonOwlbright 8 лет назад +9

    I HAVE SOO MANY QUESTIONS..

    • @morningmadera
      @morningmadera 8 лет назад

      +Jason Owlbright
      post some of them, maybe I can help with some answers ...

    • @frankschneider6156
      @frankschneider6156 8 лет назад

      +CeaoS
      Why did they cast Gal Gadot and not The Rock as Wonder Woman ?

    • @morningmadera
      @morningmadera 8 лет назад

      Frank Schneider
      Because of the Higgs field ...

  • @bagandtag4391
    @bagandtag4391 8 лет назад +5

    I would ask a deep question but I barely grasped what he was talking about Q_Q

  • @dejayrezme8617
    @dejayrezme8617 6 лет назад

    Sibling stars... that is a beautiful idea. Somewhere lost in the galaxy are star systems that share a common ancestry to us and maybe have similar compositions of matter.

  • @NickRoman
    @NickRoman 8 лет назад +2

    I immediately went to vote on the Webby. This channel is awesome!

  • @dann6954
    @dann6954 8 лет назад +3

    This is off topic but what would happen if someone was near a black hole and was experiencing time dilation that, say, made 1 hour for the person near it = 20 years for someone not being affected by the time dilation, tried to use radio communication to talk to the person far enough away to not be experiencing it?

    • @MCTutorialmaker
      @MCTutorialmaker 8 лет назад

      Should be nothing special.. The radio waves would travel at the speed of light to the person outside this heavy time dialation zone and this person will receive the message when these radio waves arrive.. Though their relative velocity to any one of the persons should change over time as they move away from the black whole.. What you have in mind as a direct radio communication only works at very small distances.. It's basicly still the sending and receiving of radio waves travelling at the speed of light

    • @williamjones1271
      @williamjones1271 8 лет назад

      +Robin Ansorge (Rob24) but still the base oscillation of the time dilated region should be red shifted as to related to the proportion of time dilation, so a 1hr message from the dilated region would take 20yrs to receive and be audibly proportionate , making any form of information transfer tedious.

    • @MCTutorialmaker
      @MCTutorialmaker 8 лет назад

      +William Jones right.. The received message would be kind of stretched out

    • @dann6954
      @dann6954 8 лет назад

      +William Jones Interesting, thanks for the answer!

  • @ahorrell
    @ahorrell 8 лет назад +5

    Them: "We'll need to peer into the mathematics"
    Me: "Aaaaaaarrrrghhhhhhh nooooooooooo I'm so stuuuuupid"

  • @Xenro66
    @Xenro66 8 лет назад

    Every single time I see the zooming out effect at 4:35, I keep thinking "maybe this is quantum foam to a larger universe?", and then start thinking that if we keep zooming IN on something we will see this sort of pattern, and zooming in further will reveal clusters and whatnot. It just intrigues me.

  • @iamjimgroth
    @iamjimgroth 8 лет назад +1

    This is my favourite channel and I just realised I wasn't subscribed to it. Too bad that didn't mean I had missed any episodes.

  • @PinkBroBlueRope
    @PinkBroBlueRope 8 лет назад +6

    under serious pressure here to think of something witty so i can become one of the top comments

    • @ouderwetsss
      @ouderwetsss 8 лет назад

      Society is hard, i feel you

  • @thetruthfulchannel6348
    @thetruthfulchannel6348 8 лет назад +5

    I will outlive the universe.

    • @whiteautumn3167
      @whiteautumn3167 8 лет назад

      +The Truthful Channel
      Sure

    • @uhbayhue
      @uhbayhue 8 лет назад +5

      good luck buddy

    • @Ryan-xo8fj
      @Ryan-xo8fj 8 лет назад

      Good luck getting past the time of time itself.

    • @kobil316SH
      @kobil316SH 8 лет назад +2

      +The Truthful Channel mee too, so far so good

  • @deusexaethera
    @deusexaethera 5 лет назад +1

    In some other universe that has no dark energy and is expanding at exactly its escape velocity, a physicist is recording an educational video. He is discussing the possible implications of a universe that does have dark energy and is thus slowly tearing itself apart, and laments at the grim future faced by any life that might exist there.

