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Conference noted::sf

Title:Arcana Caelestia
Notice:Directory listings are in topic 2
Moderator:NETRIX::thomas
Created:Thu Dec 08 1983
Last Modified:Fri Jun 06 1997
Last Successful Update:Fri Jun 06 1997
Number of topics:1300
Total number of notes:18728

1146.0. "Dark Matter in SF" by CUPMK::WAJENBERG () Wed Jun 02 1993 14:20

Is anyone writing and SF based on the current crop of "dark matter" theories?
These are a family of astrophysical theories positing the existence of large 
quantities of unseen material in the universe.  In some of these theories, the 
"dark matter" is qualitatively different from ordinary matter, virtually 
intangible, like neutrinos.  (In one version, dark matter IS neutrinos.)  In 
all of them, the bulk of the universe is made of dark matter.

I can think of several SFish uses for the stuff.

Suppose one can get usable energy by "burning" dark matter.  It amounts to
burning vacuum and raises the possibilities of "dark reactors" and "dark 
bombs."

Suppose (which is a bit more likely for thermodynamic reasons) that one can
convert dark matter into ordinary matter by some expenditure of energy that
might be large on the human scale but still small compared to manufacturing
the object out of raw energy to start with.  You get various kinds of
abundance technology, and conservation laws become, perhaps, a mere nuissance.
It would certainly help an SF technology like that of Star Trek, where mass
conservation is broken almost every time someone fires a phaser or a 
transporter malfunctions.

Suppose that, in addition to the ever-popular "energy being," SF can now
introduce the phantasmal "dark matter being."  There is no prima facie reason
why such creatures should be antisocial, but the very name has Lovecraftian
overtones, heightened by the fact that the "dark universe" simply *outweighs*
the "normal" universe ("Normal?!" he shrieked. "You think your little rut
of daylight and sanity is the cosmic *norm*? Ah-hahahahaha!!") by ten to one.

It only remains for the author to exploit the also fashionable idea that there
may be seven or so extra dimensions to the continuum.  If this is linked in
some manner to dark matter, "dark beings" become "unimaginable" and "inde-
scribable" in the Lovecraftian manner, simply by being multidimensional.
(I should point out that current theory also implies that these extra 
dimensions are wrapped up smaller than a proton, but, hey, if we listened to
current theory too much, we'd never have hyperdrive.)

Or, of course, the "dark universe" could be much like our own only more
dramatically satisfying, with, say, ten times the furniture, including ten
times the number of habitable planets.  Then you have a widget that converts
between "dark" and "light" matter, and start your hero on his adventures.

Earl Wajenberg
T.RTitleUserPersonal
Name
DateLines
1146.1VMSMKT::KENAHEscapes,Lies,Truth,Passion,MiraclesWed Jun 02 1993 14:334
    Go for it, Earl -- sounds like you're well on your way to
    a story or twelve...
    
    					andrew
1146.2REGENT::POWERSThu Jun 03 1993 13:178
One of Charles Sheffield's "McAndrew" stories was in Analog a year or two ago
in which McAndrew and his woman pilot friend head out past the Oort cloud
to examine dark matter.  Sheffield's take was that the dark matter was a form
of cosmic string, and that it would (and did) interact strongly with normal
matter in proximity.
Not Lovecraftian in any way, but that's the genre (hard SF) for you.

- tom]
1146.3Glory LaneTPSYS::BUTCHARTTNSG/Software PerformanceFri Jun 04 1993 11:455
    There's also "Glory Lane" by Piers Anthony (I think), where the
    "missing mass" plays a central role - as one of the characters in the
    story.
    
    /butch
1146.4QUIVER::ANILFri Jun 04 1993 23:3615
    re .0

    Some interesting ideas there.. I haven't seen anything like
    that in recent books.  You might want to take .1's advice
    seriously!

    I thought that "A Brief History of Time" by Stephen Hawking
    had plenty of material with potential.  The current leading writers
    don't seem to have the interest or background to bring
    the science alive though, unlike the notables of yesteryear.

    An aside: has anyone in this conference gotten a story published
    in Analog or any other magazine?  How hard/easy is it?
    Any tips, words of wisdom,.. from the experience would be
    appreciated, by mail or here. --anil
1146.5KERNEL::JACKSONPeter Jackson - UK CSC TP/IMMon Jun 07 1993 15:304
    "The Man Who Would Be Kzin" from the Man-Kzin Wars series features a
    'ghost star' composed of dark matter.
    
