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Astronomers Find Most Distant Protocluster of Galaxies
The Bad Astronomer writes "Using the monster 8.2-meter Subaru telescope, astronomers have identified the most distant cluster of galaxies ever found: a collection of galaxies at a staggering distance of 12.7 billion light years. This is the most distant cluster ever seen that has been confirmed spectroscopically (PDF). Technically, it's a protocluster, since it's so young — seen only a billion years after the Big Bang itself — the cluster must still be in the process of formation."
Includes all-wheel drive and a boxer-engine.
It is incredible what we can accomplish as humans, imagine if we did not waste trillions on useless battles for the hear and minds of primitive retarded people with stone age believes.
12.7 billion years ago it might have been 12.7 billion light years away, but where is it now?
Exactly where we see it. The 12.7 billion years haven't passed, because there is no common point of reference between us and them for that time to have passed in.
"Now" and "then" makes no sense except for local distances, without introducing FTL, time travel and violating causality. We can only measure round trip times, not one way time.
The photons haven't experienced 12.7 billion years of travel - they just left.
If this makes your head hurt, good.
The funny thing about relativity is that is that in our frame of reference, this is happening NOW, not 12.7 billion years ago.
That's what I've never understood. For it to be happening right now, to me, it stands to reason that if we look far enough away we could see the light from the big bang. Which means that everything that has ever happened is always happening everywhere. Which means that we always have existed in the state that we exist in today and will always exist in the state that we existed in billions of years ago.
Oh no, I've gone cross-eyed.
Perhaps the universe is in fact curved and 12.7 billion years "across" and we are looking at the formation of the milky way and other local galaxies...
Ascalante: Your bride is over 3,000 years old.
Kull: She told me she was 19!
Wrong on several counts. What the 12.7 refers to is when the light left the cluster in question (in billions of years). At the time the light left the cluster it was actually much closer to us than 12.7 light years. The observable universe is actually larger in light years than the time since the Big Bang, due to the expansion of space. This expansion also stretched the travel time for the cluster's light to reach us. Now the cluster (to the extent 'Now' has any meaning) may be 25+ light years away (I apologize for the imprecision, as I don't have the exact figures at hand).
There is no absolute "now" in the universe since we have the concept of relative simultaneity. The photons reaching us from there have "just left" according to them even though they may seem to have traveled a huge distance according to a third party observer. Since time dilates and space shrinks as you approach the speed of light, every photon reaches its destination "instantly"
So while we can talk about "now" and "then", it's meaningless on an absolute scale. For this reason, when light from someplace reaches us, we treat it as if it's happening "now". Because if you were a photon, you would reach every place instantly.
Short answer: yes. For anything traveling at luminal speeds, time is not perceived. If you were a photon, it might take you 12.7 billion years to get here, but for you it is an instant.
The world's burning. Moped Jesus spotted on I50. Details at 11.
The speed of light is infinite, because due to relativistic effects, time has stopped. Only an outside observer sees something moving at the "speed of light"; to the photon itself, no time passes.
You couldn't see light from the Big Bang itself because it took until nearly 400,000 years after the Big Bang for the Universe to cool sufficiently for photons to find a clear path through the charged ions. It's this first wave of freed photons that form the Cosmic Microwave Background Radiation.
The world's burning. Moped Jesus spotted on I50. Details at 11.
To paraphrase: Astronomer: What am I looking at? When does this happen in the Big Bang? Telescope Operator: Now. You're looking at now, sir. Everything that happens now, is happening now. Astronomer: What happened to then? Telescope Operator: We passed then. Astronomer: When? Telescope Operator: Just now. We're at now now. Astronomer: Go back to then. Telescope Operator: When? Astronomer: Now. Telescope Operator: Now? Astronomer: Now. Telescope Operator: I can't. Astronomer: Why? Telescope Operator: We missed it. Astronomer: When? Telescope Operator: Just now. Astronomer: When will then be now? Telescope Operator: Soon.
Whenever one of these astronomy articles comes up about seeing a galaxy or cluster "near the big bang", there's one fundamental question which has always bothered me. . .
