| Topic: |
Science > Physics |
| User: |
"MikeTEACHR" |
| Date: |
16 Jan 2004 06:03:35 AM |
| Object: |
Q: Boiling Water Thrown = Snow??? |
Hello!
First, ex-hs science teacher here. Not looking for a homework answer.
But I just saw on TV people throwing cups of boiling water into the air and
WOW!
Obviously you're producing a lot of steam and the lights will enhance that; but
what exactly is happening? Believe me I just spent 20 minutes chucking water
into the air, and it *feels* as if some of what falls back might qualify as a
bit of ice, but how big? I hesitate to call it 'snow' as the Media likes to do,
unless it's precipitating out of the air...
Why boiling only? Nucleation sites al la bubbles in a glass of beer, but
temperature induced instead of pressure? Or is that going the other direction?
Ugh. And please excuse any water/atmospheric physics faux pas;
any one no a little bit on this phenom?
Feel free to email:
miketeachr at aol dot com [it's not spam, it's a guy with a slightly burnt arm
asking a physics Q]
.
|
|
| User: "Uncle Al" |
|
| Title: Re: Q: Boiling Water Thrown = Snow??? |
16 Jan 2004 12:37:05 PM |
|
|
MikeTEACHR wrote:
Hello!
First, ex-hs science teacher here. Not looking for a homework answer.
But I just saw on TV people throwing cups of boiling water into the air and
WOW!
Obviously you're producing a lot of steam and the lights will enhance that; but
what exactly is happening? Believe me I just spent 20 minutes chucking water
into the air, and it *feels* as if some of what falls back might qualify as a
bit of ice, but how big? I hesitate to call it 'snow' as the Media likes to do,
unless it's precipitating out of the air...
If you spit into the air and it crackles frozen before it hits the
ground, it is "cold." When it is this cold even folks in central
Canada pull on windbreakers.
Hot water/coffee tossed into the air is the same sort of thing. It is
more spectacular for the abundantly pulse-evolved water vapor
flash-freezing as well.
Why boiling only? Nucleation sites al la bubbles in a glass of beer, but
temperature induced instead of pressure? Or is that going the other direction?
Ugh. And please excuse any water/atmospheric physics faux pas;
any one no a little bit on this phenom?
It freezes. Saliva or coffee, it's no big deal. Go out each morning,
scrape the frozen squirrels off your window panes, and save them for
the communal spring feast. It's also a good time to tell your rancid
old granny to take her walker and go down to the liquor store for a
fifth of Lagavulin single malt scotch: win-win; unless she falls and
breaks the bottle.
--
Uncle Al
http://www.mazepath.com/uncleal/
(Toxic URL! Unsafe for children and most mammals)
"Quis custodiet ipsos custodes?" The Net!
.
|
|
|
| User: "Zipperhead" |
|
| Title: Re: Q: Boiling Water Thrown = Snow??? |
16 Jan 2004 04:27:27 PM |
|
|
In article <40082F51.C72F0DED@hate.spam.net>, says...
Here it gets so cold if you pee outside you need a stick
to knock of the ice.
.
|
|
|
| User: "Uncle Al" |
|
| Title: Re: Q: Boiling Water Thrown = Snow??? |
16 Jan 2004 05:10:17 PM |
|
|
Zipperhead wrote:
In article <40082F51.C72F0DED@hate.spam.net>, says...
Here it gets so cold if you pee outside you need a stick
to knock of the ice.
Anything that kills blackflies is a good thing! Meanwhile, the Inuits
are looking south and wondering what all the fuss is about.
--
Uncle Al
http://www.mazepath.com/uncleal/
(Toxic URL! Unsafe for children and most mammals)
"Quis custodiet ipsos custodes?" The Net!
.
|
|
|
| User: "" |
|
| Title: Re: Q: Boiling Water Thrown = Snow??? |
17 Jan 2004 05:25:42 AM |
|
|
In article <40086F59.B3A41005@hate.spam.net>,
Uncle Al <> wrote:
Zipperhead wrote:
In article <40082F51.C72F0DED@hate.spam.net>,
says...
