Re: Missing term

[Dan Crowe <dcrowe@SOTC.ORG>]

You learn something new every day.  I've had the definition of "fusion" backwards for over 25 years, and this is the first time anyone has corrected me.  I checked all the textbooks I have that discuss heat of fusion - approximately two dozen textbooks - and only one of them, Hecht's algebra/trig-based book, clearly identifies fusion with melting, as opposed to freezing; the rest are ambiguous.  I received a complimentary copy of Hecht's book just a couple of months ago, and this is the first time I've looked at it.  The following quote from the textbook I used in college, Halliday and Resnick, implies that fusion is freezing:

"The heat of fusion of water is 80 kcal/kg and represents the amount of heat that must leave water when it freezes at atmospheric pressure."  (Halliday & Resnick, Fundamentals of Physics, 2d ed., p. 390)

I also checked the three dictionaries I have at home, and they all agree that "fusion" is a synonym for "melting".

Over the years, I've told hundreds of students that "fusion" meant "freezing".

Another term that could be used for "solidification" is "crystallization".  Is there any reason to prefer one over the other?  Is "freezing" preferable to both?

(And I still prefer "desublimation" to "deposition".)

Daniel Crowe
Oklahoma School of Science and Mathematics
Ardmore Regional Center
dcrowe@sotc.org


-----Original Message-----
From: Larry Cartwright [mailto:exit60@CABLESPEED.COM]
Sent: Thursday, August 28, 2003 6:39 PM
To: PHYS-L@lists.nau.edu
Subject: Re: Missing term


Dan Crowe wrote:
> Fusion is the transition from a liquid to a solid.
> The counterpart to "fusion" is "melting".  (I can't think of
> any synonym for "melting" that ends in "ion".)

According to my references, you've got your interpretation of "fusion"
exactly backwards.  The confusion is understandable, since the f-word
has pretty much dropped out of thermodynamics usage in today's physics
literature; only the term "heat of fusion" persists.

According to my 1901 Carhart & Chute text, "When a body changes from the
solid to the liquid state by the application of heat, it is said to
melt, or fuse, and the change is called melting, fusion, or
liquefaction."  From my 1964 Dull, Metcalfe & Williams text, "Change of
state from a solid to a liquid is called fusion ... Fusion is the
scientific term for what is commonly called melting, or liquefaction."

The electrical fuse, invented about a century ago, gets its name from
its function: a metal link that *melts* when excessive current raises
its temperature sufficiently.

So the phase change terminology would correctly be:
vaporization - condensation
sublimation - deposition
fusion - solidification (i.e. melting - freezing)

Best wishes,

Larry

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Larry Cartwright                    Retired Physics Teacher
<exit60@cablespeed.com>              Charlotte MI 48813 USA
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