Precision of language is most important.

Without it evil will rule.

"Liberal" use to mean a person for liberty until FDR usurped the term.

"Conservative" use to mean small government until Bush got a hold of that.

People who subvert language are using deception. Your brain is your only
defense against such slavery that will follow.

PDW,

When was the last time you've seen a 225HP outboard on a sailboat?




http://community.webtv.net/tassail/ThomPage

"Gilligan" wrote in message . ..
| The propeller does boil the water. It is a scientific fact and I shall offer
| irrefutable proof:
|
| http://www.brooklyn.cuny.edu/bc/ahp/MBG/MBG4/Joule.html
|
| Quotes:
|
| "In the following years he took to measuring the amount of heat generated by
| every mechanical process he could think of. He enclosed wooden paddles
| inside an insulated container and used a falling weight to turn a shaft and
| churn the paddles. Friction caused the water in the container to heat up,
| and Joule measured the heat change. From this the work done could be
| compared with the amount of heat that had been produced.
|
| By 1843 he was ready to publish. Called the mechanical equivalent of heat,
| this is value for the amount of work required to produce a unit of heat, and
| is calculated as 41,800,000 ergs. (One erg is the work done in moving a one
| gram mass through a one centimeter distance)."
|
|
|
| So, as one can plainly see that in the mid-1800's it was recognized that the
| churning of propellers heat the water. In the case of the cavitating
| propeller, the slippage is so great that the energy that would normally go
| into propelling a great ship forward goes, instead, into raising the caloric
| content of the fluid medium surrounding said propeller causing boiling and
| cavitation.
|
| Hence, the propeller boils the water, causing cavitation.
|
| My tea kettle has a propeller in it and boils water quite quickly with no
| application of heat.


I'm not denying that mechanical energy applied to water will cause
its temperature to rise but it doesn't cause it to boil in the case
of a yacht's propeller. There isn't enough energy outputted to any
ship's propeller that can cause the ocean around it (and cooling it) to boil.
No, it isn't the boiling of water that causes cavitation. It is the lowering
of pressure that causes the water to vaporize.

The very chart to which you posted a link proves this to be true.
http://encarta.msn.com/media_4615415...for_Water.html
It shows there are a couple ways to skin a cat. Water can
be vaporized by adding heat, or by lowering pressure. A prop might
add a tiny bit of heat but it subtracts great amounts of pressure.
It is the subtraction of pressure that causes cavitation.

Ready to say UNCLE yet?

Paladin

--
Posted via a free Usenet account from http://www.teranews.com

"Gilligan" wrote in message . ..
| Precision of language is most important.
|
| Without it evil will rule.
|
| "Liberal" use to mean a person for liberty until FDR usurped the term.
|
| "Conservative" use to mean small government until Bush got a hold of that.
|
| People who subvert language are using deception. Your brain is your only
| defense against such slavery that will follow.
|

IAWTP. And, nobody ever accused DSK of having a brain...

Paladin

--
Posted via a free Usenet account from http://www.teranews.com

"Paladin" noneofyourbusiness.www wrote in message
...

"Gilligan" wrote in message
. ..
| The propeller does boil the water. It is a scientific fact and I shall
offer
| irrefutable proof:
|
| http://www.brooklyn.cuny.edu/bc/ahp/MBG/MBG4/Joule.html
|
| Quotes:
|
| "In the following years he took to measuring the amount of heat
generated by
| every mechanical process he could think of. He enclosed wooden paddles
| inside an insulated container and used a falling weight to turn a shaft
and
| churn the paddles. Friction caused the water in the container to heat
up,
| and Joule measured the heat change. From this the work done could be
| compared with the amount of heat that had been produced.
|
| By 1843 he was ready to publish. Called the mechanical equivalent of
heat,
| this is value for the amount of work required to produce a unit of heat,
and
| is calculated as 41,800,000 ergs. (One erg is the work done in moving a
one
| gram mass through a one centimeter distance)."
|
|
|
| So, as one can plainly see that in the mid-1800's it was recognized that
the
| churning of propellers heat the water. In the case of the cavitating
| propeller, the slippage is so great that the energy that would normally
go
| into propelling a great ship forward goes, instead, into raising the
caloric
| content of the fluid medium surrounding said propeller causing boiling
and
| cavitation.
|
| Hence, the propeller boils the water, causing cavitation.
|
| My tea kettle has a propeller in it and boils water quite quickly with
no
| application of heat.


I'm not denying that mechanical energy applied to water will cause
its temperature to rise but it doesn't cause it to boil in the case
of a yacht's propeller. There isn't enough energy outputted to any
ship's propeller that can cause the ocean around it (and cooling it) to
boil.
No, it isn't the boiling of water that causes cavitation. It is the
lowering
of pressure that causes the water to vaporize.

The very chart to which you posted a link proves this to be true.
http://encarta.msn.com/media_4615415...for_Water.html
It shows there are a couple ways to skin a cat. Water can
be vaporized by adding heat, or by lowering pressure. A prop might
add a tiny bit of heat but it subtracts great amounts of pressure.
It is the subtraction of pressure that causes cavitation.

Ready to say UNCLE yet?


I can tell I am battling against a person of towering intellect who does not
back down when guided by the light of truth.

I must give in and say Uncle.

Who is this man so knowledgeable in the ways of science?

