starship-design: charts

[Steve VanDevender <stevev@efn.org>]

Mike writes:
 > Another thing that I was very, very curious about: are there
 > any charts that show the stars in our section of the galaxy
 > and how far our communications can be heard, maybe relative to
 > a highlighted area or something similar?  I would be very
 > interested to learn about such a chart.  Again, thank you.

Since such a chart would have to be in three dimensions, I don't
know of any easy pictorial representation.

I've done some work on my own with trying to reduce the Gliese
near star catalog, and now the much more accurate and extensive
HIPPARCOS catalog, into a 3-d star map.  However, anything I
could come up with any time soon would be an X application for
displaying the map (I'm actually generating it with the intent of
building a relativistic spacecraft simulation).  If you want the
raw data file, I already have that, but it's big.

As an upper bound on the problem, our communications could
conceivably be detected within a sphere centered on the Solar
system with a radius in light-years of the number of years that
we've been generating radio signals capable of leaving Earth's
atmosphere.  Taking more factors into account is more difficult,
as we don't really know that much about the distribution of
interstellar gas and dust in our local area, which would have the
most effect on further attenuation of radio signals.