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Space Science

Hubble Finds a Galaxy 12.8 Billion Years Old 134

Posted by kdawson
from the dark-ages dept.
I Don't Believe in Imaginary Property writes "Hubble's Near Infrared Camera and Multi-Object Spectrometer (NICMOS) has discovered the 12.8B year old galaxy now known as A1689-zD1. Using gravitational lensing of the massive Abell 1689 cluster of galaxies, they were able to find a surprisingly bright young galaxy from only 700 million years after the Big Bang, during the cosmic 'dark ages.' Researchers are itching to study the object with the upcoming Atacama Large Millimeter Array (to go online in 2012) and James Webb Space Telescope (to launch in 2013)."
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Hubble Finds a Galaxy 12.8 Billion Years Old

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  • by Anonymous Coward on Tuesday February 12, 2008 @06:43PM (#22399784)
    a desire for us to get off its lawn.
  • Can you say, "we totally made this up to continue getting funding, remember to plug the new Telescope we're launching soon."
  • How do they know how old it is anyway?
    • Re: (Score:3, Informative)

      by TheOnlyJuztyn (813918)
      Redshift [wikipedia.org]
      • by goarilla (908067)
        my question ? where do they get the reference light to base their redshift off
        it could just be a very HOT star eg a star with some odd materials and thus more red light
        can someone please elaborate
        • by ricree (969643)
          I don't know the answer, but I'm pretty sure it's been discussed somewhere on the astronomy podcast. At any rate, it's a great show for anyone who is interested in astronomy. I'd especially recommend listening to their series on the objects of the solar system.
          Astronomy Cast [astronomycast.com]
        • by tweak13 (1171627)
          http://en.wikipedia.org/wiki/Redshift [wikipedia.org]

          The picture at the top of that page is a pretty good explanation. Basically you just take the absorption lines of some known materials and compare them to the absorption lines seen in whatever is being observed.
        • by wanerious (712877)
          It's pretty easy to tell the difference between a true cosmological redshift, where all the spectral lines are shifted by some scale percentage, and red light from a star in our own galaxy that does not have redshifted spectral lines. Red stars look red because most of their light in the visible part of the spectrum is red, not because the spectral lines have been shifted.
      • by Bob-taro (996889)
        Yeah, redshift, but even your linked article casts doubt on it's accuracy:

        The Hubble law's linear relationship between distance and redshift assumes that the rate of expansion of the universe is constant. However, when the universe was much younger, the expansion rate, and thus the Hubble "constant", was larger than it is today. For more distant galaxies, then, whose light has been travelling to us for much longer times, the approximation of constant expansion rate fails, and the Hubble law becomes a non-linear integral relationship and dependent on the history of the expansion rate since the emission of the light from the galaxy in question. Observations of the redshift-distance relationship can be used, then, to determine the expansion history of the universe and thus the matter and energy content.

        While it was long believed that the expansion rate has been continuously decreasing since the big-bang, recent observations of the redshift-distance relationship using Type Ia supernovae have suggested that in comparatively recent times the expansion rate of the universe has begun to accelerate.

        Maybe we need a new law -- the farther away an object is, the more assumptions we have to make to pretend we know anything about it. Another thing I always wondered about redshift - what if the object in question is itself moving at a high speed unrelated to the apparently uniform "expansion" we see with other objects? Wouldn't that affect the amount of red shift and throw off the distance estimate?

    • by jo42 (227475) on Tuesday February 12, 2008 @06:54PM (#22399906) Homepage
      They look it up in the Hitchhiker's Guide to The Galaxy - Universe Edition.
      • They originally tried to looked it up in Hitchiker's Guide to The Galaxy - Home Basic Edition, but received an error of, "Sorry, that information is not available in this edition. Would you like to upgrade?"
    • by Mantaar (1139339) on Tuesday February 12, 2008 @06:58PM (#22399948) Homepage
      Since c is most likely a constant we can say: something that is x light years away is y years old (actually, x = y for most cases, I think.). How do we measure the distance between our galaxy and another? No rocket science (but [theoretical] astrophysics):

      http://hubblesite.org/reference_desk/faq/answer.php.id=45&cat=galaxies [hubblesite.org]

      Though I have no idea how exactly they did it this time. That's just the general procedure. According to TFA that's just an estimation and the exact age of the galaxy is yet to be determined; that's what those new telescopes would be useful for.

