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Astronomers Find an Old-Looking Galaxy In the Early Universe
schwit1 tips news that a team of astronomers has studied one of the most distant galaxies ever observed and found puzzling results. The light we're seeing from this galaxy comes from roughly 700 million years after the Big Bang, so on the cosmic scale, it's quite young. But the galaxy appears much older than astronomers expected. Their paper was published today in Nature.
At this age it would be expected to display a lack of heavier chemical elements — anything heavier than hydrogen and helium, defined in astronomy as metals. These are produced in the bellies of stars and scattered far and wide once the stars explode or otherwise perish. This process needs to be repeated for many stellar generations to produce a significant abundance of the heavier elements such as carbon, oxygen and nitrogen. Surprisingly, the galaxy A1689-zD1 seemed to be emitting a lot of radiation in the far infrared, indicating that it had already produced many of its stars and significant quantities of metals, and revealed that it not only contained dust, but had a dust-to-gas ratio that was similar to that of much more mature galaxies.
Too much gravity to explain galaxies? 85% of it is dark matter.
Too little gravity to explain stuff at larger scales and times than that? 70% is dark energy.
Leaving ~5% as visible matter. If we adjusted our fundamental assumptions by assuming 95% of the universe is everywhere and otherwise undetectable to account for our observations being only 5% predictive, how exact do you think the overarching science really is to begin with?
IMO we'll need new and better detection techniques to make any real progress- or, if we are stuck with the current level of observations for a couple hundred years, maybe it'll be discerned that way. We just have a lot better luck with the former than the latter.