Submitted by SunCloud-777 t3_zy30z3 in todayilearned
Reply to comment by PeachSnappleOhYeah in TIL Snow is an excellent insulator because it consists of about 90–95 percent trapped air (fresh). This is the reason why igloos are warmer inside than outside, and why some animals in colder regions build snow caves to spend the winter while hibernating. by SunCloud-777
Water is an excellent conductor of heat, that's why it's so often used as a coolant.
The term they meant to use is "Heat Capacity".
Water has a high heat capacity; it takes a relatively high amount of heat (energy) to cause a change in temperature.
This is also why it makes a good coolant, as it can then transfer that heat.
this is really really wrong
water is not a good heat conductor, look it up.
edit: here's a link link
> In terms of heat conductivity, water is classified as a poor thermal conductor and acts as an insulator by resisting the flow of heat through it.
wow, this goes to show how much upvotes actually mean
I don’t think there’s an agreed upon definition of “good” conductors.
In an engineering context it’s a mediocre conductor and can’t compare to most metals, but in a wilderness survival context water is a very good conductor of heat and is to be avoided at all costs if you want to stay warm.
In practice it’s a better conductor than snow, rock, and any other material you’ll find since it’s a liquid (I know that’s not technically correct, but in practice it might as well be).
> I don’t think there’s an agreed upon definition of “good” conductors.
heat conductivity is measurable, and predictable link
The unit of thermal conductivity, k = J/s⋅m⋅C°
there's a table listing some materials.
one of the really unusual characteristics of water is its low heat conductivity, which is a basis of its importance for life on earth... if water conducted heat more, it would freeze faster, potentially also from the bottom up, and global temperatures might swing too fast to support life. the same goes for ice and it's unique characteristics.
Yes there is an element of heat capacity and other thermodynamic terms going on... but i was keeping it simple for the person i was commenting to. if someone doesn't know why an igloo doesn't melt, it's easier to explain with terms they might know better.
You didn't address a single thing I said. I'm aware that it's measurable and I don't need the physics lesson. Besides, you're not in any position to be lecturing anyone on thermodynamics.
i did address where you were flat out wrong, and then provided a scientific example as to why you were wrong. that you dismissed it, says all i need to know about this discussion with you.
"Good" is a subjective measure. No one has defined a cutoff point between good and bad conductors. You did not address that at all. I said that "in an engineering context it’s a mediocre conductor" and you just provided numbers that support that conclusion.
In the context of wilderness survival, you can eliminate most materials on those lists and compare its conductivity to rocks, snow, trees, bushes, grass, air, etc. Suddenly water is a very good conductor relative to the other materials you are likely to encounter.
wow dude, you just don't give up, huh. you picked a fight and your first sentence was wrong and you're back tracking.
"oh... well 'good' is a subjective measure"...
i said it was a bad heat conductor, and you took the opposite stance, and now you're trying to qualify your answer with completely different scenarios.
seriously man, i don't want to talk to you. this discussion happened yessssssterrrrday. you are a day 2 reddit twat that reads over comments and nitpicks them to death. ain't nobody got time for that.
I said the same thing in two different ways since you didn't understand the first time. That is not back tracking. If you don't want to discuss it you can stop replying any time.
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