textfiles/drugs/gpic.txt

                    We'll Return, After This Message

                             by John Walker
                           December 1st, 1989

When the foundations of everything you think you know shift beneath you,
you can *feel* it.  The night Art Crane and I found the Message, it felt
like  that  moment  at  the  onset of an earthquake when you realize the
floor is really moving.  Even after twenty years, I  can't  recall  that
night   without  seeing  reality  shimmer  slightly,  like  the  distant
mountains on a hot day.

What  we  found  that  January  night  expunged  a century's accumulated
smugness about our place in the universe.  And the funny  thing  is,  we
weren't even looking in the right place.

In  December  of  1997  it  seemed as if humanity was well on its way to
figuring out the universe.  The discovery of the Proteus particle by  de
Vany,  Trang,  and  Zweig handed the astronomers an all-in-one answer to
the riddles of the missing mass and the  solar  neutrino  deficit.   The
human  genome  project  was  winding  down  having  yielded,  if  little
understanding, plenty of data.  The  Soviet  outer  planet  robots  were
flying  in  formation  toward  their  Jupiter  gravity  kick,  thence to
Voyager's ports of call and onward to Pluto and Charon.  The Shuttle was
expected  to  return  to  flight  any  month.   That  glorious  daylight
supernova of 1996 was just beginning to fade from the nighttime sky.

                                 ---

I figured Crane might call.  When I answered the phone on that rainy day
after  Christmas,  I  wasn't  surprised  to  hear  his  usual   request,
``Cliff--I'm  down  here  at  the office.  Could you come in and help me
with something?''

Art  Crane's a programmer, and a damned good one.  But mostly, he is the
Bach of the wild-ass conjecture.  You can't spend ten minutes  with  him
without  hearing  him suggest a new mechanism for speciation in biology,
opining that the roots of monetary inflation lie in the domestication of
animals,  or  wondering  how  we'd  know  if  just a *few* electrons had
different masses.  He writes every idea down in  a  little  notebook  he
always carries, then he types them all in to his machine every night.  I
haven't asked him how big the file is.  He reads  everything,  seems  to
know  all,  has opinions on any topic you can name but will gladly argue
either side.  He brooks no inaccurate facts or sloppy  reasoning.   He's
the  kind of person who'd be intimidating and unapproachable, if only he
ever *finished* anything.

He isn't a flake.  At least not all the time.  When he gets a Big  Idea,
he's  like  a  terrier.   He grabs it and shakes it till it falls apart.
Then he sniffs at the pieces.  For some reason, whenever he  has  a  Big
Idea,  I  always seem to get involved.  Not that I mind.  Except for the
stock market idea.  That one I minded.

Christmas day, Crane and I had been invited to Hack Watkins' for  turkey
dinner.   Later, as we watched Watkins' kids reduce their holiday bounty
to pieces siftable through chicken wire, Art was holding  forth  on  his
latest  idea--second-hand  SETI.   He  was  fascinated  by pre-discovery
observations.  Galileo spotted Neptune  and  even  charted  it  next  to
Jupiter  in one of his notebooks.  If the next night hadn't been cloudy,
he'd probably have discovered it more than 200 years before Adams and Le
Verrier.

The  year  before, more than a hundred amateur astronomers took pictures
showing the Orion supernova brightening before it burst  into  naked-eye
visibility, but not one noticed it till after the fact.  Crane said this
was inherent in modern science; building big new machines and using them
for  bold  searches  was  sexy  and easy to fund, but rarely did anybody
rummage through the  dusty  archives  until  something  interesting  had
turned  up  in  new  data.  He figured that if we ever received a signal
from another civilization, we'd probably find dozens of others buried in
the archives, easily located once we knew what to look for.

``The facts, dear Clifford, are not in our stars, but on our  shelves.''
he  said,  ``Why  don't  we  look  there?''  When  I  headed home around
midnight, he and Hack were kicking ideas back and forth about how  image
processing tools might be used to identify intelligent signals.

