Earlier than Expected: Galaxy Formation

I had intended to focus this series on fossil finds that were attributed to time periods that were earlier than previously expected, but now realize that the series needs to include a broader range of phenomena to encompass other findings that fall under the heading of gradualism and uniformitarianism. As an example, we find galaxies that are purported to have formed much earlier than previously expected.(1)

Researchers using the Subaru telescope in Hawaii have identified five distant galaxy clusters that formed five billion years after the Big Bang. They calculated the mass of the biggest galaxy in each of the clusters and found, to their surprise, that the ancient galaxies were roughly as big as the biggest galaxies in equivalent clusters in today’s Universe.

The ancient galaxies should have been much smaller, at only a fifth of today’s mass, based on galaxy-formation models that predict slow, protracted growth. “That was the reason for the surprise — that it disagrees so radically with what the predictions told us we should be seeing,” says Chris Collins of Liverpool John Moores University in Birkenhead, UK. Collins and his colleagues publish the work today in Nature.

The uniformitarian models had predicted that the galaxies would only be 20% of the observed size, yet the galaxies were found to be roughly as big as the biggest galaxies known to exist today. It seems like there may have been a bunny fossil found in the cosmological Cambrian period, but lets see how they’ll wiggle their way out of this one.

The work suggests that an earlier modelling result may have correctly posited a mechanism — a cold stream of star-nourishing hydrogen gas — by which these first massive galaxies grew so rapaciously. Taken together, the two results suggest that early galaxies grew quickly through injections of gas, rather than slowly through mergers. “We have a whole different story now about how galaxies form,” says Avishai Dekel of the Hebrew University in Israel and first author of the earlier paper.

How did they do? I’d say they did a good job of using their imagination (a gas injection from the imagination), but I don’t think they did so well in saving a uniformitarian model of galaxy formation. They at least make a prediction that could be discomfirmed/confirmed through future observation. In other words, they might be able to actually see the cold gas streams. I’ve got my fingers crossed. The point is, the time period for galaxy formation has also been reduced making things more complicated for uniformitarian models.

(1). Early galaxies surprise with size, Nature News, April 1, 2009


2 Responses

  1. “We have a whole different story now about how galaxies form,” says Avishai Dekel of the Hebrew University in Israel and first author of the earlier paper.

    They always have a “whole different story” when their “imaginings” fail them. I’m sure though that you’ll still get long-winded and multisyllabic responses defending this kind of “science.”

  2. No doubt about it DB. I’ll have another post coming soon on another unexpected finding that causes big problems for the uniformitarian view. I doubt that their faith will be shaken in any significant way, because they will always be able to imagine another scenario.

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