Chemist Breaks Down How At-Home Covid Tests Work | WIRED

I'll be very happy when we don't have to take Covid tests anymore.

But I've taken a half dozen of these at home tests over the past year or so. I don't enjoy jabbing the long cotton swab into my nose - but the idea of then jabbing that swab into the back of my throat makes me want to gag.

There's a huge amount of serious science happening here that explains how the rapid covid tests work. Cool stuff happening there.

The source of licorice/liquorice/anise flavor

I hate licorice so very much.

I hate the black licorice.

I hate anise seed and star anise and fennel - though I do like Italian sausage with fennel seeds in there.

I've never tried absinthe, though I enjoyed the green fairy scenes in Moulin Rouge.

The science of anethole and estragole is interesting to me, however.

XKCD: Coffee Cup Holes

 

Source - https://xkcd.com/2658/
Rollover text: Theoretical physicist: At the Planck length, uncountably many.

See, it's funny because...

I'll leave the middle three panels (and the rollover text) to the fine crowdsourcing folks at explainxkcd. If you don't get those, check the link.

...but the chemistry one is all mine.

The caffeine molecule...

 ...is C₈H₁₀O₂N₄ (the grey spheres are C, white are H, red are O, and blue and N).

There are two rings in the structure, so that's two holes per caffeine molecule.

If there are "10²¹ [holes] in the caffeine alone", that would mean 5 x 10²⁰ molecules of caffeine or 0.16 g caffeine.

From healthline.com, "You can expect to get around 95 mg of caffeine from an average cup of coffee. However, this amount varies between different coffee drinks, and can range from almost zero to over 500 mg."

That calculation of 0.16 g = 106 mg then seems about right.

From one of my students...

Thanks to Jose Cruz for passing this along my way.

That's pretty much exactly how I imagine oxygen acting to all the other atoms - except fluorine, of course - on the periodic table.

Why Miners Risk Their Lives To Get Sulfur From An Active Volcano | Risky Business

I am incredibly thankful for my lot in life, my fortunate place in the middle class of the American Midwest, for my job teaching in my climate-controlled classroom.

The statistic from the video - that 98.2% of worldwide sulfur is now a by-product of the petroleum refining industry - leaves me amazed that this type of sulfur mining is still being done at all, but I know that all you can do is take advantage of the natural resources around you and dig out a living from their gifts meager though they may be.