      What's even more interesting though:

      The astronomers used a relatively nearby massive cluster of galaxies known as Abell 1689, roughly 2.2 billion light-years away, to magnify the light from the more distant galaxy directly behind it. This natural telescope is called a gravitational lens.
      Remember: when you're glancing through space, you're not only taking a look at the 3 space dimensions, but the 4th, time, actually starts playing a role. The sun could explode right now and we would only notice it in about 8 minutes...
      • Since c is most likely a constant we can say: something that is x light years away is y years old (actually, x = y for most cases, I think.

        It seems illogical and improbable that X would equal Y. An object 4 light years away isn't necessarily 4 years old, it could just as easily be 4 billion years old. Unless the light from this galaxy 12.8 billion light years away just happened to come in to view on the Hubble sensor where a few moments before there was nothing, then that light could have easily been stream
      • Im wondering is c still a constant over such a large distance? I mean, for one, the light is bent around a galaxy cluster, that will change the distance its travelled. Also, its been shown in the lab that light can be slowed down, could this also have happened. I know the spped of light in a vacuum is a constant, but space isnt really a vacuum, is it? It may be mostly empty, but even a very slight effect would be quite significant over such a distance?
    • Given how far away it is, and the speed of light, you can calculate how long it took the light to get here. You know it existed that long ago. Subtract from the age of the Universe. That gives you the maximum age of the galaxy, and that's what they're quoting. It could be younger, of course.
    • They count it's teeth.
      Lot of teeth, it's young.
      Few teeth, it's old.
      Or a NASCAR or wrestling fan.
  • by Prien715 (251944) <agnosticpopeNO@SPAMgmail.com> on Tuesday February 12, 2008 @06:53PM (#22399884) Journal
    Even more interesting, I think, is the fact that since it's over 12 billion light years away, it probably doesn't exist anymore. We are in fact looking at ancient history. It could have developed "intelligent" life and they in turn, could've blown it and themselves up in some sort of "ideological" dispute.

    And in a few billion years, we'll get to watch it "live".
    • by pizza_milkshake (580452) on Tuesday February 12, 2008 @07:09PM (#22400082)
      Worse yet: editors from their "news for nerds" website posted a similar article 10 billion years ago.
    • I won't bother calculating how big a birthday cake would be necessary to hold 12.8 billion candles.
    • by gardyloo (512791)
      In our frame of reference, it certainly still exists, in every possible sense of the word. In an inertial frame of reference moving very quickly with respect to us (and it), it may well not even have been formed yet, or have flown apart (or whatever fate awaits/befell it) long ago.
    • by geekoid (135745)
      And people will complain it's a dupe.
    • by MBGMorden (803437)
      From my understanding, most galaxies would certainly stick around for more than 13 billion years. New stars form from time to time, and even the Sun (a medium mass star) has a life expectancy of around 10 billion years. Smaller stars tend to shine for longer, with red dwarfs (the most common type of star in the universe) having a life expectancy of hundreds of billions, maybe even trillions of years.

      While the specific stars that are giving off the light we see likely aren't there, that galaxy most likely
    • by JohnFluxx (413620)
      Just to be really nitpicky, it is 12 billions year old, but it's probably closer to 100 billion light years away at the moment (if it exists still)
      • by Harik (4023)
        Ok, that's got me curious - what's the cosmological model for a 13ish billion year old universe, but distances greater then 26bn LY apart? Galaxies traveling at > c for the early part of the universe?
        • by JohnFluxx (413620)
          > Galaxies travelling at > c for the early part of the universe?

          Yep. We can see redshift greater than 1 (and hence 'speeds' greater than c) for very distant objects. (That's not entirely circular - there's other ways to measure distance, such as looking at pulsars etc).

          There's also the background microwave radiation, whose temperature fits perfectly the predictions for an expanding matter-dominated 13ish billion year universe.

          There's also nucleosynthesis. If you treat the early universe as a simple
  • by Amphetam1ne (1042020) on Tuesday February 12, 2008 @07:03PM (#22400022)
    I can't be the only one that was thinking it after reading the title can I?
    • by Wylfing (144940)

      You know, it's funny, yes. But in fact I always imagined this to be part of the mythos of Star Wars. It felt easy to pretend that the reason I was sitting down in a theater in 1977 was that we had intercepted this information from a galaxy far, far away. And of course because of the speed of light it had happened ages ago. It lent a very wonderful quality to the story, I thought.

