[billnotgatez]

@curiouscat
I like your recap but

I interpreted the WIKI entry a different way.
I never thought they meant air had different properties than nitrogen and oxygen.
I never thought they implied nitrogen was combustible.
but now I see where one could read it a different way.
I leave it to the English majors to sort out how to properly write things

I find it interesting that a process that only gives ppm requires most every car in the US to have an expensive catalytic converter.
I guess those ppm add up.

If I keep typing I will get the pendant award (probably deserved already)

[Borek]

I find it interesting that a process that only gives ppm requires most every car in the US to have an expensive catalytic converter.

It is not only nitrogen oxides, but also about carbon monoxide and leftover hydrocarbons.

I guess those ppm add up.

Google for photochemical smog.