From: Amara Graps (amara@amara.com)
Date: Thu Aug 08 2002 - 15:49:30 MDT
Greetings, Extropes!
Finished with my last two conferences of this spring/summer/fall. I'm
back home in Heidelberg now. I wish to write some notes about the
meetings and Berlin and Potsdam while the topics are fresh in my mind.
Astronomy meeting: ACM, Berlin
http://berlinadmin.dlr.de/SGF/acm2002/
The Asteroids, Comets and Meteroids conference held in Berlin,
Jul 28-Aug 3, enabled about 400 scientists from all over the world to
meet and talk. The presentations of the meeting consisted of about 4/5
posters and 1/5 oral presentations: the organizers chose this new
approach in order to eliminate parallel oral sessions and to allow for
more information to be seen (posters, since the oral talks were
essentially 7 minutes...). It was a good strategy for an information-
dense meeting.
This time (ACMs are held every 3 years), the Kuiper-belt (transneptunian
objects: TNOs, centaurs) joined the traditional Asterods, Comets and
Meteors topics, but the 20 year old ACM acronym for this meeting doesn't
need to change too much if one writes 'comets' in Swedish. (Sweden was
the host country for the ACMS during the 1980s). Relatively new topics
that gained full sessions this time were about the Yarkovsky effect, an
effect appropriate for cm and larger sized particles giving a mechanism
for asteroids to jump across resonances, and binary asteroids. Binary
asteroids are those asteroids that have companions, seen so far in near
Earth, main-belt and Kuiper-belt populations. They are detected mostly
via radar (you should try to see the binary asteroid animations if you
can; incredible!), and some formation mechanisms for these objects were
discussed, which must be different for the different populations. The
term 'rubble pile' was given tighter definition too, based on two
dimensional representation of object porosity and tensile strength.
I suggest for you folks to look at the presentation abstracts online
(many topics: NEOs, collisions and impacts, TNOs / comet nuclei /
asteroid connections, binaries, rubble piles and asteroid and
comet-nucleus structure, asteroid-meteorite connection, comets / meteor
showers / interplanetary material connections, dynamics (origin of
comets, MBA->NEA evolution, Yarkovsky Effect, families, origin and
evolution of the solar system and other planetary systems, space
missions). Besides being impressed by the radar binary asteroid
observations, above, I was impressed by the Near Earth Objects impact
predictions. The predictions become very sophisticated in order to
address a complex problem (for example, the computation time to solve
the problem is longer than the time for the object to impact.). A
mathematician named Milani at the Univ of Pisa showed a technique that
he called 'virtual asteroids', which are integrated forward in time so
that one has a volume in space that represents the probability for one
particular asteroid to cross the Earth's orbit in the future. This
volume in space has a funky structure, expanding as the years progress.
He showed an animation of that too.
In the last year, at this meeting and at several earlier meetings, I
have noticed presentations about different aspects of Hoyle's panspermia
idea. I know that on this list I've been rather negative about the
theory because it has carried the 'kook factor' for more than 20 years.
That 'kook factor' seems to be fading some as more and more planetary
scientists are taking parts of the idea seriously, testing the ideas in
the lab if they can. I also noticed that a relatively new book:
_Astrobiolgy: The Quest for the Conditions of Life_, edited by Horneck
and Baumstark-Khan, Springer-Verlag, 2002 has several chapters
addressing the topic, describing relatively new results from lab
experiments.
At the ACM, the most relevant paper I saw addressing the panspermia idea
was from a colleague from Kent (UK), Mark, Burchell, who gave a poster
presentation of the rate of bacteria surviving hypervelocity dust
impacts in the laboratory. In Burchell's abstract, he said that recent
attempts to quantify the probability of life naturally migrating through
space is to break down the migration into discrete steps: ejection from
the planet, survival in space, etc. and to find an independent
probabilty for each step, then to multiply these terms in order to
arrive at an overall probability of panspermia occurring. His particular
lab experiment was to use a light gas gun firing projectiles doped with
bacteria impacting on target materials. He told me that at impacts of
>7 km/sec: nothing lives, at 5 km/sec some live, and at 1 k/-sec, all
bacteria live. He has some resent papers (published as well as just
submitted) about this topic.