    Peter
1146.6Fosil Hunter GodAIMT::PETERSBe nice or be dog foodMon Jun 07 1993 17:163
    In "Fosil Hunter" by Rbert J. Sawyer. God is an intelligent being that 
    can manipulate dark matter to effect the world.
                                     Jeff Peters 
1146.7James Hogan's "Entoverse"COUNT0::WELSHWhere have all the techies gone?Tue Jun 08 1993 11:4424
	James Hogan is a much underrated SF writer. Since he is an
	ex-DECcie, I like to keep an eye on his books. Hogan is not
	the world's greatest stylist or plot-writer, and reading his
	books is a lot like trudging up a mountain. But the view from
	the top can be great!

	This applies to his latest (as far as I know), "Entoverse".
	Although it builds on the world of several of his previous
	books, "Entoverse" can be read on its own.

	I hope the following won't be seen as a spoiler, since it is
	technical only and doesn't bear on the plot.

	Early on, Hogan explains how his aliens' faster-than-light drive
	works: in the process, he mentions a few plausible ideas which
	build on what is known about gravity and black holes. Continuous
	creation (and destruction) is part of it, with matter being
	created where there is least, and annihilated where there is
	most. Annihilation is responsible for gravity, and creation for
	the repulsion which causes the universe to expand. It's neat.

	This book gets my vote!

	/Tom
1146.8Better hurry, they're catching up!BAHTAT::EATON_NNigel EatonWed Jun 09 1993 16:1516
    
    I heard a report on BBC radio news yesterday that some scientists at 
    the University of California have calculated the mass of the Milky Way 
    (our galaxy). They've done this be using the orbit of another galaxy 
    which goes around ours (there's some clever buggers about!).
    
    It seems that the mass is much higher than can be accounted for by 
    stars, gas clouds and visible junk, providing the best evidence so far 
    for the existence of dark matter.
    
    Just thought you might be interested.....
    
    Cheers
    
    Nigel.
    
1146.9AURORA::TRUMPLERHelp prevent truth decay.Thu Jun 10 1993 12:594
    Not fiction, but the latest Smithsonian has an article on dark
    matter.
    
    Mark
1146.10News reportsVERGA::KLAESQuo vadimus?Thu Jun 10 1993 20:47170
Article: 3159
From: clarinews@clarinet.com (LIDIA WASOWICZ, UPI Science Writer)
Newsgroups: clari.tw.space,clari.tw.education,clari.news.gov.agency
Subject: Astronomers uncover signs of dark matter, galactic cannibalism
Date: Mon, 7 Jun 93 13:54:26 PDT
 