I showed up at the office around sunset.  Not a soul was there, and only
a few programmers.  Crane, who never rose  before  the  crack  of  noon,
rarely  undertook  serious work before six.  I was surprised to discover
him already in his office, surrounded by a midden of  books,  pieces  of
paper, and partially consumed processed food-like substances suggesting,
by its height, that he'd been there for several hours.  He  turned  from
the screen as I walked in, ``Cliff, glad to see 'ya.  Look, we gotta get
more crunch power on this job.''

This  was  the week for it.  The company always closed between Christmas
and New Year's.  It was a tradition they called  the  ``Annual  Week  Of
Rest,''  which  was a fine joke because there was another tradition that
the programmers  would  use  a  week  devoid  of  managers,  marketeers,
meetings,  and  memoranda to try to out-do one another in huge bursts of
concentrated effort to impress each other and just  incidentally  enrich
their employer when they staggered back, bleary eyed, to another year of
``regular work.'' Not that it  was  expected,  of  course--but  all  the
computers  were  left running that week anyway.  The Exalted Founder had
started it 15 years ago and still  kept  at  it,  at  least  in  theory.
Nobody   could   tell,   actually;   he'd  gone  through  some  kind  of
comprehensional singularity and nobody understood anything he'd done  in
the last five years.

Back in '97 Xanadu still wasn't finished, but if you knew where to  look
and   how  to  access  it  on  the  Net,  you  could  get  most  of  the
machine-readable raw science data since 1970.  The Net was installing  a
new software release over the holidays and had declared connect time and
data transfers free between Christmas and January 5th to encourage users
to  test  it.   Art  proposed  to  make the most of this.  He planned to
search all kinds of astronomical data, from the earliest  radiotelescope
sweeps  to  the  downlink  from  the gamma ray imaging telescope in that
converted shuttle tank with  an  algorithm  he  called  the  ``annoyance
filter.''

``Whatever  the message is, and however they encode it, it's going to be
obvious, at least in retrospect.  Besides,'' he said, ``we have all  the
inarticulate  bozos  we  need  on  Earth.   There's no need to scour the
galaxy for more.''

He figured the message  would  be  a  picture,  and  that  it  would  be
deliberately made easy to distinguish from a noisy background.  This was
right down Crane's alley.  A couple of years before he'd  been  obsessed
with  the  idea  of  developing  a  program  to  discriminate television
programs from commercials.  He wanted to start a company to  make  boxes
that  paused  VCRs  when  commercials  came  on.   He  considered  it an
artificial intelligence challenge, ``If any idiot can fast forward  past
a  commercial,  why can't we design a program to zap 'em?'' He spent the
better part of a year's spare time tweaking  and  tuning  his  algorithm
before abandoning it; toward the end it worked pretty well, but not good
enough to sell--it recorded moody commercials and edited  out  climactic
scenes of cop shows.  It *did* zap all the car dealer ads.

He  likened  the problem to protective coloration.  ``If television is a
medium that delivers entertainment at the  price  of  advertising,  then
advertising and entertainment will co-evolve to become indistinguishable
in time.'' But in SETI, he believed, the incentives were different.

``Signal to noise!  Look, are you going to go  before  the  Congress  of
Galactic  Elders Subcommittee on Unessential Projects and try to justify
spewing terawatts of soft-sell to the stars?  Whatever they're  sending,
it's going to be obtrusive, blatant, shrill, noisy, coarse, and puffing.
It will be calibrated to attract, to rouse, and  to  entice.   Count  on
it...it's *advertising*.''

He  started by taking the commercial zapper and optimizing it for single
still frames by training it on magazine advertisements.  Then he wrote a
front  end  that  scanned bit streams and applied a Fourier transform to
recognize scan-line encoded images.  These he planned  to  link  into  a
tool  that  could process several hundred megabytes of raw data per hour
per  machine,  generating  very  few  false  positives  for  intelligent
messages.  When I showed up, he said it was ``coming along.''

