Win a bet with your friends! - Page 2

Shawnee123 · 12-03-2008, 09:49 AM

I've always wondered why, when making ice cubes, if you use hot water you'll get little peaks in your cube, like a wave. My brother told me it's not true that hot water freezes faster...so how does it peak?

Has anyone seen this as well?

xoxoxoBruce · 12-03-2008, 11:37 AM

Next time you make hot water ice cubes, peek.

Shawnee123 · 12-03-2008, 11:55 AM

I should replace my freezer door with a microwave door, then catch 'em in the act.

Scriveyn · 12-04-2008, 04:09 AM

Part of the hot water evaporates.
So
.... there is less water left in the tray to freeze and
.... the evaporation process extracts energy from the water

Clodfobble · 12-04-2008, 12:48 PM

If you read the Wiki link, they acknowledge that evaporation can play a role, but they also did an experiment where they controlled for evaporation and the hot water still froze faster.

wolf · 12-04-2008, 06:16 PM

Have the Mythbusters done this yet?

I'll take their word on it, nobody else's.

classicman · 12-04-2008, 07:05 PM

The question then becomes....

Does it freeze faster on a treadmill?

xoxoxoBruce · 12-05-2008, 02:15 AM

Quote:

Originally Posted by Clodfobble

If you read the Wiki link, they acknowledge that evaporation can play a role, but they also did an experiment where they controlled for evaporation and the hot water still froze faster.

Yes, hot water pipes freeze faster than the cold. No evaporation there.

classicman · 12-06-2008, 12:28 AM

Aren't the molecules farther apart in the hot water and thereby more susceptible to temperature change leading to a faster cooling rate?

xoxoxoBruce · 12-06-2008, 02:17 AM

Yes, and because there are less of them in a given space, there is less total latent heat.

ZenGum · 12-06-2008, 08:23 AM

But I think the experiments were done with a given amount (mass) of water.

It is so counter-intuitive, because for a hotter sample to freeze, it must first reach and pass through the colder temperature, and it is tempting to think of it as cooling from there (the colder temperature) just as the cold sample did. Obviously not.
The explanation I found most plausible is that some kind of condition is created by being at higher temperatures which survives the drop to lower temperatures. It could be an internal mixing movement or something weirder at the microphysical level.

Shawnee123 · 12-06-2008, 09:44 AM

Let me get this straight: We can send a man to the moon (don't you love that antique phrase?) but no one can find a definitive answer regarding the science of water?

I found some articles, but still, I would think that they physical properties of water had pretty much been explored.

http://math.ucr.edu/home/baez/physic...hot_water.html

http://itotd.com/articles/521/water-...boiling-myths/

Classic is right: this is not unlike the treadmill arguments.

xoxoxoBruce · 12-06-2008, 11:08 AM

Quote:

Originally Posted by ZenGum

But I think the experiments were done with a given amount (mass) of water.

Mpemba's experiment used identical volume, not mass.

classicman · 12-06-2008, 11:21 AM

Ahh zen, but there you have hit on it precisely. There is so much about water that we really do not know. It is amazing that so much of our planet and all the very life upon it relies, yet we still don't fully comprehend so many things about it.

12-03-2008, 09:49 AM	#16
Shawnee123 Why, you're a regular Alfred E Einstein, ain't ya? Join Date: Jun 2006 Posts: 21,206	I've always wondered why, when making ice cubes, if you use hot water you'll get little peaks in your cube, like a wave. My brother told me it's not true that hot water freezes faster...so how does it peak? Has anyone seen this as well? __________________ A word to the wise ain't necessary - it's the stupid ones who need the advice. --Bill Cosby

12-03-2008, 11:37 AM	#17
xoxoxoBruce The future is unwritten Join Date: Oct 2002 Posts: 71,105	Next time you make hot water ice cubes, peek. __________________ The descent of man ~ Nixon, Friedman, Reagan, Trump.

