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The Known Universe Scientifically Rendered For All to See (by AMNH)

  1. Jan 8, 2010 #1

    DevilsAvocado

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    I just have to share the most beautiful and amazing video I have ever seen.

    The Known Universe, a new film produced by the American Museum of Natural History, is for everyone with just slightest interest of our place in the Universe. If you haven’t already seen it (+2 million views on YouTube in less than a month!), enjoy the trip of your life!

    The video is based on real data (Sloan Digital Sky Survey), not an artist’s conception.

    https://www.youtube.com/watch?v=<object width="640" height="505"><param name="movie" value="http://www.youtube.com/v/17jymDn0W6U&hl=en_US&fs=1&rel=0&color1=0x006699&color2=0x54abd6&hd=1"></param><param [Broken] name="allowFullScreen" value="true"></param><param name="allowscriptaccess" value="always"></param><embed src="http://www.youtube.com/v/17jymDn0W6U&hl=en_US&fs=1&rel=0&color1=0x006699&color2=0x54abd6&hd=1" type="application/x-shockwave-flash" allowscriptaccess="always" allowfullscreen="true" width="640" height="505"></embed></object>
    (Don’t miss the 'HD option' for better video quality)

    I recommend a visit to AMNH or YouTube for the 'Full Screen option', it’s wonderful:
    http://www.amnh.org/news/2009/12/the-known-universe/

    http://www.sdss.org/

    Questions anyone? :smile:
     
    Last edited by a moderator: May 4, 2017
  2. jcsd
  3. Jan 8, 2010 #2

    DevilsAvocado

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    Edit: The Known Universe Scientifically Rendered For All to See (by AMNH)

    Wanna explore the Universe yourself?

    Well, it’s no problem! The American Museum of Natural History and the Hayden Planetarium have engaged in the 3-dimensional mapping of the Universe:

    "The Digital Universe Atlas is distributed to you via packages that contain our data products, like the Milky Way Atlas and the Extragalactic Atlas, and requires free software allowing you to explore the atlas by flying through it on your computer."

    mwM54.gif

    The package consists of The Digital Universe Atlas and Guide and the free http://virdir.ncsa.illinois.edu/partiview/" [Broken] software (industrial strength, interactive, mono- or stereoscopic viewer for 4-dimensional datasets) from the National Center for Supercomputing Applications (NCSA).

    http://www.haydenplanetarium.org/universe/download/" [Broken]

    partiview-grab.gif

    Enjoy!
     
    Last edited by a moderator: May 4, 2017
  4. Jan 10, 2010 #3

    PhanthomJay

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    Quite fascinating! I do have a question:

    Our Hubbel and other space telescopes see the light from the early galaxies and CBR reaching their lenses as they existed 13.7 billion years ago. I suspect that someone 'now' in our time, living 13.7 billion light years away from us, were to peer into their telescopes, they would see the same stuff as we do: the early galaxies and CBR, correct? Which means that actually, at this instant, what we see as the CBR and early galaxies is now occupied by galaxies and planets something like ours, which we can never have any idea of knowing because the light from those present galaxies won't reach us for another x amount of light years, if ever. Is this correct?? Or does the definition of time and instantaneity and spacetime expansion etc. , mess up this logic?
     
  5. Jan 10, 2010 #4

    DevilsAvocado

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    Yes, that’s correct (though I must emphasize – I’m only a layman). When looking back at distant galaxies we (now) see the very old light that was emitted billions of years ago. To make things a little more 'interesting' – it’s difficult to talk about a universal 'now', due to Einstein’s theory of special relativity, where space and time is not 'fixed'.

    Lorentz_transform_of_world_line.gif
    Rapidly accelerating observer moving in a 1-dimensional (straight line) "universe"

    This question has puzzled me for some years, and I thought I had all the 'basic' information needed to https://www.physicsforums.com/showthread.php?p=2508918#post2508918" (almost). :biggrin:

    Right now my brain is overheated, trying to digest all new info. My feeling though, is that it is comprehensible, if you manage to make a 'working picture' in your (layman) head... :rolleyes:
     
    Last edited by a moderator: Apr 24, 2017
  6. Jan 10, 2010 #5

    Chronos

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    We get a distorted view of the universe. Spacetime is compressed [or expanded, if you prefer] by the Hubble flow. It is difficult to say how it 'really looks' at any universal instant in time as all such projections are model dependent. Even tiny inacurracies become exponentially exaggerated over billions of light years.
     
