Scale of the galaxy | Scale of the universe | Cosmology & Astronomy | Khan Academy

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  • Опубліковано 21 гру 2024

КОМЕНТАРІ • 147

  • @BlackBeardDelight187
    @BlackBeardDelight187 13 років тому +2

    80,000 years to Alpha C! Imagine, by that time we would be a different species!

  • @canozanyilmaz5083
    @canozanyilmaz5083 11 років тому +7

    BILLIOOOON

  • @PopArt
    @PopArt 14 років тому

    Sal, thanks for loading these up with scale comparisons and analogies. We are not equipped to appreciate the massively large and super-small without analogy. I wish you could bring a 3D animator onboard at the Khan Academy to assist with presentations like this (better visuals in this case would really serve to strengthen analogies and provide a nice smooth transition from one scale to the next.) Great stuff!

  • @BlairSantos
    @BlairSantos 14 років тому

    It's just Literally Unthinkable.... Our TINY little brain would blow up if it ever tried to "get the picture"... Great video. Tnx

  • @derbigpr500
    @derbigpr500 13 років тому

    Another thing is, even though we are so incredibly tiny in galactic terms, we're still incredibly huge compared to stuff like atoms. Its really incredible how extreme scales and sizes in universe are.

  • @Iwantamansonguitar
    @Iwantamansonguitar 14 років тому +1

    @9:05 Supermassive Black Hoooole!

  • @derbigpr500
    @derbigpr500 13 років тому

    What the most amazing thing is that looking up at the sky you look into the past. Every single star (or light coming from the star) that we see, we see as it was in the past, very distant past. And looking pictures or other galaxies or pictures like deep field is just absolutely amazing. Knowing that right now, at this moment, there are trillions and trillions of other planets out there, with billions of creatures and different life forms on them..most of whom wonder if they're alone...

  • @CatholicMomof9
    @CatholicMomof9 12 років тому

    Science PROVES there is a God- no other explanation than a hugely intelligent Being creating the complexities we call our world and galaxy.... And an amazing God indeed- So much to learn in such a short 100 years (if we are lucky) on earth! :) God bless-

  • @drfoxcourt
    @drfoxcourt 14 років тому

    THanks for this video. One of the greatest problems confronting young learners is the scales involved in space, the atomic scale and geologic time.

  • @emmkayel
    @emmkayel 11 років тому

    We are arguing the same point here. The original comment said that the universe wasn't big - we are small. I'm saying that it depends what side you're looking at it from. If you're looking from the 5 ft building - then the 3 ft building is small. If you're standing on the 3 ft building then it's the 5 ft building that's big. Same thing with the universe/earth. The only people who could assume that the 4 ft building is medium are standing on the 4 ft building - have a standard for big and small.

  • @Melthornal
    @Melthornal 14 років тому

    Sal, I was thinking about the size and distances of stars yesterday morning (and it was pretty coincidental that you posted these videos a few hours later) and there is one little thing you may want to consider (it may help in blowing your mind, I don't know). Earth is traveling about 30,000 km/s. If you were to move 30,000km/s it would take about 40 years to get to Alpha Centouri. 4.2 light years is VERY far, but we manage to travel this far throughout our life span!

  • @SanjeetPadhy
    @SanjeetPadhy 9 років тому +4

    Insignificant?That's understating how small we are in comparison to the galaxy.

  • @emersonsmith0085
    @emersonsmith0085 11 років тому

    this guy gave one of the best explanations so far i heard off.
    my question is on those 1000 light years part, how many stars are there?? how do we calculate, multily 1000 *1000 * 1000 to get the volume , than divide by 5/4???

  • @imnota6
    @imnota6 11 років тому

    Size is relative. If we were the size of a group of super clusters, it'd seem less big than how it appears to us now.

  • @requshei
    @requshei 13 років тому

    When scientists depict the image of our galaxy like the one in this video, do they calclulate where they are now by calculating their trajectory or use the images they recieve of them of where they were thousands of years ago??

  • @SGRblink
    @SGRblink 13 років тому

    It`s not that the Universe is so big , it`s just that we are all so small !!!!!!!!!!