Astronomy meeting: GUCS, Potsdam
http://www.gucs2002.agnld.uni-potsdam.de/
The Galileo Ulysses Cassini Stardust (GUCS) yearly dust meeting is a
small (~50-80 people typically) workshop, of interest mainly to those
that work with in-situ collected dust data, either from spacecraft or in
the laboratories. The spacecrafts that give the acronym for this meeting
carry dust impact detectors built by Eberhard Gruen and Jochen
Kissel. From this meeting it was clear that progress is still moving
steadily forward. More lab experiments are being run now to try to
understand better time-of-flight mass spectra for hypervelocity impacts.
It's a tricky problem because plasmas produced by dust impacts are very
velocity and mass dependent, and mass lines are often not clear enough
to give an unambiguous identification of compositional elements. Also,
dust particles are a heterogenous agglomerate of many different elements,
and we don't understand well the ionization process when those particles
are ionized. In addition, dust accelerators are not capable yet of
accelerating the particles to the speeds of particles detected in space.
What I was impressed the most this year at our GUCS meeting was the fine
level at which we are able to distinguish sources of dust. It used to be
10-20 years ago, that dust was dust, and we could not say very well from
where the dust came. Now, from experiments and modeling work, we can
identify dust from:
prograde and retrograde, bound and unbound orbits,
comet Shoemaker Levy 9,
dust clouds around planetary satellites,
volcanoes on Io,
hitting the side walls and main targets of our detectors (!),
the interior of supernovae,
AGN stars,
and more.
These sources, in time and in space, speak volumes about the history and
evolution of our solar system and of the local interstellar cloud around
us.
--------
Culture: Berlin and Potsdam
Some of you know that I become antsy if I get my head into too much
science; I have to balance it somehow with cultural activities. During
my spare time at these meetings, I satisfied my cultural thirst with
visits to museums, boat rides through Berlin and the lakes around the
Gruenwald/Potsdam area. Potsdam is also a bicycling paradise, although I
didn't bring my bicycle with me on this trip.
Museums
http://www.berlinfo.com/Freetime/Art-Culture/museums_collections/
These are some of the museums I visited:
Museum of Ancient Near Eastern Antiquities in the Pergamon
Museum (Berlin - Mitte)
http://www.smb.spk-berlin.de/vam/e/s.html
Fourteen rooms are devoted to this collection in the southern wing of
the Pergamon Museum. The collection contains many important examples of
architecture, reliefs and smaller objects. Some are of great world
significance and were once excavated by German archaeologists. They
originate from the Sumerian, Babylonian, Assyrian and northern
Syrian/eastern Anatolian regions which today include Iraq, Syria, and
Turkey. The Ishtar Gate gave me goosebumps!
The Egyptian Museum
http://www.smb.spk-berlin.de/amp/e/s.html
The Egyptian Museum owns one of the world's most important collections
on Ancient Egypt. The works of art from the time of King Akhenaton
(around 1340 BC) from Tell el Amarna are of international renown.
One famous work seen here is the bust of Queen Nefertiti.
Gemäldegalerie - Picture Gallery
http://www.smpk.de/gg/e/s.html
This gallery is not advertised as a 'big' museum, however the quality of
paintings is the same as that which one finds at the most famous
museums. There are sixteen works by Rembrandt, which form one of the
largest and highest quality collections of Rembrandt paintings. They are
flanked by additional gems of Dutch and Flemish painting of the 17th
century. My favorite at this museum was Jan Vermeer van Delft: "The
glass of wine", which showed light coming through a stain-glass window,
onto a man and a woman standing next to a table with a glass of wine.
The painting literally glowed.
Potsdam:
Castles, lakes, forests, unusual architecture (Potsdam Astrophysical
Observatory), bridges between former East and West Germany.
