Theories of Sun Composition Before Fusion Discovered?

[RobertK]

Before the energy of the sun was determined to be due to atomic fusion of hydrogen, (1930s I think), what did astronomers think the sun was made of and how did they think the sun generated its heat and light? Can anyone direct me to a good book or journal article that discusses various hypotheses about the composition of the sun? I have access to a good university library and journals.

[Chris Peterson]

Before the energy of the sun was determined to be due to atomic fusion of hydrogen, (1930s I think), what did astronomers think the sun was made of and how did they think the sun generated its heat and light? Can anyone direct me to a good book or journal article that discusses various hypotheses about the composition of the sun? I have access to a good university library and journals.

Before modern science appeared in the 16th and 17th centuries, I think it was just viewed as a chemical fire of some sort. After that, it was believed to be powered by gravitational collapse (which is somewhat true, but incomplete). Lord Kelvin demonstrated near the turn of the 20th century that the Sun, thusly powered, had to be less than 20 million years old- an argument used by young Earthers. It was another 30 years before fusion was identified as the source of the Sun's output.

You might want to read about Kelvin- it's likely to lead you to more information on this subject.

[RobertK]

Thanks, Chris. I found some papers by Kelvin available online that are useful.

Robert