March 31, 2006 | David F. Coppedge

More Hints at Early Origin of Stars, Galaxies

Several articles this month showed further evidence for a growing realization in astronomy: stars and galaxies were already mature at the beginning of the universe (see, for instance, 09/21/2005 entry).  Some recent examples:

  • Spitzer Clusters:  JPL issued a press release stating that the Spitzer Space Telescope, on a “cosmic safari,” found evidence for clusters of galaxies 9 billion years old.  In the standard dating scheme, this was when the universe was a “mere” 4.5 billion years old.
  • Swift GRBs:  Astronomers reported in Nature1 the discovery, by the Swift satellite, of the earliest gamma-ray burst ever found.  The burst “happened 12.8 billion years ago, corresponding to a time when the Universe was just 890 million years old, close to the reionization era,” they said.  “This means that not only did stars form in this short period of time after the Big Bang, but also that enough time had elapsed for them to evolve and collapse into black holes” (emphasis added in all quotes).
  • Ubiquitous Galaxies:  A press release from the journal Astronomy & Astrophysics announced “Ubiquitous galaxies discovered in the Early Universe.”  Observations in far-ultraviolet and near-infrared found galaxies at redshift z=6.7, assumed to be within 5% of the birth of the universe.  Most of them were spirals, not irregulars as theory had predicted.

In the last of a 36-part series of lectures on 20th century science produced by The Teaching Company,2 Dr. Steven L. Goldman of Lehigh University listed this as one of the major challenges facing scientists in the 21st century.  After first discussing the surprise discovery that the universal expansion is accelerating (08/13/2002), he said,

A second area in astrophysics that can be construed as a cloud on the horizon is that recent observations in the years 2002-2003 suggest that – not just suggest, recent observations tell astronomers that when the universe was less than 3 billion years old, there were already galactic clusters [03/12/2003].  Not only were there galaxies… but here we have, astronomers have discovered, a modest galactic cluster (I believe that it has something like 30 some-odd galaxies in it) that goes back to less than 3 billion years after the big bang.  That’s much too much structure to have after only two and a half or 2.7 billion years of expansion.  So that is another problem that astrophysics needs to come to grips with.
    It’s not a small problem, either, because the extent of the structure that we can discover in the universe has implications for whether big bang and inflation are really capable of providing a model of the universe.  So it’s a small – it may seem like a small problem to non-specialists, but within astrophysics it’s a significant challenge.
    And then there’s the question of whether we are in fact reading the microwave background radiation correctly. [03/20/2006]   Because all of this theory is empirically supported by interpreting extremely minute ripples in the microwave background radiation.  And from those ripples, ripples in temperature, temperature inequalities on the order of ten thousandths of a degree Kelvin are – that’s the basis for trying to explain why there is as much structure as there is in the universe.  If we’re misinterpreting the microwave background radiation data, then really we have a whole new picture of the universe that might emerge.  So, that’s one set of clouds that one can anticipate that over the next decade we will potentially be seeing significant modifications in our conceptualization of the universe and its origin, and maybe even of its fate.

Goldman compared these challenges to a couple of mysteries at the beginning of the 20th century that Lord Kelvin described as “small clouds on the horizon” – (1) the inability to explain the blackbody radiation spectrum and (2) the lack of deviations of the speed of light through the ether as found by the Michelson-Morley experiment.  These two small clouds became cloudbursts a few years later when they led directly to quantum theory and relativity – theories that dramatically overhauled our conceptions of space, time and the universe.

1Cusumano et al., “Gamma-ray bursts: Huge explosion in the early Universe,” Nature 440, 164 (9 March 2006) | doi:10.1038/440164a.
2Steven L. Goldman, Lecture 36, “Looking Around and Looking Ahead,” Science in the 20th Century: A Social-Intellectual Survey, The Teaching Company, 2004.

Goldman suggested later in the lecture one possible new conception of the universe that might emerge in the years ahead: that the universe might be viewed as “some kind of information structure.”  Sound like intelligent design?  Sound like instant creation?  He asked, “and how will we understand that philosophically and physically?”  Easy: in the beginning was the Word.  Consider creation: an idea ahead of its time.

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Categories: Astronomy, Cosmology

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