  • by jd (1658)
    ...the Webb telescope is launched friday '13th, will it go around killing galaxies instead?
  • I don't know anything about cosmology, let's get that out in the open right away. Astronomy and Astrology are close cousins in my ignorant mind :)

    So it's taken the light 12 odd billion years to arrive here, It always makes me wonder whether the galaxy is 12 billion years old, or 12 billion years away - and if it is the latter, does that in any way compare to the former?

    Could you conceivably see the big bang with Hubble if the universe is only 13.5 billion years old? Does this mean they know roughly where th
    • Re: (Score:3, Insightful)

      by EEPROMS (889169)
      Astrology is to Astronomy as is a someone with a dowling rod is to a civil engineer.
    • by ChromaticDragon (1034458) on Tuesday February 12, 2008 @10:24PM (#22401698)

      So it's taken the light 12 odd billion years to arrive here, It always makes me wonder whether the galaxy is 12 billion years old, or 12 billion years away - and if it is the latter, does that in any way compare to the former?

      We get a picture of a galaxy. We can tell from redshift of the characteristics of the light that we're getting to create that picture how far/old that light is. Since we're using the understanding that the speed of light is and has always been constant, how far away and how old are directly related. What people mean is that we're seeing a picture of a galaxy from a long, long time ago. Assuming it's still there, it'd be at least 12.8 billion years old.

      Could you conceivably see the big bang with Hubble if the universe is only 13.5 billion years old? Does this mean they know roughly where the universe began and are looking in that direction? If they looked in the other direction, would they run out of things to see because nothing in the universe has traveled out that far yet?

      Sure we know where the universe began - in your belly button. Seriously, the question doesn't quite make sense (or the answer doesn't make sense - take your pick). The analogy that might help is to think of the universe like a balloon - but only the rubber sheet. not the entire thing. Light, matter, everything is within and goes round that rubber sheet. The balloon is expanding. That's what's causing the redshift, more or less. If we reverse time and view the balloon as shrinking, everything collapses into the Big Bang. But there is no "place" where the universe started. It started everywhere.

      However, I believe there is a theoretical limit beyond which we don't expect to be able to see anything. But it isn't because of the reasons you're positing. It's not because stuff isn't that far away. If I recall correctly, it has more to do with when we believe there was stuff to see.

      And to see things that happened 12 billion years ago, would you need to look 12 billion years in the other direction from where they actually happened?

      You would need to BE 12-billion light years in ANY direction from said event (and looking towards the event) AT 12-billion years past the event. Then the light from the event reaches you and you can see what happened 12 billion years ago. Say I fire 20 billion baseballs simultaneously in all directions at 60 miles an hour. Assuming no friction, interference, etc., if you are 60 miles away from where I was when I threw the balls at one hour after I threw them, you're gonna get smacked upside the head with a baseball and you'll get to experience my toss from an hour ago, 60 miles away.

      Part of what makes this particular story rather interesting, is that not a lot of light is going to reach us from something that far away. If you think of my 20 billion baseballs, you can understand that at some distance you won't get hit because the balls get spread real thin rather quickly. The light from that galaxy is spread VERY thin. The fact we're seeing it at all is because of some nifty little tricks and a whole lot of luck. Basically we're taking advantage of an ENORMOUS magnifying glass to get a better look.

      • by kalirion (728907)
        What if the redshift is caused by a much closer galaxy moving away from us normally (i.e. not through universal expansion). It could be a mere billion light years away, but with enough relative velocity it would "look" more distant. Or am I misunderstanding something?
        • by khallow (566160)
          No, you're not misunderstanding. The intervening gravitational lens complicates matters considerably too. But we don't have an idea for what would cause violation of Hubble's Law [wikipedia.org] with velocities being a significant fraction of the speed of light. To give context, we have a pretty good idea what are local galaxies (eg, large size, good detail). And none of them show extremely high velocities.
          • by kalirion (728907)
            Wouldn't that be like comparing the relative velocity of Alpha Centauri to that of a star on the opposite edge of the Milky Way?
            • by khallow (566160)
              Not really. First, the distances you mention are on the order of two magnitudes greater in ratio. In other words, we have a pretty good idea what's going on with half a billion lightyears of us. Second, unlike the galaxy, we observe a well-defined universal expansion with no observable rotation or other large scale movement. It doesn't mean you're wrong, but I'd think we'd see more incompatible observations, if there were huge velocity variations from Hubble's Law.
        • by JohnFluxx (413620)
          The spacetime on which it sits is moving 3 or 4 times the speed of light, relative to us. Even if it was moving really quite fast, it wouldn't affect the redshift by all that much.
          • by kalirion (728907)
            The spacetime on which it sits is moving 3 or 4 times the speed of light, relative to us.