There are several distinct phases in an Art Crane project.  The first is
``inspiration;'' he'll be consumed, usually without warning,  by  a  Big
Idea.   He'll  corner  everybody  in  sight,  talking  a hundred words a
minute, filling white boards with diagrams, shoving a  sheaf  of  yellow
paper  in  people's  faces,  and  otherwise  explaining why what he just
thought of is not only the most important project on the planet at  that
particular  moment,  but painfully obvious to any vertebrate.  Art has a
talent for seeing how tools can fit together to do things  they  weren't
designed  for.   His ability to estimate the difficulty of all the tasks
involved in his plans is more modest; Hack Watkins once said ``The  only
constraint  on  Crane's armwaving about holes in his designs is that his
fingertips can't exceed the speed of light.''

``Coming along'' means he's making steady  progress,  but  doesn't  have
much to show for it.  Eventually, he'll get an initial, crude version to
work,  achieving  a  characteristically  grandiose  milestone  he  calls
``initial   operating   capability.''  Thereupon  he  invariably  ``goes
ballistic'' as he begins to realize all the things he  can  add  to  the
initial  version.   ``Ballistic''  is  evocative  not  only  of  Crane's
disregard  of  external  guidance,  but   also   of   the   frenzy   and
round-the-clock  concentration that characterizes his efforts, rendering
him in this mode more a force of nature than a colleague.  This ends  at
a  point of exhaustion when he's run out of things to add to the product
or can't sustain the kind of effort he's been putting in,  whereupon  he
enters  the  ``gory  details'' period as he attempts to clean up all the
loose ends and render the result usable to people  other  than  himself.
Finally,  he deliberately ``throttles back,'' catches up on his reading,
and comes within a standard deviation or so of a normal human  being  as
he awaits the next Big Idea.

The  progression  of  phases  is as predictable as the Moon's, but their
timing  has  none  of  the  regularity  of  the  cosmos,  much  to   the
exasperation  of  all  who work with him.  Still, when he is good, he is
very good indeed.  Three times in the last decade he had  singlehandedly
come  up  with  the  concept  and initial prototype of products that now
collectively accounted for half the company's sales--each  one  stemming
from  a  Big Idea unrelated to his regular work.  This track record made
management more than willing to endure his eccentricities and propensity
to indulge in what Watkins called ``art for Art's sake.''

He  picked  up  the  pizza box to the left of his keyboard and carefully
stacked it atop a pile of books to clear a workspace.  Grabbing a yellow
pad and pen, he explained what he needed from me.  ``We can do this, but
we've only got nine days till the Net starts charging  again.   Remember
that  cycle  sucker animal you built for the inlet problem?  That's what
we need to drive the filter.''

For once, what he wanted wasn't that hard.  Last year when  we'd  worked
on  a  hypersonic  fluid  flow  problem for the Japanese spaceplane, I'd
partitioned  the  job  to  throw  all  the  idle  time  on  all  of  our
workstations at it.  This was easier.  All I had to do was take the data
stream from the Net and apportion it out to all the compute resources  I
could  lay my mitts on with an eenie-meeine-miney-moe distributor.  With
500 workstations rated at a gigaflop or better sitting  idle  until  the
new year, we'd be able to cull a lot of data in a few days.

I  went  down  the  hall to my office, turned on the monitor, and set to
work.  The linear flow of real  time  changed  into  programming  hours,
measured  more  by  the  accumulation  of  pop  cans,  pizza and chinese
take-out boxes, and crumpled sheets of yellow paper than numbers on  the
wall clock.

Art  continued  to  tune the annoyance filter while I developed tools to
obtain raw data from the Net, translate them into a uniform  format  his
program  could read, and partition the compute job among the machines in
the building.  Hours passed, then days.  I went home and  slept  when  I
was too tired to go on, and I presume he did too.

We'd  both  finished by Monday the 29th.  When I arrived, Art had queued
me mail saying ``Ready when you are.''  I walked down the  hall thinking
how  odd  it  was  that  I'd  been  collaborating on a project with him,
working in the same building, but hadn't seen him for four days.  When I
reached  his  office,  I  realized  this  was  a good thing; the remains
bespoke  a  major  ballistic  episode.   Crane's  office   resembled   a
centerfold from *Toxic Waste Monthly*.  I suppose an archaeologist could
date the slices of pizza by the quantity of mold.  I focused on the task
at hand.

