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Hubble Finds a Galaxy 12.8 Billion Years Old

Posted by kdawson on 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)."

3 of 134 comments (clear)

  1. Re:Do they cut it in half and count the rings? by TheOnlyJuztyn · · Score: 3, Informative

    Redshift

  2. Old and new... by Mantaar · · Score: 5, Informative

    Depending on your particular point in time. See, I'm not far a way from Paris, since I live in Europe. Someone in Tokyo though is pretty far away from Paris. Now you have to understand that 'time' is nothing more than another dimension. The only difference is that so far we only know how to move in one direction. So if something is far away from you in time, this could mean it's either in the future or very, very old, from your point of view.

    From our point of view, this galaxy is very old, since it existed (in the form in which we are seeing it today) a looong time ago. But if we take, say the Big Bang as the point in time to relate to, this thing isn't all that old, but rather new, young, so to speak.

    Keep in mind though, that we are seeing a very young galaxy now because the light has been traveling a while. Sort of like... I take a picture of me and then send it to India. Because of the crude nature of the Indian postal system (and the ones in between), you will only receive this picture one month or so after it was taken. So I might have grown a beard. You are seeing a young galaxy, because the medium you're seeing it through took a while to reach us. But in reality, this galaxy is rather old, because it has been growing old ever since the photons that create the image we are seeing today departed from that galaxy to finally interact with our eyes and fulfill their destiny (ouch, that was really a pathetic attempt at making this sound great).

    sigh. I'm only a layman, so I might have explained this pretty badly. You might want to take a look at this site: http://en.wikipedia.org/wiki/Light_cone it explains the general concept behind this all. Ah yeah, and relativity is worth a read, too ;-)

    --
    I'm an infovore...
  3. Re:This kind of thing confuses me by ChromaticDragon · · Score: 3, Informative

    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.