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Today's space video of the day is from the Google Tech Talk series, and is entitled Beyond Einstein: From the Big Bang to Black Holes.


Space Video of the Day Archive

Centauri Dreams reports on the highly-precise (three significant figures) measure of the age of a star. Something doesn't quite add up in the method used to date the star, though. Elements heavier than Iron cannot be formed through the regular fusion mechanism of a star; it requires more energy for the fusion to take place than is released by the fusion, so the only place these elements can form is in a type II supernova. So, the elements Uranium, Thorium, Europium, Osmium, and Iridium cannot have formed within HE 1523-0901, and instead must have formed in a nearby precursor star and then been incorporated by HE 1523-0901 sometime after the precursor star went supernova. To then use the ratios of those elements as a measure of the age of the star, by treating HE 1523-0901 as if it was a lump of rock undergoing normal radioactive decay processes, is simply not valid - the ratios of those elements originally produced in the supernova is unknown, so their present-day ratios are not an indication of HE 1523-0901's age.