PLEASE NOTE:
*
CCNet, 003/2000 - 7 January 2000
--------------------------------
QUOTE OF THE DAY
"Until Jan. 4th, 2000, the two big
NEO movies of 1998 had made
together 903 million dollars in
worldwide theatrical box office
sales alone (not even counting video
rentals and TV rights) - an
amount to ponder... Armageddon is now at
# 11 of the all-time
charts, with $ 554.4m, while Deep Impact
is at # 50 with $ 348.6m,
according to the list at http://us.imdb.com/Charts/worldtopmovies.
Earlier impact movies like
"Meteor" are not mentioned there, so
the overall sum should be close to one
billion dollars."
-- Daniel
Fischer, University of Bonn
(1) GETTING YOUR NAME IN LIGHTS
THE GUARDIAN, 6 January 2000
(2) NOT BAD FOR A START: IMPACT MOVIES GROSS 1 BILLION BUCKS
Daniel Fischer <dfischer@astro.uni-bonn.de>
(3) A FEW CITY-BUSTERS BETTER THAN ONE DINO-KILLER?
Jon Richfield <jonr@iafrica.com>
(4) CATASTROPHIC DISRUPTIONS OF MINOR PLANETS
W. Benz*) & E. Asphaug, UNIVERSITY OF BERN
(5) LABORATORY ASTEROID COLLISIONS
K.R. Housen & K.A. Holsapple, BOEING CO
(6) COLLISIONAL DISRUPTION OF ICE BY HIGH-VELOCITY IMPACT
M. Arakawa, HOKKAIDO UNIVERSTY
(7) EXPERIMENTAL STUDY OF IMPACT DISRUPTION
D.D. Durda*) & G.J. Flynn, SW RES INST
(8) CCD PHOTOMETRY OF 5 MINOR PLANETS
L.L. Kiss etal., JATE UNIVERSITY
(9) PHOTOMETRY OF 3 ASTEROIDS
M.J. Lopez Gonzalez & E. Rodriguez,
CSIC,INST ASTROFIS ANDALUCIA
============
(1) GETTING YOUR NAME IN LIGHTS
From THE GUARDIAN, 6 January 2000
Why call an asteroid 1997 XF11 when you could call it Zappafrank?
Duncan Steel explains
Thursday January 06 2000
The Guardian (London/Manchester)
There is indeed a Mr Spock out there in space. Asteroid 2309 Mr.
Spock.
It was called after a tabby cat. The feline itself was named for
the
Vulcan in Star Trek, on the grounds that he (the cat) was also
"imperturbable, logical, intelligent and had pointed
ears".
Alongside such names as 1815 Beethoven, 2001 Einstein and 2985
Shakespeare a mere cat seems an unlikely addition. Since asteroid
Spock
got its name a couple of decades back, the International
Astronomical
Union - the IAU, the world-wide body which superintends such
matters -
has tightened up its rules, specifically discouraging the
application
of pets' names.
A committee of about a dozen astronomers vet all suggested names.
If
the discoverer declines to put forward an acceptable label then
the
naming rights may be taken away.
While some names are not allowed - like terms in bad taste, or
people
best-known for military or political exploits unless they've been
dead
for at least a century (Napoleon is all right, but not Margaret
Thatcher) - the committee is not humourless.
Take 3142 Kilopi. Who was that? Well, think of the mathematical
constant p which relates the circumference of a circle to its
diameter,
and multiply by a thousand (a kilo).
I was responsible for one little piece of mischief. In Bill
Forsyth's
film Local Hero one character, Felix Happer, was desperate to
have a
comet named for him. He'll just have to make do with asteroid
7345
Happer.
After an asteroid is discovered (the IAU insists they should be
called
minor planets) it will generally take a few years before its
orbit
about the sun is well-enough determined to deserve adding to the
definitive list of asteroids. Then the discoverer can put forward
a
name.
Not their own name, though; any comet you find will get your
surname
with no argument. But for asteroids the done thing is to propose
some
other name. For one of my discoveries I suggested 9767 Midsomer
Norton,
the Somerset town where I was born.
The chairman of the asteroid naming committee is Brian Marsden,
an
Englishman who directs the Minor Planet Center at Harvard
university.
