Flash frozen to the ground...

landrovered

landrovered

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Actually crystalization is an exothermic event that temporarily raises the temperature of the liquid.
 
Blue

Blue

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J. Toronado said:
The phenomenon that hot water may freeze faster than cold is often called the Mpemba effect. We start with two containers of water, which are identical in shape, and which hold identical amounts of water. The only difference between the two is that the water in one is at a higher (uniform) temperature than the water in the other. Now we cool both containers, using the exact same cooling process for each container. Under some conditions the initially warmer water will freeze first. If this occurs, we have seen the Mpemba effect. Of course, the initially warmer water will not freeze before the initially cooler water for all initial conditions. If the hot water starts at 99.9?C, and the cold water at 0.01?C, then clearly under those circumstances, the initially cooler water will freeze first. However, under some conditions the initially warmer water will freeze first -- if that happens, you have seen the Mpemba effect. But you will not see the Mpemba effect for just any initial temperatures, container shapes, or cooling conditions.

Source:
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That's a long paragraph that tells nothing. Do you know why warmer (not really "hot") water can, under certain circumstances, freeze faster than cold water?
 
Blue

Blue

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Leslie said:
Suggestion: if you're going to quote something, please use a source that actually says something instead of simply repeating that "you have seen the Mpemba effect".

Fact is, pure water would not do such in a controlled environment; heat transfer is part of thermodynamics, and you're not gonna alter such.

However, it does appear that some people have begun to manage repeating the observation made by Mbemba. For one, if you use hard water, the heat 'softens' it by precipitating the impurities, that are present still in the cooler water, so you actually have two different waters going through the cooling process. Also, you could end up with layering effects, where stratification occurs, and you have convection cells set up that affect rates.

So, there ya go....
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LOL....yep, there ya go!

You also have to define "freeze"....are you talking frozen solid, or just frozen layer on the top? Cooler water is denser and may inhibit circulation (Les' allusion to convection cells), thereby first forming a thin ice layer at the top of the water (where the water is presumably making most contact with cold air). This ice layer then acts as an insulating layer, further inhibiting total freezing. There are so many different processes going on, it is truly fascinating. I've spent many many hours as a kid (and hell, I'll admit it: as an adult) playing around with freezing and heating experiments. It's fascinating to watch the convection cells develop and then go chaotic in a pot of water on a hot stove. My latest experiments involve the perfection of supercooling and instant freezing of beer and mixed drinks (particularly margaritas). Cool science with a practical application.
 
cdansan

cdansan

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I won't enter the water portion of the discussion because I be dumb.

My DI makes an audible sound from the center diff, if it is not locked, when the front and rear wheels are turning different rates. Accelerating from a stop, uphill in the snow on pavement will do it.

I would get it unstuck before I look for any broken parts.
Good luck, Dan
 
J. Toronado

J. Toronado

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Blue said:
I've spent many many hours as a kid (and hell, I'll admit it: as an adult) playing around with freezing and heating experiments. It's fascinating to watch the convection cells develop and then go chaotic in a pot of water on a hot stove.
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LOL....yep, there ya go!
Your fascinating experiments must keep you up late at night.
 
T

They call me Pete

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Forget all that scientific mumble jumble and get a electric jackhammer with a generator. Should be able to chisel that bitch out in no time.
 
flyfisher11

flyfisher11

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May 25, 2005
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Blue said:
LOL....yep, there ya go!

You also have to define "freeze"....are you talking frozen solid, or just frozen layer on the top? Cooler water is denser and may inhibit circulation (Les' allusion to convection cells), thereby first forming a thin ice layer at the top of the water (where the water is presumably making most contact with cold air). This ice layer then acts as an insulating layer, further inhibiting total freezing. There are so many different processes going on, it is truly fascinating. I've spent many many hours as a kid (and hell, I'll admit it: as an adult) playing around with freezing and heating experiments. It's fascinating to watch the convection cells develop and then go chaotic in a pot of water on a hot stove. My latest experiments involve the perfection of supercooling and instant freezing of beer and mixed drinks (particularly margaritas). Cool science with a practical application.
Click to expand...

Try sticking a frozen turkey in a deep fat frier and report back your findings.
 
Blue

Blue

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flyfisher11 said:
Try sticking a frozen turkey in a deep fat frier and report back your findings.
Click to expand...

I'd heard you can get one into low earth orbit that way.....
 
p m

p m

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J. Toronado said:
nada. The physics of boiling water are pretty straightforward. It all comes down to how much heat you can add to the water and how fast. It takes 1 calorie of heat energy to raise 1 milliliter of water by 1 degree C (1.8 degrees F).
Your heating element (burner or electric element) will put a certain amount of heat into the pot at a certain rate. How fast does depend on temperature, or rather the temperature difference between the heating element and the water.
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JT - has it occured to you that the temperature of the heating element may not be constant?

JT said:
The colder pot cannot overcome the fact it has started from a lower temperature and the warmer pot had a head start.
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So the hot pot of water cannot overcome the fact that it started from a higher temperature (when it is put in the freezer), and the colder pot had a head start.

There's some fine physics to phase transitions, all right, but most sources quoted in this thread have no grasp of it. It has no relevance to the task at hand, either.
 
Neil C

Neil C

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Frozen turkey into frier = Chlorine tab for gene pool.

Frozen Rover stuck to ground = Reason geese and such fly south.

Dude, hate to hear it, makes me cold just thinking about it. My dad lived in Forsythe, Montana for several years and told me horror stories of having to fix stuff in the fields during Beet harvest.

Hope you get un-stck soon. When you do, drive south till someone asks about the plug sticking out of your grill. :p

Neil
 
Leslie

Leslie

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p m said:
There's some fine physics to phase transitions, all right, but most sources quoted in this thread have no grasp of it. It has no relevance to the task at hand, either.
Click to expand...


And, my money is on the Russian's grasp of it, and capability to correctly follow it ;) (and even school me on it!)



It has been a long time since going through those problems, where the temperature of a block of ice is brought up to 0 C, then you have to go through the phase change from solid to liquid, then the temperature can continue to climb.... (if I remember it right, lol...) And again, upon reaching 100 C, has to phase change before the temperature can continue to rise.
 
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