We are told that the universe is expanding, and has been expanding for about 14 Billion years. This means that everything was much closer together back 13 Billion years ago (when the summary says we are seeing the light from). Also, light travels much faster than the universe expands. So. . . why didn't the light pass us billions of years ago?
I realize that light takes time to travel, and that's the idea behind the idea that we can "look back in time" when we look at very distant astronomical objects. . . but. . . again, why didn't the light PASS US billions of years ago, since light expands outward faster than the universe expands outward? Wouldn't the universe need to have been expanding at almost the speed of light, for us to just now receive light from 13 Bn years ago? Well, that is, that the expansion would have had to happen at about 13/14 C?
Dont know accurately, though there is a way to measure that. but based on Dark energy theory,It would be around 40 billion light years away right now.
-- It is the mark of an educated mind to be able to entertain a thought without accepting it. -- Aristotle
From the photon's point of reference, it traveled instantaneously. From our point of reference, it took 12.7 billion years for the photons to reach us.
Therefore, what we're seeing is how it looked 12.7 billion years ago.
Your error is to apply the word "ago". That implies that time passes here and there in the same frame of reference - a universal clock, if you like. That doesn't exist - time is only a local phenomenon.
From our point of view, it did not take 12.7 billion years for the photons to get here, because from our point of view, 12.7 billion years ago, that part of the universe didn't exist. There is no "then" common to us and them; only a blossom slowly opening and revealing parts of the universe to us that's new to us.
Implying the photons were teleported straight to the lens of the Subaru Telescope.
No, implying that distance and time aren't constants, but vary depending on your frame of reference.
The universe is expanding at the exact speed of light at it's "edge" (at least the edge we can just barely not see). It's expansion appears to slow on objects closer to us. So this light has been trying to travel across space as it was expanding. The distances it had to travel kept expanding and it eventually reached us after traveling for 12.7B light years (from our perspective).
Oh come on, do you guys just make this stuff up as you go? ;-)
No, seriously, I actually understood that we were seeing what was there 12.7 billion years ago -- WTF does it mean then? I thought this was what existed 12.7 billion years ago from our point of view.
That sounds dirty, and I'm not sure if it actually sheds any, er, light on this.
I think this actually confirms what I knew in university -- astrophysicists must spend much of their time drunk in order to be able to reconcile this stuff with everything else.
Lost at C:>. Found at C.
This may help:
http://en.wikipedia.org/wiki/Metric_expansion_of_space
"Who is the Journal of Quantum Physics going to believe?" --Stephen Hawking
It's always fun to watch pseudo-critical morons dance their little dance. How, pray tell, does any of this cause problems for Big Bang cosmology?
The world's burning. Moped Jesus spotted on I50. Details at 11.
No, seriously, I actually understood that we were seeing what was there 12.7 billion years ago
There you use that word again. "Ago" doesn't make sense at relativistic speeds and vast distances.
It's 12.7 billion light-years distant. Light-year is a distance, not an age.
If you travelled that distance and back at the speed of light, we would have to wait 25.4 billion years for your return. But your travel would not take that time. A person at your turning point, 12.7 billion light years distant, would not have seen you 12.7 billion years ago when you come back to us. He would just have seen you leave, and you would agree. For you, the universe contracted into near nothing and aged rapidly - for him, that aging hasn't happened yet.
All it really proves is that humans cannot comprehend distance as vast as this.
My understanding, and im sure its flawed, is that something like a Photon doesn't experience time. To it, it pops into and out of existance, one end at the surface of a star in a galaxy cluster 12.7 billion light years away, the other end at the Subaru telescope in this case. Just as suddenly as this happends, its gone again.