He is assisted by another Englishman, Gareth Williams. It was
somewhat
incongruous when three pommies joined together to name 2472
Bradman for
the great Australian cricketer. It's only fair - think of
the South
African players Kepler Wessels and Herschelle Gibbs, each of whom
have
names derived from great astronomers.
And here's a little puzzle for the cricket buffs. One other
asteroid is
named after a prominent cricketer. Like Sir Donald Bradman, this
man is
also knighted, and played for South Australia. Who is he? (No,
not Sir
Richard Hadlee, although you would be correct to think of Trent
Bridge.) So much for the names, what about the numbers? The
sequence
of minor planet names and numbers begins with 1 Ceres, discovered
on
January 1, 1801. Ceres is a behemoth, at about 600 miles across
the
largest of the asteroids. Mind you, that is still too small to
see
clearly in any telescope except Hubble, because it's so far away.
The
word "asteroid" means "star-like", because
they look like stars through
a telescope: mere pinpricks of light.
In the following decades dozens of asteroids were discovered, and
given
prosaic names derived from ancient mythologies. The Greek goddess
of
victory, Nike, had her name on an asteroid long before running
shoes and
shirts.
All was not altruistic, however. British astronomers were still
smarting
over the naming of the planet Uranus, discovered by Sir William
Herschel in 1781. To flatter the king they had wanted to call it
George's Star, but on the continent this name was rejected.
Consequently, no sooner had the twelfth asteroid been discovered
than
it was named Victoria to less than universal acclaim.
Arguments over celestial names continue. A couple of years back
we
could see the number 10,000 approaching, and the suggestion was
made
that Pluto should be allotted to that number. Although this
provoked a
furore in the media - some people felt that Pluto was being
downgraded
from a major to a minor planet - the logic was plain. Pluto had
been
spotted in 1930, but no other objects were found beyond Neptune
until,
in 1992, another lump was found in these distant reaches of the
solar
system.
Since then a couple of hundred other rocky and icy bodies ranging
up to
300 miles in size have been identified slowly circuiting in this
frigid
region. Given that Pluto is only about 1,400 miles across, one
could
question why it should be classed as a major planet, and the
others as
minor planets. Pluto is rather smaller than Mars or Mercury, or
even
our Moon. Where does one draw the line?
The solution seemed to be to add it to the list of minor planets
in a
special place, as number 10,000. But this provoked such public
outrage
that astronomers had to backtrack. In the end asteroid 10,000 was
called Myriostos (myriad actually means numbering in the tens of
thousands).
But what about 1997 XF11 or 1999 AN10? These are
"preliminary
designations". The first four numbers show the year of
discovery.
The first letter shows the half-month the object was found.
Letter A
implies January 1-15 inclusive. The order is alphabetical, the
letter I
not being used, to avoid confusion with the number one. This
means that
December 16-31 has the letter Y. Why not also skip the letter O
as it may
be confused with zero? Because then Z would be used which could
perhaps
be mistaken for a number two.
The second letter indicates the ordering within the half-month.
The
first asteroid of the year is 1999 AA, the second is 1999 AB, and
so on
except that I again is not used, producing 25
possibilities.
When asteroid discoveries were few that was fine, but once the
number
found per fortnight exceeded 25 there was a problem. The fix was
to
employ numbers after the second letter (and to be strictly
correct
these are supposed to be subscripted).
This means that 1997 XF11 was the 281st asteroid spotted in the
first
half of December 1997. It became famous because for a short while
we
thought it might hit the Earth in 2028. We now are sure it won't.
And
soon 1997 XF11 will be given a permanent number and name. Perhaps
Nearmiss would be appropriate.
There's a real Starr out there, and a Lennon, McCartney and
Harrison
too, not to mention 3834 Zappafrank and 4305 Clapton: for Eric,
not the
London suburb. There is no London in the sky, whereas Paris, Roma
and
Moskva have been up there for aeons. Check them all out on
http://cfa-www.harvard.edu/iau/lists/MPNames.html
Some readers may say they've bought star names for friends and
family,
so what's all the fuss about asteroid names? Sorry, trying to
slap your
name on a star has no greater effect than saying you've re-named
the
street or village for yourself. The post office and map makers
will pay
no attention.
Neither does the IAU recognise names for stars. Save your money.
Anyone
can print up a gilt certificate saying a star is named for you.
It
simply has no effect.
And the answer to the cricket question? 6581 Sobers. Even
Adelaide
residents tend to forget Sir Garfield played for their state for
a
while.