Here it gets so cold if you pee outside you need a stick
to knock of the ice.
Anything that kills blackflies is a good thing!
Are they dead yet?
.. Meanwhile, the Inuits
are looking south and wondering what all the fuss is about.
We aren't dressed for it. Mass. schools were cancelled; NH
schools had delayed openings. We are wimps ;-)).
At least, talking about the weather took precedence
over presidential campaigns, football, and presidential campaigns.
Not much but some.
/BAH
Subtract a hundred and four for e-mail.
.
|
|
|
|
| User: "Zipperhead" |
|
| Title: Re: Q: Boiling Water Thrown = Snow??? |
17 Jan 2004 02:42:17 PM |
|
|
In article <40086F59.B3A41005@hate.spam.net>, says...
Zipperhead wrote:
In article <40082F51.C72F0DED@hate.spam.net>,
says...
Here it gets so cold if you pee outside you need a stick
to knock of the ice.
Anything that kills blackflies is a good thing! Meanwhile, the Inuits
are looking south and wondering what all the fuss is about.
I'm used to the cold...I was married for 15 years.
.
|
|
|
| User: "" |
|
| Title: Re: Q: Boiling Water Thrown = Snow??? |
18 Jan 2004 05:29:03 AM |
|
|
In article <100j7h9656g6h28@corp.supernews.com>,
(Zipperhead) wrote:
In article <40086F59.B3A41005@hate.spam.net>,
says...
Zipperhead wrote:
In article <40082F51.C72F0DED@hate.spam.net>,
says...
Here it gets so cold if you pee outside you need a stick
to knock of the ice.
Anything that kills blackflies is a good thing! Meanwhile, the Inuits
are looking south and wondering what all the fuss is about.
I'm used to the cold...I was married for 15 years.
One of the reasons to have a male in bed is to provide foot-warming
services.
/BAH
Subtract a hundred and four for e-mail.
.
|
|
|
| User: "The Ghost In The Machine" |
|
| Title: Re: Q: Boiling Water Thrown = Snow??? |
18 Jan 2004 03:00:17 PM |
|
|
In sci.physics,
<>
wrote
on Sun, 18 Jan 04 11:29:03 GMT
<400a7fd8$0$6077$61fed72c@news.rcn.com>:
In article <100j7h9656g6h28@corp.supernews.com>,
warf@compusmart.ab.ca (Zipperhead) wrote:
In article <40086F59.B3A41005@hate.spam.net>,
says...
Zipperhead wrote:
In article <40082F51.C72F0DED@hate.spam.net>,
says...
Here it gets so cold if you pee outside you need a stick
to knock of the ice.
Anything that kills blackflies is a good thing! Meanwhile, the Inuits
are looking south and wondering what all the fuss is about.
I'm used to the cold...I was married for 15 years.
One of the reasons to have a male in bed is to provide foot-warming
services.
And here I thought we were for mowing the lawn... :-)
/BAH
Subtract a hundred and four for e-mail.
--
#191,
It's still legal to go .sigless.
.
|
|
|
| User: "" |
|
| Title: Re: Q: Boiling Water Thrown = Snow??? |
19 Jan 2004 04:48:02 AM |
|
|
In article <jpuqd1-3at.ln1@lexi2.athghost7038suus.net>,
The Ghost In The Machine <ewill@sirius.athghost7038suus.net> wrote:
In sci.physics,
<>
wrote
on Sun, 18 Jan 04 11:29:03 GMT
<400a7fd8$0$6077$61fed72c@news.rcn.com>:
In article <100j7h9656g6h28@corp.supernews.com>,
warf@compusmart.ab.ca (Zipperhead) wrote:
In article <40086F59.B3A41005@hate.spam.net>,
says...