12-03-2008, 11:55 AM	#18
Shawnee123 Why, you're a regular Alfred E Einstein, ain't ya? Join Date: Jun 2006 Posts: 21,206	I should replace my freezer door with a microwave door, then catch 'em in the act. __________________ A word to the wise ain't necessary - it's the stupid ones who need the advice. --Bill Cosby

12-04-2008, 12:48 PM	#20
Clodfobble UNDER CONDITIONAL MITIGATION Join Date: Mar 2004 Location: Austin, TX Posts: 20,012	If you read the Wiki link, they acknowledge that evaporation can play a role, but they also did an experiment where they controlled for evaporation and the hot water still froze faster. __________________ My book My other book My spirit animal

12-04-2008, 06:16 PM	#21
wolf lobber of scimitars Join Date: Jul 2001 Location: Phila Burbs Posts: 20,774	Have the Mythbusters done this yet? I'll take their word on it, nobody else's. __________________ wolf eht htiw og "Conspiracies are the norm, not the exception." --G. Edward Griffin The Creature from Jekyll Island High Priestess of the Church of the Whale Penis

12-04-2008, 04:09 AM	#19
Scriveyn amnesic-confabulatory opsimath Join Date: Oct 2006 Location: Between my ears Posts: 739	Part of the hot water evaporates. So .... there is less water left in the tray to freeze and .... the evaporation process extracts energy from the water

12-04-2008, 07:05 PM	#22
classicman barely disguised asshole, keeper of all that is holy. Join Date: Nov 2007 Posts: 23,401	The question then becomes.... Does it freeze faster on a treadmill? __________________ "like strapping a pillow on a bull in a china shop" Bullitt

12-06-2008, 12:28 AM	#24
classicman barely disguised asshole, keeper of all that is holy. Join Date: Nov 2007 Posts: 23,401	Aren't the molecules farther apart in the hot water and thereby more susceptible to temperature change leading to a faster cooling rate? __________________ "like strapping a pillow on a bull in a china shop" Bullitt

12-06-2008, 02:17 AM	#25
xoxoxoBruce The future is unwritten Join Date: Oct 2002 Posts: 71,105	Yes, and because there are less of them in a given space, there is less total latent heat. __________________ The descent of man ~ Nixon, Friedman, Reagan, Trump.

12-06-2008, 08:23 AM	#26
ZenGum Doctor Wtf Join Date: Oct 2007 Location: Badelaide, Baustralia Posts: 12,861	But I think the experiments were done with a given amount (mass) of water. It is so counter-intuitive, because for a hotter sample to freeze, it must first reach and pass through the colder temperature, and it is tempting to think of it as cooling from there (the colder temperature) just as the cold sample did. Obviously not. The explanation I found most plausible is that some kind of condition is created by being at higher temperatures which survives the drop to lower temperatures. It could be an internal mixing movement or something weirder at the microphysical level. __________________ Shut up and hug. MoreThanPretty, Nov 5, 2008. Just because I'm nominally polite, does not make me a pussy. Sundae Girl.

12-06-2008, 09:44 AM	#27
Shawnee123 Why, you're a regular Alfred E Einstein, ain't ya? Join Date: Jun 2006 Posts: 21,206	Let me get this straight: We can send a man to the moon (don't you love that antique phrase?) but no one can find a definitive answer regarding the science of water? I found some articles, but still, I would think that they physical properties of water had pretty much been explored. http://math.ucr.edu/home/baez/physic...hot_water.html http://itotd.com/articles/521/water-...boiling-myths/ Classic is right: this is not unlike the treadmill arguments. __________________ A word to the wise ain't necessary - it's the stupid ones who need the advice. --Bill Cosby

12-06-2008, 11:21 AM	#29
classicman barely disguised asshole, keeper of all that is holy. Join Date: Nov 2007 Posts: 23,401	Ahh zen, but there you have hit on it precisely. There is so much about water that we really do not know. It is amazing that so much of our planet and all the very life upon it relies, yet we still don't fully comprehend so many things about it. __________________ "like strapping a pillow on a bull in a china shop" Bullitt

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