lpetrich
Contributor
In 1835, philosopher Auguste Comte stated that we would never know the chemical composition of the stars. That was in his book Cours de philosophie positive (Course of Positive Philosophy) Comte on Astronomy
But a way of doing that seemingly impossible task was under development when he wrote that: spectroscopy.
History of spectroscopy
By the mid 18th cy., it was known that different salts would give different colors to flames, and by the early 19th cy., it was known that the Sun's spectrum had lots of dark lines in it. By the mid 19th cy., it was known that for some substance, emission lines and absorption lines had the same wavelengths, and a little later, it became well-established that each element has its own distinctive set of spectral lines. In the 1860's, Robert Bunsen and Gustav Kirchhoff discovered that the Sun has some elements that the Earth has, and William and Margaret Huggins did likewise for the stars that they observed. Thus succeeded in doing what Auguste Comte had thought impossible.
Since their first efforts, a large fraction of the stable and long-lived elements have been found in the Sun -- Abundances of the elements (data page) -- of the 83 stable and long-lived elements, 70 have been discovered in the Sun, all but 13 of them.
That's all the elements up to bismuth (83) with the exceptions of technetium (43) and promethium (61), and also thorium (90) and uranium (92).
Not surprisingly, all of them have been discovered in the Earth's crust and in meteorites, since one can examine samples of them in labs.
Solar Elemental Abundances Table of Contents Summary compares element abundances in the Sun to abundances in meteorites, finding that the less volatile elements have abundances that correlate very closely. The more volatile elements, like the noble gases, are very depleted in meteorites, because they can easily boil off as the meteorite material formed. Hydrogen, carbon, and nitrogen are also depleted.
I found the original: The Project Gutenberg eBook of Cours de philosophie positive (2/6), par Auguste Comte at Books: Auguste Comte (sorted by popularity) - Project Gutenberg I searched for "minéralogique" ("mineralogical") and I then copied and pasted into Google Translate. I succeeded in verifying that quote.
But a way of doing that seemingly impossible task was under development when he wrote that: spectroscopy.
History of spectroscopyBy the mid 18th cy., it was known that different salts would give different colors to flames, and by the early 19th cy., it was known that the Sun's spectrum had lots of dark lines in it. By the mid 19th cy., it was known that for some substance, emission lines and absorption lines had the same wavelengths, and a little later, it became well-established that each element has its own distinctive set of spectral lines. In the 1860's, Robert Bunsen and Gustav Kirchhoff discovered that the Sun has some elements that the Earth has, and William and Margaret Huggins did likewise for the stars that they observed. Thus succeeded in doing what Auguste Comte had thought impossible.
Since their first efforts, a large fraction of the stable and long-lived elements have been found in the Sun --
Abundances of the elements (data page) -- of the 83 stable and long-lived elements, 70 have been discovered in the Sun, all but 13 of them.That's all the elements up to bismuth (83) with the exceptions of technetium (43) and promethium (61), and also thorium (90) and uranium (92).
Not surprisingly, all of them have been discovered in the Earth's crust and in meteorites, since one can examine samples of them in labs.
Solar Elemental Abundances Table of Contents Summary compares element abundances in the Sun to abundances in meteorites, finding that the less volatile elements have abundances that correlate very closely. The more volatile elements, like the noble gases, are very depleted in meteorites, because they can easily boil off as the meteorite material formed. Hydrogen, carbon, and nitrogen are also depleted.
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