Re: [math-fun] Miscounting in the Cheddar Gorge ...
It seems that 98.6 is an overestimate for average human body temp. In 1992 they got a figure of 98.2: https://www.ncbi.nlm.nih.gov/pubmed/1302471 —Dan ----- From: Andy Latto <andy.latto@pobox.com> On Sat, Nov 18, 2017 at 11:11 AM, Leo Broukhis <leobro@gmail.com> wrote:
This was converted from 37.0 Celsius.
Do you have a source for the value being given to three significant figures in Celsius? I looked online, and found "Normal body temperature is considered to be 37°C (98.6°F); however, a wide variation is seen. Among normal individuals, mean daily temperature can differ by 0.5°C (0.9°F), and daily variations can be as much as 0.25 to 0.5°C" on the NIH site at https://www.ncbi.nlm.nih.gov/books/NBK331/, quoted from "Clinical Methods: The History, Physical, and Laboratory Examinations. 3rd edition.". If it varies among individuals by .5 decrees C, and daily variations can be as much as .5 degrees C, 37 seems a better description than 37.0 -----
I still have my nice mercury thermometer. I took it along when going to a medical facility in order to compare against their digital thermometer, and they agreed to the 0.1 F digit. Due to toxicity and environmental concerns about mercury, liquid metal thermometers sold today contain the eutectic alloy gallinstan, 68.5% gallium, 21.5% indium, 10% tin by weight, with a melting point of -19 C. Since gallinstan wets glass, the inner surface is coated with gallium oxide. The use of a thin inner glass tube, with low heat capacity, surrounded by a flat outer protective glass tube allows for quick equilibrium and easily read temperature. While metallic mercury is a fairly benign poison, the organometallic dimethylmercury is extremely nasty. Lack of awareness that it can penetrate latex gloves has led to a very tragic, slow death, well documented on the internet. -- Gene On Saturday, November 18, 2017, 9:52:29 AM PST, Dan Asimov <dasimov@earthlink.net> wrote: It seems that 98.6 is an overestimate for average human body temp. In 1992 they got a figure of 98.2: https://www.ncbi.nlm.nih.gov/pubmed/1302471 —Dan ----- From: Andy Latto <andy.latto@pobox.com> On Sat, Nov 18, 2017 at 11:11 AM, Leo Broukhis <leobro@gmail.com> wrote:
This was converted from 37.0 Celsius.
Do you have a source for the value being given to three significant figures in Celsius? I looked online, and found "Normal body temperature is considered to be 37°C (98.6°F); however, a wide variation is seen. Among normal individuals, mean daily temperature can differ by 0.5°C (0.9°F), and daily variations can be as much as 0.25 to 0.5°C" on the NIH site at https://www.ncbi.nlm.nih.gov/books/NBK331/, quoted from "Clinical Methods: The History, Physical, and Laboratory Examinations. 3rd edition.". If it varies among individuals by .5 decrees C, and daily variations can be as much as .5 degrees C, 37 seems a better description than 37.0 ----
At 01:39 PM 11/18/2017, Eugene Salamin wrote:
While metallic mercury is a fairly benign poison, the organometallic dimethylmercury is extremely nasty.
Lack of awareness that it can penetrate latex gloves has led to a very tragic, slow death, well documented on the internet.
Slow death indeed! When we were kids 65 years ago, we played with metallic mercury all the time. We used it to coat pennies (which used to be real copper or sometimes steel), and generally enjoy its weird properties. In addition to thermometers, you could also obtain mercury from *mercury* light switches, which were extremely *quiet*, and also *extremely reliable*. My mercury poisoning doesn't seem to have progressed very far in the last six decades... A few years ago, some kid brought a little bit of mercury to one of the high schools in the San Fernando Valley (north of Los Angeles). The authorities *emptied the entire high school*, and sent in a *hazmat team*, complete with full hazmat suits, to retrieve the mercury. To this day, I can't tell if the hazmat people just wanted to show off their brand new suits, or whether they wanted to send a signal to any businesses in the area that worked with metallic mercury. BTW, more people contract mercury poisoning in Los Angeles each year from eating too much *sushi* then have been poisoned by metallic mercury in the last ten years.
On Tue, Nov 28, 2017 at 7:49 AM, Henry Baker <hbaker1@pipeline.com> wrote:
At 01:39 PM 11/18/2017, Eugene Salamin wrote:
While metallic mercury is a fairly benign poison, the organometallic dimethylmercury is extremely nasty.
Lack of awareness that it can penetrate latex gloves has led to a very tragic, slow death, well documented on the internet.
Slow death indeed!
When we were kids 65 years ago, we played with metallic mercury all the time. We used it to coat pennies (which used to be real copper or sometimes steel), and generally enjoy its weird properties. In addition to thermometers, you could also obtain mercury from *mercury* light switches, which were extremely *quiet*, and also *extremely reliable*. My mercury poisoning doesn't seem to have progressed very far in the last six decades...
Eugene was talking about dimethyl mercury poisoning, not metallic mercury poisoning. https://en.wikipedia.org/wiki/Karen_Wetterhahn -- Mike Stay - metaweta@gmail.com http://www.cs.auckland.ac.nz/~mike http://reperiendi.wordpress.com
When I was a grad student at UT Austin I ran the sophomore physics lab one year. Sometime in the past a liter of mercury had been spilled in the lab room. Of course they cleaned it up, but it was assumed that some had escaped into the cracks of the hardwood floor. Consequently the rule was that the windows were to remain open at all times. It gets pretty cold in Austin the winter. It was a little strange to see the students huddling over instruments dressed for an assault on Everest. I think the building has been passed to the journalism department now. I wonder if they know? Brent On 11/28/2017 6:49 AM, Henry Baker wrote:
At 01:39 PM 11/18/2017, Eugene Salamin wrote:
While metallic mercury is a fairly benign poison, the organometallic dimethylmercury is extremely nasty.
Lack of awareness that it can penetrate latex gloves has led to a very tragic, slow death, well documented on the internet. Slow death indeed!
When we were kids 65 years ago, we played with metallic mercury all the time. We used it to coat pennies (which used to be real copper or sometimes steel), and generally enjoy its weird properties. In addition to thermometers, you could also obtain mercury from *mercury* light switches, which were extremely *quiet*, and also *extremely reliable*. My mercury poisoning doesn't seem to have progressed very far in the last six decades...
A few years ago, some kid brought a little bit of mercury to one of the high schools in the San Fernando Valley (north of Los Angeles). The authorities *emptied the entire high school*, and sent in a *hazmat team*, complete with full hazmat suits, to retrieve the mercury.
To this day, I can't tell if the hazmat people just wanted to show off their brand new suits, or whether they wanted to send a signal to any businesses in the area that worked with metallic mercury.
BTW, more people contract mercury poisoning in Los Angeles each year from eating too much *sushi* then have been poisoned by metallic mercury in the last ten years.
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participants (5)
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Brent Meeker -
Dan Asimov -
Eugene Salamin -
Henry Baker -
Mike Stay