  7. Jan 11, 2010 #6

    Wallace

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    Essentially yes, you are correct. There are some complications about how you define distances, so just because the Universe is 13.7 Billion years old doesn't mean that the observable universe has a radius of 13.7 Billion light years. That's because defining distances over cosmological regions is ambigous and depends on some arbitrary definitions. The other arbitrary thing is defining when 'now' is over cosmological distances. People often forgot this important fact about relativity; that events defined as simultaneous for one observer need not be simultaneous for others. Generalised to cosmology, this means that there is no unambigous way to say what something at cosmological distances is doing 'now', since to find that out, you'd need to send a light beam there, which will take longer than the age of the Universe to arrive...

    In practice, we often make the practical definition of using the temperature of the CMB to define 'now'. This is a good natural definition, since all observers will see the same kinds of things at the same CMB temperature intervals. These days there are less Quasars around than when the CMB was a bit hotter for instance. All observers in the universe would see the same thing (on average) as their observerd CMB temperature evolves.

    So, a less complication free way of saying things might be:

    "The regions of the Universe which emmitted the CMB photons we see today will consist of planets, stars, galaxies etc in much the same way as the region around us does at the time in which an observer there would see an CMB temperature of 2.7K"

    This statement is fundamental unproveable directly, but it is a consuquence of the model for the Universe we have devised based on observations.
     
  8. Jan 11, 2010 #7

    PhanthomJay

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    Thank you all!
     
  9. Jan 11, 2010 #8

    DevilsAvocado

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    Yes, you are absolutely right. Not to talk about the 'distortion of time', 13.7 billion light years travel in only 6 minutes!? :confused:

    Besides the obvious 'trouble' with Mr. Einstein’s "Now" – there are the same 'difficulties' in projecting a 3D surface of a 'sphere' onto a 2D computer screen...

    I don’t think the aim with this video is to give a complete and correct picture of the curvature and topology of the observable universe – more like providing a feel for size and dimensions, compared to Earth.

    Just imagine what the Pope Urban VIII would have looked like if Galileo Galilei in 1633 could have showed him this video as a supplement to his book The Dialogue Concerning the Two Chief World Systems... Perhaps the Pope would have looked like something like this... :surprised
    http://upload.wikimedia.org/wikipedia/en/thumb/c/ca/Galileos_Dialogue_Title_Page.png/450px-Galileos_Dialogue_Title_Page.png [Broken]
    :rofl:
     
    Last edited by a moderator: May 4, 2017
  10. Jan 11, 2010 #9

    Wallace

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    Since Urban VIII and his Ilk refused to look through Galileo's telescopes (claiming what he saw could have just been imperfections in the telescope...) I suspect he would similiary dismiss this video. Either that or burn you as a the witch you must be with your magic moving painting :biggrin:
     
  11. Jan 11, 2010 #10

    DevilsAvocado

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    Hehe! :biggrin:

    Absolutely correct conclusion. I suspect Urban VIII would claim it’s a magic bug in the system… and put both Galileo Galilei and Bill Gates + bug in the 'ovens' at max temp... :rofl:
     
  12. Jan 11, 2010 #11

    DevilsAvocado

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    Brilliant! Thanks!
     
  13. Jan 11, 2010 #12

    DevilsAvocado

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    I’ve been working on 'digesting' the Hubble volume, Observable Universe, c, CMB, Cosmological principle, etc, https://www.physicsforums.com/showthread.php?p=2514396#post2514396". :smile:

    According to Ned Wright – http://www.astro.ucla.edu/~wright/photons_outrun.html" [Broken] – this is how we should visualize the expansion of space, and two (originally) 'nearby' galaxies emitting photons:

    cphotons.gif

    Ned Wright:
    "However, all parts of the Universe started with CMBR photons, not just the two green galaxies. The picture below shows the result of releasing a ring of 72 red photons from every dot on the picture. It makes a pretty quilt pattern, but except for this pattern imposed by the artificial regularity of my galaxy grid this pattern of photons is homogeneous and isotropic, as specified by the cosmological principle."

    33wtaua.gif

    If we look at the video at around 3:30 we see the CMB as a sphere surrounding the very distant supernovas and distant galaxies, and finally the Earth:
    j6hifa.jpg

    Another perspective of the evolution of the (observable) universe:
    600px-CMB_Timeline75.jpg

    Now, my question is:
    We cannot see the light from distant galaxies and supernovas and at the same time see the CMB from these objects/regions, right? These CMB photons must have passed us a long time ago, right?

    If this is correct – shouldn’t there be a minor 'gap' in the CMB somewhere (in Ned Wright’s picture e.g.)...?

    (Maybe a stupid question...? :uhh:)
     
    Last edited by a moderator: May 4, 2017
  14. Jan 11, 2010 #13

    Wallace

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    Correct.

    Hmm, I don't really follow this, I'm not sure why you think there should be a gap?