It  took  a  couple  of  hours  to  integrate  Crane's  filter  with  my
dispatcher.  When we were done, we ran some tests to measure  the  total
compute  power we were getting, then some known data checks to make sure
we hadn't messed anything up.  Around midnight we were ready to start on
live data.  For the last several days I'd been keeping our Net link busy
transferring files we wanted to search to  our  local  server  since  we
could process on-site data much faster than remote files across the Net.
Also, I wanted to copy as much data as I  could  while  Net  access  was
free.   I  didn't  have  the  time  to  be  very  discriminating  in  my
acquisitions; if a Net site  had  some  files  of  interest  and  didn't
publish a huge amount of data, I just figured, ``Grab it all.  Let Crane
sort it out.''

I entered the command to start the root task.   It  cloned  itself  onto
every active workstation in the building, then each copy started pulling
files to be searched from the master task queue and  commenced  scanning
them   with   Crane's  annoyance  filter.   The  search  was  singularly
unexciting.  My task monitor showed the volume of data we'd  scanned  so
far,  the  percent  done,  and  the  instantaneous compute power we were
using.  There's a feeling of power that comes from knowing you're  doing
more   calculations   every   minute   than  all  of  mankind  did  from
Pithecanthropus Erectus to 1950, but the novelty of even so remarkable a
fact quickly pales into something akin to watching paint dry.

Every time Crane's annoyance filter triggered, my control program popped
up a window with the image  on  both  our  workstations  and  filed  the
picture  for  later  examination  in a directory called WOW.  The filter
seemed  to  be  working  quite  well.   We  got  an  image  about  every
hour--mostly  scanned  illustrations  from  journal articles erroneously
filed in raw data directories.  Art  figured  we  could  ditch  them  by
looking for captions, but they were appearing so infrequently he decided
not to delay the search  to  modify  the  program.   Around  three  A.M.
Tuesday  we  were  both  taken  aback  when  we  found our first genuine
interstellar  message:  a  spacecraft,  two  beings,  and   some   coded
gibberish.   Art  looked  at the source information in the title bar and
confirmed that we'd discovered the Pioneer  plaque  in  a  NASA  Goddard
planetary image archive.  ``Right message, wrong way,'' he muttered.  We
decided to call it a night.  With the search on autopilot, we could dial
in  from  our  home  machines  and  scan the images in the WOW directory
whenever we wanted.  I, for one, had no desire to spend any more time in
Crane's  office until the janitors came in next week and cleaned it with
a fire hose.

Tuesday, I slept late, gave the plants  their  biennial  sip  of  water,
unloaded  the  dishwasher, and didn't get around to dialing in to see if
anything had been found until close to  midnight.   I  looked  over  the
20-odd pictures in WOW and found the usual selection of false alarms.  I
checked the login history and saw that Art was dialing in  every  couple
of  hours to scan the pictures.  The company was closed until Monday the
5th, so we'd have the better part of a week to continue the  search.   I
figured  we  could  get through about a quarter of the obvious candidate
data on the Net in that time.  The audacity of two programmers  employed
by  a medium-sized software company searching three decades' accumulated
scientific knowledge for interstellar messages didn't occur  to  me.   I
doubt Crane was capable of entertaining such a thought.

With  the  search  for  intelligent  life  in the universe toiling away,
needing only sporadic attention, I turned my attention to serious  work.
The  company  had  bought one of the just-developed superconductive long
range NMR scanners, and I was working on a prototype  for  a  product  I
called  ``Fantastic  Voyager''  that let you fly around in a 3D image of
your  own  body  using  the  cyberspace  gear  we  made.   The  job  was
challenging both from the standpoint of identifying the different tissue
types from the NMR samples, and in developing navigation models  to  let
you trace the paths of blood vessels and nerves through the body.  Since
my home machine had all the power and storage I needed, I worked  there,
as  usual  disappearing into the project and surfacing only sporadically
to eat, sleep, or dial in to scan the WOW directory.

