I've been to some pretty dodgy places; Honduras, Croatia, Oakland and I think for the most part people anticipate being self-sufficient in times of crisis. But holy hell, you do run into some knobs abroad.
Pet Peeve rants.
- Thread starter Mathias
- Start date
That's what you get for going to Oakland.
I bet it had a specific clientele though.
Fade didn't like it.
figmentPez
Staff member
Just watched a YouTube video on how "Salt doesn't melt ice". I don't mind people nit-picking and pointing out whats technically correct, what bugs me is when people do a piss-poor job of doing that. The video was trying to say that "melting" means becoming liquid through the addition of heat, and that the salt actually takes heat away, thus it is not "melting". I have no idea if this is the correct scientific definition of "melt", since the dictionary also allows for "to become liquid; dissolve:" which does apply to what salt does to ice. Regardless, the presenter never directly said what was happening. What do you call it when salt causes ice to become liquid? I have no fucking clue, so I'm going to keep calling it melting, even if that's technically incorrect, because I need to call it something, and this nit-picking video failed to tell me what the correct term is.
Want me to approve of your technically correct nit-picking? Tell me the right answer, not just how wrong everyone else is.
Want me to approve of your technically correct nit-picking? Tell me the right answer, not just how wrong everyone else is.
so . . . melting.
figmentPez
Staff member
Well, the claimed technicality is that salt doesn't directly cause the phase change, it merely prevents any liquid water that forms from re-solidifying. He says the edges of ice are constantly undergoing a phase change, but he didn't explain why this is. In fact, he called it melting, but can that be right when the ice continues to undergo phase change even after the saltwater reaches temperatures below freezing? If it's "melting" from something else, where is the heat coming from, submerged in sub-zero liquid? I don't know. Like I said, not a clear video.
From the sun, from the Earth's core, from combustion engines, from home furnaces, etc - but mostly the first two.
What I'm implying is that "below freezing" doesn't mean there's no heat. It's more obvious on the Kelvin scale.
figmentPez
Staff member
Yes, but how is that heat getting to the ice through a colder substance? I realize that heat energy is still present, because it's not absolute zero, but how does heat travel into ice that is surrounded by something even colder? Or is the heat being transferred from the core of the ice to it's border? My I'm guess was that the ice continues to undergo a phase change at the border despite it not being raised to a temperature above zero degrees C, and thus is not technically melting by his definition, but honestly I have no idea.
As I understand it, salt water has a lower melting point than fresh water, and you can essentially call a salt/ice mixture "salt water" - so it's not technically correct to say is that salt isn't melting the ice - can't melt the ice - because the salt-ice is a single entity.
I think the problem is that he made a video to explain something that can be explained in one sentence.
Saltwater's freezing point is somewhere below -10 Celsius, so of course liquid salt water can be colder than frozen fresh water, which might only be -1 Celsius.
I think the problem is that he made a video to explain something that can be explained in one sentence.
Saltwater's freezing point is somewhere below -10 Celsius, so of course liquid salt water can be colder than frozen fresh water, which might only be -1 Celsius.
It's high school chemistry, but I can't Google a good explanation right now. But yes, making the water into a solution doesn't add heat, it lowers the freezing point.
okay, I think I finally understand what you're getting at here, why you're confused.
You're wondering why freshwater ice submerged in subzero saltwater is melting, right?
If it's doing that, it'll simply be because saltwater in contact with the ice is turning the ice's surface into a salt/ice mixture that let's it melt at the lower tempature, exactly as a grain of salt on the cube "melted" the ice in the first place.
(Also, I gotta say that a video demonstration of how road salt doesn't "melt" snow and ice would have been better if performed in a meat freezer set at -5 Celsius)
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figmentPez
Staff member
NOPE, I'm happy with my level of understanding of how salt lowers the freezing point of water. I was just wondering why the video presenter calls it melting, when he's got a very specific definition of melting that it doesn't seem to meet.
figmentPez
Staff member
And this is why the semantics of the situation are so ridiculous. It's like setting a sugar sculpture in a puddle of water and saying that the water didn't cause the sugar to collapse, the sugar's own weight did. Yeah, the water didn't exert any force on the sugar*, but it compromised the structure.
*well, it probably did with some sort of osmotic pressure, but I'm disregarding that
Only it's even more complicated than the sugar sculpture analogy, because he's saying that the boundary at the edge of the ice is constantly in flux, and doesn't explain why. If it's because the surface of the ice is colder than the air around it, and that thawing and refreezing is a result of energy transfer, that's one thing, and is easy to understand. However, if that constant phase change is a property of the boundary layer regardless of the temperature, then it's something else altogether, and I don't know enough to know which is true. If you had ice surrounded by something insoluable in water and both were well below freezing, would there still be that constant freezing/thawing on the surface of the ice? If there wouldn't be, would salt still cause the ice to undergo a phase change? The video implies that it wouldn't, as it says the salt merely prevents the water from refreezing, it doesn't cause the melting itself. And is it melting if this phase change happens without energy being added to the system?
figmentPez
Staff member
Because he also does amusing stuff with a vacuum chamber.