  • @imnota6
    @imnota6 11 років тому

    I don't get what you mean... "big" and "small" alone are not measurements, you're right... But that's my point. Without one, the other is just a perception as you put it. But if you have two examples, one big and one small, or medium, or whatever you wish that is different from the other object size-wise, than it creates a complete measurement tool. If I said a 5 foot building is big, and a 3 foot building is small, you can automatically assume a 4 foot building is medium.

  • @imnota6
    @imnota6 11 років тому

    I agree with everything but your last point. Even standing on a 5 ft building, and seeing a 3 ft building and 4 ft building, you can tell 4 ft is medium because 3 ft is smaller than 4ft, automatically meaning 4 ft is not the largest, but not the smallest (a.k.a Medium)

  • @amcbirds
    @amcbirds 14 років тому

    i never thought god could create all this by himself !!!!!!!!!!!!!

  • @ratuliut
    @ratuliut 14 років тому

    Even after finishing this video, it takes couple of minutes to response....Simply there is no word to describe the size of this universe. What the hell!

  • @jpr422
    @jpr422 13 років тому

    @blardosplats Are you talking in terms of our impact on the universe (or our understanding of it) and the world we live in?

  • @emmkayel
    @emmkayel 11 років тому

    Is size relative? It is a measurable, observable, mathematically provable truth. Is it not more that we relate to size from a particular perspective and thus it is our understanding of size that is relative? In which case, both SGRblink's and my comment would be equally applicable because we are approaching the understanding from competing perspectives - neither one of which is measurable, observable or mathematically provable.

  • @fob199
    @fob199 14 років тому

    Khan makes me love learning :D

  • @redjr242
    @redjr242 14 років тому

    This video really reminds me of the short movie: "Powers of Ten" which talks about relative sizes and distances in the universe like this khanacademy video. You guys should really Powers of Ten, thumbs up so people know. =D

  • @Goproflying
    @Goproflying 14 років тому

    ERROR: At 11:05 you compared the Oort cloud with the size of the Universe, you clearly meant the Galaxy hence 1mm ~ 100m.
    If the Oort cloud = 1 light year = 1mm in diameter, and the visible Universe is 13.7 billion light years in radius (27.4 billion light year diameter), then on that scale the visible Universe would be 17,029 miles wide (2.1 times the diameter of Earth.

  • @emersonsmith0085
    @emersonsmith0085 11 років тому

    to calculate the number of stars, we need to to know the dimater of the spiral , the lengh, and the deep high and botton. from there, we can calculate.

  • @emmkayel
    @emmkayel 11 років тому +1

    No. It's that the Universe is mind bogglingly, largely, enormously, gigantically, brain twistingly big.

  • @GonzaloBelascuen
    @GonzaloBelascuen 14 років тому

    7:27 his mind blew up LOL

  • @MsWatcheverything
    @MsWatcheverything 13 років тому

    SubhanAllah God is The Creator of all things. He is OUTSIDE of his own creation(including the concept of time) Imagine how big HE is!!! Yet people remain arrogant ....

  • @Th30Hacker
    @Th30Hacker 14 років тому

    This is AMAZING!
    I'm watching the whole "scale" series that your posting :D
    very interesting and mind blowing

  • @RubberOnRock
    @RubberOnRock 11 років тому

    Great video Sal, there is something positively fantastic about learning maths and physics from a Samuel L. Jackson voice double!!
    Just to clarify one point at 11:10, if the Solar System, including the Oort Cloud, were 1mm in diameter, the Milky Way Galaxy, not the Universe, would be the comparative size of a football field.
    If the same analogy were used and the Milky Way Galaxy was a football field, then the known observable universe would be 10 times the diameter of earth!!!

  • @norwayte
    @norwayte 14 років тому

    " I'm busy to contemplate infinity." (A yogis answer to the question, what he is doing all the time:)

  • @Destro7000
    @Destro7000 13 років тому

    @Ikus13 maybe they should say it in a Deeper Voice for Emphasis. Just so they don't sound like they're taking it for Granted.

  • @turbomania9
    @turbomania9 12 років тому

    people leave each other alone, science is meant to be fun and to be discussed and debated on otherwise we'd have all the answers. religion and biased opinions should not be suggested into this conversation. I'm a god believing person but that doesn't mean that i don enjoy the concepts of science as much as an atheist. Leave personal thoughts out and look at the facts that are presented, if you wanna believe in it do that, if you don't you don't, its ur opinion, care bout urself not someone else!