This is because its traveling at the speed of light. Time and space are linked. Beyond this my understanding breaks down, but I suspect it has something to do with moving through space at that speed, and our misunderstanding of what time really is. We experience time where there is a 'universal' time in our refrence, because really anything we need to reference is already here, moving with us at the same speed around the sun. There is no 12.7 billion years ago to this galaxy, per our reference, because nothing that is happening 'now' as you and I understand it can possibly affect us here, without violating the speed of light. We're not looking at a galaxy we're literally looking back in time at a galaxy. If this galaxy exploded ripping a hole in the fabric of space-time and ended the entire universe right now, we'd not be aware of it for another 12.7 billion years. Per our reference, nothing has happened, or will happen, for that span of time. So in effect, for us, what we're seeing is what IS happening.
Now please correct my misunderstanding, those of you lurking out there who do know better, because i'd love to understand all this!
"..... distance of 12.7 billion light years. "
If an object is 12.7 billion light years from us, the time that light takes to travel to us takes.... 12.7 billion years.
" ...the cluster must still be in the process of formation."
Nope. It _was_ in the process of formation about 12.7 billion years ago. Now that said cluster is 12.7 billion years older, and it is either very old or blown away to bits and pieces some time ago.
The distance works like a time machine, and for example we see and experience our Sun about 8 minutes 11 seconds later, which is the distance between Earth and Sun in "lightyears".
Only an outside observer sees something moving at the "speed of light"; to the photon itself, no time passes.
Not really. This was a research project, which means the very last part of the photon's trip was through part of academia. Which means it felt like exactly like 12.7 billion years.
Don't disappoint your bird dog. Go to the range.
The post I replied to was written by a moron who uses words he does not understand to make points he cannot support. If you have the words of someone who isn't a moron, then by all means provide them. This is my official "Not Polite To Worthless Fucktards Day", and you sir, qualify, with pathetic idiotic claims that you have somehow debunked Big Bang cosmology.
The world's burning. Moped Jesus spotted on I50. Details at 11.
A quick answer is to say that the universe assuredly is expanding faster than the speed of light. Or rather, it's expanding at some rate, and two sufficiently distant points will be receding from one another at the speed of light, or even greater than the speed of light. (You've no doubt heard that "nothing can travel faster than c" but in fact it's really that "energy (hence information) cannot propagate faster than c"... according to relativity spacetime itself can expand at any speed.)
A more detailed explanation can be found by reading this. The take-home message is that it's not so intuitive to think about time and distances when spacetime itself is changing as a function of time. Let's say a star is 1 billion light-years (Gly) from Earth. It emits light, and the light travels towards Earth. But since the space in between is expanding while the light is travelling, it will take more than 1 billion years for the light to reach us. And when it does, the star will no longer be 1 billion light-years away, but will be some further distance.
If you look at Figure 1 in the link above, you'll see that what happened is this:
1. When the universe was 1 billion years old, the protocluster emits some light. At this time, the distance from the cluster to Earth (actually, the position where Earth will one day form) is ~2.5 billion light-years.
2. The light travelled outwards, while the universe was expanding.
3. In the present day (age of universe: 13.7 billion years), the light reaches our location. The protocluster (which has now evolved into something else, no doubt) is now at a distance of ~27 billion light-years from us. (Note that currently the edge of the visible universe is ~46 billion light-years away. The universe is only 13.7 billion years old, but the edge is further than 13.7 billion light-years away since, again, that space is moving away from us for that whole time. C.f. comoving distance.)
So you are denying that the astronomers who captured these photons with their telescope have a frame of reference?
No common frame of reference? Yes, most certainly there isn't one, and the astronomers would agree. They only capture the photons as they arrive here, and can tell by the red-shift how far away the proto-galaxy is. But they can't tell anything about time, because the speed of time itself can't exceed the speed of light - there's no big Pratchettian clock that ticks time for everywhere in the universe.
When something happens elsewhere, it hasn't happened at all until the light cone hits us. Or, to put it another way, it's impossible to synchronize two clocks that are at any distance. You can set both to a time that appears to be the same for an observer in a third spot, but if you do so, they're not synchronized - an observer at A will think that its own clock is both preceding and running faster than the other clock, and an observer at B will think the exact same about its own clock.
Time is a local phenomenon, and this is very difficult for us to grasp because we're always experiencing the local time. To us, it ticks away at a constant rate, but this is an illusion.