[meteorite-list] Is there room for a meteorite question ?

From: Kevin Fly Hill <khill_at_meteoritecentral.com>
Date: Thu Apr 22 10:17:45 2004
Message-ID: <004601c3c0bf$a40ce1a0$6d00a8c0_at_coxinternet.com>

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Doug,

Great explaination ! It's been a long time since Chemistry class -- and =
we never got that deep. I guess I can turn off the melting pot and put =
that 10 lb Campo back on the shelf.

One question, though. You stated "since water (0.92 g/mL) in =
equilibrium at 0=C2=B0C is denser than ice (1.00 g/mL)." =20

Did you mean that the other way? Water at 1.00 g/mL ?

Thanks
Fly Hill
  ----- Original Message -----=20
  From: MexicoDoug_at_aol.com=20
  To: khill_at_cpsmedical.com ; meteorite-list@meteoritecentral.com=20
  Sent: Thursday, December 11, 2003 10:43 PM
  Subject: Re: [meteorite-list] Is there room for a meteorite question ?


  And for a more complete stab at answering your question from a proud =
"newbee". Note you really asked two questions. =20

  1. If upon cooling there is expansion and 2. If the density is the =
same as non-crystalline materials formed on earth in the same ally =
proportions.=20

  To question 1: If I understand your question properly at first reading =
you think that Fe-Ni mixtures upon cooling in the proper proportions =
forming taenite / kamacite might expand? No way. Those structures do =
not form until after the alloy is already solid, though in an amorphous =
(non-crystalline) state with selective atom mobility. Those migrations =
of atoms occur to release heat energy flowing out of the system because =
of decreasing boundary temperatures and the law of heat flowing from =
higher to colder temperatures. The migrations are happening as these =
new crystal structures settle down from vibrations and fall into their =
little unit cells, allowing for a more dense material. For an expansion =
they would have to rip apart the already developed solid =
structure...causing perhaps a very brittle substance even.

  Now your other question, whether the "terrestrial" amorphous material =
has the same density as a "crystalline" meteorite material. That's =
something I'm sure you know if you think a minute. Of course it does =
not have the same density. So save your iron meteorites for better =
experiments, and don't melt them to see. The amorphous material =
probably won't even have as an extremely precisely definable density. =
It ought to vary because it is amorphous. Whether statistics averages =
the density out or not is a separate question and of course will depend =
on exactly what alloy %'s you have and how well they are mixed on a =
macro scale...the history of how the sample was cooled, etc. Does =
graphite have the same density as diamond? No.

  You cite water, when freezing, as expanding as your model, since water =
(0.92 g/mL) in equilibrium at 0=C2=B0C is denser than ice (1.00 g/mL). =
Water is weird, and one of the anomalous things that explains life. The =
short answer on why it expands upon decreasing temperature at =
atmospheric pressure from 4=C2=B0C to 0=C2=B0C is a softening of proton =
(hydrogen) bonding and disruption of that nicely organized structure as =
it is an ionic (solution) type attraction that is destroyed as the =
molecules begin to fall down from their bounciness caused by higher =
temperatures. So the destruction of the hydrogen bonds happens upon =
cooling. Another way to say that is the melting of the hydrogen bonds =
upon cooling=E2=80=A6 In its amorphous, hydrogen-bondless state oxygen =
atoms find themselves not tolerating such close density as before when =
all were moderated by the hydrogen atoms. So they repel each other an =
average of about 8% volume increase. Water would be less than 0.92 g/mL =
at room temperature if not for the hydrogen bonding. Probably about =
0.90, and then it would behave like most of the other molecules upon =
freezing.

  There are no comparably scaled ionic like attractions going on in the =
metal alloys as they cool. So there is no comparison to the special =
case of water. Additionally, you should know that water ice has about =
20 described crystalline structures, and they are, not coincidentally, =
not all the same density! You need to know the history of it. Do you =
think super cooled hail is the same as the cubes floating in your ice =
tea? No. And the rockhounds can probably come up with a good list of =
structures with different densities but the same molecular proportions.

  Every sample is individual: so back to the meteorite experiment. Each =
meteorite has a different history as in temperatures and pressures. =
Each has different impurities, so you will need to do more that just =
reproduce the alloy proportions...actually by now it seems pretty clear =
that the proposed experiment is not a good idea. All those impurities =
disrupt perfect conditions. So oceans don't freeze at 0=C2=B0C, they =
are a few degrees colder, because of the impurities. All that affects =
densities, not to mention any molecular flatulence causing micro pores, =
uniformly or not. Ooops. Just checking to see if anyone read this =
far...