Zipperhead wrote:
In article <40082F51.C72F0DED@hate.spam.net>,
says...
Here it gets so cold if you pee outside you need a stick
to knock of the ice.
Anything that kills blackflies is a good thing! Meanwhile, the Inuits
are looking south and wondering what all the fuss is about.
I'm used to the cold...I was married for 15 years.
One of the reasons to have a male in bed is to provide foot-warming
services.
And here I thought we were for mowing the lawn... :-)
Nope. Chickens.
/BAH
Subtract a hundred and four for e-mail.
.
|
|
|
| User: "The Ghost In The Machine" |
|
| Title: Re: Q: Boiling Water Thrown = Snow??? |
19 Jan 2004 11:00:22 AM |
|
|
In sci.physics,
<>
wrote
on Mon, 19 Jan 04 10:48:02 GMT
<400bc7c5$0$6089$61fed72c@news.rcn.com>:
In article <jpuqd1-3at.ln1@lexi2.athghost7038suus.net>,
The Ghost In The Machine <ewill@sirius.athghost7038suus.net> wrote:
In sci.physics,
<>
wrote
on Sun, 18 Jan 04 11:29:03 GMT
<400a7fd8$0$6077$61fed72c@news.rcn.com>:
In article <100j7h9656g6h28@corp.supernews.com>,
warf@compusmart.ab.ca (Zipperhead) wrote:
In article <40086F59.B3A41005@hate.spam.net>,
says...
Zipperhead wrote:
In article <40082F51.C72F0DED@hate.spam.net>,
says...
Here it gets so cold if you pee outside you need a stick
to knock of the ice.
Anything that kills blackflies is a good thing! Meanwhile, the Inuits
are looking south and wondering what all the fuss is about.
I'm used to the cold...I was married for 15 years.
One of the reasons to have a male in bed is to provide foot-warming
services.
And here I thought we were for mowing the lawn... :-)
Nope. Chickens.
Erm...perhaps you can elaborate on that?
*puzzled look*
/BAH
Subtract a hundred and four for e-mail.
--
#191, -- who is definitely not a farm boy :-)
It's still legal to go .sigless.
.
|
|
|
| User: "" |
|
| Title: Re: Q: Boiling Water Thrown = Snow??? |
20 Jan 2004 05:18:53 AM |
|
|
In article <hiatd1-9hu.ln1@lexi2.athghost7038suus.net>,
The Ghost In The Machine <ewill@sirius.athghost7038suus.net> wrote:
In sci.physics,
<>
wrote
on Mon, 19 Jan 04 10:48:02 GMT
<400bc7c5$0$6089$61fed72c@news.rcn.com>:
In article <jpuqd1-3at.ln1@lexi2.athghost7038suus.net>,
The Ghost In The Machine <ewill@sirius.athghost7038suus.net> wrote:
In sci.physics,
<>
wrote
on Sun, 18 Jan 04 11:29:03 GMT
<400a7fd8$0$6077$61fed72c@news.rcn.com>:
In article <100j7h9656g6h28@corp.supernews.com>,
warf@compusmart.ab.ca (Zipperhead) wrote:
In article <40086F59.B3A41005@hate.spam.net>,
says...
Zipperhead wrote:
In article <40082F51.C72F0DED@hate.spam.net>,
says...
Here it gets so cold if you pee outside you need a stick
to knock of the ice.
Anything that kills blackflies is a good thing! Meanwhile, the
Inuits
are looking south and wondering what all the fuss is about.
I'm used to the cold...I was married for 15 years.
One of the reasons to have a male in bed is to provide foot-warming
services.
And here I thought we were for mowing the lawn... :-)
Nope. Chickens.
Erm...perhaps you can elaborate on that?
Chickens will eat the lawn plus all meat, especially insects.
The lawn goes in one end and poop and eggs come out the other
end.
/BAH
Subtract a hundred and four for e-mail.