He indicates he has a PhD in chemistry, so you can't write him off as a crackpot. Here's the video in question:
So far as I can tell it's semantics. He demonstrates that putting salt on the ice has more water output than ice merely sitting there under the same environmental conditions, which most people would consider melting.
He asserts, however, that since he's actually lowering the temperature of the whole thing, then it's not actually melting.
Honestly that explanation doesn't hold water for me. My best guess is that perhaps within the world of professional chemistry this is not considered "melting" but all I see is a bunch of solid H2O changing into liquid once salt is added. Given that it's a solution, perhaps what he's trying to point out is that it's no longer (technically) water, but if so he's completely avoiding saying it (ie, a 10 second video).
So maybe he's not a crackpot, but he understands clickbait videos and is actively generating confusion at best, outright misinformation at worst, in order to generate revenue.
What he completely fails to provide, though, is a use for his particular explanation. At best it's just something for people to argue about and "well actually" each other, but the explanation doesn't provide much useful information that helps the audience understand the world better, nevermind information they can actively use in some aspect of their life.
So far as I can tell it's semantics. He demonstrates that putting salt on the ice has more water output than ice merely sitting there under the same environmental conditions, which most people would consider melting.
He asserts, however, that since he's actually lowering the temperature of the whole thing, then it's not actually melting.
Honestly that explanation doesn't hold water for me. My best guess is that perhaps within the world of professional chemistry this is not considered "melting" but all I see is a bunch of solid H2O changing into liquid once salt is added. Given that it's a solution, perhaps what he's trying to point out is that it's no longer (technically) water, but if so he's completely avoiding saying it (ie, a 10 second video).
So maybe he's not a crackpot, but he understands clickbait videos and is actively generating confusion at best, outright misinformation at worst, in order to generate revenue.
What he completely fails to provide, though, is a use for his particular explanation. At best it's just something for people to argue about and "well actually" each other, but the explanation doesn't provide much useful information that helps the audience understand the world better, nevermind information they can actively use in some aspect of their life.
Having to wash your hands with cold water.
I don't know if the boiler is down in my building, but I can't stand freezing my hands while trying to get clean.
I am always a little off put when I use a men's room in a high traffic place, and the water from the hot tap is cold. It just puts a bug in the back of my mind that the employees don't have clean hands.
I don't know if the boiler is down in my building, but I can't stand freezing my hands while trying to get clean.
I am always a little off put when I use a men's room in a high traffic place, and the water from the hot tap is cold. It just puts a bug in the back of my mind that the employees don't have clean hands.
i thought it was the friction of rubbing your hands that took care of the bacteria not the warm water
Just the soap and water, heat does not really matter. It just seems like it should.i thought it was the friction of rubbing your hands that took care of the bacteria not the warm water
Well heat could but you would suffer horrible burns at temps capable of killing bacteria instantly
GasBandit
Staff member
i thought it was the friction of rubbing your hands that took care of the bacteria not the warm water
Hotter water is more effective at removing oil from skin than cold (and bacteria lives in the oil), but yes, the heat needed to actually kill bacteria would burn your skin badly. By the same token, hot water removing all that oil can make your skin drier, causing irritation. However, cold water can cause skin irritation and broken capillaries. The conventional wisdom of the moment is to use tepid water.
Washing hands is not about killing bacteria. It's about removing some of them and dirt from your hands. Scrub your hands and make a lather/suds and rinse without rubbing your hands (like doctors on tv). The suds lift the bacteria/oil and create micelle that is rinsed away. If you rub your hands while rinsing, you are potentially spreading the bacteria/filth around on your hands and under your nails, etc.
Besides, even if you washed your hands with bleach and boiling water and killed all the bacteria on your hand, the commensal bacteria on your arms would repopulate your hands in a few hrs. Also, the good commensal bacteria on your skin protect you from infectious bacteria that may end up on your skin.
Besides, even if you washed your hands with bleach and boiling water and killed all the bacteria on your hand, the commensal bacteria on your arms would repopulate your hands in a few hrs. Also, the good commensal bacteria on your skin protect you from infectious bacteria that may end up on your skin.
I wash my hands with warm water, just because I hate cold water on my hands.
The building where I have my internship has no hot water. On purpose. It's great. /s
fade
Staff member
My street has no sidewalks, like most of Houston. I was always taught that if there is no sidewalk and you're walking in the street (it's a suburb with very low traffic by design), that you walk on the left side toward oncoming traffic. But so many people walk on the right side. That irritates the crap out of me. I've even asked a friend who was doing it, and she says, "Oh yeah, I know you're supposed to walk on the left, but everybody else was already over here." I'm not like the walk dictator or anything, but consistency means someone's not going to get plowed over by one of the teen drivers peeling out through the neighborhood.
And the bicycles are flying down the left side then.[DOUBLEPOST=1510843321,1510843210][/DOUBLEPOST]
I actually missed a lawnmower being driven down left shoulder of a 60mph highway by only a foot, in the dark.
figmentPez
Staff member
Media trope that needs to die: "Just agree with your wife/girlfriend, even when she's wrong, she's right." How the fuck is that ever healthy behavior?