	 BERKELEY, Calif. (UPI) -- Unique outer space measurements point to
the existence of mysterious, hotly debated ``dark'' matter and galactic
cannibalism, researchers reported Monday at a major astronomy meeting.
	Based on the first calculation of the orbit of an object outside the
Milky Way, astronomers have concluded the galaxy contains about 10 times
more mass in a gigantic unseen halo at its outer reaches than in its
visible stars.
	``This measurement is much more reliable than all previous
determinations,'' Douglas Lin of the University of California, Santa
Cruz, said at the 182nd national meeting of the American Astronomical
Society.
	``It proves the existence of dark matter beyond a doubt. This is firm
evidence even for the skeptics.''
	A consensus has been long in coming, partly because of the mind-
boggling distances involved, partly because of the substance's ethereal
nature.
	``It may be some strange elementary particles or black holes floating
around or something else altogether,'' Lin said in an interview.
	Lin and his team spent 14 years meticulously examining the minutely
shifting positions of hundreds of stars to determine the orbit of the
Large Magellanic Cloud -- Earth's nearest galactic neighbor -- around the
Milky Way.
	``We measured for the first time the side motion of the orbit, a
missing piece of information critical to determining the mass of our own
galaxy,'' Lin said in an interview.
	``The size and speed of the LMC's orbit require that the Milky Way
have a mass equivalent to 600 billion suns, even though we can only see
enough objects to account for 100 billion suns or less.''
	While some controversial studies have projected about 20 times more
unseen than visible material between galaxies, Lin's measurement
provides the highest and most definitive estimate of dark matter within
a single galaxy.
	Even so, the figure falls short of the proportion of dark matter
astronomers think is necessary to halt the expansion of the universe,
Lin said.
	While the orbit of the LMC offers partial clues to the fate of the
universe, it also points to the galaxy's own ultimate demise, he said.
	``The cloud eventually will merge with our own galaxy as the Milky
Way's intense gravity bites off chunks of matter with each passing
orbit,'' Lin theorized.
	``We're witnessing the ongoing process of galactic cannibalism, so
called because the galaxy tries to swallow its own kind.''
	He based the claim on his find of 12 dwarf galaxies and globular
clusters -- younger than the rest of the stars in the Milky Way -- in the
plane of the LMC's orbit.
	``This suggests they were torn off by gravity during the LMC's last
flyby, 2.5 billion years ago,'' he said.
	To define the galaxy's orbit, Lin first had to determine how quickly
it moves across the sky, as opposed to its velocity toward Earth.
	``Trying to detect a year's movement of the LMC was like standing in
San Francisco and trying to measure the speed of a person on top of the
World Trade Center in New York City who takes one step sideways in one year.''
	The feat was achieved by scrutinizing pictures of the LMC, taken in
1974 and in 1989, to compare the position of 250 stars. The nearly
imperceptible shift indicated the distance the LMC had moved in the 15
years.
	The astronomers concluded the cloud hurtles across the sky at 147
miles per second relative to the center of the Milky Way, which it
approaches at 34 miles per second.
	Lin used the information to derive LMC's orbit, which takes 2.5
billion years to complete. The egg-shaped path takes it from about 200,
000 light years away from Earth -- where it is now -- out to 400,000 light
years.
	In contrast, the Milky Way's disk of stars is some 100,000 light-
years across. A light year is the distance covered by light traveling at
186,000 miles per second.
	``The LMC's velocity shows a large gravity, which can only be
provided if there's a large amount of mass,'' Lin said. ``Obviously,
there's more mass in the galaxy than meets the eye. The concept of dark
matter continues to be controversial, but we keep building evidence upon
evidence for its existence.''


Article: 3162
From: clarinews@clarinet.com (UPI)
Newsgroups: clari.tw.space,clari.local.texas,clari.local.sfbay
Subject: Galaxy found with little dark matter
Date: Mon, 7 Jun 93 15:50:50 PDT
 
	BERKELEY, Calif. (UPI) -- In a galaxy far, far away, astronomers said
Monday they have found little evidence of ``dark'' matter -- a discovery
that lends no force to theories that the mysterious material abounds in
the universe.
	To test the supposition that invisible material, called cosmic dark
matter, makes up most of the universe -- with visible stars and galaxies
comprising just a small percentage -- the astronomers studied the galaxy
M105.
	The galaxy 33 million light-years from Earth in the constellation of
Leo ``is the prototypical elliptical galaxy in all our textbooks and
probably the single most studied elliptical galaxy in the sky,'' said
Robin Ciradullo of Pennsylvania State University.
	As in all galaxies, the motion of the stars of M105 reflect the
amount of gravity present in their environment, George Jacoby of the
Kitt Peak National Observatory said at the 182nd national meeting of the
American Astronomical Society.
	``The faster the stars are moving, the more gravity must be present
to prevent them from leaving the galaxy,'' Ciardullo said.
	Since certain very bright objects called planetary nebulae emit their
light at only a few specific colors or wavelengths, the researchers
compared pictures of M105 taken through a filter that let through one of
these wavelengths with those taken through a different-color filter.
	They, thus, measured the nebulae velocities.
	``This first reliable stellar-based measurement of the total mass of
a normal, elliptical galaxy is significant because, until now,
astronomers could measure stellar velocities only near the center of
elliptical galaxies, having to guess about the distribution of matter in
the outer regions,'' Jacoby said.
	Astronomers who had found the cold gas present in the outer regions
of spiral galaxies moves too fast to be held by just the gravity of the
galaxy's stars assumed the extra gravity came from otherwise undetetable
dark matter, he said.
	M105, however, is different.
	``Near its center, where there is a lot of visible mass and the
gravitational field is strong, the planetary nebulae move fast. On the
outside, where the attraction due to visible matter is small, the
nebulae move slowly,'' Ciardullo said.
	``Its overall behavior is exactly what you would expect from a galaxy
made of ordinary stars -- no extra invisible matter is needed to explain
the observations.''
	It is too soon to say whether M105 is typical of elliptical galaxies,
Ciardullo said, ``but it is now apparent we can take nothing for granted
about the distribution of dark matter in the universe.''