The Glienicke Bridge is known as the Bridge of Spies, because several
times, spies were exchanged here between the former Soviet Union and the
West.
http://www.glienicke-bridge.com/Bridge_of_Spies/bridge_of_spies.html
The first time this happened was on the 10th February 1962, when the
American pilot Francis Gary Powers and the KGB spy Rudolf Ivanevich Abel
were exchanged. A boat ride shows the underside of the bridge which is
slightly different colors on the 'west' side and the 'east' side.
There are still many 'signs' of former East Germany, traces of the wall
and the heavy fortification/security splitting the country. You can
still see the house in Potsdam where the Potsdam meeting was held
between Roosevelt, Churchill and Stalin, deciding the fate of former
Nazi Germany. East Berlin is undergoing massive construction; I would
say that 1/5 of Berlin is in the process of being rebuilt, the skyline
is full of cranes. Some new parts in Berlin, such as the Potsdammer
Platz is glass and glitz and colored lights and soul-less. I hear that
the young people prefer the eastern Berlin side these years because it
is 'real'. Another interesting fact about Berlin is that one often finds
*two* of the same large cultural features (especially with the museums
and galleries) because the two parts of Berlin were developing currently
side by side for 30 years. It's a graphic result of an experiment when
two parts of the same city diverge with two totally different systems
imprinted on them. It made me sad to see it. And I hope that not all of
the buildings are renovated: I think that it's important to keep some of
the buildings with the bullet holes and bomb shells on the walls: to not
forget.
Einsteinturm, "Einstein's Tower"
A solar observatory at the Astrophysical Institute Potsdam
http://aipsoe.aip.de/descr/teleskop-e.html
The Einsteinturm is the outer wrap of a telescope to observe the Sun.
Originally, the telescope was built to prove one of the predictions of
the theory of general relativity, namely that the lines in the spectrum
of the Sun should be shifted due to its large gravitation. Einstein
supported construction and operation of the telescope although he never
worked with it himself. The scientific layout of the telescope was done
by Erwin Finlay-Freundlich, who also observed with it after its
completion. From the outside, the telescope is really something to see,
it looks like a large, funky corrigated phallic symbol!
http://aipsoe.aip.de/Jubilaeum/
Buddy Bär (Bär-lin, get it?)
Berlin has an art and city-promoting effort underway involving ceramic(?)
bears a little larger than humans placed at various locations all over
the city. If a person pays about 1300 Euros for a bare bear, and gets
(or pays) an artist to paint a theme on the bear, that decorated bear
will be placed in the city (I don't the procedure for the location for
the bear) for all to see. Children like to climb on top. Tourists take
pictures. Contests are held to find as many bears as possible in a set
period of time (there are about 400 now). The bear paintings are very
imaginative, artists are enjoying the new venue for their work, the city
earns some money (well, Berlin is broke...), the city is promoted
positively, and the project supports a feeling of community among the
residents. I like this idea alot.
http://www.buddy-baer.com/en/show/index.html
http://www.buddy-baer.com/idee/index.html
You can choose from three bear 'types'
der Akrobat,
der Tänzer
der Tänzer
Here are a few that I like:
#016, #017, #018, #019 (cartoon bears by Laerin Kurtu)
#045, #046 (Seasons Bär)
#094 (Ursus Culinarius)
#120 (Mystos)
#109 (Bärenburger Tor)
#110 (Gedächtnis-Bär)
#147 (Urlaubbär)
#150 (Die Mumie)
#155 (Love-Bär)
#170 (New Bärlin)
#246 Tänzerin Aida
Bär-ly yours, late on a Thursday night,
Amara
-- ******************************************************************** Amara Graps, PhD email: amara@amara.com Computational Physics vita: ftp://ftp.amara.com/pub/resume.txt Multiplex Answers URL: http://www.amara.com/ ******************************************************************** "If you don't get a good night kiss, you get Kafka dreams." -Hobbes
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