Wednesday night I stopped by Bart Lazslo's New Year's Eve  party  for  a
couple  of hours and was amused to hear Crane grandiloquently describing
our little holiday  hack  as  the  ``Crane/Slatkin  Quest  For  Galactic
Intelligence.'' He related our discovery of the Pioneer plaque much more
dramatically than I could have, or, for  that  matter,  than  the  facts
justified.   He'd  brought  a portable computer and hooked it up to show
pictures from the WOW directory on  Bart's  projection  TV.   He'd  even
programmed  a  scrolling subtitle, ``LIVE from the accumulated wisdom of
mankind.''  Much to the amusement of those irritated by  Crane's antics,
that  night  the  fount  of wisdom yielded up a scatter plot of globular
cluster velocities, what appeared to be  a  calibration  signal  for  an
interferometry  run,  and,  at the stroke of midnight, an order form for
the ``Proceedings of  the  1993  IAU  Vienna  Workshop  On  Relativistic
Jets''.  Sue Hardiman went to the piano and composed a song on the spot.
All I remember is,

        Crane pursued the aliens,
        Through the archives on the Net.
        But the aliens came and kidnapped Crane,
        In their Relativistic Jets.

When I left, they were still adding verses of  monotonically  decreasing
quality.  Crane was singing along lustily.

I  spent  the  rest  of  the  week in a happy blur, working on Fantastic
Voyager.  Every now and then Crane or I would notice  something  amusing
in  the  WOW  directory  and  send mail pointing it out, but otherwise I
didn't pay much attention to the search.   By  Sunday  night,  Fantastic
Voyager  was  working  pretty  well.  After tiring of flying lazy orbits
around my pancreas, I finished up the documentation describing Fantastic
Voyager.   Another  part  of the Week of Rest tradition was that the day
the company reopened, papers describing the programmers' projects  would
appear  in  everybody's  mailbox and the software would be on display in
the Demo Lab.  After I queued the paper to the mail system, I drove down
to  the  office  around midnight to install Fantastic Voyager on the lab
machine and make sure it worked there.  Also, I wanted to  double  check
that  the  Quest was set to shut down before 5 A.M. when the Net started
charging again.  At normal prime time rates, our data transfers for  the
Quest  would've  gone  through my monthly salary every day, and I wasn't
about to get docked a couple of weeks' pay due to a typo.

Crane was in his office, writing up his Week of Rest project, a redesign
of an obscure internal algorithm that would speed up one of our products
about  30%.   He'd  actually cleaned the place up, to the extent of even
returning most of the books to the bookshelves that covered  the  walls.
We chatted for a couple minutes, then I went down to the Demo Lab and he
returned to his documentation.  As usual, my demo didn't work the  first
time--I  had  to  dial  into  my  home  machine  and copy some files and
rebuild.  Anyway, it was almost three before I was  satisfied  it  would
work that afternoon.

I went back to my office and locked up, then stopped by Crane's  on  the
way  out.   He'd finished and queued his document, and was idly flipping
through the 150 or so  pictures  in  WOW.   He  said  we'd  accomplished
something  worthwhile  and  suggested  we should write a paper about the
Quest.  Every  message  we'd  found,  after  all,  was  the  product  of
intelligence.   If  we'd  broadcast  the  Net  feed  to  the  stars, any
civilization with  our  program  would  have  found  ample  evidence  of
intelligence.  He thought we might be able to persuade the investigators
on the various radiotelescope projects to routinely run our filter  over
their data, forwarding all the images it found to us for examination.