.
|
|
|
| User: "The Ghost In The Machine" |
|
| Title: Re: Q: Boiling Water Thrown = Snow??? |
20 Jan 2004 11:00:33 AM |
|
|
In sci.physics,
<>
wrote
on Tue, 20 Jan 04 11:18:53 GMT
<400d208b$0$15589$61fed72c@news.rcn.com>:
In article <hiatd1-9hu.ln1@lexi2.athghost7038suus.net>,
The Ghost In The Machine <ewill@sirius.athghost7038suus.net> wrote:
In sci.physics,
<>
wrote
on Mon, 19 Jan 04 10:48:02 GMT
<400bc7c5$0$6089$61fed72c@news.rcn.com>:
In article <jpuqd1-3at.ln1@lexi2.athghost7038suus.net>,
The Ghost In The Machine <ewill@sirius.athghost7038suus.net> wrote:
In sci.physics,
<>
wrote
on Sun, 18 Jan 04 11:29:03 GMT
<400a7fd8$0$6077$61fed72c@news.rcn.com>:
In article <100j7h9656g6h28@corp.supernews.com>,
warf@compusmart.ab.ca (Zipperhead) wrote:
In article <40086F59.B3A41005@hate.spam.net>,
says...
Zipperhead wrote:
In article <40082F51.C72F0DED@hate.spam.net>,
says...
Here it gets so cold if you pee outside you need a stick
to knock of the ice.
Anything that kills blackflies is a good thing! Meanwhile, the
Inuits
are looking south and wondering what all the fuss is about.
I'm used to the cold...I was married for 15 years.
One of the reasons to have a male in bed is to provide foot-warming
services.
And here I thought we were for mowing the lawn... :-)
Nope. Chickens.
Erm...perhaps you can elaborate on that?
Chickens will eat the lawn plus all meat, especially insects.
The lawn goes in one end and poop and eggs come out the other
end.
Ah, OK. Unfortunately they, like we males, tend to squawk a lot... :-)
Not exactly the best for urban living. (Are they bright enough to
stay off the road? I suspect not...)
/BAH
Subtract a hundred and four for e-mail.
--
#191,
It's still legal to go .sigless.
.
|
|
|
| User: "" |
|
| Title: Re: Q: Boiling Water Thrown = Snow??? |
21 Jan 2004 04:15:46 AM |
|
|
In article <phuvd1-6f.ln1@lexi2.athghost7038suus.net>,
The Ghost In The Machine <ewill@sirius.athghost7038suus.net> wrote:
In sci.physics,
<>
wrote
on Tue, 20 Jan 04 11:18:53 GMT
<400d208b$0$15589$61fed72c@news.rcn.com>:
In article <hiatd1-9hu.ln1@lexi2.athghost7038suus.net>,
The Ghost In The Machine <ewill@sirius.athghost7038suus.net> wrote:
<snip>
One of the reasons to have a male in bed is to provide foot-warming
services.
And here I thought we were for mowing the lawn... :-)
Nope. Chickens.
Erm...perhaps you can elaborate on that?
Chickens will eat the lawn plus all meat, especially insects.
The lawn goes in one end and poop and eggs come out the other
end.
Ah, OK. Unfortunately they, like we males, tend to squawk a lot... :-)
Not exactly the best for urban living. (Are they bright enough to
stay off the road? I suspect not...)
Neither are men. At least chickens don't need a $35K testosterone
producing machine to cross the road.
/BAH
Subtract a hundred and four for e-mail.