"Thom Stewart" wrote in message
...
PDW,

When was the last time you've seen a 225HP outboard on a sailboat?


http://mymacforsale.blogspot.com/

http://www.macgregorsailors.com/phpB...5c10 0fd04a3e

"Gilligan" wrote in message . ..
|
| "Paladin" noneofyourbusiness.www wrote in message
| ...
|
| "Gilligan" wrote in message
| . ..
| | The propeller does boil the water. It is a scientific fact and I shall
| offer
| | irrefutable proof:
| |
| | http://www.brooklyn.cuny.edu/bc/ahp/MBG/MBG4/Joule.html
| |
| | Quotes:
| |
| | "In the following years he took to measuring the amount of heat
| generated by
| | every mechanical process he could think of. He enclosed wooden paddles
| | inside an insulated container and used a falling weight to turn a shaft
| and
| | churn the paddles. Friction caused the water in the container to heat
| up,
| | and Joule measured the heat change. From this the work done could be
| | compared with the amount of heat that had been produced.
| |
| | By 1843 he was ready to publish. Called the mechanical equivalent of
| heat,
| | this is value for the amount of work required to produce a unit of heat,
| and
| | is calculated as 41,800,000 ergs. (One erg is the work done in moving a
| one
| | gram mass through a one centimeter distance)."
| |
| |
| |
| | So, as one can plainly see that in the mid-1800's it was recognized that
| the
| | churning of propellers heat the water. In the case of the cavitating
| | propeller, the slippage is so great that the energy that would normally
| go
| | into propelling a great ship forward goes, instead, into raising the
| caloric
| | content of the fluid medium surrounding said propeller causing boiling
| and
| | cavitation.
| |
| | Hence, the propeller boils the water, causing cavitation.
| |
| | My tea kettle has a propeller in it and boils water quite quickly with
| no
| | application of heat.
|
|
| I'm not denying that mechanical energy applied to water will cause
| its temperature to rise but it doesn't cause it to boil in the case
| of a yacht's propeller. There isn't enough energy outputted to any
| ship's propeller that can cause the ocean around it (and cooling it) to
| boil.
| No, it isn't the boiling of water that causes cavitation. It is the
| lowering
| of pressure that causes the water to vaporize.
|
| The very chart to which you posted a link proves this to be true.
| http://encarta.msn.com/media_4615415...for_Water.html
| It shows there are a couple ways to skin a cat. Water can
| be vaporized by adding heat, or by lowering pressure. A prop might
| add a tiny bit of heat but it subtracts great amounts of pressure.
| It is the subtraction of pressure that causes cavitation.
|
| Ready to say UNCLE yet?
|
|
| I can tell I am battling against a person of towering intellect who does not
| back down when guided by the light of truth.
|
| I must give in and say Uncle.
|
| Who is this man so knowledgeable in the ways of science?
|

And, it's a rare pleasure to meet a man who's willing to learn and
admit his (very rare) mistakes. But, I suppose you're as learned
as you are because you're willing to consider alternate views
with an open mind as well as a fondness for language as a tool
and a standard. (unlike the likes of DSK). I'm willing to bet
you're either a libertarian or a staunch Goldwater conservative.

One must wonder. Does the faulty use of language produce a
liberal or does liberalism result in a faulty use of language...

Paladin

--
Posted via a free Usenet account from http://www.teranews.com

Paladin wrote:

Go to a dictionary and look up the definition of boil.
You will note that it mentions application of heat.

OK:

From my Funk and Wagnalls:

boil v.i. 1. To be agitated by escaping gaseous bubbles, usually from
the effect of heat: said of liquids.

Clearly the application of heat is not necessary.

I'm sure you have heard of people involved in high altitude research
talking of the possibility of having ones blood boil if exposed to near
vacuum. You appear to be engaging in an act of sophistry.

Cheers
Marty

Thom Stewart wrote:

PDW,

When was the last time you've seen a 225HP outboard on a sailboat?

http://community.webtv.net/tassail/ThomPage

The all new Mac26XXX ?

Cheers
Marty

"Martin Baxter" wrote in message ...
| Paladin wrote:
|
| Go to a dictionary and look up the definition of boil.
| You will note that it mentions application of heat.
|
| OK:
|
| From my Funk and Wagnalls:
|
| boil v.i. 1. To be agitated by escaping gaseous bubbles, usually from
| the effect of heat: said of liquids.

Looks to me as it this definition also speaks to the application of heat.

|
| Clearly the application of heat is not necessary.

Not according to the definition above -- note the word 'usually.'
This means there might be a rare case or two where 'to boil' does
not result from application of heat such as blood boiling when
one is mad but that case is only a euphemism.

When one is talking in the realm of physics, as is the case
of a cavitating propeller, boil has a definite meaning - that
of adding heat. But, since a prop subtracts pressure to a
much greater extent that it adds heat, vaporization occurs
because of low pressure vaporization and not high temperature
boiling.

| I'm sure you have heard of people involved in high altitude research
| talking of the possibility of having ones blood boil if exposed to near
| vacuum. You appear to be engaging in an act of sophistry.

And, they are incorrectly using the verb boil. If exposed to a
vacuum the human body will freeze and not boil or explode as
shown in some silly movies . And, if it should happen to out gas,
it would be due to a very temporary pressure differential and
will have little to do with temps.

There's nothing deceptive about a reasoned use of language.

Paladin

--
Posted via a free Usenet account from http://www.teranews.com