PLEASE NOTE:
*
Date sent: Fri, 04 Jul 1997 12:09:05 -0400 (EDT)
From: Benny J Peiser <B.J.PEISER@livjm.ac.uk>
Subject: TAURID DEMONS & CIVILISATION COLLAPSE
To: cambridge-conference@livjm.ac.uk
Priority: NORMAL
'TAURID DEMONS', CLIMATE CHANGE & THE COLLAPSE OF MANKIND'S
FIRST URBAN
CIVILISATIONS
"Davis (1996) has reminded us of Clube and Napier's impact
theory, and asked 'Where is the archaeological and geological
evidence for the role of their 'Taurid Demons' in human
history? The abrupt climate change at 2200 BC, regardless of
an improbable impact explanation, situates hemispheric social
collapse in a global, but ultimately cosmic, context."
[Harvey Weiss: Late Third Millennium Abrupt Climate Change
and Social Collapse in West Asia and Egypt. In: H Dalfes, G
Kukla, H Weiss (eds.) Third Millennium BC Climate Change and
Old World Collapse. Heidelberg/Berlin: Springer Verlag 1997,
p. 719/20]
During the last two decades, researchers have discovered
compelling
evidence for abrupt climate change and civilisation collapse in
addition to sea level changes, catastrophic inundations and
widespread
seismic activity in many areas of the world at around 2200/2300
BC.
Climatological proxy data together with sudden changes in
lacustrine,
fluvial and aeolian deposits have been detected in the
archaeological,
geological and climatological records. The most comprehensive
survey of
this particular climate disaster which coincided with (and most
likely caused) the collapse of mankind's first urban
civilisations can
be found in the above mentioned volume on "Third Millennium
BC Climate
Change and Old World Collapse." Although there is still
considerable
disagreement about the "absolute" date of this
catastrophe, a growing
number of scholars agree that we are indeed dealing with an
abrupt
natural dissater with devastating effects on civilisations in
West
Asia, Europe and North Africa, but which was perhaps a global
event.
When, between 1980 and 1988, the Society for Interdisciplinary
Studies
(SIS) published Moe Mandelkehr's pioneering research papers on
archaeological, geological and climatological evidence for global
climate and social catastrophes at around 2300 BC, Moe had
gathered
more than 350 references to back up his hypothesis with
scientific
data.
Now, almost 20 years later, 40 researchers from around the world
have
compiled the a.m. volume on the same event(s), analyzing and
summerizing some 1700 references on abrupt climate change and
social
collapse around 4200/4300 BP.
In his concluding paper, Prof Harvey Weiss (Yale University) sums
up
this new picture of "Old World Collapse" which is
slowly evolving from
recent research findings. I have attached extracts from his paper
since
it sheds light on the current thinking of one of America's
leading
Bronze Age specialists.
Benny J Peiser
P.S. Dr Marie-Agnes Courty, the French geologists and soil
expert, who
has analysed the geological and geochemical evidence for the
Mesopotamian 3rd Millennium system collapse (see SCIENCE
261:995-1003),
will present new research findings regarding this event at
Fitzwilliam
College next Saturday, 12th July.
-----------------------------------------------------------------
Extracts from:
Harvey Weiss (1997), Late Third Millennium Abrupt Climate Change
and
Social Collapse in West Asia and Egypt. In: Dalfes, Kukla, Weiss
(eds.)
Third Millennium BC Climate Change and Old World Collapse.
Heidelberg/Berlin: Springer Verlag 1997, pp. 718-720]
"Within the past five years new tools and new data for
archaeologists,
climatologists, and historians have brought us to the edge of a
new
era in the study of global and hemispheric climate change and its
cultural impacts. The climate of the Holocene, previously assumed
static, now displays a surprising dynamism, which has affected
the
agricultural bases of pre-industrial societies. The list of
Holocene
climate alterations and their socio-economic effects has rapidly
become
too complex for brief summary. Any list would need to include,
however,
the tenth to fourteenth century Medieval Warm Epoch (Hughes and
Diaz
1994) that promoted viticulture in England, cereal agriculture in
Iceland (Street-Perrot 1994), the collapse of Norse Greenland
settlement (McGovern 1990) and the demise of Anasazi agriculture
in the
Southwest (Fish and Fish 1994).
