wrote:
ve3... wrote:

Household tip: For some unknown reason, hot water pipes freeze
before cold water pipes.
A trickle of water will prevent pipes from freezing.
Thed Global warming debate will resume in July.

This arctic air has hit the left coast as well.

The deal with the hot water pipe freezing first is due to the lack of
dissolved gasses in the water. That is, the heating process takes the
dissolved gasses out of the water, which in turn makes it easier to
freeze.
"""""""""""""""""""""""""""""""""""""""""""""""""" """""""""""""""""""""""
Alas, It ain't so simple. The finest scientific minds of our time have
been unable to come up with a theory that can be proved by experiment.
Current theories include:
- evaporatve cooling
-convection
-dissolved gases
-surrounding environment

The finest scientific minds of our time fool around with experiments
for a while, find that they cannot isolate the variables, and go back
to their lucrative defense dept contracts where things go boom and life
is much simpler.
Aristotle noticed the freezing effect around 350bc but not much was
known about scientific method then and his deduction worked for him.
The modern name for the phenomena is "the Mpemba effect" after an
African student who found that he could freeze hot milk faster than
cold milk. ( to make ice cream)

For those who have way too much time on their hands Google
Why do hot water pipes freeze before cold water pipes?
You will get 1,100,000 hits.

For those with limited time an instructive article from Physics Web
"Does Hot Water Freeze First?"
can be found at:
http://physicsweb.org/articles/world/19/4/4

A scholarly article," Hot water Can Freeze Faster Than Cold?!?", can be
found at:::
http://arxiv.org/ps_cache/physics/pdf/0512/0512262.pdf

This would be a great subject for a science project or even a Phd
thesis.

ve3... wrote:
wrote:\\\

The deal with the hot water pipe freezing first is due to the lack of
dissolved gasses in the water. That is, the heating process takes the
dissolved gasses out of the water, which in turn makes it easier to
freeze.
"""""""""""""""""""""""""""""""""""""""""""""""""" """""""""""""""""""""""
Alas, It ain't so simple. The finest scientific minds of our time have
been unable to come up with a theory that can be proved by experiment.
Current theories include:
- evaporatve cooling
-convection
-dissolved gases
-surrounding environment

snips

The key to all of these is that there is something about both fluids,
apart from temperature, that is not equal.

If you have two identical, equal water fluids whose only difference is
temperature, I would bet good money that the cold one will freeze first
- it simply has to lose a lot less energy to get to the phase change.

I think the best experiment would be not to avoid the presence of
nucleation sites, but to make sure that each vessel has a roughly equal
load of them, guaranteeing that freezing would occur as soon as
possible for each one (just like in nature, where nucleation sites are
abundant).

Bruce Jensen

This is a long and perhpas delerious shot but there may something called
thermal momentum a far reach but here goes. The hot water may be cooling at
a faster rate and forgets to wait on the cold water to catch up.
"bpnjensen" wrote in message
ups.com...
ve3... wrote:
wrote:\\\

The deal with the hot water pipe freezing first is due to the lack of
dissolved gasses in the water. That is, the heating process takes the
dissolved gasses out of the water, which in turn makes it easier to
freeze.
"""""""""""""""""""""""""""""""""""""""""""""""""" """""""""""""""""""""""
Alas, It ain't so simple. The finest scientific minds of our time have
been unable to come up with a theory that can be proved by experiment.
Current theories include:
- evaporatve cooling
-convection
-dissolved gases
-surrounding environment

snips

The key to all of these is that there is something about both fluids,
apart from temperature, that is not equal.

If you have two identical, equal water fluids whose only difference is
temperature, I would bet good money that the cold one will freeze first
- it simply has to lose a lot less energy to get to the phase change.

I think the best experiment would be not to avoid the presence of
nucleation sites, but to make sure that each vessel has a roughly equal
load of them, guaranteeing that freezing would occur as soon as
possible for each one (just like in nature, where nucleation sites are
abundant).

Bruce Jensen

Henry Kolesnik wrote:
This is a long and perhpas delerious shot but there may something called
thermal momentum a far reach but here goes. The hot water may be cooling at
a faster rate and forgets to wait on the cold water to catch up.
"bpnjensen" wrote in message
ups.com...
ve3... wrote:
wrote:\\\

The deal with the hot water pipe freezing first is due to the lack of
dissolved gasses in the water. That is, the heating process takes the
dissolved gasses out of the water, which in turn makes it easier to
freeze.
"""""""""""""""""""""""""""""""""""""""""""""""""" """""""""""""""""""""""
Alas, It ain't so simple. The finest scientific minds of our time have
been unable to come up with a theory that can be proved by experiment.
Current theories include:
- evaporatve cooling
-convection
-dissolved gases
-surrounding environment

snips

The key to all of these is that there is something about both fluids,
apart from temperature, that is not equal.

If you have two identical, equal water fluids whose only difference is
temperature, I would bet good money that the cold one will freeze first
- it simply has to lose a lot less energy to get to the phase change.

I think the best experiment would be not to avoid the presence of
nucleation sites, but to make sure that each vessel has a roughly equal
load of them, guaranteeing that freezing would occur as soon as
possible for each one (just like in nature, where nucleation sites are
abundant).