.
|
|
|
| User: "The Ghost In The Machine" |
|
| Title: Re: Q: Boiling Water Thrown = Snow??? |
22 Jan 2004 08:06:56 AM |
|
|
In sci.physics,
<>
wrote
on Wed, 21 Jan 04 10:15:46 GMT
<400e6349$0$2429$61fed72c@news.rcn.com>:
In article <phuvd1-6f.ln1@lexi2.athghost7038suus.net>,
The Ghost In The Machine <ewill@sirius.athghost7038suus.net> wrote:
In sci.physics,
<>
wrote
on Tue, 20 Jan 04 11:18:53 GMT
<400d208b$0$15589$61fed72c@news.rcn.com>:
In article <hiatd1-9hu.ln1@lexi2.athghost7038suus.net>,
The Ghost In The Machine <ewill@sirius.athghost7038suus.net> wrote:
<snip>
One of the reasons to have a male in bed is to provide foot-warming
services.
And here I thought we were for mowing the lawn... :-)
Nope. Chickens.
Erm...perhaps you can elaborate on that?
Chickens will eat the lawn plus all meat, especially insects.
The lawn goes in one end and poop and eggs come out the other
end.
Ah, OK. Unfortunately they, like we males, tend to squawk a lot... :-)
Not exactly the best for urban living. (Are they bright enough to
stay off the road? I suspect not...)
Neither are men. At least chickens don't need a $35K testosterone
producing machine to cross the road.
"BMW. The Ultimate Chicken-Mashing Machine."
(For the record, I own a Saturn SL2, maybe $20K new.
I'm not sure I see the point of a BMW, Porsche, Ferrari,
or Lambhorgini when one's simply going to get stuck in
commute traffic anyway. Heck, a Trabant could probably
keep up... :-) I've also seen a number of Mini Coopers
running around. Cadillacs or Lincolns might make some
sense, mostly because one wants to be comfortable as one
is creeping along at 2 mph because of a big wreck in
heavy traffic up ahead. :-) Personally, though, I think
the new Lincolns look extremely ugly.)
/BAH
Subtract a hundred and four for e-mail.
--
#191,
It's still legal to go .sigless.
.
|
|
|
| User: "" |
|
| Title: Re: Q: Boiling Water Thrown = Snow??? |
23 Jan 2004 06:25:53 AM |
|
|
In article <2bb4e1-7k2.ln1@lexi2.athghost7038suus.net>,
The Ghost In The Machine <ewill@sirius.athghost7038suus.net> wrote:
In sci.physics,
<>
wrote
on Wed, 21 Jan 04 10:15:46 GMT
<400e6349$0$2429$61fed72c@news.rcn.com>:
In article <phuvd1-6f.ln1@lexi2.athghost7038suus.net>,
The Ghost In The Machine <ewill@sirius.athghost7038suus.net> wrote:
In sci.physics,
<>
wrote
on Tue, 20 Jan 04 11:18:53 GMT
<400d208b$0$15589$61fed72c@news.rcn.com>:
In article <hiatd1-9hu.ln1@lexi2.athghost7038suus.net>,
The Ghost In The Machine <ewill@sirius.athghost7038suus.net> wrote:
<snip>
One of the reasons to have a male in bed is to provide
foot-warming
services.
And here I thought we were for mowing the lawn... :-)
Nope. Chickens.
Erm...perhaps you can elaborate on that?
Chickens will eat the lawn plus all meat, especially insects.
The lawn goes in one end and poop and eggs come out the other
end.
Ah, OK. Unfortunately they, like we males, tend to squawk a lot... :-)
Not exactly the best for urban living. (Are they bright enough to
stay off the road? I suspect not...)
Neither are men. At least chickens don't need a $35K testosterone
producing machine to cross the road.
"BMW. The Ultimate Chicken-Mashing Machine."
(For the record, I own a Saturn SL2, maybe $20K new.
I'm not sure I see the point of a BMW, Porsche, Ferrari,
or Lambhorgini when one's simply going to get stuck in
commute traffic anyway.
<ahem> Chick appeal.
.. Heck, a Trabant could probably
keep up... :-) I've also seen a number of Mini Coopers
running around. Cadillacs or Lincolns might make some
sense, mostly because one wants to be comfortable as one
is creeping along at 2 mph because of a big wreck in
heavy traffic up ahead. :-) Personally, though, I think
the new Lincolns look extremely ugly.)
