• Deepest galaxy cluster ever pictured by Hubble
    125 replies, posted
[IMG]http://news.bbcimg.co.uk/media/images/72141000/jpg/_72141567_abell2744.jpg[/IMG] [QUOTE]The "deepest ever" image of a group of galaxies - "Pandora's Cluster" - has been captured by the Hubble Space Telescope. The blue arcs in the picture are distant galaxies as they appeared 12 billion years ago - not long after the Big Bang. The hidden objects are revealed through the "magnifying lens" of the cluster Abell 2744. The image was unveiled at the 223rd meeting of the American Astronomical Society (AAS) in Washington DC. It is the first in a set of super-deep views of the Universe taken by Hubble's Frontier Fields observing programme, and published on the Arxiv preprint server. In the foreground are the colourful spirals and elliptical galaxies of Abell 2744, a massive cluster in the constellation Sculptor. It is nicknamed Pandora for its strange and violent formation history, which unleashed many new phenomena to astronomers.[/QUOTE] SOURCE: [url]http://www.bbc.co.uk/news/science-environment-25648219[/url]
Wild. So because of the finite speed of light, we're watching the early universe unfold. Shouldn't it be possible with further study to get an idea of the general location of the big bang?
Dude, the big bang was everywhere. At least, that's what my last-semester astronomy class told me.
Well, I suppose the fabric of the universe expanded because of the big bang, so it was technically everywhere at once. But surely there must be a region of space at the centre of the universe that can somehow be detected by observing the motion of galaxies?
[QUOTE=archangel125;43466327]Well, I suppose the fabric of the universe expanded because of the big bang, so it was technically everywhere at once. But surely there must be a region of space at the centre of the universe that can somehow be detected by observing the motion of galaxies?[/QUOTE] Well I suppose if we followed all of the galaxies backwards until they are in one place, that would be where the Big Bang happened
The universe is expanding from all points in space.
Nope. The way it basically works is that you can pick a centre for the expansion anywhere and it is right. Basically everywhere really is the centre. There is a good minutephysics on this, but I'm on my phone. Edit: Thanks
[media]http://www.youtube.com/watch?v=W4c-gX9MT1Q[/media]
[QUOTE=Why485;43466405][media]http://www.youtube.com/watch?v=W4c-gX9MT1Q[/media][/QUOTE] but... it didn't answer the question
Why is everything blue? Shouldn't it be red due to redshift?
space is biiiiig
[QUOTE=SIRIUS;43466557]but... it didn't answer the question[/QUOTE] we don't know. (we would have to not be in the universe to know where the universe is.)
[QUOTE=Laserbeams;43466775]Why is everything blue? Shouldn't it be red due to redshift?[/QUOTE] afaik its because of the "magnifying" glass (a galaxy) they used to get the image. [quote]Normally too dim for Hubble to see, these galaxies were revealed through gravitational lensing focused on the massive cluster Abell 1689 in the constellation Ursa Major.[/quote] [quote]They appear brighter thanks to the lensing phenomenon, but are also smeared, stretched and duplicated - like faces in a funhouse mirror[/quote] but yea, unless the image is a modified visual spectrum, it should be red
I just find it staggering that we can take pictures of objects (however large they are) that are 12 BILLION light-years away. We just invented the car a little over a century ago and we're doing this. For all our faults, we are a remarkable species.
[QUOTE=SIRIUS;43466557]but... it didn't answer the question[/QUOTE] It did. Just like everybody said in the thread already, the Big Bang was everywhere. There is no central point you can trace back all the galaxies from, because the Big Bang wasn't an explosion at some specific point. It was a rapid expansion of all of space and time, and that expansion is still happening now.
I love space. I'd fuck space
[QUOTE=Why485;43466907]It did. Just like everybody said in the thread already, the Big Bang was everywhere. There is no central point you can trace back all the galaxies from because the Big Bang wasn't an explosion at some specific point. It was an explosion of all of space and time, and expansion that it still happening right now.[/QUOTE] That doesnt even make sense. Its all going away from a point. If it wasnt a point, we'd see blueshift in some galaxies.
[QUOTE=areolop;43466929]That doesnt even make sense. Its all going away from a point. If it wasnt a point, we'd see blueshift in some galaxies.[/QUOTE] The point you're referring to is your point of reference, which for us would be the planet Earth. This is why everything appears to be moving away from us. If you were in some other galaxy, then the Milky Way, along with all other galaxies, would also appear to be moving away from you. The video covers this exact same thing. Another way to think about the Big Bang, and why there's no center, is the balloon analogy. Imagine if the surface of a balloon represented the entire universe. When the big bang happened, that balloon was just a tiny dot, but it quickly inflated to a much larger size. This makes everything on the balloons surface move away from each other because the space between everything is getting larger. From the surface of the balloon, which would be our universe, what is the "center" from which everything is expanding? There isn't one. No matter where you stand, everything is moving away from you. There is no central point of expansion.
[QUOTE=archangel125;43466327]Well, I suppose the fabric of the universe expanded because of the big bang, so it was technically everywhere at once. But surely there must be a region of space at the centre of the universe that can somehow be detected by observing the motion of galaxies?[/QUOTE] (I'm by no means an expert on this but this is how I understand it.) What you have to understand is that if our current understanding of the universe is right its not just the stuff expanding in the universe its the literal space it occupies. Imagine a the universe is room and literally every part of it is expanding pushing all of the furniture away from each other faster than light itself at some points. Its impossible to really gauge the middle because the distances between objects are constantly changing. Its not as simple as finding where a bomb went off from the debris.(this is how I think a lot of people visualize it.) [QUOTE=Why485;43466991]The point you're referring to is your point of reference, which for us would be the planet Earth. This is why everything appears to be moving away from us. If you were in some other galaxy, then the Milky Way, along with all other galaxies, would also appear to be moving away from you. The video literally covers this exact same thing. Another way to think about the Big Bang, and why there's no center, is the balloon analogy. Imagine if the surface of a balloon represented the entire universe. When the big bang happened, that balloon was just a tiny dot, but it quickly inflated to a much larger size. This makes everything on the balloons surface move away from each other because the space between everything is getting larger. From the surface of the balloon, which would be our universe, what is the "center" from which everything is expanding? There isn't one. No matter where you stand, everything is moving away from you. There is no central point of expansion.[/QUOTE] You explained that much better than I did.