Bruce Jensen
"""""""""""""""""""""""""""""""""""""""""""""""""" """""""""""""""""""""""""""
from Yahoo:
"...for such a seemingly simple substance, water is surprisingly
complex, and its behaviour is poorly understood. The Mpemba effect is
just one of 38 anamolies of H2O."

Experiments to examine any theory have to contend with an enormous
number of variables.
A paper from London South Bank University examines a few anamolies. Do
not miss "icosahedral water clusters" at the bottom of the page.
http://www.lsbu.ac.uk/water/explan.html

Tell them to make up their minds.Back in the 1960's 1970's it was about
another ice age.Then along comes global warming and now it's global
freezing.I am getting tired of all of that global this,global
that,global maybe crap.This is the first time in this part of the year I
have ever seen my yard staying green and the grass and those weird
looking flowers in my yard are growing in my yard.Yesterday,I noticed
some the Dafodills in my yard are are starting to show those little
yellow tips.
cuhulin,not a globalist

I recall one time when I was you we went camping overnight and each of us
brought a clear glass gallon of water. The jugs were left outside the tent
on the ground. That night we had a pretty good freeze. I was first up and
went to get take a leak and get a drink. I could see that the water hadn't
frozen. So I picked up a jug opened it and hoisted it to my mouth and to my
amazement the water froze in an instant. The other jug didn't. One was
city tap water and the other was from a well and I can't recall which was
which. I recall reporting the phenomena in grade 9 science and we found out
about supercooled liquids. A very interesting phenomena when you consider
that the jug that freezes nearly instantaneously has to give up a bunch of
latent heat. Since then I've seen that happen with beer thats been in the
freeze but its not as dramatic because they all do it and you can't see as
well, and there's many more other things in solution lke alcohol,etc.

--

73
Hank WD5JFR
"ve3..." wrote in message
ups.com...

Henry Kolesnik wrote:
This is a long and perhpas delerious shot but there may something called
thermal momentum a far reach but here goes. The hot water may be cooling
at
a faster rate and forgets to wait on the cold water to catch up.
"bpnjensen" wrote in message
ups.com...
ve3... wrote:
wrote:\\\

The deal with the hot water pipe freezing first is due to the lack
of
dissolved gasses in the water. That is, the heating process takes
the
dissolved gasses out of the water, which in turn makes it easier to
freeze.
"""""""""""""""""""""""""""""""""""""""""""""""""" """""""""""""""""""""""
Alas, It ain't so simple. The finest scientific minds of our time have
been unable to come up with a theory that can be proved by experiment.
Current theories include:
- evaporatve cooling
-convection
-dissolved gases
-surrounding environment

snips

The key to all of these is that there is something about both fluids,
apart from temperature, that is not equal.

If you have two identical, equal water fluids whose only difference is
temperature, I would bet good money that the cold one will freeze first
- it simply has to lose a lot less energy to get to the phase change.

I think the best experiment would be not to avoid the presence of
nucleation sites, but to make sure that each vessel has a roughly equal
load of them, guaranteeing that freezing would occur as soon as
possible for each one (just like in nature, where nucleation sites are
abundant).

Bruce Jensen
"""""""""""""""""""""""""""""""""""""""""""""""""" """""""""""""""""""""""""""
from Yahoo:
"...for such a seemingly simple substance, water is surprisingly
complex, and its behaviour is poorly understood. The Mpemba effect is
just one of 38 anamolies of H2O."

Experiments to examine any theory have to contend with an enormous
number of variables.
A paper from London South Bank University examines a few anamolies. Do
not miss "icosahedral water clusters" at the bottom of the page.
http://www.lsbu.ac.uk/water/explan.html

Henry Kolesnik wrote:
This is a long and perhpas delerious shot but there may something called
thermal momentum a far reach but here goes. The hot water may be cooling at
a faster rate and forgets to wait on the cold water to catch up.

I've thought of this too, and it is very tempting - but taken by itself
it violates the law and concept of "flux is proportional to the
gradient," and so I have to ween myself off the impulse.

Bruce Jensen

The higer the altitude,the thinner the air,the longer it takes to boil
water.Less oxygen in the air,the higher the altitude.At 20,000 feet
altitude,a shotgun sounds like striking a match.Five million years ago
there was about twenty percent more oxygen in the air.Where did the
oxygen go?
cuhulin

bpnjensen wrote:

Henry Kolesnik wrote:
This is a long and perhpas delerious shot but there may something called
thermal momentum a far reach but here goes. The hot water may be cooling at
a faster rate and forgets to wait on the cold water to catch up.

I've thought of this too, and it is very tempting - but taken by itself
it violates the law and concept of "flux is proportional to the
gradient," and so I have to ween myself off the impulse.

Bruce Jensen

BJ, could this just be a simple case of water behaving badly?

Father Michael.

In article ,
Father Mike wrote:

bpnjensen wrote:

Henry Kolesnik wrote:
This is a long and perhpas delerious shot but there may something
called thermal momentum a far reach but here goes. The hot water
may be cooling at a faster rate and forgets to wait on the cold
water to catch up.

I've thought of this too, and it is very tempting - but taken by
itself it violates the law and concept of "flux is proportional to
the gradient," and so I have to ween myself off the impulse.


BJ, could this just be a simple case of water behaving badly?

All I know is global warming won't be enough to thaw the brain freeze
affecting Al Gore or the rest of the global warming crowd.

--
Telamon
Ventura, California