Article: 3163
From: clarinews@clarinet.com (UPI)
Newsgroups: clari.tw.space,clari.local.texas,clari.tw.education
Subject: Dark matter seems to act as magnifying glass
Date: Mon, 7 Jun 93 15:50:50 PDT
 
	BERKELEY, Calif. (UPI) -- Massive clumps of invisible matter in
clustered galaxies seem to act as huge gravitational magnifying glasses
in space, brightening the most distant known objects, astronomers
reported Monday.
	The finding raises questions about the composition of galaxy clusters
2 billion light-years away and quasars -- the brightest and farthest
observable bodies in the universe -- 8 billion light-years from Earth,
the scientists said at the 182nd National Meeting of the American
Astronomical Society.
	A light-year is the distance covered in one year by light traveling
186,000 miles per second.
	In a long-studied effect known as gravitational lensing, gravity from
the unseen clumps -- called cosmic dark matter -- in and near the galaxy
clusters bends and amplifies the quasar light. Many of the quasars would
be too dim to see without nature's magnifying glass.
	Astrophysicists examining this effect while observing individual
galaxies had used theories of mass distribution in the universe to
predict gravitational lensing in clusters would be paltry, revealing
perhaps 1 percent more quasars than could be seen in an unamplified
section of sky.
	Instead, clumped galaxies were found to account for 70 percent more
quasars than could otherwise be seen, said Liliya Rodriques-Williams, an
astronomer at the University of Washington.
	``The result suggests there is more cosmic dark matter clumped on a
larger scale than anyone had suspected,'' she said. ``There's a lot more
to learn about clusters, the early universe and gravitational lensing.''
	The study's ramifications in astronomy are profound. Quasars and
other distant objects may not be as they appear. While lensing reveals
more of the universe, it also ``plays havoc with what we see,'' she said.
	``The quasars are so far away, they lie behind many clusters, so our
view of the early universe is wavy and distorted. It's like looking back
in time through bathroom-window panes or through a case of soda bottles
or from the bottom of a rippled swimming pool.''

1146.11REGENT::POWERSFri Jun 11 1993 17:367
A fact question, despite this string being in the fiction file....

Is dark matter presumed to be linked with galaxies, or are there
separate chunks of matter, dark matter-only galaxies in effect,
or is it possible that dark matter pervades intergalactic space as well?

- tom]
1146.12Through a screen darkly.CUPMK::WAJENBERGFri Jun 11 1993 19:3516
    Dark matter is definitely thought to be associated with galaxies
    (some galaxies, anyway) and to explain the distribution of orbital
    velocities of stars within them.
    
    More hypothetically, it may have gathered in clumps early in the
    history of the universe and gravitationally affected the formation of
    galaxies and their clusters and superclusters.
    
    More hypothetically still, dark matter may be hanging around in inter-
    galactic space, providing enough mass to flatten spacetime or curve in 
    back on itself.
    
    People have sometimes suggested there is more than one kind of dark
    matter.
    
    Earl Wajenberg
1146.13personally, I think it's a lot of cold rocks!!QUARRY::petertrigidly defined areas of doubt and uncertaintyFri Jun 11 1993 19:369
Well, dark matter is called that because we can't see it.  It may be
some strange form of  matter, or rather, one form of it may be some 
strange form of matter, but I don't think you'll find a dark matter
galaxy in the same way you might find an anti-matter galaxy.  The tend to 
associate it with galaxies, but as no one really knows enough about it,
there is no reason to suspect there might not be inter-galactic clouds of
dark matter.