            Seems a bit circular. "We know galaxy is far away because the redshift is caused by expansion. We know redshift is caused by expansion because galaxy is far away."

            And maybe I don't understand relativity, but it seems to me that if our galaxy and that one were moving away from each other (due to expansion) at 3 or 4 times the speed of light at the time that the light was emitted, we'd never see that light. I'm pretty s
            • by JohnFluxx (413620)
              Yes, you'll never see any light that it emits _now_. But you are seeing the light that it emitted 18 billion years ago, a time when it was moving close, but not faster than, the speed of light, relative to us.

              It can seem somewhat circular, but pretty much everything in physics is. E.g.:
              We know gravity exists because when we drop things, they fall. We know something will fall because gravity will pull it down.
              and
              The electric field strength is defined as proportional to force
              • by kalirion (728907)
                Yes, you'll never see any light that it emits _now_. But you are seeing the light that it emitted 18 billion years ago, a time when it was moving close, but not faster than, the speed of light, relative to us.

                I'm guessing you mean 12.8 billion years ago. In any case this makes your comment of "The spacetime on which it sits is moving 3 or 4 times the speed of light, relative to us. Even if it was moving really quite fast, it wouldn't affect the redshift by all that much." invalid because the redshift is ba
                • by JohnFluxx (413620)
                  Yeah, you'd think so. But almost all of the red shift occurs _as it is moving through space_.

                  The light has a certain wavelength. But then spacetime expands underneath, as it is moving. So the wavelength increases (red shifts).

                  By the time it reaches us, it's redshift indicates a speed that is pretty much equal to the current speed of the galaxy.

                  (And yeah, I meant 12.8 billion years)
    • Re: (Score:2, Informative)

      by chrisb33 (964639)
      A lot of cosmology is non-intuitive, but that's what makes it cool :) I'm not an expert myself, but I can point you in the right direction:

      Could you conceivably see the big bang with Hubble if the universe is only 13.5 billion years old?

      Essentially, yes! You can't see quite back to the big bang itself because at the very beginning the temperatures were too high to allow photons to move freely, but you can get pretty close by observing the Cosmic Microwave Background [wikipedia.org] which was released when the universe became transparent.

      Does this mean they know roughly where the universe began and are looking in that direction? If they looked in the other direction, would they run out of things to see because nothing in the universe has traveled out that far yet?

      This is always a sticking point of understanding, but the answer is simple - th

      • by Scruss (1130173)
        Essentially you are the center of the universe, your own universe. That for some poeple is hard to get their heads around, once you do it starts to get easier. So next time someone says to you "You think you are just the center of the universe dont you?" You can honestly say, "Yes, yes I do."
    • by PFI_Optix (936301)
      I can't imagine how we'd ever see the Big Bang, as the light from it would be on the leading edge of the universe expanding ever outward. If the universe is expanding from a single point in space, we're probably not that far away from being able to determine where that point, within a sizable margin of error.

      If we were to look away from the point of origin, we should be able to see the same leading edge, whatever is closest to the Big Bang light that emits its own light so that we can see it. This assumes,
    • by JohnFluxx (413620)
      It means that the galaxy is 12 billion years old. Its current distance would be several times further away - possibly 90 billion light years away or so (just rough estimate, without doing the calculations).

      The reason is because while the light has been travelling to us, the spacetime has been expanding, making its distance a lot larger.

      In fact, the galaxy is probably moving many times the speed of light away from us currently.

      Others have pointed out that the big bang happened 'everywhere'. This is correct
  • by Anonymous Coward
    How do they know how old it is?

    Because it's so far away?

    How do they know it's so far away?

    Because of how long its light took to reach us?

    How do they know how long it's light took to reach us?

    Well, light goes so fast, and it gets pulled this way and that on the way here and uhhhhhhhhh, well, we're totally guessing, OKAY!!!!!!!!

    lol
    • They assume the speed of light has been constant over time (a reasonable assumption), and then they can easily calculate both the spatial and temporal distance.
  • What's a 'large millimeter' when it's at home?

    Why not use a small millimeter? Is size really that important?

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