[mosaicwolf]

"So astronomers are seeing this particular burst as it existed 13 billion years ago, because the light took that long to reach Earth observers."

Ummmm....I don't get it. If this is right, we are assuming that the universe was as large (the expansion from 13 billion years) as it is today.

[muawiyah]

Not eactly. This is telling you what it was like 13 billion years ago. We were much closer then. Of course we were also part of a dust cloud and only later were compressed into atoms by red giants and then exploded out to reform as the chunks of stuff that collided together to form this (or another) planet.

We've been exploding outward with the expansion of the Universe, so that explosion of 13 billion years ago was, it turns out, lagging behind us a bit.

[Ernest_at_the_Beach]

All of this distance hoopla is based on the red shift...but that is now in serious question by a Scientist who was an associate of Hubble...we had a thread on that....will see if I can find it.

[Ernest_at_the_Beach]

Well here is the astronomer:

Halton Christian Arp

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Working in these observatories he has made becoming classical "the Catalogue of Peculiar Galaxies" ("Arp's Catalogue" or "Atlas of Peculiar Galaxies of Arp"), where information on galaxies distinguished in "abnormality" that is diversion from usual spiral structure are gathered. In notations and references these galaxies have name of Arp + catalogue number.

At the begining of the scientific activity Dr. Arp was engaged in search of novae in М31 under leading of Edwin Hubble.

In 1983 he was invited to staff of Max Planck Astrophysical institute in Munich.

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One of major astronomical discovery of Dr. Arp is that the quasars or, in another words, quasi-stellar objects (QSO) are local objects ejected from the core of active galactic nuclei (AGN). The theory was originally proposed in the 1960s as an alternative to Maarten Schmidt's explanation for QSOs, which stated that they were very distant galaxies that appeared to be highly redshifted because of the expansion of the universe [1]. The implication of the hypothesis was that most of the observed redshift of these QSOs must have a non-cosmological or "intrinsic" origin. Arp has suggested that the QSO emission may instead be ejecta from active galactic nuclei. Nearby galaxies with both strong radio emission and peculiar morphologies, particularly M87 and Centaurus A, appeared to support Arp's hypothesis [2]. In his books, Arp has provided his reasons for believing that the Big Bang theory itself is wrong, citing his research into QSOs. Instead, Arp supports the redshift quantization theory for describing the redshifts of galaxies [3].

Since Arp originally proposed his theories in the 1960s, however, telescopes and astronomical instrumentation have advanced greatly; the Hubble Space Telescope was launched, multiple 8-10 meter telescopes (such as those at Keck Observatory) have become operational, and detectors such as CCDs are now more widely used. These new telescopes and new instrumentation have been used to examine QSOs further. QSOs are now generally accepted to be very distant galaxies with high redshifts. Moreover, many objects that are high-redshift counterparts to normal nearby galaxies have been identified in many imaging surveys, most notably the Hubble Deep Field[4]. Moreover, the spectra of the high-redshift galaxies, as seen from X-ray to radio wavelengths, match the spectra of nearby galaxies (particularly galaxies with high levels of star formation activity but also galaxies with normal or extinguished star formation activity) when corrected for redshift effects.[5 - 7]

Nonetheless, Arp has not wavered from his stand against the Big Bang and still publishes articles stating his contrary view in both popular and scientific literature, frequently collaborating with Geoffrey Burbidge and Margaret Burbidge.[8]

[LibWhacker]

I've been asking myself, physicists, and anyone else who might know, that same question for 30 years now. I might have totally screwed up the explanation, but here's what I've come away with: It seems to have something to do with "inflation," the claim that the universe increased in linear size by a factor of 10²⁶ in a fraction of a second. I've even seen some claims that it increased by a factor of 10^10,000,000. Boy, that'd make your ears pop! Anyway... In inflation theory, the universe increased to about one-third of its present size in almost an instant.

So the light from this gamma-ray burster had quite a ways to go to get to us when the GRB exploded 630 million years later. Now, you might think the light would get to us in 4 or 5 billion years since that supposedly was the size of the universe back then and since, by relativity theory, the speed of light is constant for all observers. However, that does not apply when space itself is being created in between the two points all the while light is traversing the gulf. Thus, it has taken 13 billion years to get here, not 4 or 5 billion.

I'm not a physicist and, like I said, I don't know if I got it exactly right, but that's the best I can do to cobble together the answers I've gotten over the years from various experts. Cheers!