  • @DonGordalia
    @DonGordalia 14 років тому

    This reminds me of the final scene of Men in Black

  • @Rebar77_real
    @Rebar77_real 13 років тому

    mind officially boggled, good lord. Can't wait till hyperspace...

  • @kyleag9
    @kyleag9 13 років тому

    never questioned this before but if night sky is mostly if not all milky way, how can we see andromeda? i dont understand how good telescopes are but even some of these distances seem crazy for a telescope let alone andromeda

  • @ImposingSumo
    @ImposingSumo 14 років тому

    @Ikus13 They may be right. The only position you can really take regarding life is purely agnostic. I am inclined to think it likely there is life elsewhere, but, in the absence of evidence, all that can be said is "I don't know". For example, if the chances of life arising were less than one in "The number of stars in the universe", i.e, under ordinary circumstances, spontaneous abiogenesis would be considered impossible, then a universe of this size would be needed to make it happen once.

  • @Yora21
    @Yora21 12 років тому

    Oh, this will get fun by the time we get to the Hubble Ultra Deep Field. ^^

  • @007SPIDER007
    @007SPIDER007 14 років тому

    why is this not in high school curriculum?
    this should be basic science knowledge

  • @GoodCat01210
    @GoodCat01210 13 років тому

    @237Michael wormholes allow travel over great distances to take seconds.
    the technology is there, its all theoretical but its there.

  • @TeganES
    @TeganES 14 років тому

    this is so awesome!

  • @cheesechuck12
    @cheesechuck12 12 років тому

    Mind officially BLOWN!!!!!

  • @techstepman
    @techstepman 11 років тому

    ...quoting Kaidan Alenko...."Big place"

  • @joshy1024
    @joshy1024 12 років тому

    So just to explain the scale of the Milky Way Galaxy, if the Oort Cloud was 1 mm thick, then the entire galaxy would be about 100,000 mm wide, which is about 100 meters or 1 football field.
    Make me feel happy I bought the Samsung "Galaxy" S3. :P

  • @lumburgapalooza
    @lumburgapalooza 12 років тому

    But on scales of complexity, I'd say it's generally greater as you get bigger. Electrons may be very difficult to observe due to technological restraints but the universe is difficult to observe for the same reason a horse is difficult to observe (or comprehend) if you're a bacterium in its colon.

  • @rax7
    @rax7 14 років тому

    even the biggest star is a tiny little grain of sand when it compares to a galaxy. and a galaxy is a tiny little grain of sand when it compares to the universe. and the universe is a tiny little grain of sand when it compares to _____.

  • @jpr422
    @jpr422 14 років тому

    Kind of gives you an idea on how insignificant we are.

  • @JCarter3000
    @JCarter3000 14 років тому

    We're nothing, and we're just now starting to realize it.

  • @PhilipK100
    @PhilipK100 13 років тому

    I seriously think there are more beings out there for two reasons...
    1) Why would God use all his abilities just to make a nice pretty multiverse for us to look at?
    2) What did Jesus Christ say? "I have sheep that are not of this pen"
    Makes you wonder how our creator could make so many different beings each with their own personality and thoughts. Genesis is definatly an interesting read :)

  • @thehoodatron
    @thehoodatron 12 років тому

    The universe is infinitely big and thus we and everything else in it are infinitely small

  • @SuzLa1
    @SuzLa1 14 років тому

    @Ikus13 Look up Sumerian artifacts. They knew the planets went around the sun and talked about people coming from the sky.

  • @villagepunk
    @villagepunk 14 років тому

    Mind=Blown

  • @thomasmicheal5480
    @thomasmicheal5480 6 років тому

    So, is it possible to discover new stars or other bodies in space in the coming years because their light took longer to reach us then the whole time we've existed, if they came into formation after the earth?

  • @PocketFullaRain
    @PocketFullaRain 11 років тому

    Amazing!!!!!!!!

  • @requshei
    @requshei 13 років тому

    I mean the stars are not equal distant from each other as they were thousands of years ago. The night sky would look completely different in thousands of years wouldnt it? The scientists must pick a specific date so all stars are in the same time zone to get an accurate image.