  • @martinphipps2
    @martinphipps2 4 года назад

    I kind of wish my RUclips algorithm didn't order videos based on topic. This is my tenth video in a row about the cosmological constant.

  • @Eassstt
    @Eassstt 7 лет назад +3

    Guys please name the songs you use

    • @MrCrystalm8
      @MrCrystalm8 7 лет назад

      Too many channels out there never bother to name the music they use, it can be frustrating.

  • @ShynyMagikarp
    @ShynyMagikarp 8 лет назад +3

    This is based upon the homogeneity of the universe.. don't things like the Sloan Great Wall and the Hercules-Corona Borealis Great Wall call these types of assertions into question though?

    • @kobil316SH
      @kobil316SH 8 лет назад +2

      +Lilz kinda

    • @mcarp555
      @mcarp555 8 лет назад

      +Lilz No, because over the expanse of the Universe, even those huge structures don't amount to much. It's like saying the density of an eyelash in a swimming pool should change the overall homogeneity of the pool.

    • @ShynyMagikarp
      @ShynyMagikarp 8 лет назад

      +mcarp555 I'm not sure you understand that I'm not the one suggesting this. Professional cosmologists are suggesting this now too. Not me. Them. I'm just asking how he can bring up the topic without making any mention of them?

    • @tonywells7512
      @tonywells7512 8 лет назад

      +Lilz At the moment cosmologists can only speculate about whether these huge structures need an explanation beyond what is already known, or whether they are just a coincidental arrangement of structures which fit the model. We need to wait for more data across bigger slices of space, there are several surveys being planned to measure the distances to billions of galaxies across half the sky.

    • @ShynyMagikarp
      @ShynyMagikarp 8 лет назад

      +Tony Wells yeah. As of right now it's known whether these super structures obey our understanding of the large scale universe (cosmological principle) or defy our understanding, i just think that it was weird to make no mention of it at all in this video.

  • @JACK-ze8rp
    @JACK-ze8rp 8 лет назад

    brilliant episode again , always watch these before bed so I can have space dreams , now its going to be a big rip nightmare, thanks anyway space time

  • @bharathtej2426
    @bharathtej2426 8 лет назад

    Voted! But you don't need a competition to prove you are good! You indeed are the best! A Mystic like me is now understanding astrophysics with utmost ease!

  • @Afrojackfan
    @Afrojackfan 8 лет назад +128

    HEY PBS
    Could you make a Video to the Flat Earthers im really really really tired of them.
    greetings from germany

    • @gmddeathangel3008
      @gmddeathangel3008 8 лет назад +2

      +Bimmer Mike They probably wont for a long time.

    • @Afrojackfan
      @Afrojackfan 8 лет назад

      +GMD DeathAngel why?

    • @gmddeathangel3008
      @gmddeathangel3008 8 лет назад +1

      Bimmer Mike Because they already plan their schedule a month ahead.

    • @Afrojackfan
      @Afrojackfan 8 лет назад

      +GMD DeathAngel ah ok yeah i know but in a Distant future it doesnt matter when :D

    • @pbsspacetime
      @pbsspacetime  8 лет назад +42

      +Bimmer Mike We have some plans, yeah. In the meantime there's this: ruclips.net/video/Aj6Kc1mvsdo/видео.html and VSauce nailed it with this one: ruclips.net/video/VNqNnUJVcVs/видео.html

  • @rashaadhudson1
    @rashaadhudson1 8 лет назад +6

    94 likes 4 views RUclips Logic

    • @garethdean6382
      @garethdean6382 8 лет назад +1

      +Chronickilla Spambots can spam view videos, so views are scanned and processed, this takes time. Likes are just added since you can't spam them.

  • @MythicalSkull13
    @MythicalSkull13 8 лет назад

    This is one of my favourite channels on RUclips, yet I've never fully understood a single video

  • @xBaDaBiNgx
    @xBaDaBiNgx 8 лет назад

    It really grinds my gears how his right shoulder hangs slightly lower than his left!!!