Re: [Phys-l] sudden Vacuum freezing

["Michael Edmiston" <edmiston@bluffton.edu>]

Responding to Brian Whatcott...

> I am disappointed that both John D and Mike take it as given, that
> the energy flux is inextricably tied to the overt change of state.
> I suspect that Connie Tyree is closer to the mark, with a covert
> structural alignment accounting for the energy flux.

I can't speak for John, but I didn't take it as given.  I've made a lot of 
cooling curves involving supercooling and have not seen any evidence of a 
new structure between ordinary liquid and ordinary solid during 
supercooling.  Upon the start of freezing the latent heat effect is profound 
and returns the temperature of the mix to the normal freezing point implying 
a normal change of state.

>  Just cos it don't agree with the standard story, doesn't mean
>  it's wrong....    :-)

What I have measured appears to be the standard story.

> And she's DONE the experiment!

No she hasn't.  The experiment requires calorimetry, and to be definite it 
requires x-ray crystallography to observe the new structural state.

And, if we want to be nitpicky, if indeed there is a new structure between 
water and ice during supercooling, then she/we/whoever is not observing the 
sudden freezing of liquid water to ice.  Rather, the observation is the 
change of state from "some as yet unnamed state" to ice.

The hesitancy I would have to claim I know all about this would include the 
following: (1) I have not done a literature search to find if anyone has 
evidence of this new state; (2) my experiments have not been done carefully 
enough nor in the proper manner to look for this new state.  That is, my 
cooling curves have been fairly rapid (not overnight in a freezer), and with 
stirring.

More simple experiments which any of us could try would include: (a) open a 
bottle of the "solidified water" as observed in John M's movie and see if it 
is truly all solid.  (b) Put a thermocouple or thermistor in the bottle 
before cooling, then hook the thermocouple to a recorder before initiating 
the "freezing" and see what temperature the thing comes to.  If it jumps up 
to zero Celsius that would imply a normal partial freezing resulting in an 
ice-water mix.  If it jumps up to something less than zero that would imply 
it didn't start in the normal liquid structure and the end result is not an 
ice-water mix; rather, the result is totally solid or yet another structural 
state not yet named.

Michael D. Edmiston, Ph.D.
Professor of Chemistry and Physics
Bluffton University
1 University Drive
Bluffton, OH 45817
419.358.3270
edmiston@bluffton.edu