Still earlier, in the Andes, the late 6th century Moche
civilization
suffered a 30 year drought followed by severe El-Nino flooding;
the
Moche capital was destroyed, field and irrigation systems swept
away,
and widespread famine ensued (Shimada et al. 1991). Between 1000
and
1100 AD the Tiwanaku empire collapsed with the deterioration of
its
regional agricultural systems. Chronic drought, now documented in
the
Quelccaya ice cap, was too severe and long-lasting for the
Tiwanaku
agroengineers. And now the first hard data for the role of
climate
change in the 750- 1000 AD Maya collapse: prolonged drought
beginning
at ca. 800 AD, a two hundred year period identified as the driest
episode of the past 8000 years.
The subject of this volume, 2200 BC abrupt climate change, brings
the
study of Holocene climate dynamics to the Old World and forces
reconsideration of Old World climate - culture dynamics within
ancient
civilizations. One month prior to our publication (Weiss et al.
1993)
of the Tell Leilan abrupt climate change study, Sirocko et al.
(1993)
had identified within the marine sediment record a century scale
dust
flux event and aridification, ca. 3500 BC. over North Africa and
Arabia. The ramifications of this event for Mesopotamian and
Egyptian
state formation remain to be determined with archaeological
studies
that can document the event and its social effects "on the
ground." The
Tell Leilan abrupt climate change study differed from the Sirocko
study
in that it was "on the ground" both climatically and
archaeologically,
and had almost half a century of background data, hypotheses, and
argumentation within the literatures of Mesopotamian, Palestinian
and
Egyptian archaeology, as well as the archaeology of the Aegean,
central
and eastern Europe, the Ukraine and Russia. Hence the challenge
of that
study and the challenge which subsequent data collection and
synthesis
presents for traditional epigraphers (sic) historiography of this
period, and especially the collapse of Akkad. Traditional third
milllennium historiography (e.g., Yoffee, 1995; Michalowski,
1993)
remains isolated from synchronous developments in adjacent
regions and
the realities of dynamic soils and landscapes, the economics of
imperialized agro-production, and abrupt climate change.
The challenges ahead, however, for archaeologists,
geoarchaeologists,
and climatologists are impressive. As the contributions to this
volume
make clear, the [quantification] of that which has been
identified in
various archaeological and natural records is a necessary first
step
towards the resolution of still conflicting data sets, the full
description of the 2200 BC abrupt climate change, and its
eventual
explanation. Outstanding quantitative issues are the chronology
of the
beginning of the abrupt climate change as well as for its
problematic
terminus, geoclimatic processes of wind turbulence, dust
deposition,
glass shard/tephra/ deposition, aridification, and river flow,
across
the range of Old World environments during this time frame.
Hundreds of years after the event, a cuneiform collection of
"prodigies," omen predictions of the collapse of Akkad,
preserved the
record that "many stars were falling from the sky"
(Bjorkman 1973:106).
Closer to the event, perhaps as early as 2100 BC, the author of
the
Curse of Akkad alluded to 'flaming potsherds raining from the
sky'
(Attinger 1984). Davis (1996) has reminded us of Clube and
Napier's
impact theory, and asked "Where is the archaeological and
geological
evidence for the role of their 'Taurid Demons' in human
history?" The
abrupt climate change at 2200 BC, regardless of an improbable
impact
explanation, situates hemispheric and social collapse in a
global, but
ultimately cosmic, context."