I don't care about looks; I'm more interested in something that
works without babysitting.
/BAH
Subtract a hundred and four for e-mail.
.
|
|
|
| User: "The Ghost In The Machine" |
|
| Title: Re: Q: Boiling Water Thrown = Snow??? |
23 Jan 2004 11:00:34 AM |
|
|
In sci.physics,
<>
wrote
on Fri, 23 Jan 04 12:25:53 GMT
<401124df$0$2823$61fed72c@news.rcn.com>:
In article <2bb4e1-7k2.ln1@lexi2.athghost7038suus.net>,
The Ghost In The Machine <ewill@sirius.athghost7038suus.net> wrote:
In sci.physics,
<>
wrote
on Wed, 21 Jan 04 10:15:46 GMT
<400e6349$0$2429$61fed72c@news.rcn.com>:
In article <phuvd1-6f.ln1@lexi2.athghost7038suus.net>,
The Ghost In The Machine <ewill@sirius.athghost7038suus.net> wrote:
In sci.physics,
<>
wrote
on Tue, 20 Jan 04 11:18:53 GMT
<400d208b$0$15589$61fed72c@news.rcn.com>:
In article <hiatd1-9hu.ln1@lexi2.athghost7038suus.net>,
The Ghost In The Machine <ewill@sirius.athghost7038suus.net> wrote:
<snip>
One of the reasons to have a male in bed is to provide
foot-warming
services.
And here I thought we were for mowing the lawn... :-)
Nope. Chickens.
Erm...perhaps you can elaborate on that?
Chickens will eat the lawn plus all meat, especially insects.
The lawn goes in one end and poop and eggs come out the other
end.
Ah, OK. Unfortunately they, like we males, tend to squawk a lot... :-)
Not exactly the best for urban living. (Are they bright enough to
stay off the road? I suspect not...)
Neither are men. At least chickens don't need a $35K testosterone
producing machine to cross the road.
"BMW. The Ultimate Chicken-Mashing Machine."
(For the record, I own a Saturn SL2, maybe $20K new.
I'm not sure I see the point of a BMW, Porsche, Ferrari,
or Lambhorgini when one's simply going to get stuck in
commute traffic anyway.
<ahem> Chick appeal.
"Ooooh, c'mere big boy. I want to [censored] your [censored]
because I really like your car..."
Uh huh. Now there's a basis for a stable, long-lasting relationship...
:-)
(Then again, it takes all kinds, and it does give one something
to do while stuck in commute traffic...though one might want
to postpone certain activities until they can at least get
to the road shoulder, in the interests of public safety.
True story: there's at least one video, released by
British traffic authorities [*], of a couple parked next to
an emergency phone getting, erm, amorous. The authorities
were told in no uncertain terms to go elsewhere when they
called this pair on said phone. I don't know if he got
a ticket/pursued/captured or not.)
.. Heck, a Trabant could probably
keep up... :-) I've also seen a number of Mini Coopers
running around. Cadillacs or Lincolns might make some
sense, mostly because one wants to be comfortable as one
is creeping along at 2 mph because of a big wreck in
heavy traffic up ahead. :-) Personally, though, I think
the new Lincolns look extremely ugly.)
I don't care about looks; I'm more interested in something that
works without babysitting.
One of the reasons I like a Saturn, admittedly. I wonder if
they and Timex will ever merge... :-) (To be fair, mine did
have some electrical problems at one point, but that's been
about it.)
/BAH
Subtract a hundred and four for e-mail.
[*] I saw it on _World's Worst Drivers 2_, which was at one point
broadcast on The Discovery Channel and/or The Learning Channel.
If aliens do ever land anywhere and start recording their
observations, they're going to wonder about us, methinks... :-)
--
#191,
It's still legal to go .sigless.