We talked about how we should phrase such a paper and what journal might
publish  it,  and so on, in the kind of lazy-days bull session exhausted
programmers are prone to as they sit on a virtual veranda on  the  banks
of  the  Mighty  Megaflop  and  watch  time and data flow by.  ``Peep.''
Another image popped up on the screen: a NASA logo.  Crane hit  the  key
to  file  it away.  It was already four, so we decided to sit around and
make sure the  Quest  terminated  on  schedule  at  4:50.   Nobody'd  be
expecting  any  programmers  to  show  up much before two P.M., so there
wasn't  any  reason  not  to  see  it  through.   Our  conversation  was
describing  a  chaotic  orbit  around the usual attractors of evolution,
anarchy,  programming  languages,  quantum   electronics,   and   office
politics, when we got another ``Peep.'' It was 4:32:19.217 PST.

I  can vouch for the time; it's in the execution log.  My memory of what
happened after the image popped up on Crane's screen  is  less  precise.
We  glanced at the screen, then we stared at it.  The image filled about
a quarter of the screen; it was 2039 by 2053 pixels.   Four  bold  black
diagonal  stripes  set off each corner and continued as thin alternating
black  and white pinstripes along the edges of the image.  Had the upper
left  stripe  proclaimed   ``New!,''   the   layout   would've   blended
indistinguishably into *Time* or *Scientific Enquirer*.  What was within
the border was another matter entirely.

The figures on the right were humanoid, but not human.  They were simply
the best aliens  I'd  ever  seen:  there  wasn't  a  single  missing  or
disproportionate characteristic about them, but they were *all wrong* to
be humans.  There were two  adults,  male  and  female--the  female  was
holding  a  little  one.   On the left was what was clearly a conversion
table between binary numbers represented by ``-'' and  ``|''  and  eight
digit  symbols.   The middle of the picture was divided into four boxes,
three with a large central dot, curved lines, and nomenclature using the
eight  digits.   The  fourth  contained  what  could  only  be an orrery
presentation of a planetary system.  At the bottom were four rows of  64
of the digits given at the left of the picture.

Crane  wasn't  a  practical  joker and neither was I, but after Lazslo's
party all the usual suspects knew what we were up to, and half  a  dozen
of  them would enjoy nothing more than sending us on a merry chase.  Art
rolled his chair over to the screen to check the source.  I looked  over
his shoulder.  We looked at each other.  Suddenly I knew how Penzias and
Wilson must have felt when they concluded that they'd either  discovered
pigeonshit  in  their antenna or the birth cry of the Universe.  What we
were looking at was either the most brilliantly executed  gotcha  I  had
ever  encountered,  or,  well...precisely  what  it appeared to be.  Art
copied the source identifier, ``HGIDB11-23@NIH.GOV'' into his  notebook,
tore  out  the  page, and said ``I think you'd better verify this across
the Net, and don't use any software we've developed this  week;  it  may
have been tricked.''

Just  to  be  extra careful, I dialed into one of the commercial compute
services the company subscribed to and used standard retrieval and image
processing  tools in that system's library to extract the image from the
location Crane's filter had spotted it, accessing the  read-only  master
published  copy of the database across the Net.  It took me two hours to
be sure.  When I  returned  to  Crane's  office,  the  eastern  sky  was
brightening  with  dawn.   It was going to be one of those windy January
days when the air is so clear even  the  distant  mountains  seem  close
enough  to  touch.   Yet on this morning, only the weather seemed clear.
Crane had also been checking out the Message.

If I'd been more selective in choosing data to  scan,  we'd  never  have
found  it.   There  could  be no doubt; the Message was real, and it was
right smack in the middle of where it most definitely didn't belong.  We
had found it in the NIH Human Genome database.

                                  ---

Every  human  who'd turned his eyes skyward wondering, ``Are we alone?''
had been carrying the answer, all along, in  every  cell  of  his  body.
Since  then  the  same  Message has been found in every mammalian genome
that's been dumped, yet nowhere else in the animal kingdom.  That checks
with  the  age  of the Message.  Three of the boxes in the middle of the
Message are orthogonal views of the Local Group  galaxies,  centered  on
the  nucleus  of  the  Milky Way.  Running their motion forward from the
positions in the chart to the present day dates the Message at about 250
million  years  before  the present: just about the age of mammals.  The
orrery indicates they came from the fifth planet  of  a  star  with  six
terrestrial  planets  and  three  gas giants.  Which star?  Nobody has a
clue, and what with differential motion over an entire  circuit  of  the
Galaxy, any position in the Message would be worthless anyway.

