"Take any solid element that doesn’t vaporize, and heat it to, say, 700 degrees and you will find it emits exactly the same spectrum of light as any other solid element also at 700 degrees."

Is this really true? I thought that the elements (compounds?) could be identified by the wavelengths of light they emitted when heated. This article on Wikipedia seems to confirm that. https://en.wikipedia.org/wiki/Emission_spectrum Maybe the statement is true for solid materials.

I didn't read much past that point. Maybe I'm oblivious to the point the author was trying to convey, but I find it hard to get past statements that appear to be obviously false.