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Most distant event ever observed
Posted: Sat Apr 25, 2009 7:52 pm
by Qev
Assuming you don't count the CMB as an event, of course.
![Smile :)](./images/smilies/icon_smile.gif)
A gamma-ray burst at a whopping-huge z=8.1, or more than 80 Gpc.
http://www.tng.iac.es/news/2009/04/24/grb/
Re: Most distant event ever observed
Posted: Sat Apr 25, 2009 11:50 pm
by astrolabe
Hello All,
I'm struggling to understand this. I know what I want to say but can't quite articulate it at this time. Quite frankly I find this event hard to believe. 1) Either our Universe is much larger than we think or 2) much older or 3) both.
Re: Most distant event ever observed
Posted: Sun Apr 26, 2009 1:11 am
by harry
G'day from the land of ozzzz
Hello Astrolabe
Why do you find the event had to believe?
Am I reading it right to be about 13.1 Grs away or is it 80 Grs?
Re: Most distant event ever observed
Posted: Sun Apr 26, 2009 1:20 am
by harry
G'day
September 23rd, 2008
Scientists Detect “Dark Flow:” Matter From Beyond the Visible Universe
http://www.universetoday.com/2008/09/23 ... -universe/
Just as unseen dark energy is increasing the rate of expansion of the universe, there’s something else out there causing an unexpected motion in distant galaxy clusters. Scientists believe the cause is the gravitational attraction of matter that lies beyond the observable universe, and they are calling it “Dark Flow,” in the vein of two other cosmological mysteries, dark matter and dark energy. “The clusters show a small but measurable velocity that is independent of the universe’s expansion and does not change as distances increase,” said lead researcher Alexander Kashlinsky at NASA’s Goddard Space Flight Center in Greenbelt, Md. “The distribution of matter in the observed universe cannot account for this motion.”
“We never expected to find anything like this,” he said.
What do you think of this link?
How Can We See Galaxies 47 Billion Light Years Away When the Universe is Only 13 Billion Years Old?
http://www.everyjoe.com/articles/how-ca ... s-old-191/
Re: Most distant event ever observed
Posted: Sun Apr 26, 2009 1:27 am
by harry
G'day from the land of ozzzz
Hubble's Deepest View Ever of the Universe Unveils Earliest Galaxies
http://hubblesite.org/newscenter/archiv ... /07/image/
Re: Most distant event ever observed
Posted: Sun Apr 26, 2009 12:02 pm
by JimJast
astrolabe wrote:1) Either our Universe is much larger than we think or 2) much older or 3) both
According to Einstein's gravitation (not very popular lately though) our universe is much older (actually it is
eternal) and the distance to the farthest point of its space (the other pole of 3-sphere universe) is about 13 Gpc. Another thing is that the redshift in Einstein's gravitation is related to the amount of matter around the redshifted object, which only on average is related to the distance.
Re: Most distant event ever observed
Posted: Sun Apr 26, 2009 2:36 pm
by Chris Peterson
JimJast wrote:astrolabe wrote:1) Either our Universe is much larger than we think or 2) much older or 3) both
According to Einstein's gravitation (not very popular lately though) our universe is much older (actually it is
eternal) and the distance to the farthest point of its space (the other pole of 3-sphere universe) is about 13 Gpc. Another thing is that the redshift in Einstein's gravitation is related to the amount of matter around the redshifted object, which only on average is related to the distance.
I say this not to convince Jim, because I don't think that's possible.
But to anybody else reading this stuff and wondering, there aren't different kinds of General Relativity, there is only one kind of gravitation described by GR, and the expanding, spacetime Universe, as supported by cosmological redshift, fits fully and beautifully within the predictions of GR.
A vast amount of excellent theory and observation leads to the conclusion that the Universe is about 13.7 billion year old, which given its expansion rate means that the greatest comoving distance we can see is about 47 billion light years. That describes the observable universe only, a sphere centered on our location as observers. The actual size of the universe is almost certainly much larger, but how much larger is unknown. It is forever beyond our ability to directly observe most of the Universe, and subtle differences in both theory and observation lead to very different conclusions. So more definitive answers about what is outside the observable universe will have to wait for refinements to theory, which in turn will require better measurements than we are currently capable of.
Re: Most distant event ever observed
Posted: Sun Apr 26, 2009 6:18 pm
by astrolabe
Hello All,
Thank you for your replies. Harry, the links are superb but as my thoughts coalesce I have to say that what I meant was that I didn't have a problem with the event itself as much as the time of the event. 600 million yrs. after the beginning of the Universe is pretty early on IMHO for a GRB to occur. I don't know much about these things but I was under the impression that they seem to happen in the 6-9 billion year time frame so this event seemed to me to be so far out of the usual pattern as to be questioned.
I felt a similar flag go up when I read about the unexpected "blob" that was half the size of the Milky Way at 800 million yrs. after the beginning. I felt WRT the GRB that it's "early" occurrence should mean that the gamma burst should have passed through our neighborhood billions of years ago unless spacetime was expanding faster than c in that epoch and so the burst couldn't reach us until now. It all seems so counterintuitive to be true. And, as you all know, ICBW- would't be the first time, won't be the last!
