A Fire Upon the Deep ending

Hal Finney (hal@rain.org)
Sun, 25 May 1997 14:26:54 -0700


I was pleased to see Max mention a few weeks ago that Vernor Vinge is
working on a book tentatively titled "A Deepness in the Sky". I assume
this is related to "A Fire Upon the Deep", which is one of my favorite
SF novels.

In re-reading AFUTD though I find that the parts I liked best were the
high tech space adventures, the descriptions of future technology,
and the usenet-style galactic newsgroup postings. I didn't really
care for the parts about the dog packs and their medieval plotting.
So it will be interesting to see what direction he goes with the new book.

One thing I didn't like about the ending to AFUTD is that it seemed so
destructive. Readers will recall that the Countermeasure, activated by
the "godshatter" within Pham Nuwen, has altered the boundaries of the
zones of thought, pushing the Slow Zone up into what used to be the
Transcend. This effectivelly killed the Blight since it could not
live within such conditions.

However, this also will wreak terrible destruction on the other
civilizations in that part of the galaxy, which have become dependent on
FTL communication and transportation, and possibly other technologies
that won't work in the Slow Zone. As Vinge has a character say,
"In some ways the Revenge was a worse thing than the Blight itself."
Truly this is burning down the village in order to save it.

When I read the book the first time I had the impression that the
extension of the Slow Zone occured throughout the galaxy. Sandor at
the Zoo, a tough and smart newsgroup poster, had speculated that the
previous incarnation of the Blight and its subsequent destruction marked
the beginning of recorded history. This would presumably have been a
galaxy wide event, otherwise the unaffected regions would no doubt have
passed down some legends about such a dramatic occurance.

Actually Vinge leaves the magnitude of the Zone changes somewhat ambiguous.
Ravna's instruments indicate that Tines World, at the former bottom of the
Beyond, is now 1,000 to 30,000 ly deep within the Slow Zone. The Beyond
was about 5,000 ly deep, so this would be consistent with the Slow Zone
extending far into the Transcend.

The last item in the book is a news posting from the "Society for
Rational Investigation" saying that they are getting no response from
sites to spinward. Apparently they are right on the edge of the extended
Slow Zone. They are also getting no response from sites in the Transcend
above the affected region, confirming that the Slow Zone does in fact
extend high enough to engulf the Powers up there.

So, the Slow Zone extends high, but how wide is the affected region? I did
a bit of detective work to get some information. The Society for Rational
Investigation is mentioned a couple of times earlier, and its location is
given. Unfortunately two different numbers are used in my edition. In
chapter 18 it is described as "Probably a single system in Middle Beyond,
5700 light-years antispinward of Sjandra Kei." In chapter 40 the same
description is used, except the distance is 7500 ly antispinward. So it
is around 5700-7500 ly antispinward of Sjandra Kei. Sjandra Kei is itself
about 1500 ly spinward of Tines World, putting SRI about 4000-6000 ly
antispinward of them.

If we assume that the Zone disturbance is roughly symmetrical around Tines
World, then this suggests that the affected region is about 10,000 ly wide,
extending maybe 10,000 ly out, to include all of the inhabited part of the
Transcend above Tines World, and hopefully including all the area which
had been grabbed by the Blight.

I tried to get some information about how wide the Blight's region was.
A few High Beyond civilizations are described as under its control.
One way to judge how far these are away is by looking at the language
translation paths. They all end up as Triskweline, apparently a widely
used language in that part of the galaxy.

Arbitration Arts is the first High Beyond civilization conquered.
Their messages are translated as Firetongue->Cloudmark->Triskweline.
However the first two are High Beyond trade languages apparently capable
of carrying high level protocol packets, something like an advanced
version of Java applets. The Blight uses these to subvert Arbitration
Arts, and after that nobody uses the High Beyond languages any more,
they stick to the Middle Beyond ones. So basically this civilization is
going directly to Triskweline, suggesting it is close by. Similarly,
Sandor Arbitration Intelligence at the Zoo is another powerful High
Beyond "military corporation" which gets taken over by the Blight.
Their messages are directly in Triskweline, with no translation, again
suggesting that they are located roughly "above" Tines World.

All this is consistent with the Blight's range still being relatively
limited (on the galactic scale) at the time that the Countermeasure
was activated, so that even though the Zone disturbance was relatively
localized, it is reasonable to assume that all of the Blight was in
fact engulfed. That's good. There is so much death and destruction in
the novel that it would be a real tragedy if it had failed to accomplish
its purpose.

The remaining puzzle then is why the destruction of the Blight this time
is seemingly less harmful to the galaxy as a whole than the previous
incarnation. Throughout the novel there is no hint that anyone remembers
any earlier instance of the Blight. My guess is that in fact the previous
time the Blight was activated, its destruction required a far more
powerful defense. Perhaps it spread much faster before a Countermeasure
could be found and activated. After all, it was a near enough thing
this time. Yet by Sandor's speculations, the Countermeasure would have
been widely distributed throughout the galaxy to be ready if and when
the Blight is activated again. So even if this particular instance had
been destroyed, assuming the Low Beyond remains relatively free from the
Blight's control (perhaps something like Vichy France), someone might
eventually stumble on the Countermeasure and find out how to activate it,
or perhaps something the Blight would do would eventually trigger it.

We might assume that the activation of the Countermeasure in the novel
was finely tuned by the godshatter so that it would do no more damage
than was necessary. Since the Blight was being destroyed relatively
early in its spread, only a limited shift of the Zonal boundaries would
be enough to eradicate it.

What this theory suggests then is that at some point in the past, the
Slow Zone was extended into the Transcend on a nearly galaxy-wide basis
in order to destroy a Blight which had conquered the galaxy, controlled
the Upper Beyond absolutely, and through agents had a great deal of
control over the rest of the Beyond. The Countermeasure was activated,
the Zonal boundaries extended, and ever since then they have been receding
until they are at the size observed "today".

One problem with this is that the Zones are said to be shrinking at
710 m/s. This is about 2000 ly per billion years. So if the Slow Zone
was pushed out beyond the Transcend, it would need to shrink more like
10,000 ly to be back to where it is today, requiring 5 billion years.
But this is much longer than their history seems to go back. Possibly the
surge is more temporary, shrinking back at a much faster rate initially,
then slowing down as the Zones approach their "natural" states. In that
case the previous incarnation of the Blight might have happened only a
billion or two years ago.

Hope you enjoy this bit of speculation -