  PS Ice floats. Can you imagine solid pieces of metal alloy floating =
as it is melted...that was the easier explanation...

  Saludos
  Doug Dawn
  Mexico

  En un mensaje con fecha 12/11/2003 2:58:13 PM Mexico Standard Time, =
khill_at_cpsmedical.com escribe:





    Question: When water turns to ice the change to a crystal =
structure
    expands the volume (decreases density). Does this density/expansion =
change
    also occur with the development of taenite/kamacite
    lattices? ie. at the same temperature is the density of an iron =
meteorite
    match the density of a "terrestrial" matching mixture that is
    "noncrystalline"? Guess you could melt down one of your irons and =
compare?

    Fly Hill

>----- Original Message -----=20
>From: "mark ford" <markf_at_ssl.gb.com>
>To: <meteorite-list_at_meteoritecentral.com>
>Sent: Tuesday, December 09, 2003 8:41 AM
>Subject: RE: [meteorite-list] Is there room for a meteorite =
question ?
>
>
>>
>>
>>
>>
>>
>>On the same note, thermal expansion...
>>
>>Presumably as the core solidifies (cools down) it would contract, =
would
>>it not?, what effect would that have on the crystalline structure
>>(widmanstatten) would there be a gradual stress/distortion in the
>>taenite/kamacite boundries ?
>>
>>
>>I guess as the core is such a big mass, any significant thermal
>>contraction distortion would hardly be noticeable in a small hand
>>specimen but I would imagine the thermal contraction in something =
the
>>size of a large planetary body would be massive.
>>
>>
>>
>>Mark Ford
>>
>>
>>
>>
>
    =
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whom it
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    >>message from your system. You must not disclose it to any other =
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    >>copy or distribute it or use it for any purpose.
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<DIV><FONT face=3DArial size=3D2>Doug,</FONT></DIV>
<DIV><FONT face=3DArial size=3D2></FONT>&nbsp;</DIV>
<DIV><FONT face=3DArial size=3D2>
<DIV><FONT face=3DArial size=3D2>Great explaination !&nbsp; It's been a =
long time=20
since Chemistry class -- and we never got that deep.&nbsp; I guess I can =
turn=20
off the melting pot and put that 10 lb Campo back on the =
shelf.</FONT></DIV>
<DIV>&nbsp;</DIV></FONT></DIV>
<DIV><FONT face=3DArial size=3D2>One question, though.&nbsp; You =
stated&nbsp; "since=20
water (0.92 g/mL) in equilibrium at 0=C2=B0C is denser than ice (1.00 =
g/mL)."&nbsp;=20
</FONT></DIV>
<DIV><FONT face=3DArial size=3D2></FONT>&nbsp;</DIV>
<DIV><FONT face=3DArial size=3D2>Did you mean that the other way?&nbsp; =
Water at=20
1.00 g/mL ?</FONT></DIV>
<DIV><FONT face=3DArial size=3D2></FONT>&nbsp;</DIV>
<DIV><FONT face=3DArial size=3D2>Thanks</FONT></DIV>
<DIV><FONT face=3DArial size=3D2>Fly Hill</FONT></DIV>
<BLOCKQUOTE=20
style=3D"PADDING-RIGHT: 0px; PADDING-LEFT: 5px; MARGIN-LEFT: 5px; =
BORDER-LEFT: #000000 2px solid; MARGIN-RIGHT: 0px">
  <DIV style=3D"FONT: 10pt arial">----- Original Message ----- </DIV>
  <DIV=20
  style=3D"BACKGROUND: #e4e4e4; FONT: 10pt arial; font-color: =
black"><B>From:</B>=20
  <A title=3DMexicoDoug_at_aol.com=20
  href=3D"mailto:MexicoDoug_at_aol.com">MexicoDoug@aol.com</A> </DIV>
  <DIV style=3D"FONT: 10pt arial"><B>To:</B> <A =
title=3Dkhill_at_cpsmedical.com=20
  href=3D"mailto:khill_at_cpsmedical.com">khill@cpsmedical.com</A> ; <A=20
  title=3Dmeteorite-list_at_meteoritecentral.com=20
  =
href=3D"mailto:meteorite-list_at_meteoritecentral.com">meteorite-list@meteor=
itecentral.com</A>=20
  </DIV>
  <DIV style=3D"FONT: 10pt arial"><B>Sent:</B> Thursday, December 11, =
2003 10:43=20
  PM</DIV>
  <DIV style=3D"FONT: 10pt arial"><B>Subject:</B> Re: [meteorite-list] =
Is there=20
  room for a meteorite question ?</DIV>
  <DIV><BR></DIV><FONT face=3Darial,helvetica><FONT lang=3D0 =
face=3DArial size=3D2=20
  FAMILY=3D"SANSSERIF">And for a more complete stab at answering your =