    Say we look in the direction of some galaxy. The CMB photons that were sent from the region around that galaxy at the time of re-combination (why the CMB was sent on its way) have indeed passed by our location at some time in the past. However, we can still see CMB photons coming from that direction, but the regions where they originated from are even further away.

    Maybe this will help; if we look in any direction, then for every second that passes, we see CMB photons that originated from a location further and further away. Think of this like and long line of soldiers lined up in front of you, each a bit further from you than the rest. If they all fire their guns at you, then you'll be hit by a succession of bullets, each subsequent one originating from a location further away than the previous one.

    Note that this means observing the CMB is in principle a little different from observing a galaxy, because with a galaxy you continuously see photons from the same object, even if that object is in principle getting further and further away with each passing moment. On the other hand, when we look at the CMB, we are continually seeing radiation from different 'objects' each passing moment. In practice human lives are too short for us to measure the difference, so it doesn't make a practical difference.
     
  15. Jan 11, 2010 #14

    DevilsAvocado

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    I don’t know how to thank you! Many many thanks!!!

    I feel this is slowly accepted by my confused brain, (earlier) lost in translation (from math). This explains CMB 'in a nutshell': "when we look at the CMB, we are continually seeing radiation from different 'objects' each passing moment"

    Cool!!

    Now, some new 'thoughts' popup: In the young universe, let’s say around formation of the first stars (400 million yrs after BB) the 'night sky' must have been extremely bright, right? A pretty hot (3000 K?) CMB (high energy photons) and a more 'compressed' universe, right?

    But then again, the chances for intelligent amoebas with eyes :bugeye: were not outstanding at this early stage, so maybe no one saw it...? :biggrin:

    Another question: The solution to Olbers paradox is the fact that the universe expands and has a finite age. Is this also the reason the fermions (matter) don’t get in the way (blocking) the CMB from more distant parts of the universe?
    (Or did I just prove that I don’t understand this at all?? :blushing:)
     
  16. Jan 11, 2010 #15
    I am sure that Wallace will correct me if I am wrong, but CMB photons are photons which are left after temperature dropped enough for stable atoms to form, and universe became transparent. So, they are not exactly radiation from different 'objects'.

    In the early opaque universe, these photons were bouncing around through Thomson scattering. When universe diluted and cooled enough for charged particles to combine to atoms, it became transparent, allowing photons to move freely. Result is that there were photons zooming in and from every possible direction, which we register today as CMB.
     
  17. Jan 12, 2010 #16

    Wallace

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    My bad on the use of 'objects'. You describe the origin of the CMB correctly, I used 'objects' in the 'scare quotes' in order to help explain the idea of getting the radiation from successively more distant regions as time goes on. By 'object' I meant some small region of hot gas, but I should have spelled that out to avoid any confusion!
     
  18. Jan 12, 2010 #17

    DevilsAvocado

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    Thanks S.Vasojevic & Wallace for the clarification.

    The CMB doesn’t belong to a specific 'object' (electron/molecule/star/galaxy), but is the remaining 'glow' (everywhere) from the very hot BB.

    Any thoughts on: https://www.physicsforums.com/showthread.php?p=2527155#post2527155"

    It’s a little puzzling to me that the CMB can penetrate the 'wall' of matter surrounding us. In the http://en.wikipedia.org/wiki/Millennium_Run" [Broken] (computer N-body simulation) a cube about 2 billion light years in length is populated by about 20 million 'galaxies' (and over 10 billion 'particles' of dark matter) – it seems pretty dense... and hard for the more distant CMB to penetrate (at least I would expect some 'imprint' on the CBM as a result of this) ...?

    https://www.youtube.com/watch?v=<object width="640" height="505"><param name="movie" value="http://www.youtube.com/v/yyfpFfWq7Bc&hl=en_US&fs=1&rel=0&color1=0x006699&color2=0x54abd6&hd=1"></param><param [Broken] name="allowFullScreen" value="true"></param><param name="allowscriptaccess" value="always"></param><embed src="http://www.youtube.com/v/yyfpFfWq7Bc&hl=en_US&fs=1&rel=0&color1=0x006699&color2=0x54abd6&hd=1" type="application/x-shockwave-flash" allowscriptaccess="always" allowfullscreen="true" width="640" height="505"></embed></object>
     
    Last edited by a moderator: May 4, 2017
  19. Jan 12, 2010 #18

    Wallace

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    Indeed there are various 'imprints' left on the CMB by the structures in the Universe. One of the more important of these imprints are the Integrated Sachs Wolf effect, which is actually a bit like gravitational lensing on a very large scale. The existence of this is actually an important independent bit of evidence for dark energy; you only get the ISW effect in Universes with dark energy.

