Several things the article claims, which I was unaware of: The content of blue wavelengths in seemingly "white" LEDs; the content of blue light even in 'warm' L

Several things the article claims, which I was unaware of: The content of blue wavelengths in seemingly "white" LEDs; the content of blue light even in 'warm' LEDs (more minor but still present vs incandescent); and the impact of light position relative to the "horizon".