.
|
|
|
| User: "" |
|
| Title: Re: Q: Boiling Water Thrown = Snow??? |
25 Jan 2004 06:31:07 AM |
|
|
In article <g2u7e1-1b5.ln1@lexi2.athghost7038suus.net>,
The Ghost In The Machine <ewill@sirius.athghost7038suus.net> wrote:
In sci.physics,
<>
wrote
on Fri, 23 Jan 04 12:25:53 GMT
<401124df$0$2823$61fed72c@news.rcn.com>:
In article <2bb4e1-7k2.ln1@lexi2.athghost7038suus.net>,
The Ghost In The Machine <ewill@sirius.athghost7038suus.net> wrote:
In sci.physics,
<>
wrote
on Wed, 21 Jan 04 10:15:46 GMT
<400e6349$0$2429$61fed72c@news.rcn.com>:
In article <phuvd1-6f.ln1@lexi2.athghost7038suus.net>,
The Ghost In The Machine <ewill@sirius.athghost7038suus.net> wrote:
In sci.physics,
<>
wrote
on Tue, 20 Jan 04 11:18:53 GMT
<400d208b$0$15589$61fed72c@news.rcn.com>:
In article <hiatd1-9hu.ln1@lexi2.athghost7038suus.net>,
The Ghost In The Machine <ewill@sirius.athghost7038suus.net>
wrote:
<snip>
One of the reasons to have a male in bed is to provide
foot-warming
services.
And here I thought we were for mowing the lawn... :-)
Nope. Chickens.
Erm...perhaps you can elaborate on that?
Chickens will eat the lawn plus all meat, especially insects.
The lawn goes in one end and poop and eggs come out the other
end.
Ah, OK. Unfortunately they, like we males, tend to squawk a lot...
:-)
Not exactly the best for urban living. (Are they bright enough to
stay off the road? I suspect not...)
Neither are men. At least chickens don't need a $35K testosterone
producing machine to cross the road.
"BMW. The Ultimate Chicken-Mashing Machine."
(For the record, I own a Saturn SL2, maybe $20K new.
I'm not sure I see the point of a BMW, Porsche, Ferrari,
or Lambhorgini when one's simply going to get stuck in
commute traffic anyway.
<ahem> Chick appeal.
"Ooooh, c'mere big boy. I want to [censored] your [censored]
because I really like your car..."
Uh huh. Now there's a basis for a stable, long-lasting relationship...
:-)
When JMF was dying, people started avoiding him. So I encouraged
him to buy a testosterone-producing car. It generated all kinds
of interest wherever he went and people started talking to him
again.
<snip>
/BAH
Subtract a hundred and four for e-mail.
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| User: "John Bailey" |
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| Title: Re: Q: Boiling Water Thrown = Snow??? |
16 Jan 2004 01:12:27 PM |
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On 16 Jan 2004 12:03:35 GMT, (MikeTEACHR) wrote:
But I just saw on TV people throwing cups of boiling water into the air
any one know a little bit on this phenom?
I just did a series of searches on the Mpemba effect, of which this
seems to be a version.
I concluded that while there is broad, general agreement as to the
seemingly paradoxical effect of warm water freezing in some sense
faster than cold, there is no confirmed theory or common agreement as
to why this is the case.
http://www.school-for-champions.com/science/mpemba.htm (quoting)
The Mpemba Effect states that hot water changes its state from liquid
to solid--or freezes--faster than cold water. This does not seem to
make sense, but it has been discovered to be true.
Evaporation, conduction, convection and dissolved gases are possible
reasons the effect works. You may have to try different configurations
to verify this effect. (end quote)
The case I was trying to explain was the effect in household water
pipes. My plumber said that 8 out of 10 pipe breaks in cold weather
are hot water pipes. (Mine was too) In the pipe case, evaporation and
convection do not seem to apply. I settled on dissolved gases
explaination (hot water has less dissolved gasses) plus the flow of
water unique to household pipes because leaky toilet valves keep a
small flow going but only in the cold water pipes, not the hot.