Duncan Steel is a space researcher at the university of Salford,
and
minor planet 4713 Steel
Copyright Guardian Media Group plc.
============
(2) NOT BAD FOR A START: IMPACT MOVIES GROSS 1 BILLION BUCKS
From Daniel Fischer <dfischer@astro.uni-bonn.de>
Dear Benny,
until Jan. 4th, 2000, the two big NEO movies of 1998 had made
together
903 million dollars in worldwide theatrical box office sales
alone (not
even counting video rentals and TV rights) - an amount to
ponder...
Armageddon is now at # 11 of the all-time charts, with $ 554.4m,
while
Deep Impact is at # 50 with $ 348.6m, according to the list at
http://us.imdb.com/Charts/worldtopmovies.
Earlier impact movies like
"Meteor" are not mentioned there, so the overall sum
should be close
to one billion dollars.
Daniel Fischer
============
(3) A FEW CITY-BUSTERS BETTER THAN ONE DINO-KILLER?
From Jon Richfield <jonr@iafrica.com>
Benny,
A Ms is not nearly as good as a Miss, but may be better than a
Mr.
I am worried about some aspects of the discussions on acceptable
options for dealing with possible impactors. No one could doubt
that if
we have the time and the resources to react, the intelligent
choice is
to deal with a direct threat by nudging it gently, safely and
economically into a harmless orbit (and preferably an orbit that
will
not tempt the media into orgies of speculation at every
subsequent
thrilling near miss.) However, we have no guarantee that every
dinosaur-killer will give us a twenty-year warning. So suppose
that we
are lucky and get just a five-year warning of some billion-ton
stray
from the Oort cloud. That would be hopelessly too little time to
deflect it unless it had been aiming for the merest graze.
We know very well that if such a mass strikes practically
anywhere on
the planet, our technological infrastructure is pretty well
doomed and
our prospects for following in the tracks of the dinosaurs are
excellent.
We also know that we can neglect the physical strength of the
visitor.
Whether the impact comes from a gigatonne cloud of density 0.5 or
a
gigatonne rock of density 2.5 will not make much difference. So
people
have pointed out that nuking an incoming mass is a pretty iffy
expedient. It may not do any useful deflection and to
exchange a hit
by a rock or snowball for a hit by a compact cloud or even a
shotgun
burst of large fragments might do little more than spread the
pleasure.
And yet I am moved to reflect on the difference between being hit
by a
hammer and being hit by a pillow. How relevant the
difference would
be, I am not sure, because the largest bomb we ever have built
would
not vaporise a really large body, say of the order of a
gigatonne. But
all the same, let us consider a few scenarios.
Start by unrealistically supposing that we could reduce our
incoming
cubic km to a cloud of gas or gravel spread roughly evenly
over a
diameter of some 10000km. An impact from a rock with a
cross section
of 1km^2 would be a disaster. However, if we first converted it
to a
roughly 80000000km^2 spray, it should reach the ground only as
dust. On
a planetary scale that shouldn't be too much worse than many a
sizeable
volcanic eruption in terms of suspending dust in the atmosphere,
and
the impact would be spread over at least many minutes, so the
problem
of flash burns or shock waves should reduce to triviality.
To be sure, the gross amount of heat deposited in the atmosphere
should
not be much affected, in fact it would be greatly increased,
because
normally most of the heat would wind up in the crust, while now
it
would all stop in the atmosphere. However, it would be almost all
in
the upper atmosphere. There would be negligible downward
transport by
conduction or convection, and a great deal of the radiation would
be
back into space.
All right, so a scenario of a benign dust impact is not
plausible, but
then what are the alternatives? Here are a few:
Suppose the body breaks into a lot of dangerous lumps plus small
debris. The debris would be not much of a problem, and it is
quite
conceivable that the big lumps would drift apart and miss the
planet
altogether. Another triumph for Rock Budgers! Alternatively
suppose
that now just one or a few of the large lumps hit the planet.
Cool
comfort, if we may be permitted the term in such a hot context,
but it
is comfort all the same. We should prefer a few city busters to
one
dino killer any day! In fact, suppose we do in fact split the
dino
killer into a shotgun-blast of city killers, and all of them then
hit
the planet; that might have some embarrassing effects, but
frankly I
think that our infrastructure (and therefore our civilisation)
would
survive them a lot better than we could survive the dino killer.
