|
0 members (),
619
guests, and
1
robot. |
|
Key:
Admin,
Global Mod,
Mod
|
|
|
|
Joined: Oct 2004
Posts: 1,696
Megastar
|
OP
Megastar
Joined: Oct 2004
Posts: 1,696 |
While watching the Mens speed skating finals at the Winter Olympics, on TV. I was surprised to see that the Skate Rink Officials, sprayed HOT water over the ice rink, to keep the ice glasslike smooth, between groups of races.
The Canadian commentator stated this was because hot water froze quicker than cold.
I had heard this story many years ago, but the use of hot water, seemed like a joke to me.
I certainly never thought that this fact, would be put to such an unusual practical use.
Not sure why this is true..... but I assume its because the warmer water makes for a better contact with the ice.?
So the warmer water loses its latent heat very slightly quicker, due to contact and evaporation, than cold?
Should we all start to put warm water in the fridge ice freezing trays to save energy?
Hmmm, Not such a straightforward answer as it looks.
But water does have some strange propertys. It can remain a liquid both well above boiling point, and well below freezing. Providing its pure, and kept motionless in a smooth non-nucleating container.
And of course pure (distilled) water is an INSULATOR!
Hehe. Not a lot of people know that.
.  . "You will never find a real Human being - Even in a mirror." ....Mike Kremer.
|
|
|
|
|
Joined: Feb 2007
Posts: 1,840
Megastar
|
|
Megastar
Joined: Feb 2007
Posts: 1,840 |
Fascinating. As always, Mike, you get me reading, in this case about the Mpemba Effect. The effect is not yet understood but, given the supposed reasons it, I'm not convinced that it necessarily occurs in the case of the ice rink. There's a less mysterious reason for using hot water in that case: during use the surface of the ice is sculpted not only into valleys but also into hills - cold water would tend to freeze on top of them, whereas hot water would tend to level them before freezing.
"Time is what prevents everything from happening at once" - John Wheeler
|
|
|
|
|
Joined: Jun 2005
Posts: 1,940
Megastar
|
|
Megastar
Joined: Jun 2005
Posts: 1,940 |
Is it possible that the commentator doesn't actually understand the reason for this? I was about to posit my own idea why this is done and I see that ready has the same idea.
|
|
|
|
|
Joined: May 2007
Posts: 212
Senior Member
|
|
Senior Member
Joined: May 2007
Posts: 212 |
While watching the Mens speed skating finals at the Winter Olympics, on TV. I was surprised to see that the Skate Rink Officials, sprayed HOT water over the ice rink, to keep the ice glasslike smooth, between groups of races.
The Canadian commentator stated this was because hot water froze quicker than cold.
I had heard this story many years ago, but the use of hot water, seemed like a joke to me.
I certainly never thought that this fact, would be put to such an unusual practical use.
Not sure why this is true..... but I assume its because the warmer water makes for a better contact with the ice.?
So the warmer water loses its latent heat very slightly quicker, due to contact and evaporation, than cold?
Should we all start to put warm water in the fridge ice freezing trays to save energy?
Hmmm, Not such a straightforward answer as it looks.
But water does have some strange propertys. It can remain a liquid both well above boiling point, and well below freezing. Providing its pure, and kept motionless in a smooth non-nucleating container.
And of course pure (distilled) water is an INSULATOR!
Hehe. Not a lot of people know that. I don't buy that at all. It's a matter of joules. Put 33 degree water in a tray and a tray of 100 degree water in a frezer at the same time. By the time the 100 degree water is 33 degrees is someone gonna tell me the 33 degree water is still 33 degrees? I think what happened is that (I've heard) hot water freezes clearer, less bubbles and what not in it. I think somewhere along the way the two got mixed up. Pretty simple to test though... And have you ever sen the PBS NOVA show on absolute zero? If you haven't check it out, very cool. Sorry about the pun. Which reminds me of a thing today... I'm in Home Depot today to get a drain snake. I'm walking down the plumbing aisle and I don't see it so I ask the Home Depot guy, "where's the drain snakes"? Home Depot guy says, "you walked right by them, they're right there", (points). So I says, "If it had been a snake, it would have bit me". Aaaaaaaaaah... sorry.