It looks like a clusterfuck.
It is sometimes hard to fully realize the scale of the universe in which we live in. I mean, we have barely made it out of our own solar system and that seems like massive achievement alone. Just looking at that picture makes me feel pathetically small.
and the expansion theory isnt proven. Its just accepted until we have further knowledge of matter.. [4% Baryon - what we see, 23% cold dark matter, 73% dark energy] Theres three theories for expansion: Closed Flat and Open [img]http://i.imgur.com/p8OwjlU.png[/img]
Anyone else get the feeling of being insignificant when you look at pictures like that and realize how grand the scale of the universe truly is?
the cosmology chapter from my astronomy book, as well as my astronomy teacher, said that most of the relevant body of researchers agree with a flat universe. it was tough to understand at the time but i sort of just started believing it for now. i quite like it the best out of the three, actually.
[QUOTE=Cureless;43467136]Anyone else get the feeling of being insignificant when you look at pictures like that and realize how grand the scale of the universe truly is?[/QUOTE] I think my feelings on space are best summed up as [img]https://dl.dropboxusercontent.com/u/5636656/krad.gif[/img]
[QUOTE=Why485;43466907]It did. Just like everybody said in the thread already, the Big Bang was everywhere. There is no central point you can trace back all the galaxies from, because the Big Bang wasn't an explosion at some specific point. It was a rapid expansion of all of space and time, and that expansion is still happening now.[/QUOTE] I really don't want to be a jackass but I'm pretty sure you're wrong, the minutephysics video is right in some way, but it is wrong as well. If you take the ENTIRE universe as a frame of reference, you can find where the big bang happened. Of course, we can't use the entire universe as a frame of reference because we can't even see all of it (because of the speed of light, of course). However, there is a place where the big bang happened, though I'm sure it's very empty right about now.
[QUOTE=Advancedrock;43467670]I really don't want to be a jackass but I'm pretty sure you're wrong, the minutephysics video is right in some way, but it is wrong as well. If you take the ENTIRE universe as a frame of reference, you can find where the big bang happened. Of course, we can't use the entire universe as a frame of reference because we can't even see all of it (because of the speed of light, of course). However, there is a place where the big bang happened, though I'm sure it's very empty right about now.[/QUOTE] What you're implying with that is that the universe expanded into something. (If I'm understanding you right, which I may not have.) That there's something outside the universe in which the universe expanded into. You aren't the first to suggest that, but it's not the current commonly accepted theory. The current and accepted theory is as the video and I described it. Here's a couple more articles written by astronomers on the subject: [url]http://curious.astro.cornell.edu/question.php?number=71[/url] [url]http://www.astronomycast.com/2008/02/ep-77-where-is-the-centre-of-the-universe/[/url] [url]http://math.ucr.edu/home/baez/physics/Relativity/GR/centre.html[/url] The balloon analogy I mentioned earlier isn't perfect, but it's a very good approximation. [quote]The balloon analogy is very good but needs to be understood properly—otherwise it can cause more confusion. As Hoyle said, "There are several important respects in which it is definitely misleading." It is important to appreciate that three-dimensional space is to be compared with the two-dimensional surface of the balloon. The surface is homogeneous with no point that should be picked out as the centre. The centre of the balloon itself is not on the surface, and should not be thought of as the centre of the universe. If it helps, you can think of the radial direction in the balloon as time. This was what Hoyle suggested, but it can also be confusing. It is better to regard points off the surface as not being part of the universe at all. As Gauss discovered at the beginning of the 19th century, properties of space such as curvature can be described in terms of intrinsic quantities that can be measured without needing to think about what it is curving in. So space can be curved without there being any other dimensions "outside". Gauss even tried to determine the curvature of space by measuring the angles of a large triangle between three hill tops.[/quote]
to bring down the number of dimensions involved, try finding a point on the surface of a sphere that can be proven as the "center". take the ambiguity of that and scale it up to three dimensions and you'll have what i thought was a good analogy five minutes ago
[QUOTE=JXZ;43468032]to bring down the number of dimensions involved, try finding a point on the surface of a sphere that can be proven as the "center". take the ambiguity of that and scale it up to three dimensions and you'll have what i thought was a good analogy five minutes ago[/QUOTE] How do we know that its a sphere? How do we know if theres not another repenting force changing our expansion? This is some serious space shit
[QUOTE=Advancedrock;43467670]I really don't want to be a jackass but I'm pretty sure you're wrong, the minutephysics video is right in some way, but it is wrong as well. If you take the ENTIRE universe as a frame of reference, you can find where the big bang happened. Of course, we can't use the entire universe as a frame of reference because we can't even see all of it (because of the speed of light, of course). However, there is a place where the big bang happened, though I'm sure it's very empty right about now.[/QUOTE] If that was the case, we'd see blue shift in everything between us and the 'centre' - but everything we view is red shifted - everything is moving away from everything else, which doesn't make sense if everything was expanding from a single defined centre.
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