Interesting faxes thread

[The Carnivore]

Originally Posted by a1call

https://www.telegraph.co.uk/science/...l-alive-earth/

Temperature – tardigrades can survive:
A few minutes at 151 °C (304 °F)[51]
30 years at −20 °C (−4 °F)[52]
A few days at −200 °C (−328 °F; 73 K)[51]
A few minutes at −272 °C (−458 °F; 1 K)[53]

https://en.m.wikipedia.org/wiki/Tardigrade

I find it more surprising that people can also survive whole-body exposures to temps exceeding 151 C for a few minutes, without suffering significant injuries:
https://www.nytimes.com/2010/08/27/w...kiln.html?_r=0

Later that day, Mr. Seo’s ovens are packed with something new: people, who huddle inside where the temperature still hovers around 200 degrees Celsius (nearly 400 Fahrenheit), so hot that synthetic clothes are banned because they can melt.

[xilman]

Originally Posted by The Carnivore

I find it more surprising that people can also survive whole-body exposures to temps exceeding 151 C for a few minutes, without suffering significant injuries:
https://www.nytimes.com/2010/08/27/w...kiln.html?_r=0

Only mildly surprising to me.

I've spent 20 minutes at 105C and a few minutes at 120C without significant discomfort.

Some USAF experiments back in the 70s showed that people can survive 120C for an hour or more as long as they are naked, sitting on low thermal conductivity materials such as cork, and have enough cool water to drink.

Hairless mammals have seriously effective cooling mechanisms.

I wouldn't want to try 150C though.

[Uncwilly]

The US military has done tests and exposed people to over 200C while at the same time cooking a steak in the same area.

And here is an infographic:
https://cdn.mos.cms.futurecdn.net/Gu...zWf-970-80.jpg

[Dr Sardonicus]

I remember seeing a TV program - perhaps about people setting records - which had a segment about a man who endured a very high temperature for a number of minutes. He sat in a small room or enclosure which was heated by a large number of incandescent lamps, sweating profusely. He spoke about his experience, saying it had occurred to him that a batch of cookies could have been baking next to him while he was in there. That would indicate he endured a temperature of around 400 F (204 C) for about 10 minutes.

I had previously read that people could endure "enough heat to cook a steak."

I have experienced 100 C or perhaps a bit more for 20 minutes on a number of occasions, in a sauna. It wasn't unpleasant, except for when I was on a bench near the ceiling, and somebody dumped some water in the basin of rocks on top of the stove. That steam was scalding!

[Uncwilly]

Originally Posted by Dr Sardonicus

I have experienced 100 C or perhaps a bit more for 20 minutes on a number of occasions, in a sauna.

I have retrieved items out of a 550 C furnace before barehanded. Yes, actually picking up items that were at 550. They were low thermal mass, highly conductive, and the contact area was small.

I will dig out the details of the tests I mentioned above later.

[a1call]

DO NOT TRY THIS AT HOME!


https://youtu.be/yTOCAd2QhGg

[xilman]

Originally Posted by Dr Sardonicus

I have experienced 100 C or perhaps a bit more for 20 minutes on a number of occasions, in a sauna. It wasn't unpleasant, except for when I was on a bench near the ceiling, and somebody dumped some water in the basin of rocks on top of the stove. That steam was scalding!

Yes, having low humidity is critical.

[Uncwilly]

Originally Posted by Uncwilly

The US military has done tests and exposed people to over 200C while at the same time cooking a steak in the same area.

Originally Posted by Uncwilly

I will dig out the details of the tests I mentioned above later.

From an old Guinness book (from the time when it was a useful reference)

The highest dry-air temperature endured by naked men in the US Air Force experiment in 1960 was 400° F [204°C] and for heavily clothed men 500° F [260° C]. (Steaks require only 325° F [162.8 ° C].) Temperatures of 284° F [140° C] have been found quite bearable in sauna baths.

[xilman]

Originally Posted by Uncwilly

I have retrieved items out of a 550 C furnace before barehanded. Yes, actually picking up items that were at 550. They were low thermal mass, highly conductive, and the contact area was small.

I will dig out the details of the tests I mentioned above later.

At the other end of the scale, I have dipped my hands in liquid nitrogen on a number of occasions.

One of our favourite tricks with newbie chemists was to put some rubber tubing in LN2 and spray them with droplets; then to smash the tubing on a bench to shower them with rubber shrapnel, and finally to stir the Dewar with a forefinger for 30 seconds or so and then hit the bench hard with the same finger.