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44
votes
4answers
4k views

Being in a solid state, why is ice slippery? [duplicate]

Saying that ice is slippery is like saying that water is wet -- it's something we've known for as long as we can be said to have known anything. Presumably, humans as a species knew ice was slippery ...
15
votes
1answer
861 views

Why doesn't breath condense around poop of flies on the window's glass?

One day it was raining outside and I was breathing on the glass of my window. I noticed that around the spots of fly poop there is a circle where vapor does not condense. With time the circle becomes ...
4
votes
2answers
66 views

Why water vapour condense easier in contact with a solid?

Reading about cloud formation, I learned that to a droplet to form, the water vapour needs a Cloud Condensation Nuclei, which is an aerosol with a size in the order of 0.0001mm. And if no CCN is found ...
2
votes
1answer
21 views

How to calculate the volume of water in a certain amount of air, given the relative humidity?

If, according to the weather forecast, the current humidity is 90%, how can I calculate the volume of water that could be extracted from a certain volume of that air?
2
votes
2answers
149 views

Cloud chamber temperature

I'm planning to build a small cloud chamber. The design is the usual: alcohol evaporates at the top by gently heating it with a thin wire and small current. The vapour sinks to the bottom of the ...
2
votes
0answers
137 views

How far we can see in the thickest possible fog?

There is quite foggy day today here, I cannot see end of the street. This made me think about how much worse can it be. So here is my question: how thick a fog can be? What's the smallest visibility ...
2
votes
0answers
420 views

How can I interpret negative values of potential evapotranspiration?

If I extract Potential Evaporation (PET, W/m$^2$) from the National Centers for Environmental Prediction (NCEP), climate reanalysis data (downloadable as netCDF files here), there are some negative ...
1
vote
2answers
306 views

How does a dehumidifier work?

I have read sites like this, but I am just not getting it yet. I'm looking to understand the variables involved, which I think are: air moisture content air flow (cfm?) condenser surface area? ...
1
vote
2answers
40 views

What caused a fluctuating cloud to form in a jet engine intake on a humid day?

I was on a commercial flight in a 737 stationary at idle on a taxiway. It had recently stopped raining so the relative humidity was likely near 100% and the air temperature was about "light jacket" ...
1
vote
1answer
276 views

How does a thin film of soap help defog bathroom mirrors?

We often find bathroom mirrors get fogged while hot water is used. Looking this up on the internet, we find several easy solutions: use a hot air blower use a heater behind the mirror vinegar + ...
1
vote
1answer
53 views

How do I determine when this object is about to get covered in dew? I can measure the environment parameters

There is a large disk of glass sitting outside, it is pretty thick and wide. Via different sensors hooked up to a controller, I can measure the air temperature, glass temperature (on the surface), and ...
1
vote
0answers
33 views

Cost vs. purity producing liquid oxygen [closed]

We are a group of rocket amatures who build rockets using LOX and ethanol as propellent. We normally buy the LOX from supplier. But lately we have been discussing if there is an easy way to produce it ...
1
vote
0answers
54 views

Can I use computer fans and tubes to lower the air temperature below dew point?

I suppose to build a small dehumidifier, but I am narrowing the question down into its logics. I have relatively powerful computer fans, water cooling radiator and some metal tubings. With the idea ...
0
votes
2answers
40 views

Solar stills with Wine [closed]

Is it possible to obtain more concentrated alcohol by using wine in a solar still instead of seawater? If yes, as I suspected, how does the concentration (of alcohol) of the distillate vary with ...
0
votes
3answers
111 views

Latent heat of condensation

Regarding atmospheric processes, I understand that energy is required to evaporate water by moving molecules further apart i.e. a phase change from liquid to gas. The air then ascends into the ...
0
votes
1answer
143 views

Is there a name for a substance that is a gas at room temperature?

Is there a name for a substance that is a gas at room temperature, such as Hydrogen, Helium, Neon, Argon, Krypton, Xenon, Chlorine, Fluorine, Bromine, Nitrogen, and Oxygen. I am writing a paper where ...
0
votes
1answer
433 views

Liquid nitrogen condensing oxygen out of the air

In this video, a pool of liquid nitrogen in a metal bowl can cool it enough so that oxygen from the air condenses at the bottom: ...
0
votes
1answer
8k views

Thermodynamics: Are pressure and temperature enough to calculate enthalpy?

From the chart above, it looks like it is possible to calculate enthalpy from just pressure and temperature. After a few hours of Googling my question, I'm not able to find anything helpful. My ...
0
votes
2answers
66 views

Would oxygen in a container condense automatically at night in the exosphere?

If a container filled with pure oxygen and fitted with leak-proof valves were to be dumped into the exosphere at night, would the contained oxygen condense?
0
votes
0answers
9 views

Do things get more moist when put inside a normal fridge?

Do things get more moist when put inside a normal fridge? I am fairly certain they do because with the cooling of normal air there will be an increase in pressure, I understand this through an ...
0
votes
2answers
58 views

Why do cold drinks get sweaty?

I drink a lot of iced tea and live in a very humid part of the country. My drink accumulates so much water, I had to purchase coasters to collect all the water dripping from the sides. Where does ...
0
votes
0answers
22 views

What factors determine how long airplane condensation stays in the air?

My understanding is that the turbulence formed by the flight of an airplane has low-pressure zones with low temperatures that cause water molecules to condense to form a fog. My question is about the ...
0
votes
2answers
459 views

Compression and expansion

Why is it that solids on compression [As in striking a hammer etc.] heat up, but liquids and gases on compression [Pressurizing liquids causes them to freeze or gases to liquify] cool down? Can ...
-1
votes
3answers
5k views

High and low pressure area and raining

In the high-pressure area it is mostly likely that there is sun. In low pressure area it is mostly likely that rain will occur. Because of the law that ...
-1
votes
2answers
283 views

What is a good read about Manning condensation? [closed]

I was assign in a course to give half an hour talk about Manning condensation. I read Wikipedia article about it as a starter, but it's only two paragraphs long and only point to the original paper ...