PeterT
1146.14MACHO AliensCUPMK::WAJENBERGMon Jun 14 1993 15:0125
    Re .13:
    
    Scientifically, I tend to prefer the "cold rocks" version of dark
    matter, too.  (Called MACHOs: MAssive Compact Halo Objects, "halo"
    referring to the galactic halo where most of them would be.  The more
    exotic alternative, mentioned in .0, is WIMPs: Weakly Interacting
    Massive Particles.  They must have thought hard with both hands fo a
    fortnight to come up with that pair of names.)  Thought the "rocks" are
    usually said to be planet-sized.
    
    Even MACHOs have dramatic possibilities, though not as many, I think,
    as WIMPs.  There really *could* be dark galaxies of MACHOs, vast clouds
    of  sunless rogue planets like ultra-frigid versions of Jupiter and
    Neptune.  If there are, then they are perhaps the typical galaxy, and
    visible galaxies are simply dark ones with about 10% of the mass tied
    up in stars for some reason.
    
    Life on MACHO worlds might not be likely, but SF doesn't go around by
    "likely," and ultra-frigid lifeforms living on MACHO worlds or their
    problematical and icy moons would have *lots* of opportunity for
    colonization.  We could be living in a world where cryogenic lifeforms
    are the norm and molten-ice-based creatures like ourselves are exotic
    exceptions.
    
    Earl Wajenberg
1146.15New Book that includes dark matterROCK::BELLMon Jun 28 1993 15:383
   Margaret Weiss's new book Ghost Legion has dark matter.

Shane
1146.16Review of alternate book on DMVERGA::KLAESQuo vadimus?Thu Jul 29 1993 17:05153
Article: 39988
From: kauel@mentorg.com (Kendall Auel)
Newsgroups: sci.astro
Subject: Tom's Book
Date: 28 Jul 1993 20:54:50 GMT
Organization: Mentor Graphics Corporation
 
Tom was gracious enough to send me a review copy of his book, and I
agreed to review it for our local astronomy club newsletter.  Here is
the finished review: 
 
----------------
 
The Bookshelf
 
DARK MATTER, MISSING PLANETS AND NEW COMETS
(PARADOXES RESOLVED, ORIGINS ILLUMINATED)
Tom Van Flandern (North Atlantic Books, $18.95, 428 pages)
 
by Kendall Auel
 
While reading this book, I remembered that Johannes Kepler had a
reputation for having off-beat and unusual ideas.  Yet he is
remembered today for solving the age-old mystery of planetary motion. 
History will show whether Tom Van Flandern will rank with Kepler, but
he certainly has some unusual ways of looking at things. 
 
If you are uncomfortable with the current thinking in the field of
cosmology, such as the Big Bang theory, redshifts, or dark matter,
then this book may appeal to you.  While many people have questioned
these theories, rarely are they questioned by a professional
astronomer.  Tom Van Flandern is one of the rare people who actually
has the credentials to hold the mainstream thinking in astronomy up to
scrutiny. 
 
The following biography is printed on the back of his book:

  Tom Van Flandern earned his Ph.D. in celestial
  mechanics from Yale University in 1969.  He directed
  the Celestial Mechanics Branch of the Nautical Almanac
  Office of the U.S. Naval Observatory, has taught
  astronomy and has been a consultant to the Jet
  Propulsion Laboratory.  He is a frequent contributor to
  scholarly technical journals and astronomy magazines.
 
The new theories presented are not described with mathematical
precision, but are presented as general concepts.  Many of these
concepts are radically different from current mainstream thinking in
the fields of physics and cosmology.  For example, Dr. Van Flandern
proposes that gravity is due to a flux of ultra-fast particles he
calls C.G.'s (for classic gravitons).  C.G.'s are hypothesized to
travel at least 1000 times faster than light.  For short distances,
the force is inverse-squared.  But for cosmological distances, the
C.G.'s collide and cause a gradual reduction of gravitational force. 
This eliminates the need for dark matter to explain galactic
rotations.  Van Flandern proposes some observations which could
validate or falsify his notion of C.G.'s. 
 
This is one aspect of Dark Matter that is very compelling. Throughout
the book, Van Flandern makes predictions based on his theories that
are contrary to predictions made by current theories.  Thus, he gives
us a way to falsify his ideas.  He also makes the point that if his
predictions match observation, this does not prove his theory.  It
only provides additional weight to the evidence in favor of his ideas.
It is clear that Van Flandern is a seasoned researcher who clearly
understands the scientific method. 
 
