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Distant Universe

Discussion in 'Science & Technology' started by Drone, May 6, 2012.

  1. Drone

    Drone

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    The most distant galaxy ever detected. It's called MACS 1149-JD and it's .... 13.2 billion light-years away

    [​IMG]

    That's really far away.

    http://phys.org/news/2012-09-astrophysicists-spy-ultra-distant-galaxy-cosmic.html

    It was really hard to detect it, say thanks to gravitational lensing and strongest telescopes, but unlike previous detections of galaxy candidates in this age range, which were only glimpsed in a single color, this newfound galaxy has been seen in five different wavebands.



    Totally unrelated: btw the oldest object, a star called HE 1523-0901 which is 13.2 billion years old located only 7500 ly from Earth.

    And one of the oldest globular clusters is M15, located in the constellation Pegasus (~ 35000 ly away). It's 12 billion years old.

    Last edited: Dec 7, 2012
  2. Aquinus

    Aquinus Resident Wat-man

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    If something is 13 billion light years away, aren't we seeing that galaxy from 13 billion years ago since it takes billions of years for the light to actually get to us? So wouldn't it be more accurate that this galaxy was 13 billion light years away from us, 13 billion years ago and we might be witnessing something that happened in the past? So technically wouldn't that mean that it was a protocluster that long ago? Couldn't it be very possible that the galaxy has already formed and we just haven't seen it yet?
  3. Drone

    Drone

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    In the article (and so in my post above) it's said that galaxy is less than 200 million years old (not even a toddler). Indeed it was so 13.2 billion years ago. Now that galaxy is full grown but to see it you need to wait another 13.2 billion years.
  4. Aquinus

    Aquinus Resident Wat-man

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    That just means that the galaxy is 13.4 billion years old, and we're seeing it from 13.2 billion years ago. We're just seeing the past, the galaxy isn't actually that young. It's more of a "how things used to be." So we can't say its forming because over 13.2 billion years, it most likely has mostly formed by now. Just because we haven't seen it yet doesn't mean it hasn't happened. :p

    "If a tree in the forest falls and there is no one to hear it, did the tree actually make a noise when it fell?"
  5. Drone

    Drone

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    That can be said just about everything you see in everyday life :p It happens because it's limited by speed of light. Carl Sagan explained it well with a "magical camera".

  6. Easy Rhino

    Easy Rhino Linux Advocate

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    when you look through a telescope you are indeed time traveling. hell, if you have working eyes you are time traveling. the computer monitor that you see in front of you...well that image your brain processed is of how that monitor existed 0.000000000000000000000000000000001 seconds ago. so the computer monitor you "see" is not the same one that actually exists the moment you see it. now try and fall asleep tonight :pimp:
  7. Aquinus

    Aquinus Resident Wat-man

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    .000000000000001 seconds is a little less than 13.2 billion years. Also, your brain needs to interpret what you're seeing, so it's a little longer so you're working in the millisecond range. :)

    The point I'm trying to say is that the time it takes light to get to you at a monitor isn't significant because very little changes have taken place since the light was emitted and when you saw it. Another galaxy on the other hand is nothing like it is right now, with how we're seeing it. That's all I'm saying.
  8. Drone

    Drone

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    It would be awesome when future humans will travel for long distances. Then they could look back from some distant galaxy at young Earth and see how life formed.
  9. Easy Rhino

    Easy Rhino Linux Advocate

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    well duh. but it still shows the point of relativity. perception is reality to all living creatures.
  10. Benetanegia

    Benetanegia New Member

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    As stupid as it sounds, I never thought of that. What a practical way of learning history!! Amazing stuff.
  11. Drone

    Drone

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    Lol yeah but I was only 50% serious about that. Let's say we travel 50 000 light years away and look back. How strong a telescope has to be to see what's happening on Earth's surface. How far could we zoom in :eek:
  12. Easy Rhino

    Easy Rhino Linux Advocate

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    you would have to travel faster than the speed of light for it to work which would essentially be traveling through time.
  13. phanbuey

    phanbuey

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    we would have to teleport a few billion light years away, and then point a telescope powerful enough to record what little incoming light is left.

    or we could just record history by making up stuff for the parts that we dont know/like like we have always done :D .
  14. Drone

    Drone

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    I see. What if it was possible if that light (from the young Earth) could be reflected and sent back and people of let's say 50th century could see it.
  15. Benetanegia

    Benetanegia New Member

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    :laugh: Come on guys we are talking about FTL travel defying or circumventing (warp drive, wormhole, etc.) the laws of physics and you're all nitpicking about the telescope*?? :p

    EDIT: And yeah I was talking about more like travelling 500 light years. Maybe even only travel ~50 light years and see who the fuck killed JFK. Both the shorter travel and required augmentation, are more realistic.

