I just found out

AShadeOfClear

Banned
Jul 19, 2001
283
0
0
I just found out out why you get water droplets on the cup of a cold drink. I knew it was called condensation, but wasn't sure exactly why it happened. My theory was that the water droplets seeped through the cup somehow by altering its molecular structure. How embarssing :eek: I know there are lots of bits and peices of things I don't know that I really should. Anybody else catch themselves learning these simple grade-school type things?
 

ggavinmoss

Diamond Member
Apr 20, 2001
4,798
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rolleye.gif
 

Viper GTS

Lifer
Oct 13, 1999
38,107
433
136
That's a surprisingly common misconception.

My dad's a welder, it's amazing how many people he works with think that the metal "sweats" (as in loses water it has stored in it) when heated & cooled.

Viper GTS
 

CraigRT

Lifer
Jun 16, 2000
31,440
5
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nice.. ever find yourself wondering why you get static on your clothes? get back to us in a bit when you find an answer.. :D

hehe..
 

bmacd

Lifer
Jan 15, 2001
10,869
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Originally posted by: Yield
nice.. ever find yourself wondering why you get static on your clothes? get back to us in a bit when you find an answer.. :D

hehe..

How do clothes get "staticky"? I mean, why do they stick and get static cling when you take them out of the dryer?

You have probably noticed that during the winter you can rub your feet on the carpet and then shock your friend (or sibling) by touching them, and that you can make your cat's fur stick up (and really annoy them) by rubbing your hand back and forth on their fur. What is common to these situations and the dryer situation? The act of rubbing and the dry climate are the common elements. When objects are rubbed together, charge may be transferred from one object to the other. Some objects like to give off negative charge and some like to receive negative charge, depending on the material of which they are made. The excess charge resides on the surface of the object (if it is an insulator) and causes the object to be attracted to or repelled by other objects, depending on their net charge. Thus, the object sticks to other objects. What does the dry climate have to do with anything? As you heard about in lecture, air is an insulator, but since water is a conductor, moist air is able to move charge from one place to another fairly easily. In dry climates, the excess charge residing on the surface of an object remains there until the object comes into direct contact with another object. In moist climates, the excess charge residing on the surface of the object is dissipated through contact with the moist air.

source

-=bmacd=-
 

notfred

Lifer
Feb 12, 2001
38,241
4
0
This from the guy who needs constant mental stimulation.....

I guess by "mental stimulation" you meant Sesame Street, right?
 

zephyrprime

Diamond Member
Feb 18, 2001
7,512
2
81
Anybody else catch themselves learning these simple grade-school type things?
Yes but those things are usually related to girls not simple physics.

And also, it is possible for small quanities of water to diffuse into rocks but the quanitities involved are really small compared to the quanitity of water that condenses on a glass.