What? I've a drawing I want here. How I do that?
|
|
|
|
|
Joined: Oct 2004
Posts: 1,696
Megastar
|
|
OP
Megastar
Joined: Oct 2004
Posts: 1,696 |
While watching the Mens speed skating finals at the Winter Olympics, on TV. I was surprised to see that the Skate Rink Officials, sprayed HOT water over the ice rink, to keep the ice glasslike smooth, between groups of races.
The Canadian commentator stated this was because hot water froze quicker than cold.
I had heard this story many years ago, but the use of hot water, seemed like a joke to me.
I certainly never thought that this fact, would be put to such an unusual practical use.
Not sure why this is true..... but I assume its because the warmer water makes for a better contact with the ice.?
So the warmer water loses its latent heat very slightly quicker, due to contact and evaporation, than cold?
Should we all start to put warm water in the fridge ice freezing trays to save energy?
Hmmm, Not such a straightforward answer as it looks.
But water does have some strange propertys. It can remain a liquid both well above boiling point, and well below freezing. Providing its pure, and kept motionless in a smooth non-nucleating container.
And of course pure (distilled) water is an INSULATOR!
Hehe. Not a lot of people know that. I don't buy that at all. It's a matter of joules. Put 33 degree water in a tray and a tray of 100 degree water in a frezer at the same time. By the time the 100 degree water is 33 degrees is someone gonna tell me the 33 degree water is still 33 degrees? I think what happened is that (I've heard) hot water freezes clearer, less bubbles and what not in it. I think somewhere along the way the two got mixed up. Pretty simple to test though... And have you ever sen the PBS NOVA show on absolute zero? If you haven't check it out, very cool. Sorry about the pun [quote=Mike Kremer} Yes you are right it would be pretty easy to test in practice with a reasonable difference between cold water and hot water. I have no idea just what would be considered the max reasonable difference between Hot and Cold. But I was reading the previous post by Redewenur, here he mentioned the Mpemba effect. seems it was named after an itinerant African school boy who had great difficulty in convincing his teachers. Until he used two buckets of water. Google -Mpemba effect (there are a few to choose from)
. . "You will never find a real Human being - Even in a mirror." ....Mike Kremer.
|
|
|
|
|
Joined: Aug 2007
Posts: 84
Member
|
|
Member
Joined: Aug 2007
Posts: 84 |
|
|
|
|
|
Joined: May 2007
Posts: 212
Senior Member
|
|
Senior Member
Joined: May 2007
Posts: 212 |
This morning I took a glass of hot water and a glass of cold water and put them in the freezer.
The cold water froze WAY before the hot water.
It wasn't even close.
What? I've a drawing I want here. How I do that?
|
|
|
|
|
Joined: Jun 2005
Posts: 1,940
Megastar
|
|
Megastar
Joined: Jun 2005
Posts: 1,940 |
This morning I took a glass of hot water and a glass of cold water and put them in the freezer.
The cold water froze WAY before the hot water.
It wasn't even close.
Completely irrelevant and inappropriate, but I'm really starting to like you. Also completely irrelevant to the topic, I suggest the following experiment to you if you are ever in a very cold climate and are inclined to a bit of amusement: I think it needs to be at least 40 below (excluding wind chill) and the colder the better. Fill a glass with hot water - as hot as you can get it from the tap. Go outside. Find an area of pristine snow where you can see what impacts it. Throw the hot water into the air and see how much hits the snow. Here's a demonstration of a similar experiment: http://boingboing.net/2009/01/15/spraying-hot-water-a.htmlWe used to get a fair kick out of doing this when our family lived in Alaska.
|
|
|
|
|
Joined: May 2007
Posts: 212
Senior Member
|
|
Senior Member
Joined: May 2007
Posts: 212 |
[quote=Marchimedes]This morning I took a glass of hot water and a glass of cold water and put them in the freezer.