question=20
  from a proud "newbee".&nbsp; Note you really asked two =
questions.&nbsp;=20
  <BR><BR>1. If upon cooling there is expansion and 2. If the density is =
the=20
  same as non-crystalline materials formed on earth in the same ally=20
  proportions. <BR><BR>To question 1: If I understand your question =
properly at=20
  first reading you think that Fe-Ni mixtures upon cooling in the proper =
  proportions forming taenite / kamacite might expand?&nbsp; No =
way.&nbsp; Those=20
  structures do not form until after the alloy is already solid, though =
in an=20
  amorphous (non-crystalline) state with selective atom mobility.&nbsp; =
Those=20
  migrations of atoms occur to release heat energy flowing out of the =
system=20
  because of decreasing boundary temperatures and the law of heat =
flowing from=20
  higher to colder temperatures.&nbsp; The migrations are happening as =
these new=20
  crystal structures settle down from vibrations and fall into their =
little unit=20
  cells, allowing for a more dense material.&nbsp; For an expansion they =
would=20
  have to rip apart the already developed solid structure...causing =
perhaps a=20
  very brittle substance even.<BR><BR>Now your other question, whether =
the=20
  "terrestrial" amorphous material has the same density as a =
"crystalline"=20
  meteorite material.&nbsp; That's something I'm sure you know if you =
think a=20
  minute.&nbsp; Of course it does not have the same density.&nbsp; So =
save your=20
  iron meteorites for better experiments, and don't melt them to =
see.&nbsp; The=20
  amorphous material probably won't even have as an extremely precisely=20
  definable density.&nbsp; It ought to vary because it is =
amorphous.&nbsp;=20
  Whether statistics averages the density out or not is a separate =
question and=20
  of course will depend on exactly what alloy %'s you have and how well =
they are=20
  mixed on a macro scale...the history of how the sample was cooled, =
etc.&nbsp;=20
  Does graphite have the same density as diamond?&nbsp; No.<BR><BR>You =
cite=20
  water, when freezing, as expanding as your model, since water (0.92 =
g/mL) in=20
  equilibrium at 0=C2=B0C is denser than ice (1.00 g/mL).&nbsp; Water is =
weird, and=20
  one of the anomalous things that explains life.&nbsp; The short answer =
on why=20
  it expands upon decreasing temperature at atmospheric pressure from =
4=C2=B0C to 0=C2=B0C=20
  is a softening of proton (hydrogen) bonding and disruption of that =
nicely=20
  organized structure as it is an ionic (solution) type attraction that =
is=20
  destroyed as the molecules begin to fall down from their bounciness =
caused by=20
  higher temperatures.&nbsp; So the destruction of the hydrogen bonds =
happens=20
  upon cooling.&nbsp; Another way to say that is the melting of the =
hydrogen=20
  bonds upon cooling=E2=80=A6&nbsp; In its amorphous, hydrogen-bondless =
state oxygen=20
  atoms find themselves not tolerating such close density as before when =
all=20
  were moderated by the hydrogen atoms.&nbsp; So they repel each other =
an=20
  average of about 8% volume increase.&nbsp; Water would be less than =
0.92 g/mL=20
  at room temperature if not for the hydrogen bonding.&nbsp; Probably =
about=20
  0.90, and then it would behave like most of the other molecules upon=20
  freezing.<BR><BR>There are no comparably scaled ionic like attractions =
going=20
  on in the metal alloys as they cool.&nbsp; So there is no comparison =
to the=20
  special case of water.&nbsp; Additionally, you should know that water =
ice has=20
  about 20 described crystalline structures, and they are, not =
coincidentally,=20
  not all the same density!&nbsp; You need to know the history of =
it.&nbsp; Do=20
  you think super cooled hail is the same as the cubes floating in your =
ice=20
  tea?&nbsp; No.&nbsp; And the rockhounds can probably come up with a =
good list=20