P.S. Harry I think the 600 million year estimate puts the event at your 13.1 b.yr. time slot, which is what? 23 billion l.yrs. away?
Re: Most distant event ever observed
Posted: Mon Apr 27, 2009 7:06 am
by harry
G'day astrolabe
You are correct in questioning the 600 million years to form GRB.
Even to form the 10^9 galaxies that we observe and the mega collisions and mergers and so on.
====================================
Hello Chris in one of my last posts I said that you were a crank pot. I'm very sorry for that outburst, its not in my nature.
You do have a main stream thought line. Good or bad is left for TIME to decide.
Its funny how the observable universe puts mother Earth at the centre it reminds me of the dark ages.
Re: Most distant event ever observed
Posted: Mon Apr 27, 2009 2:52 pm
by aristarchusinexile
astrolabe wrote:Hello All,
I'm struggling to understand this. I know what I want to say but can't quite articulate it at this time. Quite frankly I find this event hard to believe. 1) Either our Universe is much larger than we think or 2) much older or 3) both.
Yup Astro .. 600 million years poses some questions. However, with infinite power at work, 600 million years can also be viewed as a very long time (especially on a raft.)
Re: Most distant event ever observed
Posted: Mon Apr 27, 2009 2:55 pm
by aristarchusinexile
harry wrote:G'day
September 23rd, 2008
Scientists Detect “Dark Flow:” Matter From Beyond the Visible Universe
http://www.universetoday.com/2008/09/23 ... -universe/
Just as unseen dark energy is increasing the rate of expansion of the universe, there’s something else out there causing an unexpected motion in distant galaxy clusters. Scientists believe the cause is the gravitational attraction of matter that lies beyond the observable universe ..
I remember this stuff speculated on long ago .. more than 40 years ago .. they called it the Great Attractor towards which everything was rushing to, not to be confused with the latter day small and localized Great Attractor.
Re: Most distant event ever observed
Posted: Mon Apr 27, 2009 2:59 pm
by aristarchusinexile
Chris Peterson wrote: there is only one kind of gravitation described by GR, and the expanding, spacetime Universe, as supported by cosmological redshift, fits fully and beautifully within the predictions of GR.
Then why wasn't Einstien completely happy with it?
P.S. You're not a crank pot, Chris, you're just consentric.
Re: Most distant event ever observed
Posted: Mon Apr 27, 2009 3:20 pm
by Chris Peterson
aristarchusinexile wrote:Then why wasn't Einstien completely happy with it?
Any complex theory is likely to be a work in progress. As such, its proponents are not going to be completely happy with it at any time. I don't know of any "big question" modern theories for which this isn't the case. That doesn't mean that such theories are substantively wrong, only that they are incomplete.
Re: Most distant event ever observed
Posted: Mon Apr 27, 2009 5:58 pm
by aristarchusinexile
Chris Peterson wrote:aristarchusinexile wrote:Then why wasn't Einstien completely happy with it?
Any complex theory is likely to be a work in progress. As such, its proponents are not going to be completely happy with it at any time. I don't know of any "big question" modern theories for which this isn't the case. That doesn't mean that such theories are substantively wrong, only that they are incomplete.
While we're mentioning Relativity, how can non-locality be demonstratable if Relativity says it's not possible? I asked this before, with urls for reference, and got no reply.
Re: Most distant event ever observed
Posted: Mon Apr 27, 2009 6:28 pm
by Chris Peterson
aristarchusinexile wrote:While we're mentioning Relativity, how can non-locality be demonstratable if Relativity says it's not possible? I asked this before, with urls for reference, and got no reply.
What do you mean by "relativity" in this case? That is, specifically what are you saying predicts that non-locality is not possible? With respect to the limitations on locality established by relativistic QM, it is not clear that a violation has been demonstrated with high confidence. Finally, it remains entirely possible that GR and/or QM will be adjusted to come into better agreement with each other- that's really what finding a unified theory is all about. The fact that either GR or QM may be wrong in some cases (which is very likely) doesn't mean that both are not fundamentally correct.
Re: Most distant event ever observed
Posted: Wed Apr 29, 2009 1:11 pm
by must-b-nuts
Just a question: GRB 090423 If this object is observed at 13.1 Billion light years away it has had 13.1 Billion years to move farther away in an expanding universe and the universe is at least 26.2 billion years old, or twice as old as observed. It is most likely that the time/distance limits observed are limited by our ability to observe and obfuscated by background 'noise' from a/our local 'Big Bang" interstellar matter and subatomic particles.
Is a 'crank pot' a cross between a 'crack pot' and a cranky, grumpy person?
Must-b-nuts
Re: Most distant event ever observed
Posted: Wed Apr 29, 2009 2:32 pm
by Chris Peterson
must-b-nuts wrote:Just a question: GRB 090423 If this object is observed at 13.1 Billion light years away it has had 13.1 Billion years to move farther away in an expanding universe and the universe is at least 26.2 billion years old, or twice as old as observed. It is most likely that the time/distance limits observed are limited by our ability to observe and obfuscated by background 'noise' from a/our local 'Big Bang" interstellar matter and subatomic particles.
