Wikipedia:Reference desk/Archives/Science/2021 December 30

= December 30 =

Smell of ozone after breathing under blanket
I noticed that if I cover myself fully with blanket and then remove it after several minutes, when CO2 concentration underneath becomes uncomfortable, I smell an ozone-like scent in the air for a couple of seconds. Is it because of the contrast between fresh air and that under blanket when nose becomes briefly sensitive to oxygen? 212.180.235.46 (talk) 16:55, 30 December 2021 (UTC)
 * More likely you have created some ozone by disharging the static charge you built up in the blanket. Abductive  (reasoning) 21:30, 31 December 2021 (UTC)

Smell of pre-industrial air
Per Carbon dioxide, its current concentration is about 412 ppm by volume, having risen from pre-industrial levels of 280 ppm. Does it imply somewhat different smell of pre-industrial air (possibly more fresh-like) or is that difference still small to smell? 212.180.235.46 (talk) 17:03, 30 December 2021 (UTC)
 * Although carbon dioxide is said to have a sharp, acidic, odor at high concentrations, we don't currently detect that at ~ 412 ppm and levels would need to rise substantially higher to notice anything. You might notice the smell as you open a bottle of fizzy drink but personally I wouldn't even call that "sharply acidic". Mike Turnbull (talk) 17:30, 30 December 2021 (UTC)
 * I can vouch that it has. During a tour of a brewery we were shown the fermentation of the beer and I put my nose in the vessel and sniffed.  Ouch.  Very sharp and quite painful.--Phil Holmes (talk) 09:55, 31 December 2021 (UTC)
 * That notwithstanding, I think that the pre-industrial air smelled rather different anyway. Mostly thanks to all the other pollutants produced by industry and modern traffic. PiusImpavidus (talk) 23:03, 30 December 2021 (UTC)
 * Given that in most of the world people used wood fires for heating and cooking, I would imagine that would be the most common smell. HiLo48 (talk) 02:56, 31 December 2021 (UTC)
 * In some places wood was expensive and too rare to burn. Other things like animal fat, dried dung, peat, moss, grass and plant waste were used.  Martin of Sheffield (talk) 10:20, 31 December 2021 (UTC)
 * Yes. That's why I said "most". I guess whatever they used for cooking and heating would have been the dominant smell. And some of those would have been VERY dominant!. HiLo48 (talk) 22:35, 31 December 2021 (UTC)
 * I'm not even sure about "most", however with no proof either way I can't say for certain. What is interesting though is how the type of fire, and whether is was also used for heating, influences the style of cooking.  The cooler slow burning fires tend to lead to curries, stews and similar.  Hotter wood, charcoal or sea coal allows roasting and ovens, though if the fire is only lit intermittently the cuisine may have to have plenty of quick cooking meats.  Picking up on, it's interesting to try to define "pre-industrial".  In 1257–1259, coal from Newcastle upon Tyne was shipped to London for the smiths and lime-burners building Westminster Abbey which does sound a bit industrial.  It was in 1306 the Henry Edward I tried to ban coal fires in London because of the pollution. Martin of Sheffield (talk) 23:08, 31 December 2021 (UTC)