In article <1111182463.354684.316710@z14g2000cwz.googlegroups.com>,
Ken S. Tucker <dynamics@vianet.on.ca> wrote:

Gregory L. Hansen wrote:

In article <39pfheF65onsaU1@individual.net>,
FrediFizzx <fredifizzx@hotmail.com> wrote:
I trust the experiment had been run with water and the same effect

wasn't

found?

Of course...
IIRC, (40 years ago) we used a 1 inch x 8 inch
test tube and a candle under the bottom, held
it with a clothes peg.
It would boil up 2-3 times then boom, splat,
I felt a noticable recoil.
A few years later a China man who lived there
as a kid in the 30's explained how he and his
friends would use a spoon to scrape off deposits
from urinals and toilets to make fireworks.

I'm almost tempted to try that myself, if it weren't so gross.
But it seems like it would be easier to just pee in a beaker and boil it
down. Still gross.
--
"The preferred method of entering a building is to use a tank main gun
round, direct fire artillery round, or TOW, Dragon, or Hellfire missile to
clear the first room." -- THE RANGER HANDBOOK U.S. Army, 1992

In article <mjones-E4635D.14125618032005@spectator.sj.sys.us.xo.net>,
Mitchell Jones <mjones@21cenlogic.com> wrote:

In article <d1f3e5$slg$1@mail.specsol.com>,

Mitchell Jones <mjones@21cenlogic.com> wrote:

<snip>

***{Meaning, I suppose, that some of the water flashes to steam at the
bottom, and spits the rest of the liquid out the top of the tube? And
the chip is there, I guess, to acquire the kinetic energy in place of
the liquid, and then give it back via frictional losses, thereby keeping
the liquid in the tube? I guess that makes sense. --MJ}***

No, it provides nucleation points which causes bubbles to form.

***{The bubbles, presumably, would be steam. Steam does not form due to
"nucleation points." It forms because that portion of the water received
its heat of vaporization. After a bubble forms, of course, the point in
question can be described as a "nucleation point," but that does not
mean nucleation is the *cause* of the formation of the bubble. It is, in
fact, just another way of saying a bubble formed. The cause is the fact
that the water at that location got the heat it needed to flash to
steam. That would be the water in contact with the wall of the test tube
adjacent to the point where the heat was applied.

Ever heat liquids in test tubes with and without boiling chips? It makes
a difference, and you can see where the bubbles form.

Mitchell Jones <mjones@21cenlogic.com> wrote:

In article <d1f3e5$slg$1@mail.specsol.com>,

Mitchell Jones <mjones@21cenlogic.com> wrote:

<snip>

***{Meaning, I suppose, that some of the water flashes to steam at the
bottom, and spits the rest of the liquid out the top of the tube? And
the chip is there, I guess, to acquire the kinetic energy in place of
the liquid, and then give it back via frictional losses, thereby
keeping
the liquid in the tube? I guess that makes sense. --MJ}***

No, it provides nucleation points which causes bubbles to form.

***{The bubbles, presumably, would be steam. Steam does not form due to
"nucleation points." It forms because that portion of the water received
its heat of vaporization. After a bubble forms, of course, the point in
question can be described as a "nucleation point," but that does not
mean nucleation is the *cause* of the formation of the bubble. It is, in
fact, just another way of saying a bubble formed. The cause is the fact
that the water at that location got the heat it needed to flash to
steam. That would be the water in contact with the wall of the test tube
adjacent to the point where the heat was applied. The advantage of
applying the heat from the side would be that if a volume element
flashed to steam at that location, it would mainly thrust the liquid in
the tube horizontally, toward the opposite wall, rather than vertically,
and out of the test tube. --MJ}***

Pure babble.

It is the sharp points that get the bubbles started, nothing more,
nothing less.

It is the same physics that causes a clean cup of water heated in a
microwave to boil over when you dump the instant coffee in it.

***{Instant coffee contains lots of volatile oils that vaporize at
temperatures well below the boiling point of water. The foaming that you
see occurs despite the fact that none of the water is flashing to steam.
Each point where a bubble appears, of course, is a "nucleation point,"
because that's just another way of saying a bubble appeared there. But,
again, it is the fact that enough heat was delivered to vaporize the
oil, which is the cause of the bubble formation at that location. There
are, of course, "condensation nuclei"--i.e., particles which facilitate
condensation--but a parallel notion of "vaporization nuclei" would be a
stretch under the best circumstances, and it certainly does not apply to
the situation we are discussing. --MJ}***

Yet more babble.

Substitue dried sand, diamond dust, or anything else you like with sharp
points for the coffee and you get the same result.

Google "superheated water", 11,900 hits.