🚀 go-pugleaf

>/* Written 11:26 am  Apr  8, 1988 by seeker@iuvax.cs.indiana.edu in uiucdcsp:sci.misc */
>/* ---------- "ice cubes" ---------- */
>This is a serious question, no flames please.
>
>Can somebody tell me exactly why ice cubes float?  It seems I ought to know
>but I don't.
>-- 
>Karen Lynn White             "On a clear disk you can seek forever..." 
>Computer Science                                    
>Indiana University           ARPA: seeker@iuvax.cs.indiana.edu
>Bloomington, IN  47405       UUCP: {pyramid,ihnp4,pur-ee,rutgers}!iuvax!seeker
>/* End of text from uiucdcsp:sci.misc */

Is this some kind of test?

In article <7549@iuvax.cs.indiana.edu> seeker@iuvax.cs.indiana.edu (Karen
Lynn White) writes:
>Can somebody tell me exactly why ice cubes float?

Easy: they are less dense than water.

Okay, why are they less dense than water?

The answer lies in something called `hydrogen bonding'.  There is
a weak attraction between the hydrogen atoms in one water molecule
and the oxygen atom in another.  This force is too weak to have
much effect on water, especially above 3 or 4 degrees C, but below
that temperature, and most of all in ice, it tends to arrange the
molecules into tetrahedral patterns.  These take more space than
the random arrangements, which makes the ice less dense than the
water.

Molecular biologists can tell you more about how hydrogen bonding
is important to life-as-we-know-it.  Apparently it is part of
the reason DNA works.  `Gosh Mr. Science, you mean we're alive
because ice floats?' `That's right kids!  Isn't science amazing?' :-)
-- 
In-Real-Life: Chris Torek, Univ of MD Comp Sci Dept (+1 301 454 7163)
Domain:	chris@mimsy.umd.edu	Path:	uunet!mimsy!chris

In article <7549@iuvax.cs.indiana.edu> seeker@iuvax.cs.indiana.edu (Karen Lynn White) writes:
>This is a serious question, no flames please.

>Can somebody tell me exactly why ice cubes float?  It seems I ought to know
>but I don't.

Water at 0 C is denser than ice at 0 C (i.e. water expands about 4% when
it freezes).  So, an ice cube floats for the same reason a piece of wood does.

As I (hopefully, correctly) recall water reaches its maximum density at
about 4 C.

Hal Chambers

In article <7549@iuvax.cs.indiana.edu> seeker@iuvax.cs.indiana.edu (Karen Lynn White) writes:
>This is a serious question, no flames please.
>
>Can somebody tell me exactly why ice cubes float?  It seems I ought to know
>but I don't.

It is like this:  

Water is one of nature's most intriguing substances in that it becomes less
dense when it freezes.  The reason for this is the extensive hydrogen bonding
in water.  At low temperatures (like when it freezes), the hydrogen bonds form
a complex, ordered network that holds the water molecules in a tetrahedral (I
think) lattice.  As the ice heats up and the molecules vibrate more, the latticebreaks down and the water basically "collapses" on itself, causing an increase
in density.  Ice floats because it is less dense than liquid water.

-- 
                                           
Alexander B. Granok  			"I love school...              
ncar(hao)!udenva!agranok                         it's the work I hate."

Everyone seems to agree that ice is less dense than water..ie it expands as it
freezes.  Archimedes concluded that an object is bouyed up by a force equal to
the weight of the water it displaces.  Since an ice cube now displaces more 
water than it weighs, it floats.  That's Archimedes principle.


Tom Blockovich
    at Digital Equip. Corp.         slovax::Blockovich
                                 or (801)268-3392

    at UofU                         tom@cs.utah.edu
                                 or (801)581-5805