*
Date sent: Fri, 04 Jul 1997 08:46:37 -0400 (EDT)
From: Benny J Peiser <B.J.PEISER@livjm.ac.uk>
Subject: Live From Mars - Update #42
To: cambridge-conference@livjm.ac.uk
Priority: NORMAL
From: Ron Baalke <BAALKE@kelvin.jpl.nasa.gov>
L I V E F R O M M A R S - A Passport to Knowledge Project
UPDATE # 42 - July 2, 1997
SPECIAL REPORT: BEHIND THE SCENES FOR PATHFINDER'S LANDING ON
MARS
PART 1: A mile-a-minute day
PART 2: A long road nearing the end
PART 2: Subscribing/unsubscribing: how to do it
______________________________________________________
A MILE-A-MINUTE DAY
Rob Manning
July 2, 1997: 6:30pm Pacific
This has been a mile-a-minute type of day. I'll tell you, the
excitement and drama of what's going on is up to a high pitch.
Everyone's fingers are clammy!
I slept pretty well last night, though I did wake up at 4 a.m. to
do
some work. I sat in my bathrobe at my dining room table going
through
all these numbers, looking at the times and getting the idea that
yes,
this IS going to work!
When we run through the software in our testbed we actually can
watch
all the events that happen. We have support equipment that
listens in
to what the computer and the hardware are doing, including
opening the
airbags and rockets (even though there are no real rockets
opening). We
can make sure that all the events that are supposed to happen,
happen
and that they are happening at the right instant. We're actually
trying
to make sure that everything happens to within a fraction of a
second
of accuracy. When we do one of these tests, it produces a whole
ream of
paper that unfortunately we have to go through by hand to really
understand what's going on. However, every time we run these
tests the
software causes the rockets to fire within a few thousandths of a
second of when they're supposed to fire. This is better than we
need,
by a lot! It's so much fun to confirm that over and over again!
I spent the rest of today answering a lot of fast questions from
the
media. Our science team did a press conference and all of us were
eagerly listening to see how they would handle the bombardment of
questions. We're interested to know what kind of questions people
have,
so we can tune our answers to match the questions. One of the
problems
we have is that we're so familiar with this mission, we know all
the
details, that it's hard to really know how much other people know
about
it. So we basically try to listen to other people's questions and
who's
doing the asking and then try to judge how to explain all of
this.
There are a lot of complicated series of events. It's especially
hard
talking with television reporters because we have to explain
things
very succinctly and quickly, most importantly very quickly,
without
using any acronyms and trying to use words that people can see
very
visually. It takes practice and we're practicing.
Tonight, in my free time (which I have very little of!) I'm
working on
a script that I'm going to read during the landing. I'm trying to
synchronize my talking with what I think should be going on at
each
given moment. I know there's going to be a lot of people
listening, all
over the world, and I have to make sure I say the right thing and
that
I don't misplace my tongue. Most importantly, I have to keep my
concentration up because I have to get up at 1 a.m. to spend the
early
morning hours as mission manager for that phase of the descent
and
landing.
Just a few moments ago, we may have sent (we don't know yet for
sure)
the very last command to the spacecraft until after it lands. We
do the
best job we can aiming for Mars, but Mars moves! Mars' position
is
being influenced by Jupiter and the asteroids. Just today we
started to
see a tug of Mars. Right now Mars looks like the Moon from Earth;
that's how big it is if you were on the spacecraft. We are less
than a
million miles from Mars. And at that distance Mars is starting to
pull
a little bit and the spacecraft is starting to very slowly
accelerate
toward Mars, as if it's falling into Mars. Hopefully it falls
just the
right way so it skims the atmosphere to slow down.
It looks like we are a little bit off target, but not too much.
We're
not going to do to much to change the direction of travel but we
want
to tell the software onboard exactly where it's going so the
spacecraft
will open the parachute at just the right height. Even though the
software onboard Pathfinder is running and the clocks are
ticking,
anytime between now and 8:30 a.m., Pacific, Friday, we can send
commands to the spacecraft to update these key parameters that
control
how the parachute gets opened. We have the ability to very
quickly
generate these commands based on the latest knowledge of where
we're
going. and that's based on information gathered by our
navigators.
