de-icing a vehicle

ROTFL. Myth. Busted long ago.

Uh, no.

What happens in most "home experiments" involving putting a tray of hot water in the freezer and a tray of cold water in the freezer is this: The tray with hot water initially melts the thin coating of ice on the freezer's shelf, which then re-flows and forms a good bond to the bottom of the ice tray allowing faster cooling of the try by conduction. The tray of cold water does not get this benefit and rests atop the thin layer of ice on the freezer shelf, and is forced to cool only by cold air flow. If you place your hot and cold water trays in the freezer on

*dry* towels which eliminates cooling by conduction, the tray of cold water ALWAYS FREEZES FIRST. You canna change the laws of physics, you can only misinterpret them.

Steve wrote in news:hcCdnbtT0IPiZcLanZ2dnUVZ snipped-for-privacy@texas.net:

Not a myth goof ball. proven many times out side, not in a freezer, no container to change the results. KB

innews:hcCdnbtT0IPiZcLanZ2dnUVZ snipped-for-privacy@texas.net:

Utter nonsense. For water to freeze heat has to be extracted and it has to be brought to a freezing temperature. Hot water has a lot more eneregy to be extracted and that will take longer than cold water. Unless you are living in some parallel universe with it's own set of physics laws.

As a test place water that is one degree above freezing and water that is one degree below boiling into equal containers. Leave them in a freezing compartment or outside in zero degreee weather and time.

innews:hcCdnbtT0IPiZcLanZ2dnUVZ snipped-for-privacy@texas.net:

I have actually pulled off the experiment showing hot water freezing first in school and at home for my Dad.... I used aluminum ice cube trays. It was a 'lot' colder than 0F though, more like -20F.

Here is a decent description of what is going on:

I don't know which theory works, but one or more comes into play for sure.

Mike

86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00 'New' frame in the works for '08. Some Canadian Bush Trip and Build Photos:

Yeah, you've repeated a faulty experement. Weigh the the trays when cold water is used and when hot water is used. If the weight isn't the same then you aren't making a valid comparison.

I lost a bet on this. Hot water freezes first.

Correct, I won't say there aren't tricks of physics to it, no one claimed it made any sense....

But the end result is two apparently even trays of water freeze at different times with no apparent outside influences on it. This happens both for skimming over and cubing solid and is repeatable.

For 'whatever' reason...

LOL

Mike

86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00 'New' frame in the works for '08. Some Canadian Bush Trip and Build Photos:

innews:hcCdnbtT0IPiZcLanZ2dnUVZ snipped-for-privacy@texas.net:

on:

I read through a couple of different articles including the Wikipedia note on the Mpemba effect. Hot water is purported to freeze faster than cold water under certain conditions but there is no agreement on what those conditions are. For it to occur apparently the difference in temperatures cannot be wide. However there are several disagreements including about what constitutes freezing, how temperature is measured and whether the effect of hot water evaporation should be considered.

I'm left with the impression that under certain circumstances you might see something occur if you are willing to ignore the impact of certain variables. Just as some people believe they see something in the Turin shroud.

"John S." wrote in news: snipped-for-privacy@d4g2000prg.googlegroups.com:

I can assure you after years of thawing hog waters out, hot water will deff. freeze faster in the very cold (0 degrees F on down) much faster than cold tap water. Fill a 5 gal bucket of hot water from the hot water heater and one with cold tap water and you will have a large chunk of frozen water to get out of the hot water bucket, while only skiming over the cold water. Add a cold wind and it is even more noticable. KB

Same goes for plumbing pipes. There is a hot and a cold pipe running parallel and the hot one is always the one that freezes and bursts.

Mike

86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00 'New' frame in the works for '08. Some Canadian Bush Trip and Build Photos: