The Sword and Laser discussion

Hi,

I felt like donning a cloak of speculation and talking about the science in A Fire Upon the Deep. Since Vinge was a Professor of Mathematics I think it is safe to assume he has used speculative science as a basis for his fictional Milky Way. Possible mild spoilers of the science. No plot

The key speculation is the Zones of Thought that the galaxy is divided into:The Unthinking Depths, The Slow Zone, The Beyond and The Transcendence (see image at the bottom). I am ignoring his FTL drive as this is a pretty standard SF trope and his method is not particularly new or interesting.

This is a very dramatic speculation as it implies that the physical laws depend on your location. This is a big deal as it breaks conservation of momentum and many other basic consepts in Physics (most of modern physics assumes independence of location: Noether's theorem).

At the time of writing there was some speculation that the physical constants describing the Universe may be changing as the Universe ages to help explain the data that eventually led to the proposal of dark energy. There have also been speculations that different parts of the Universe could be made of anti-matter to explain why it is missing. These both appear to have little evidence supporting them.

My speculation is based around what could be causing these zones of thought. At the time of writing the book no one new anything about Dark Energy so the first obvious candidate is Dark matter. Unfortunately it doesn't fit the bill as it has the wrong properties (I am pretty sure Vinge would have known this). Dark matter has a reasonably uniform density inside a galaxy and extends a long way past the edge of a galaxy and its smooth distribution does not seem enough to give sharp zone boundaries.

The zone boundaries remind me of state changes (i.e. solid to liquid). The zones can move and change location. The description of the boundary of The Slow Zone suggests that what is causing the change in the properties of space-time acts like a fluid. This suggests a particle that interacts (compare with the dipole on a water molecule). This again rules out dark matter. This particles would also have to have an associated filed that inhibits faster than light travel and computer processing speed (limiting the power of any intelligence, think of the human brain as a computer).

Vinge is essentially suggesting a completely new set of particles with shadow interactions that sits beside us and is not dark matter. Of course it may all just be an invention to allow him to tell the story he wants to tell.

There are some hints throughout the book that the Zones are artificial and the Unthinking Depths are a prison for something even worse than the Blight. If that's the case, then perhaps it's best to think of the Zones as a field being projected out from the center of the galaxy that somehow warps the metric of space-time in a way that degrades computational power.

My understanding is that the Zones are an analogy for the stages of human development from the "Unthinking Depths", through our current "Slow Zone" and into the "Transend" representing the Post - singularity world. Vinge is a proponent of the Technological Singularity in which exponential change results in a world incomprehensible to us now :
http://mindstalk.net/vinge/vinge-sing...

The problem with that is, how do you write a story about an incomprehensible world? His answer was to turn it on it's side, so that the time axis became the space axis, providing both a way to introduce the concept and highlight features of the stages, such as mind uploads and AIs.

I really wish I could track down the interview in which (I believe) I read this many years ago. My apologies for not linking to it.

Sean wrote: "If that's the case, then perhaps it's best to think of the Zones as a field being projected out from the center of the galaxy that somehow warps the metric of space-time in a way that degrades computational power. "

My understanding is that it's not "computational power" that's degraded, but the speed of light itself. This affects space travel (there's no FTL travel lower than the Beyond) and also the speed of electric impulses possible in brains and computers.

Not sure how this affects beings that go from the Slow Zone to the Beyond, though, when their brains would suddenly start working faster, presumably...

Tobias wrote: "Not sure how this affects beings that go from the Slow Zone to the Beyond, though, when their brains would suddenly start working faster, presumably..."

The way it was described in those books I read, I sort of figured that it effected artificial minds really quickly and obviously, but much, much more slowly in organic beings. You'd really have to compare a newcomer to someone born there to make a difference. That was my interpretation.

Tobias wrote: "Sean wrote: "If that's the case, then perhaps it's best to think of the Zones as a field being projected out from the center of the galaxy that somehow warps the metric of space-time in a way that ..."

I'm not so sure. It's not like ships in the Beyond are physically traveling faster than 186,000 miles per second; they're using a jump technology similar to what we see in Battlestar Galactica. If I remember the description we get late in the book, the Zones affect how far a ship can jump in a single go. My take is that the issue lies in the navigational computations. In the High Beyond, a computer can calculate a hundred light year jump in a single second, but as a ship travels lower, the processing power decreases and the ship has to make ever smaller jumps.

The Slow Zone, then, is the boundary line at which it either becomes impossible for a computer to handle the jump calculations, or at the very least, the calculations become so slow that it's faster to travel the distance by conventional means.