The Navigation team works together to take our best estimate of
where
we think we're going and figure out exactly how to take that
information and propagate it to the ground. They can actually
simulate
the spacecraft flying through a computer-generated atmosphere and
figure out how the lift and drag work. Pathfinder looks like a
funny-shaped glider and we can actually go through the process of
simulating that whole lift, drag and acceleration due to gravity
(the
tug of Mars) all the way down until that point where the
parachute
opens up and beyond. We do this over and over again with the new
information we get.
The parachute will open up anywhere from about 5 km above the
ground to
as high as 11 km or more. In fact it looks like, from where we're
coming right now, we're going to open the parachute a little on
the
high side, which means it'll take a longer time to soar to the
ground.
The spacecraft is soaring to the ground at a very, very high
speed and
once the parachute opens it has got a lot to do: get rid of the
heat
shields, repel down a 20-meter bridle, turn on the radar and
start
looking for the ground and begin the processing. On top of all of
this,
Pathfinder has to have enough time to figure out how high it is
above
the ground and how fast it's going in order to open the airbags.
The
airbags open about 1000 feet above the ground and once they open,
the
lander can no longer see the ground through the airbags. That's
the
reason that we do these updates-to get a better sense of where
we're
going and to get the parameters just right.
The command we sent about 15 minutes ago is still flying through
space
at this minute. It only takes about 1000 bits of information,
which we
send from the Deep Space Network in Goldstone, CA. These 1000
bits are
shipped up one bit at a time, back-to-back. But even though it
takes
awhile to get all those bits out the antenna, by the time the
last bit
is out, the first bit is still flying through space. All those
thousand
bits are like little soldiers marching in series until they get
to
Mars, at which time they'll be received one at a time by the
spacecraft.
My day isn't over yet. Now I must prepare for tomorrow's press
conference...
______________________________________________________
A LONG ROAD NEARING AN END
Linda Robeck-Fuhrman, Deputy Mechanical Engineering Manager for
Pathfinder Assembly, Test, and Launch Operations
July 2
For Linda, Pathfinder's July 4th landing is the end of a long
road
begun just over two years ago, when she joined the Pathfinder
team for
the Assembly Test and Launch Operations phase of the Pathfinder
mission. ATLO, as they call it, is where a spacecraft makes its
last
stop on Planet Earth, first at JPL's Spacecraft Assembly Facility
(SAF), and finally at the test and launch facilities at Kennedy
Space
Center. At KSC, affectionately referred to as "the
Cape", the
spacecraft goes through final test and assembly, is mated to the
launch
vehicle for yet another round of testing, and then ultimately
lifts off
for the trip to Mars. It was just over a year ago that Linda
helped
pack up Pathfinder to begin its long road to Mars, starting with
a
four-month intensive effort at the Cape. But even before launch,
the
events of this hectic week of July 4 1997 were very much in the
minds
of the entire Pathfinder team.
"We were there from June through mid-December, and it was
round-the-clock action the entire time." Linda was in charge
of the
group which assembled and tested the Pathfinder lander. It was a
challenging time, since when the inevitable problems came up,
Linda's
team had to improvise tests and solutions on the spot, far from
the
support of the main JPL facility in California.
"One serious issue that came up was in how the spacecraft
would respond
to the venting of cooling fluid, which happens right before final
approach to the planet on July 4. The concern was that the
venting
fluid would act as a thruster, either spinning the spacecraft or
pushing it off-course. My team had to devise a way to measure the
mechanical characteristics of the spacecraft there on-site at the
Cape,
to prove to ourselves and those back at JPL that the venting
could be
done without disrupting the spacecraft's motion or
attitude."