Dark Matter could really be two books.  The first section describes
what Van Flandern calls the "Meta Theory", which includes C.G.'s along
with things called "matter ingredients" (M.I.'s) and the "light
carrying medium" (L.C.M.).  The second section is primarily devoted to
Van Flandern's theory that a large planet in our solar system exploded
about 3 million years ago.  This theory predicts that asteroids and
comets have a common origin, and predicts that they have numerous
small bodies orbiting them. Mainstream astronomers do not expect
asteroids or comets to have satellite bodies, generally speaking.  In
particular, Van Flandern's theory of comets is radically different
from the generally-accepted theory. 
 
I found this book to be well written, thought-provoking, and
interesting to read.  I was not particularly swayed toward Van
Flandern's theories, but the factual arguments he presents are at
least educational.  Van Flandern seems attracted to radical ideas, and
makes some rather large leaps in logic to support them.  For example,
he suggests that novae may actually be matter-antimatter annihilation
of a planet instead of an exploding star.  When making his most
outlandish proposals, Van Flandern is careful to label them as
speculation.  It is this speculation, however, that makes some of his
other less radical notions lose some of their credibility.  Perhaps
recognizing this, he makes the point in the final chapter that the
most valuable discoveries in science have always been the
extraordinary ones. 
 

Article: 40017
From: wats@scicom.AlphaCDC.COM (Bruce Watson)
Newsgroups: sci.astro
Subject: How to recognize the sincere pseudo-scientist
Date: 28 Jul 93 18:51:37 GMT
Organization: Alpha Science Computer Network, Denver, Co.
 
This is from Martin Gardener's Fads and Fallacies in the Name
of Science, 1952. I'll keep it brief.
 
"There are five ways in which the sincere pseudo-scientist's paranoid
tendencies are likely to be exhibited.
 
(1) He considers himself a genius.
 
(2) He regards his colleagues, without exception, as ignorant blockheads.
 
(3) He believes himself unjustly persecuted and discriminated against.
 
(4) He has strong compulsions to focus his atacks on the greatest
    scientists and the best-established theories.
 
(5) He often has a tendency to write in complex jargon, in many cases
    making use of terms and phrases he himself has coined."
-- 
Bruce Watson (wats@scicom.alphaCDC.COM) 

Article: 40018
From: tom@ssd.csd.harris.com (Tom Horsley)
Newsgroups: sci.astro
Subject: Re: How to recognize the sincere pseudo-scientist
Date: 29 Jul 1993 12:27:49 GMT
Organization: Harris Computer Systems Division
 
>(5) He often has a tendency to write in complex jargon, in many cases
>    making use of terms and phrases he himself has coined."
 
I don't read many (actually any) astronomy technical papers, but I can
definitely state that this last attribute is not confined to pseudo
scientists, at least in the field of computer science. It is
apparently a requirement to get a paper published :-). 
 
I sometimes get really tired of plodding through a paragraph full of
some new notation someone came up with, only to discover after several
hours of hard sledding (by running an algorithm equivalence matching
algorithm in my head) that they have been describing something I
already understood perfectly well, and that even has a name commonly
used in the literature. One little hint that they were simply
introducing a well known concept at the beginning of the equations,
and I could have skipped all that work. 
--
======================================================================
domain: tahorsley@csd.harris.com       USMail: Tom Horsley
  uucp: ...!uunet!hcx1!tahorsley               511 Kingbird Circle
                                               Delray Beach, FL  33444
+==== Censorship is the only form of Obscenity ======================+
|     (Wait, I forgot government tobacco subsidies...)               |
+====================================================================+

1146.17Possible MACHO foundVERGA::KLAESQuo vadimus?Wed Sep 22 1993 16:0640
From:	US1RMC::"ASTRO%GITVM1.BITNET@uga.cc.uga.edu" "Astronomy Discussion 
        List" 22-SEP-1993 01:31:26.57
To:	Multiple recipients of list ASTRO <ASTRO%GITVM1.BITNET@uga.cc.uga.edu>
CC:	
Subj:	MACHO news from Mt. Stromlo

----------------------------Original message----------------------------

----- Forwarded message begins here -----
Description: MACHO news from Stromlo
From: MJD          Date: 21-SEP-1993

"On Tuesday September 14 the MACHO project discovered an event in the
light curve of an LMC star that closely resembles the type of
gravitational microlensing event the project has been looking for. The
star involved is a clump giant (V~19.5) which brightened by about a
factor of 6 and then faded over a period of order 30 days. This light
curve was highly achromatic and time symmetric as would be expected
from a lensing event of a single star by a MACHO. The implied MACHO
mass is in the range 0.03 to 0.3 Msol and the fit to the theoretical
light curve is excellent. Despite the apparent "Gold Plated" nature of
this event, there remains the possibility that it is not a microlensing
event at all but simply some previously undiscovered kind of variable
star."