For
one thing they would not cause significant focussing of shock
waves at
the other end of the planet. For another they should cause less
destructive quakes and tsunamis.
Now, would anyone care to tell me why we should prefer to stand
still
for the dino killer instead of having a go at nuking it, always
assuming
that we have no time to deflect it gradually?
Cheers,
Jon
=============
(4) CATASTROPHIC DISRUPTIONS OF MINOR PLANETS
W. Benz*) & E. Asphaug: Catastrophic disruptions revisited.
ICARUS,
1999, Vol.142, No.1, pp.5-20
*) UNIVERSITY OF BERN,INST PHYS,SIDLERSTR 5,CH-3012
BERN,SWITZERLAND
We use a smooth particle hydrodynamics method to simulate
colliding
rocky and icy bodies from centimeter scale to hundreds of
kilometers in
diameter in an effort to define self-consistently the threshold
for
catastrophic disruption. Unlike previous efforts, this analysis
incorporates the combined effects of material strength (using a
brittle
fragmentation model) and self-gravitation, thereby providing
results in
the ''strength regime'' and the ''gravity regime,'' and in
between.
In each case, the structural properties of the largest remnant
are examined. Our main result is that gravity plays a dominant
role in
determining the outcome of collisions even involving relatively
small
targets. In the size range considered here, the enhanced role of
gravity is not due to fracture prevention by gravitational
compression,
but rather to the difficulty of the fragments to escape their
mutual
gravitational attraction. Owing to the low efficiency of momentum
transfer in collisions, the velocity of larger fragments tends to
be
small, and more energetic collisions are needed to disperse them.
We
find that the weakest bodies in the Solar System, as far as
impact
disruption is concerned, are about 300 m in diameter. Beyond this
size,
objects become more difficult to disperse even though they are
still
easily shattered. Thus, larger remnants of collisions involving
targets
larger than about 1 km in radius should essentially be
self-gravitating
aggregates of smaller fragments. (C) 1999 Academic Press.
===========
(5) LABORATORY ASTEROID COLLISIONS
K.R. Housen*) & K.A. Holsapple: Scale effects in
strength-dominated
collisions of rocky asteroids. ICARUS, 1999, Vol.142, No.1,
pp.21-33
*) BOEING CO,SHOCK PHYS,MS 8H-05,POB 3999,SEATTLE,WA,98124
The application of laboratory collision experimental results to
the
larger scales of asteroid impacts is complicated by the fact that
the
dynamic strength of rock typically decreases as the loading
duration
increases. Because loading times increase with the size scale of
a
collision, large bodies are effectively weaker than small ones.
While
this effect has been postulated for over a decade, it has never
been
verified in actual collision experiments. This paper summarizes
collision tests performed under the conditions required to
examine
scale effects, i.e., increasing the size scale of the experiment
while
holding the impact velocity and impact kinetic energy per target
mass
constant. Granite targets are used, with a diameter variation of
a
factor of 18, The larger targets experienced significantly more
collisional damage than small ones, confirming a decrease in
dynamic
strength with increasing size scale. The results are compared to
a
scaling model based on the concept that fragmentation is
accomplished
through the growth and coalescence of preexisting flaws.
Measurements
of the actual flaw-size distribution are used to validate the
model.
Field observations of flaw and fault sizes at scales to 10 km are
used
to construct a scaling model that is believed to apply to the
shattering of a wide range of rock types. The results show that
kilometer-sized rocky bodies may be significantly weaker than
indicated
by previous estimates, (C) 1999 Academic
Press.
==========
(6) COLLISIONAL DISRUPTION OF ICE BY HIGH-VELOCITY IMPACT
M. Arakawa: Collisional disruption of ice by high-velocity impact
ICARUS, 1999, Vol.142, No.1, pp.34-45
*) HOKKAIDO UNIVERSTY,INST LOW TEMP SCI,KITA KU,KITA 19 NISHI
8,SAPPORO,HOKKAIDO 060081,JAPAN
High-velocity impact among icy planetesimals is a physical
phenomenon
important to the planetary evolution process in the outer Solar
System.