  • @hedonism13
    @hedonism13 14 років тому

    @Chnamanjx
    Recent studies that adjust the drake equation to what we presently know about our galaxy show that there could potentially be as many as 10 intelligent, broadcasting lifeforms in our galaxy alone.

  • @PLURIC
    @PLURIC 13 років тому

    @Ikus13 The evidence is what will ultimately be authoritative concerning intelligent life in other star systems. Have you ever heard of the Fermi Paradox? Its interesting to read about.

  • @Ikus13
    @Ikus13 14 років тому

    And there are still idiots out there that authoritatively declare we're the only intelligent life in the Universe. I can't think of a more underestimated and often misused word than "Universe". It's simply unfathomable, yet people refer to it way too lightly.

  • @veto050
    @veto050 12 років тому

    SubhanAllah

  • @thisisnotanick
    @thisisnotanick 14 років тому

    @ImposingSumo Agnostic would be to say "I cannot know", not "I do not know".

  • @urbnplnr1234
    @urbnplnr1234 14 років тому

    So would you say that there's a quasar in the Milky Way?

  • @Matkatamiba
    @Matkatamiba 14 років тому

    And this is nothing compared to the rest of the universe, in which there are billions more galaxies

  • @genobahamut1337
    @genobahamut1337 14 років тому

    @zackboomer As I said, it's not the position that there are no gods/deities. It is just simply not believing in them. Not believing does not mean believing against or that there are none. It means that you simply do not believe in them. It's like the ruling "not guilty" to borrow someone else's explanation. Not guilty doesn't mean innocent, it means that you don't have evidence to claim them to be guilty. Just the same, I have no reason to thing god is real. Doesn't mean I believe there is none.

  • @ImposingSumo
    @ImposingSumo 14 років тому

    @zackboomer I don't know any atheists that would claim that. Atheism is, in a nutshell: "In the absence of evidence to support this supernatural theistic claim, I don't believe. If evidence is presented, I will change my belief".

  • @niconikko
    @niconikko 13 років тому

    Universe is Science. God shall never be included in the discussion.

  • @imnota6
    @imnota6 11 років тому

    I don't think you understand the term "relative"...
    Relative: Considered in relation or in proportion to something else
    For something to be "big" you have to compare it to something "small", or else "big" can be ANYTHING, and vice versa for things that are small. It really is as simple as that... I think you were over thinking it a bit too much.

  • @mnightsky
    @mnightsky 12 років тому

    And we are extremely big in comparison with an electron !

  • @30LayersOfKevlar
    @30LayersOfKevlar 14 років тому

    @postmarvi Thats not matter of a belief. Information presented here is a scientific FACT.

  • @LethalLithiumLi
    @LethalLithiumLi 13 років тому

    Maybe you should be more specific, There are less solar systems then there are stars because there are sometimes multiple stars per system.

  • @CODfishGaming
    @CODfishGaming 9 років тому +1

    I'm James Harris. This has got me thinking and in the future if there is a more accurate ancestry site with actual facts of ancestors and they have tweets and posts of your ancestors. Then I want to greet my great great great grandchildren. Thank you for looking me up. I was born in 2000!!!! Isn't that a cool year!!! I'm a 15 year old kid doing my homework and I will be decomposed and turned into dirt and (I don't know too much about chemical bonding) but maybe even in the air you breath. Make sure to tell me if you made it to Mars. How's Earth? Global warming happen yet? Have fun learning about the creation of the Internet, cell phones and stuff. Good luck to you if you take Advanced World History cause that's a lot of stuff from like 1900 to 2100.

    • @nv1211
      @nv1211 4 роки тому +1

      ... hmm 1900-2100? If you were 15, why were you here? :thonk:

  • @daniel1c
    @daniel1c 11 років тому +3

    I think you called the 'galaxy' 'univrrse' by mistake in your football field and grain of sand example

    • @SuperYtc1
      @SuperYtc1 7 років тому

      Daniel CZ Agreed. It seemed too small to be the whole universe.

  • @maulcs
    @maulcs 14 років тому

    @Melthornal Actually, the Earth only travels at around 30 km/s.

  • @aimalkhan123
    @aimalkhan123 13 років тому

    How can all this just exist by it self ?