    Another important thing is the Sunyaev-Zel'dovich effect by which the hot gas in clusters leaves on imprint on the CMB on small scales through inverse Compton scattering (i.e. the CMB photons bouncing of the hot electrons in the cluster). We can use this in order to find clusters in the sky and hence learn about how many clusters there are and their distribution. Measuring this is pretty cutting edge, with the first SZ discovered clusters being found only the last year or two by the South Pole Telescope.

    You can find some info in detail (and some very nice animations) on Wayne Hu's site. Just google 'Wayne Hu CMB' or something like that.

    In addition to things that imprint a useful signal onto the CMB, there are also things that imprint a lot of noise that doesn't tell us anything very interesting, but makes it harder to extract just the CMB. The Milky Way is the biggest source of such noise. The process of removing all these unwanted 'foreground' is a major part of the processing of CMB data, and takes a lot of effort and clever techniques.

    The other way to think about why the CMB isn't completely blocked by 'a wall of matter' is to realise that once structures like galaxies and clusters have formed, the density contrast is the Universe is huge. Essentially you have these very dense blobs surrounding by vast regions of near vaccum. Think about our own solar system, in terms of a volume average it is almost completely dominated by near empty space. This means that even though there are a lot of galaxies etc in the Universe, they are small in size compared to the space they occupy. This means that there are plenty of free lines of site from us to the CMB they don't have anything in the way.
     
  20. Jan 13, 2010 #19

    DevilsAvocado

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    Very interesting and amazing info, thanks!

    Here I am, a mumbling &:uhh:& rambling layman speculating on the 'properties' of CMB, and it looks like I where somehow right!? The universe is a fantastic place!! :cool:

    Confirming DE and finding unknown clusters from CMB is amazing.

    When you mentioned the Milky Way one of my sleepiest neurons woke up and said – Hey! I’ve seen this!? And of course I should have remembered (before asking questions :wink:)... this is obvious (even to me):

    081015_k_5yr_512.png

    Fantastic achievement to manage to remove this 'blob'!

    I found http://background.uchicago.edu/~whu/" [Broken] and it contains a lot of useful info, and beautiful animations. I’m especially fond of this one (by Andrey Kravtsov):

    avk_evol.gif

    A bigger version can be found http://cosmicweb.uchicago.edu/filaments.html" [Broken]. (Must be something wrong with my brain – this excites me more than any Hollywood SFX!? :biggrin:)

    Also found (Andrey Kravtsov?) http://astro.uchicago.edu/~andrey/soft/p3d/p3d.html" [Broken] where one can find more tools (for Linux).

    Then I found that PF (of course!) https://www.physicsforums.com/showthread.php?t=274265" (COBE) talking at Serious Play 2008!! This wraps it all up quite nicely. A fine supplement to the video from AMNH:

    "At Serious Play 2008, astrophysicist George Smoot shows stunning new images from deep-space surveys, and prods us to ponder how the cosmos -- with its giant webs of dark matter and mysterious gaping voids -- got built this way."

    George Smoot: The design of the universe
    https://www.youtube.com/watch?v=<object width="640" height="505"><param name="movie" value="http://www.youtube.com/v/c64Aia4XE1Y&hl=en_US&fs=1&rel=0&color1=0x006699&color2=0x54abd6"></param><param [Broken] name="allowFullScreen" value="true"></param><param name="allowscriptaccess" value="always"></param><embed src="http://www.youtube.com/v/c64Aia4XE1Y&hl=en_US&fs=1&rel=0&color1=0x006699&color2=0x54abd6" type="application/x-shockwave-flash" allowscriptaccess="always" allowfullscreen="true" width="640" height="505"></embed></object>

    http://video.ted.com/talks/podcast/GeorgeSmoot_2008P_480.mp4"


    Edit:
    For those interested in high-res videos of The Millennium Simulation (and spectacular fly-through) it can be found here:
    http://www.mpa-garching.mpg.de/galform/virgo/millennium/
     
    Last edited by a moderator: May 4, 2017
  21. Jan 14, 2010 #20

    Wallace

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    I'm not sure how much you'd be interested DB, but installing Linux as a duel boot option alongside Windoze is insanely easy these days with the latest disutributions of Linux. You could then use some of those tools you found that run only under Linux/Unix, if that floats your boat. I use Ubuntu, but Fedora, Suse etc are all pretty simple to use, not like in the old days where you needed to be an expert just to get it installed.

    Possibly this works for others as well, but with Ubuntu you can download and burn onto a CD an Ubuntu-Lite application which boots straight from the CD, allowing you to try out Ubuntu without having to install it on your hard drive. It's slower in this mode, but it might even be enough to let you play with some of those apps you've found.
     
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