In order to study this phenomenon, impact experiments on water
ice were
made by using a two-stage light gas gun installed in a cold
room(-10
degrees C) to clarify the elementary processes of collisional
disruption and to study the reaccumulation and the escape
conditions of
the impact fragments. Cubic ice targets ranging in size from 15
to 100
mm were impacted by a nylon projectile of 7 mg with an impact
velocity
(v(i)) from 2.3 to 4.7 km/s. The corresponding mass ratio of the
projectile to the target (m(p)/M-t) ranged from 10(-3) to 10(-6),
which
is two orders of magnitude lower than that used in previous
studies
(Arakawa et al. 1995, Icarus 118, 341-354). As a result, we
obtained
data on elementary processes such as attenuation of the shock
wave and
fragmentation dynamics. We found that the shock pressure
attenuates in
the ice target according to the relation of P proportional to
(L-p/r)(2), irrespective of the mass ratio between 10(-3) and
10(-
5), where L-p is the projectile size and r is a propagation
distance.
The largest fragment mass (m(l)) normalized by the original
target mass
has a good relationship to a nondimensional impact stress (P-I,
NDIS)
defined as the ratio of the antipodal pressure to the material
strength. This relationship is described as m(l)/M(t)proportional
to
P-I(-1.7) for a wide range of impact conditions (50 m/s < v(i)
< 4 km/s
and 10(-1) < m(l)/M-t, < 10(-6)), and shows the utility of
NDIS. Using
a measured shock wave decay constant of 2, the reaccumulation and
the
escape conditions of icy bodies in high-velocity collisions were
estimated. As a result, it was clarified that a rubble pile could
be
formed when large icy bodies (radius > 20 km) reaccumulated.
On the
other hand, when smaller icy bodies (radius < 2 km) disrupted
catastrophically, all fragments escaped and a rubble pile was
never
formed. (C) 1999 Academic Press.
==========
(7) EXPERIMENTAL STUDY OF IMPACT DISRUPTION
D.D. Durda*) & G.J. Flynn: Experimental study of the impact
disruption
of a porous, inhomogeneous target. ICARUS, 1999, Vol.142, No.1,
pp.46-55
*) SW RES INST,1050 WALNUT ST,SUITE 426,BOULDER,CO,80302
Measurements of the densities of interplanetary dust particles
and
unweathered stone meteorites indicate that both have significant
porosity on the microscopic scale, In addition, the chondritic
stone
meteorites are generally inhomogeneous, typically consisting of
strong,
millimeter-size, olivine chondrules embedded in a weaker,
fine-grained
matrix, Since target porosity is known to influence energy
partitioning
in cratering and disruption, we have begun a series of
experiments to
study the impact disruption of inhomogeneous assemblages of two
materials of different strengths and which exhibit significant
porosity, Experiments were performed on three similar to 300-g
targets
of porphyritic olivine basalt, consisting of millimeter-size
olivine
phenocrysts in a fine-grained vesicular matrix (simulating a
stone
meteorite). Using the NASA Ames Vertical Gun, each target was
impacted
by a 1/4-in. diameter aluminum sphere at a speed of similar to 5
km s(-
1). To avoid measuring the secondary effects of fragmentation
caused by
material impacting on the walls of the gun chamber, we monitored
primary debris using passive detectors. We measured the
size-frequency
distribution of the small fragments using thin foils. Most foils
showed
only small depressions, sometimes containing fragments of debris,
indicating relatively low velocity debris. One foil showed
similar to
300 puncture holes from high-speed particles, presumably a
localized
jet or cone of target or projectile ejecta, The size-frequency
distribution was quite steep down to the similar to 10- to 20-mu
m
limit where particle size was comparable to foil thickness.
Aerogel
cells were employed to capture dust-size primary debris. Using an
in
situ chemical analysis technique, we distinguished matrix from
olivine
and determined that fragments <100 mu m in size were matrix
while the
majority of the largest fragments (> 200 mu m in size) were
olivine, We
also collected the debris from the floor of the gun chamber, The
largest fragments (significantly bigger than individual olivine
phenocrysts) were representative of bulk target material, In the
millimeter-size range we found a large number of isolated olivine
crystals, indicating the target experienced preferential failure
along
the phenocryst-matrix boundaries. All three shots showed distinct
changes in the slopes of the mass-frequency distribution near 0.4
g,
the size of typical olivine phenocrysts. This suggests that the
mechanical failure of the material was affected by the presence
of the
phenocrysts. If our results are directly applicable to chondritic
meteorites, then impact cratering and disruption of chondritic
asteroids may overproduce olivine-rich material from chondrules
in the
millimeter-size range and olivine might be underrepresented at
smaller
sizes in the primary debris. (C) 1999 Academic Press.