Whoever wove that Message into our DNA meant it to last until we figured
out how to read it--it's built inextricably into the protein  expression
mechanism  so  any organism with a corrupted copy won't be viable.  It's
obvious in retrospect.  If a visitor wants to leave a message,  why  not
make  it  a self-reproducing, error-correcting message that any sentient
race would stumble upon as soon as they undertook  to  reverse  engineer
their own design?

Crane immediately suggested what's become the consensus hypothesis about
the number at the bottom of the Message.  He thinks it's the product  of
very  large  prime numbers and that when we manage to factor it, they'll
be the key to decode the second Message.  Two problems: first, we either
need  to  learn  a  whole  lot  more  about factoring, build computers a
million times faster than the latest quantum electronic models, or  else
wait  the  tens of millions of years it looks like factoring that number
will take.

Second, we have yet to find the other Message.  Nothing  more  has  been
found  in the genome, although Crane and many others suspect the factors
of the key number may direct us to additional  information  there.   The
intensive  radio  SETI program sparked by the Message has proved barren.
So have the planetary explorations of the past 15 years, spawned by  the
possibility  that  those  who placed the Message may have left a calling
card somewhere in the Solar System.  More recently, the  limitations  of
robots  in  seeking  the unexpected has triggered the rapid expansion of
the human presence into space.  If we've found  nothing,  we've  learned
much, and perhaps we've taken our first steps in the footprints of those
who left the Message in our genes.

Crane believes that when we find the second Message and are able to read
it,  we'll have proved ourselves ready for the instructions it contains.
He thinks it will tell us how to find those who left it, and how  to  go
there.   We'll  return, after this Message, and I think they'll be proud
of us.  They were already proud  when  they  put  the  Message  there  a
Galactic year ago.  Proud enough to have signed their work.

                                THE END

                                  ---

                        References and in-jokes


CALENDAR FOR THE PERIOD OF THE STORY

         December 1997               January 1998
       S  M Tu  W Th  F  S        S  M Tu  W Th  F  S
          1  2  3  4  5  6                    1  2  3
       7  8  9 10 11 12 13        4  5  6  7  8  9 10
      14 15 16 17 18 19 20       11 12 13 14 15 16 17
      21 22 23 24 25 26 27       18 19 20 21 22 23 24
      28 29 30 31                25 26 27 28 29 30 31

...GALILEO SPOTTED NEPTUNE...
        Kowal  and  Drake  confimed the Galileo observation in the early
        1980s.

...NOT IN OUR STARS, BUT ON OUR SHELVES...
        Shakespeare, Julius Caesar, Act I, Scene II, 140/1681 

...OBTRUSIVE, BLATANT, ...ENTICE."
        Ludwig von Mises, Human Action, Chapter XV, Section 13.

...DIRECTORY CALLED WOW.
        WOW is an in-joke among SETI people.  A one-time observation  of
        a  signal  near  the galactic center passed virtually every test
        for an interstellar beacon and is referred to as the WOW source.
        It has never been observed since.

...TENS OF MILLIONS OF YEARS...
        According  to  Dorothy  Denning, Cryptography and Data Security,
        Addison-Wesley, 1983, the fastest factoring  algorithm  runs  in
        Exp[Sqrt[Log[n]  Log[Log[n]]]] time, where n is the number to be
        factored.  If we  assume  a  computer  that  can  execute  10^10
        primitive  factoring  operations  per second, then the number of
        years to factor a number n is given by:
 
            opssec = 10^10
            secyear = 365.2524 24 60 60
            facyears[n_] := (N[factime[n]] Years) / (opssec secyear)
 
        Hence, for our 4 lines of 64 octal  digits  each,  we  have  the
        factoring time in years as: facyears[8^(4 64)], or 4.03711e7.