This object is observed with a redshift of 8.2, meaning it happened 13.1 billion years ago. Since then the Universe has expanded, so the object's current distance from us (called the comoving distance) is around 30 billion light years. None of this changes the 13.7 billion year age of the Universe.
The most distant thing we observe is the cosmic microwave background, with a redshift of over 1000, a distance just short of 13.7 billion ly, and a comoving distance of about 46 billion ly.
Re: Most distant event ever observed
Posted: Wed Apr 29, 2009 4:10 pm
by aristarchusinexile
Chris Peterson wrote: The fact that either GR or QM may be wrong in some cases (which is very likely) doesn't mean that both are not fundamentally correct.
It also means they could be fundamentally wrong. But I'm not concerned, really, just curious .. it's nice not to have credentials which tie me to a school of thought.
Re: Most distant event ever observed
Posted: Wed Apr 29, 2009 4:19 pm
by bystander
Re: Most distant event ever observed
Posted: Wed Apr 29, 2009 6:26 pm
by neufer
Surely they mean more than 8.0 Gpc = 26.1 billion light-years. (ligth-years?)
Re: Most distant event ever observed
Posted: Wed Apr 29, 2009 7:37 pm
by Chris Peterson
neufer wrote:Surely they mean more than 8.0 Gpc = 26.1 billion light-years. (ligth-years?)
Yes. Those pesky little decimal points and zeros seem to cause no end of problems in scientific stories that migrate to the popular press. Sometimes they're even messed up in the original press releases.
Re: Most distant event ever observed
Posted: Fri May 01, 2009 4:33 am
by GregLeavengood
Perhaps one of you chaps can clear up my confusion. Shouldn't the gamma burst have hit us long before now? At the point of the Big Bang, all matter begins expanding out in all directions, the leading edge at the fastest speed, right? Even the very fastest rate would still have to be well below light speed though, right? So, a mere 630 million years of sub-light expansion isn't much of a head start for a light-speed gamma ray to overcome with 14-plus billion years to do it in. Even if, for the sake of arguement, the gamma source and the material that would one day become us were on exactly opposite vectors away from the central original point, doubling the lead, that's still only 1.26 billion years worth of relatively slow motoring next to a gamma ray. Say, for instance, we were talking about a speed ratio of 2 to 1. Wouldn't the light catch us in 2 or 3 billion years? Instead, we're getting hit over 14 billion years later, meaning that gamma ray actually travelled a distance of 14 billion light years to reach us, so the gap must have been much more formidable than I'm figuring. What am I missing here, guys?
Greg Leavengood
Ankeny, Iowa
Re: Most distant event ever observed
Posted: Fri May 01, 2009 5:13 am
by Chris Peterson
GregLeavengood wrote:Perhaps one of you chaps can clear up my confusion. Shouldn't the gamma burst have hit us long before now? At the point of the Big Bang, all matter begins expanding out in all directions, the leading edge at the fastest speed, right? Even the very fastest rate would still have to be well below light speed though, right? So, a mere 630 million years of sub-light expansion isn't much of a head start for a light-speed gamma ray to overcome with 14-plus billion years to do it in. Even if, for the sake of arguement, the gamma source and the material that would one day become us were on exactly opposite vectors away from the central original point, doubling the lead, that's still only 1.26 billion years worth of relatively slow motoring next to a gamma ray. Say, for instance, we were talking about a speed ratio of 2 to 1. Wouldn't the light catch us in 2 or 3 billion years? Instead, we're getting hit over 14 billion years later, meaning that gamma ray actually travelled a distance of 14 billion light years to reach us, so the gap must have been much more formidable than I'm figuring. What am I missing here, guys?
A couple of things. First, there was (and is) no leading edge to the Big Bang. Every point is expanding away from every other point, and the expansion rate increases with distance. There is no center, and no edge. Second, there is no limit on the rate of expansion- two points can even be separating from each other at faster than light. That's why the visible Universe (the part we can see because there has been enough time for its light to reach us) is actually more than 90 billion light years across, even though it's only existed for 13.7 billion year. The space between us and the GRB has expanded a lot since the event happened 13+ billion years ago.
Most distand GRB
Posted: Fri May 01, 2009 5:35 am
by bicyclebones
Can the location of the most distant GRB tell us the direction of where the Big Bang occurred?
Re: Most distant event ever observed
Posted: Fri May 01, 2009 8:15 am
by harry
G'day from the land of ozzzzzzz
Chris said
A couple of things. First, there was (and is) no leading edge to the Big Bang. Every point is expanding away from every other point, and the expansion rate increases with distance. There is no center, and no edge. Second, there is no limit on the rate of expansion- two points can even be separating from each other at faster than light. That's why the visible Universe (the part we can see because there has been enough time for its light to reach us) is actually more than 90 billion light years across, even though it's only existed for 13.7 billion year. The space between us and the GRB has expanded a lot since the event happened 13+ billion years ago.
Than how does redshift apply with this logic. The intrinsic properties wiuld shoot the data out of the roof.