The cold water froze WAY before the hot water.
It wasn't even close.
Completely irrelevant and inappropriate, I'm sorry, did you suddenly run outta bandwidth there and not have enough room to post why you say that? Or is it just the standard spaz impulse to naysay. What about my question of two trays of water? Standard Marchimedes logic, what say you. but I'm really starting to like you. Well, I've been here since May of '07, so, way to be decisive.
Last edited by Marchimedes; 02/18/10 10:46 PM.
What? I've a drawing I want here. How I do that?
|
|
|
|
|
Joined: Mar 2006
Posts: 4,136
Megastar
|
|
Megastar
Joined: Mar 2006
Posts: 4,136 |
I think it involves the rapid loss of heat by the hot water that produces a area of lowered pressure , just like a rapid gain of heat causes a area of high pressure.
the lowered pressure decreases the temperature in the area even further which allows for a flash freezing of the water molecules.
like in a pressure cooker.
the electrons move further out in their orbit as they gain energy and expand into steam.
in this case the electrons move further inward in their orbit as they lose energy and shrink into ice.
although a volume of water increases as it freezes , its volume increases because the way that the water molecules line up and form crystals with space between the molecules of the crystals.
3/4 inch of dust build up on the moon in 4.527 billion years,LOL and QM is fantasy science.
|
|
|
|
|
Joined: Jun 2005
Posts: 1,940
Megastar
|
|
Megastar
Joined: Jun 2005
Posts: 1,940 |
"Or is it just the standard spaz impulse to naysay."
You quoted the phrase, "Completely irrelevant and inappropriate, "however, that was only partial quote. That phrase applied not to your quote which preceded it, but the remainder of MY quote which followed after the comma. That is, I was saying that my own experiment was irrelevant and inappropriate.
Your post WAS relevant, because rather than argue about something back and forth, you actually did an experiment that anyone could do. Therefore, kudos to you. And despite the fact that you're a jerk, yes, you are starting to grow on me.
|
|
|
|
|
Joined: May 2007
Posts: 212
Senior Member
|
|
Senior Member
Joined: May 2007
Posts: 212 |
"Or is it just the standard spaz impulse to naysay."
You quoted the phrase, "Completely irrelevant and inappropriate, "however, that was only partial quote. That phrase applied not to your quote which preceded it, but the remainder of MY quote which followed after the comma. That is, I was saying that my own experiment was irrelevant and inappropriate. Oh, okay, you can see how I might misinterpret that, right? Your post WAS relevant, because rather than argue about something back and forth, you actually did an experiment that anyone could do. Therefore, kudos to you. Why thank you. And despite the fact that you're a jerk, yes, you are starting to grow on me. I know, wierd how that works, ain't it?
What? I've a drawing I want here. How I do that?
|
|
|
|
|
Joined: May 2007
Posts: 212
Senior Member
|
|
Senior Member
Joined: May 2007
Posts: 212 |
Someone starts a post, I get all into it, and one person replies.
That's just sad man.
Where do my views come from if this is the case?
I reposted this at a friggin POLITICAL SITE of all things and had more fun with it than you stiffs did here.
Come on, I'm friggin dying here.
Hey, how about if I posted all the other science sites I've been banned from in my thread?
I'm seeing nuttin.
So, just like it is, eh?
Fine. Then.
You know, if this site ever has a party, I'm going home with all the hot chicks.
All one of them.
What? It's a friggin joke come on you nerds, geeks, I'm one of you, I can take you to the promised land.
Non-virginityville.
Man, tuff crowd.
What? I've a drawing I want here. How I do that?
|
|
|
|
|