The data does look pretty convincing and the best-guess mass for the
lensing object is 0.06 Msol (i.e. brown dwarf) - but note that the
object may well be a luminous star, so they may not have found DARK
matter. But it does seem to show they can see the right sort of event,
and that such events do occur.

------ Forwarded message ends here ------

% ====== Internet headers and postmarks (see DECWRL::GATEWAY.DOC) ======
% Date:         Wed, 22 Sep 1993 01:28:22 EDT
% Sender: Astronomy Discussion List <ASTRO%GITVM1.BITNET@uga.cc.uga.edu>
% From: "<phacb@pippin.cc.flinders.edu.au>" <phacb@[129.96.250.30]>
% Subject:      MACHO news from Mt. Stromlo
% To: Multiple recipients of list ASTRO <ASTRO%GITVM1.BITNET@uga.cc.uga.edu>

1146.18RE 1146.17VERGA::KLAESQuo vadimus?Wed Sep 22 1993 21:1160
Article: 3443
From: clarinews@clarinet.com (BILL PERRY)
Newsgroups: clari.tw.space,clari.local.california
Subject: Scientists see evidence of 'dark matter'
Date: Tue, 21 Sep 93 11:23:28 PDT
 
	SYDNEY (UPI) -- An international astronomy team reported Tuesday that
it has observed the first evidence that dim stars called ``MACHOs'' are
part of the dark matter that makes up over 90 percent of the universe.

	The discovery opens up ``a whole new chapter in astronomy,'' said
Steve Maran, an astronomer at NASA's Goddard Space Flight Center in
Greenbelt, Md. ``A lot of us feel the biggest unsolved mystery is the
nature of the dark matter in the universe.''

	What the teams saw supports theories that MACHOs -- Massive Compact
Halo Objects -- comprise at least some of the dark matter in space.
MACHOs are thought to be dim stars, called brown dwarfs, or planet-sized
bodies like Jupiter, situated in the halo adjacent to the Milky Way
galaxy, said Professor Alex Rodgers of the Mount Stromlo Observatory
near Canberra.

	To make their observation, the Australian team and a U.S. team at the
Lawrence Livermore National Laboratory and the University of California,
Berkeley, monitored about 3.3 million stars for one year.

	The mere fact that the scientists were able to conduct such
observations and analyze the data was a feat in itself, Maran said.

	The evidence for the MACHOs came when the astronomers observed 
``microlensing'' -- when one star appeared to increase to seven times its
normal brightness and then return to normal over a two-month period.

	The star being observed was an ordinary star that had given no
indication of other stellar activity that could account for the increase
in brightness, Rodgers said.

	He said microlensing is believed to occur when a massive object
crosses the line of sight between a telescope on earth and a star in a
distant galaxy. The gravity of the object acts as an amplifying lens,
which makes the star appear brighter for a short time. The event is
temporary since the star, the object and the telescope are moving
relative to one another.

	``There is no question that this remarkable event occurred,'' said
team leader Charles Alcock, a physicist with the Livermore laboratory. 
``But we now have to keep working to find more of them.''

	Alcock said no conclusions could yet be drawn regarding how plentiful
MACHOs are or how much of the galaxy's dark matter consisted of MACHOs.

	The scientists from the Mount Stromlo observatory, near
Canberra; the Siding Spring Observatory, in California, and the
University of California announced their findings at the same time
that a similar, but separate observation was made by a team from the
French National Laboratory at Saclay, near Paris. 

	The findings were released from Mount Stromlo simultaneously with
similar announcements at two scientific conferences being held in Italy.