  of structures with different densities but the same molecular=20
  proportions.<BR><BR>Every sample is individual: so back to the =
meteorite=20
  experiment.&nbsp; Each meteorite has a different history as in =
temperatures=20
  and pressures.&nbsp; Each has different impurities, so you will need =
to do=20
  more that just reproduce the alloy proportions...actually by now it =
seems=20
  pretty clear that the proposed experiment is not a good idea.&nbsp; =
All those=20
  impurities disrupt perfect conditions.&nbsp; So oceans don't freeze at =
0=C2=B0C,=20
  they are a few degrees colder, because of the impurities.&nbsp; All =
that=20
  affects densities, not to mention any molecular flatulence causing =
micro=20
  pores, uniformly or not.&nbsp; Ooops.&nbsp; Just checking to see if =
anyone=20
  read this far...<BR><BR>PS Ice floats.&nbsp; Can you imagine solid =
pieces of=20
  metal alloy floating as it is melted...that was the easier=20
  explanation...<BR><BR>Saludos<BR>Doug Dawn<BR>Mexico<BR><BR>En un =
mensaje con=20
  fecha 12/11/2003 2:58:13 PM Mexico Standard Time, khill_at_cpsmedical.com =
  escribe:<BR><BR>
  <BLOCKQUOTE=20
  style=3D"PADDING-LEFT: 5px; MARGIN-LEFT: 5px; BORDER-LEFT: #0000ff 2px =
solid; MARGIN-RIGHT: 0px"=20
  TYPE=3D"CITE"><BR><BR><BR>Question:&nbsp;&nbsp; When water turns to =
ice the=20
    change to a crystal structure<BR>expands the volume (decreases=20
    density).&nbsp; Does this density/expansion change<BR>also occur =
with the=20
    development of taenite/kamacite<BR>lattices?&nbsp; ie.&nbsp; at the =
same=20
    temperature is the density of an iron meteorite<BR>match the density =
of a=20
    "terrestrial" matching mixture that is<BR>"noncrystalline"?&nbsp; =
Guess you=20
    could melt down one of your irons and compare?<BR><BR>Fly=20
    Hill<BR><BR>&gt;----- Original Message ----- <BR>&gt;From: "mark =
ford"=20
    &lt;markf_at_ssl.gb.com&gt;<BR>&gt;To:=20
    &lt;meteorite-list_at_meteoritecentral.com&gt;<BR>&gt;Sent: Tuesday, =
December=20
    09, 2003 8:41 AM<BR>&gt;Subject: RE: [meteorite-list] Is there room =
for a=20
    meteorite question=20
    =
?<BR>&gt;<BR>&gt;<BR>&gt;&gt;<BR>&gt;&gt;<BR>&gt;&gt;<BR>&gt;&gt;<BR>&gt;=
&gt;<BR>&gt;&gt;On=20
    the same note, thermal =
expansion...<BR>&gt;&gt;<BR>&gt;&gt;Presumably as the=20
    core solidifies (cools down) it would contract, would<BR>&gt;&gt;it =
not?,=20
    what effect would that have on the crystalline=20
    structure<BR>&gt;&gt;(widmanstatten) would there be a gradual=20
    stress/distortion in the<BR>&gt;&gt;taenite/kamacite boundries=20
    ?<BR>&gt;&gt;<BR>&gt;&gt;<BR>&gt;&gt;I guess as the core is such a =
big mass,=20
    any significant thermal<BR>&gt;&gt;contraction distortion would =
hardly be=20
    noticeable in a small hand<BR>&gt;&gt;specimen but I would imagine =
the=20
    thermal contraction in something the<BR>&gt;&gt;size of a large =
planetary=20
    body would be =
massive.<BR>&gt;&gt;<BR>&gt;&gt;<BR>&gt;&gt;<BR>&gt;&gt;Mark=20
    =
Ford<BR>&gt;&gt;<BR>&gt;&gt;<BR>&gt;&gt;<BR>&gt;&gt;<BR>&gt;<BR>&gt;-----=
---------------------------------------------------------------------<BR>=
&gt;--<BR>&gt;&gt;The=20
    information contained in this email may be commercially=20
    sensitive<BR>&gt;and/or<BR>&gt;&gt;legally privileged. It is =
intended solely=20
    for the person(s) to whom it<BR>is<BR>&gt;&gt;addressed. If you are =
not a=20
    named recipient, you are on notice of =
its<BR>&gt;status.<BR>&gt;&gt;Please=20
    notify the sender immediately by reply e-mail and then=20
    delete<BR>this<BR>&gt;&gt;message from your system. You must not =
disclose it=20
    to any other person,<BR>&gt;&gt;copy or distribute it or use it for =
any=20
    =
purpose.<BR></BLOCKQUOTE><BR><BR></BLOCKQUOTE></FONT></FONT></BODY></HTML=
>
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Received on Fri 12 Dec 2003 09:53:00 AM PST


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