============
(8) CCD PHOTOMETRY OF 5 MINOR PLANETS
L.L. Kiss*), G. Szabo, K. Sarneczky: CCD photometry and new
models of 5
minor planets. ASTRONOMY & ASTROPHYSICS SUPPLEMENT SERIES,
1999,
Vol.140, No.1, pp.21-28
*) JATE UNIVERSITY,DEPT EXPT PHYS,DOM TER 9,H-6720 SZEGED,HUNGARY
We present new R filtered CCD observations of 5 faint and
moderately
faint asteroids carried out between October, 1998 and January,
1999.
The achieved accuracy is between 0.01-0.03 mag, depending mainly
on the
target brightness. The obtained sinodic periods and amplitudes:
683
Lanzia - 4(h).6 +/- 0(h).2, 0.13 mag; 725 Amanda > 3(h).0,
greater than
or equal to 0.40 mag; 852 Wladilena - 4(h).62 +/- 0(h).01; 0.32
mag
(December, 1998) and 0.27 mag (January; 1999); 1627 Ivar -
4(h).80 +/-
0(h).01; 0.77 mag (December, 1998) and 0.92 mag (January. 1999).
The
Near Earth Object 1998 PG unambiguously showed doubly-periodic
lightcurve, suggesting the possibility of a relatively fast
precession
(P-1 = 1(h).3: P-2 = 5(h).3). Collecting all data from the
literature,
we determined new models for 3 minor planets. The resulting spin
vectors and triaxial ellipsoids hare been calculated by an
amplitude-
method. Sidereal periods and senses of rotation were calculated
for two asteroids (683 and 1627) by a modified epoch-method. The
results are: 683 - lambda(P) 15/195 +/- 25 degrees, beta(P) = 52
+/- 15
degrees; a/b = 1.15 +/- 0.05, b/c = 1.05 +/- 0.05, P-sid =
0(d).1964156
+/- 0(d).0000001; retrograde; 852 - lambda(P) = 30/210 +/- 200,
beta(P)
= 30 +/- 10 degrees, a/b = 2.3 =/- 0.3, b/c = 1.2 +/- 0.2; 1627 -
lambda(P) = 145/325 =/- 8 degrees, beta(P) = 34 +/- 6 degrees,
a/b =
2.0 +/- 0.1, b/c = 1.09 +/- 0.05, P-sid = 0(d).1999154 +/-
0(d).0000003; retrograde. The obtained shape of: 1627 is in good
agreement with radar images by Ostro et al. (1990).
Copyright 2000, Institute for Scientific Information Inc.
============
(9) PHOTOMETRY OF 3 ASTEROIDS
M.J. Lopez Gonzalez*) & E. Rodriguez: Stromgren photometry of
40
Harmonia, 45 Eugenia and 52 Europa.ASTRONOMY & ASTROPHYSICS
SUPPLEMENT
SERIES, 1999, Vol.139, No.3, pp.565-574
*) CSIC,INST ASTROFIS ANDALUCIA,POB 3004,E-18080 GRANADA,SPAIN
The Asteroids 40 Harmonia, 45 Eugenia and 52 Europa have been
studied
photometrically. From their lightcurves synodic periods of
8(h)54(m)36(s), 5(h)42(m)00(s) and 5(h)37(m)46(s), and maximum
amplitudes of 0.(m)15, 0.(m)12 and 0.(m)20, have been deduced for
40
Harmonia, 45 Eugenia and 52 Europa, respectively. Improved
solutions
for the sense of rotation, sidereal period, pole orientation and
shape
properties are proposed. Copyright 2000, Institute for Scientific
Information Inc.
----------------------------------------
THE CAMBRIDGE-CONFERENCE NETWORK (CCNet)
----------------------------------------
The CCNet is a scholarly electronic network. To
subscribe/unsubscribe,
please contact the moderator Benny J Peiser <b.j.peiser@livjm.ac.uk>.
Information circulated on this network is for scholarly and
educational use only. The attached information may not be copied
or
reproduced for any other purposes without prior permission of the
copyright holders. The fully indexed archive of the CCNet, from
February 1997 on, can be found at http://abob.libs.uga.edu/bobk/cccmenu.html