"Another situation we faced, which seems kind of funny now,
is when we
were doing the final closing of the lander. This lander structure
consists of "petals" which fold up around the rover,
electronics, and
science instruments, and will be opened up again when the lander
is
safely on Mars. Anyway, this event turned out to be a big public
spectacle; Dan Goldin (NASA Administrator) was giving a speech on
the
same day, and there was a huge crowd of media people and cameras
around
to witness our buttoning-up of the spacecraft. Well, the petals
didn't
close all the way. We were horrified! We could see that there was
a
tiny space between each of the petals, when they were supposed to
be
sealed tightly. None of the visiting guests could tell, because
the
gap was small and unless you really knew what to look for you
couldn't
see it. But we knew that it was supposed to fit perfectly and
that
something had to be wrong. We had to call off the live video feed
into
the press conference and send all the press home.
Then began the frantic scrambling to find the problem. It turned
out
that we had never put the whole lander together before with
everything
on it at one time, and it was now much heavier than it used to
be;
parts of the lander were sagging under their own weight. The
sagging
made the parts not quite fit right, which forced us to really
look
closely at the parts, called "latches" , that held the
petals together.
It turned out to be serendipitous, because when we really looked
at it,
we realized we needed some modifications to the latches to make
darned
sure the thing would work on Mars, even though Mars gravity is
much
lower than that on Earth. To fix the problem, we actually had
people
back at JPL pull parts off of an engineering model of the
spacecraft,
modify them slightly, and then hand-carry them out to the Cape to
replace the identical parts we removed from the real spacecraft.
It worked out just fine, but it was a desperate few days."
Back at JPL, Linda has taught the Pathfinder operations team
everything
she knows about the lander and how it was put together. She won't
be
actually involved in the landing activities -- unless something
unexpected happens, which means the operations team might be
calling
her for her expert opinion.
"I'm wearing a beeper, and they know they can call me any
hour of the
day or night. I'll be on pins and needles the whole time, hoping
they
don't need to."
Linda's beeper may also go off this week for an entirely
different sort
of crisis -- a TV or newspaper crew needs someone to interview,
right
away!
"I'm on the 'Interview List', which means I'll be available
at any time
to give a commentary on what's going on or to explain something
in the
mission or spacecraft. Over the last few weeks, they've given us
training on how to deal with the media, the kinds of angles that
reporters would like to know about, and even what to wear for TV!
What's funny is that I've actually heard from a few high school
friends
of mine, who are now in the news business and are calling me to
use the
personal touch to get the inside story."
"I'm planning to be at JPL for the whole series of events
this week --
no, no Fourth of July vacation, but we'll still be celebrating.
I'm
going to watch the launch events with the rest of my crew from
ATLO.
These people include guys from the machine shop, technicians, and
engineers. We've got a little conference room at the Lab with a
TV
monitor, a microwave -- we're even getting a fire permit for a
BBQ pit
right outside! The first spacecraft activity I'll be watching for
closely will be that coolant venting event we worried about way
back
during ATLO. This will happen about 9 in the morning of the 4th.
Pretty soon after that, data coming back from the spacecraft will
let
us know whether things worked out OK. Since it was something I
was
personally involved in, I'll be anxious to see the results. After
that,
we won't be able to see much during the descent to the planet
surface,
so we won't know for sure everything worked until sometime later
in the
afternoon. We'll be biting our fingernails until then. I just
know
that it will be successful, though, and I'm especially excited
about
seeing that first picture.
You see, I first got interested in space as a teen-ager, when I
saw
the pictures sent back from Mars by the Viking lander. Now, just
like
the first picture from Viking on Mars was of its very own foot --
you
could even see a footprint in the dust where the lander had
apparently
bounced once! -- these first pictures from Pathfinder will be of
its
own open side petals. For me, it will be like coming full-circle;
years
after marveling at those first pictures from Mars, I'll be seeing
Mars
again -- but through the eye of a spacecraft that I helped build
with
my own hands. I can't wait."