    And TBH what real interest would really have to see the Earth billions of years ago? It' would be just a normal planet, in a normal star, We have trillions of such objects we can study from "home".
  16. Aquinus

    Aquinus Resident Wat-man

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    Heisenberg would disagree with you.

    The further away you travel from earth the less light that actually gets to you coming from our planet. There could come a point where you would be too far to see it, and honestly you don't have to get too far away from our solar system for that to happen. Earth is tiny in the grand scheme of things.
  17. Drone

    Drone

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    Heisenberg was a pessimist. There's gravitational lensing.
  18. Aquinus

    Aquinus Resident Wat-man

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    You can't focus light if it isn't any there. No kind of lense is going to help you here especially with how far away you have to go from the earth. :confused:
  19. Benetanegia

    Benetanegia New Member

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    Light is there. Maybe too dim for current tech to extract any information from it. Maybe too dispersed. The fact that we can see galaxies 13.4 billion light years away from us says that, first light is there, and second that it can stay "focused" enough for us to see.

    A massive cloud of nanoreceptors in space each capable of detecting light intensity down to a single photon or neutrino and capable of "recording" their momentum (the loss of position info is irrelevant, position is roughly that of the receptor). Info passed to a "computer" capable of interpreting that info, determining the procedence of particles based on momentum and nearby objects (starts, galaxies, etc) that might have influenced are processed and recognized and taken into account too. And finally constructing an "aproximate" image. Aproximate and vague in subatomic level, but since resolution is down to subatomic level, the accuracy of each "pixel" becomes irrelevant, the overall picture is accurate to our eyes.
    Last edited: Sep 21, 2012
  20. 3870x2

    3870x2

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    Its conceited, and some of us here at TPU are Christians, and science freaks.

    Atheists aren't the only people that are happy about the separation of church and state.:toast:

    With the equivalent hubble telescope at your house, you still wouldn't be able to see your house from your job. Going by this logic your house must be very far away:D

    You would have to be travelling faster than the speed of light to be able to see light from the earth in the past, it isn't just a matter of travelling x distance. This could be alleviated by warping (folding space-time) which has recently been revisited due to some amazing discoveries.

    I have a feeling you know all of this already.
    Last edited: Sep 21, 2012
  21. Drone

    Drone

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    Yes I do know that. I was thinking about wormholes because space and time are related. But the universe is a strange thing even if it's 13.7 billion years old, there's something beyond that point because the diameter of the universe is much bigger than 13.7.
  22. 3870x2

    3870x2

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    BTW I love your enthusiasm in this sub-forum, keep up the amazing threads!
    Drone says thanks.
  23. Drone

    Drone

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    Hubble eXtreme Deep Field (XDF)

    [​IMG]

    It is the deepest image of the sky ever obtained and reveals the faintest and most distant galaxies ever seen. It allows us to explore further back in time than ever before. :eek:

    That's so impressive! It's amazing how the Universe is truly changing as it ages.

    Fascinating. Astronomers plan to push the XDF even deeper, into a time when the first stars and galaxies formed and filled the early "dark ages" of the Universe with light. Good luck to them :toast:

    http://phys.org/news/2012-09-hubble-extreme-deepest-view-universe.html
  24. xBruce88x

    xBruce88x

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    There's still one more thing to consider... earth's location "x" amount of years ago when you go to look back at it... since earth is always moving it won't be "here" when you go to look back at it "x" lightyears away, you'd have to figure out where the old earth would be at in the past.

    this brings up an interesting theory (well i just thought of it)... if we could accurately pinpoint earth's exact location say... 50 light years away (and therefore 50years) ago, would it be possible to aim the telescope at that exact spot and see our old reflection if you will...
    Last edited: Sep 27, 2012
  25. largon New Member

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    If we found a way to travel that 50 LYs in less than 50 years (let alone several millenia) I'd reckon we'd have more interesting things to do than building a telescope to look back at Earth only to see ourselves of the past pondering on how to travel to that spot 50 LYs away...

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