1146.19Earthly problem slows dark matter searchVERGA::KLAESQuo vadimus?Mon Dec 20 1993 02:0336
Article: 5008
From: clarinews@clarinet.com (UPI)
Newsgroups: clari.tw.space,clari.local.california,clari.tw.science
Subject: Fire stymies search for dark matter in space
Date: Fri, 17 Dec 93 13:38:28 PST
 
	LIVERMORE, Calif. (UPI) -- A fire at Australia's Mount Stromlo
Observatory has damaged key equipment used by California scientists in
their search for mysterious, hotly debated ``dark'' matter in space.

	Lawrence Livermore National Laboratory astronomers said Friday the
Nov. 28 blaze will cost the lab some $134,000 to repair the downed main
computer and the electronics that control the telescope they were using.

	The scientists say they must halt their search for massive compact
halo objects, or MACHOs, until mid or late January. Astronomers reported
what is believed to be the first sighting of a MACHO -- made with the
Mount Stromlo telescope -- Sept. 20.

	Astronomers have been contesting the existence of the invisible
matter. When studies earlier this year showed the Milky Way Galaxy
contains about 10 times more mass in a gigantic unseen halo at its outer
reaches than in its visible stars, some scientists said that was proof
enough of the existence of dark matter.

	A consensus has been long in coming, partly because of the mind-
boggling distances involved, partly because of the substance's ethereal
nature.

	Dark matter could be made up of some strange elementary
particles or black holes floating around or something else altogether.

	Smoke from the fire, which started in a relay in the telescope
control electronics cubicle, wafted into the computer, ruining its
integrated circuit boards. 

1146.20More MACHO evidence foundVERGA::KLAESQuo vadimus?Mon Jan 17 1994 16:3666
Article: 3680
From: clarinews@clarinet.com (UPI)
Newsgroups: clari.tw.space,clari.tw.education,clari.local.california
Subject: More evidence found of MACHOs in space
Date: Fri, 14 Jan 94 13:48:55 PST
 
	ARLINGTON, Va. (UPI) -- Space watchers scanning the Milky
Way's mysterious ``dark'' matter Friday reported finding more evidence
of invisible Massive Compact Halo Objects, believed to account for 90
percent of the galaxy's mass. 

	Many scientists theorize unseen, hotly debated material,
called cosmic dark matter, makes up most of the Universe -- with
visible stars and galaxies comprising just a small percentage. 

	In studying data for six million stars, following the
brightness of each for more than a year, the team of astronomers and
physicists observed what could be more so-called ``gravitational
lensing events,'' first reported last fall. 

	The finding adds to the growing evidence indicating the
presence of MACHOs, said Charles Alcock, team leader from Lawrence
Livermore National Laboratory in California, at the annual meeting of
the American Astronomical Society. 

	MACHOs are believed to resemble the planet Jupiter, inhabit
the ``halo'' on the galaxy's outer edges and account for more than 90
percent of the mass of the Milky Way, Alcock said. 

	The evidence is ``compelling'' that most of the mass in the
Universe is invisible to current astronomical observations and that
this dark matter in the Milky Way is spread out through a gigantic
invisible halo at the galaxy's outer reaches, he said. 

	Earlier studies indicated massive clumps of invisible matter
in clustered galaxies seem to act as huge gravitational magnifying
glasses in space, brightening far-off objects. 

	In a long-studied effect known as gravitational lensing,
gravity from the dark matter bends and amplifies light from space
objects. For example, many quasars -- at 8 billion light-years from
Earth, the most distant known objects -- would be too dim to see
without nature's magnifying glass. 

	``Identifying the dark matter is one of the most pressing
scientific questions for the 1990s,'' Alcock said. ``We must keep
working to find many more events.'' 

	A consensus on the existence of dark matter has been long in
coming, partly because of the mind-boggling distances involved, partly
because of the substance's ethereal nature. 

	Astronomers believe the dark matter may be some strange elementary
particles or blacks holes floating around or something else altogether.

	Determining the existence and amount of dark matter is
important to astronomers who have calculated a proportion of the
invisible material they think is necessary to halt the expansion of
the Universe. 

	The international MACHO search team includes scientists from
the lab,  supported by the Department of Energy; the Center for
Particle Astrophysics at the University of California, supported by
the National Science Foundation, and the Mount Stromlo and Siding
Springs Observatory near Canberra, Australia.