  • @thedarkestknight4060
    @thedarkestknight4060 4 роки тому

    It’s kind of scary when you now that your so small

  • @danb7601
    @danb7601 Рік тому

    its funny how scale is just relative and nothng is actually only big or only small

  • @ninjaturtle205
    @ninjaturtle205 13 років тому

    so every star has a solar system with planets? wikipedia says there are six million solar systems with planets and 200-400 billion stars.

  • @archaedemos
    @archaedemos 14 років тому

    anutha great video :}

  • @T4l0nITA
    @T4l0nITA 13 років тому

    11:10 i think you meant our galaxy as a hole, not the universe

  • @ArtemisTemariRebel4
    @ArtemisTemariRebel4 13 років тому

    DAMN! srry forgive my language but its true! Is our sun rotating and circling around the center of the milky way?

  • @maulcs
    @maulcs 14 років тому

    It's very frustrating to know that we won't be traveling to any other stars in our lifetimes. Or galaxies for that matter. Pisses me off.

  • @Dr0ctagonapus5
    @Dr0ctagonapus5 11 років тому

    That's a lot of space for a single planet with life on it. Hmm...

  • @xC0M9UT3RxG33Kx
    @xC0M9UT3RxG33Kx 13 років тому

    @INMATE2468 Well you do seem like a very smart individual, judging from your great grammar use. I guess all of us have no option, other than to take your word for it. Thank you kind stranger, for explaining to me how I'm supposed to live the rest of my life! And such a nice way of putting it by the way. I hope you have a great day :)

  • @Ninjastripy
    @Ninjastripy 12 років тому

    And electrons are extremely big in comparison to a quark!

  • @DarkShadowMegadeth
    @DarkShadowMegadeth 13 років тому

    I think NASA knows SO MUCH MORE and they're not telling us. :(

  • @smalboalex99
    @smalboalex99 13 років тому

    go to 7:25 and he stutters so much!

  • @justinv3
    @justinv3 14 років тому

    @stainermcbain so you're saying that what many millions of people call 'God' are simply aliens? Did nicholas cage star in a movie that depicted this?

  • @Mancunian786
    @Mancunian786 13 років тому

    @niconikko God is the creator of the universe and everything in it.

  • @xPloSiVgT
    @xPloSiVgT 12 років тому

    Stop breaking my mind Sal D;

  • @maulcs
    @maulcs 14 років тому

    yes

  • @mac195000
    @mac195000 6 років тому

    Queeper belt?

  • @awesomefordays9186
    @awesomefordays9186 4 роки тому

    How small is earth

  • @ImposingSumo
    @ImposingSumo 14 років тому

    @thisisnotanick I disagree. I am agnostic about whether the cheese in my fridge has gone off, in that I presently don't know. However, once I have evidence one way or the other, i.e. I check by smelling the cheese, then I have become a 'Gonstic', that is, I have the knowledge of the state of the cheese in my fridge. An Agnostic says "I don't know". He makes no claim as to whether that knowledge is ultimately attainable. To claim such a thing would be to claim knowledge would it not?

  • @ImposingSumo
    @ImposingSumo 14 років тому

    @ImposingSumo I'm not saying that is the case, just that circumstantial evidence can be presented for both sides. None of which proves anything.

  • @Su0ni0ni
    @Su0ni0ni 12 років тому

    Did you really mean a grain of sand represents the solar system in a football field that is the universe? That sounds a bit big, did you mean the football field is the galaxy?

  • @JacobRoeglin
    @JacobRoeglin 13 років тому

    yeah and all this was made and put into perfect balance by chance right? *sarcastic Laugh*

  • @Chnamanjx
    @Chnamanjx 14 років тому

    @Ikus13 Do you know the odds of the right conditions for life to exist? Or life to evolve? Or a civilization species to evolve?
    Sure there are aliens, at this very moment, there is an alien civilization right now, unfortunately due to odds, it's 100 million galaxies away.

  • @rory12349
    @rory12349 13 років тому

    when he said the grain of sand and the football field.. did he mean the football field is the galaxy not universe?

  • @BlaiseIgirubuntu
    @BlaiseIgirubuntu 13 років тому

    And I thought my city was huge and a year was long...

  • @MrSanjayV
    @MrSanjayV 13 років тому

    1 person disliked this video. I dont fully blame him, i can barely believe this either.