For the case shown on TV, I assume evaporative cooling of a rapidly
diminishing mass of water would be the primary factor. What's left
when the rest evaporates gets really cold very quickly.
John Bailey
http://home.rochester.rr.com/jbxroads/mailto.html
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| User: "Tony" |
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| Title: Re: Q: Boiling Water Thrown = Snow??? |
16 Jan 2004 04:44:11 PM |
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(John Bailey) wrote in message news:<40083530.365997930@news-server.rochester.rr.com>...
On 16 Jan 2004 12:03:35 GMT, (MikeTEACHR) wrote:
But I just saw on TV people throwing cups of boiling water into the air
any one know a little bit on this phenom?
I just did a series of searches on the Mpemba effect, of which this
seems to be a version.
I concluded that while there is broad, general agreement as to the
seemingly paradoxical effect of warm water freezing in some sense
faster than cold, there is no confirmed theory or common agreement as
to why this is the case.
I have *no* idea what the Mpemba effect is. Is it how you say
"colligative properties" in ebonics, vis a vis "Education Reform"?
Google "colligative properties" 10,300 hits.
Everybody here screeches about the Second Law, I wouldn't expect
them to get it. This is a much better example of thermodynamics
in action. Solutions have elevated boiling points and depressed
freezing points, compared to the pure solvent. This is called
"boiling point elevation" and freezing point depression", by us
practical chemists. How about that?
Physics types argue endlessly whether it's a real effect. Us
chemists use it all the time. Check out the anti-freeze/anit-boilover
solution in your car's radiator (how can it do both at once?),
and ponder why the ocean is so resistant to freezing compared
to the rivers that flow into it. Contemplate gasses dissolved in
water.
Cheers,
Tony.
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| User: "MikeTEACHR" |
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| Title: Re: Q: Boiling Water Thrown = Snow??? |
16 Jan 2004 08:53:54 PM |
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Hey thanks to all who responded.
I actually got some great pics this morning trying this; I know you have no
reason to trust a hyperlink so it's miketheteacher dot com etc.
What I am wondering now is this; how much state change is really going on?
Ironically, a photo of this makes for the appearence of frozen spheres that
must be ice because people aren't familiar with water at zero-G; when in fact
it's just that, water globules.
My guess is a minimum diameter for a given temp for freezing within a unit
time. Perhaps a fine atomized mist would behave, umm... hmmm.
Or is the effect the opposite? Is it just a massive case of the water, now with
increased surface area exposed, just quickly emits much more steam?
Mike
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| User: "Andrew Resnick" |
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| Title: Re: Q: Boiling Water Thrown = Snow??? |
20 Jan 2004 08:35:12 AM |
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In <20040116215354.21874.00000068@mb-m22.aol.com> MikeTEACHR wrote:
Hey thanks to all who responded.
I actually got some great pics this morning trying this; I know you
have no reason to trust a hyperlink so it's miketheteacher dot com etc.
What I am wondering now is this; how much state change is really going
on?
Ironically, a photo of this makes for the appearence of frozen spheres
that must be ice because people aren't familiar with water at zero-G;
when in fact it's just that, water globules.
My guess is a minimum diameter for a given temp for freezing within a
unit time. Perhaps a fine atomized mist would behave, umm... hmmm.
Or is the effect the opposite? Is it just a massive case of the water,
now with increased surface area exposed, just quickly emits much more
steam?
I think the central issue is how fast the heat flows. When the
temperature difference between water and environment is high, more heat
flux occurs than when the temperature difference is low. For small
drops, the large heat flux causes very rapid (and large) changes in
temperature, and the changes in temperature occur faster than the change
in heat flux. So small droplets of hot water will change their
temperature much faster than small drops of cold water.
Impurities in the water will simply allow the ice to nucleate faster and
easier.
--
Andrew Resnick, Ph. D.
National Center for Microgravity Research
NASA Glenn Research Center
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