The errors that caused the recent Clinton campaign material to appear
on this list were entirely my own. Together with John Mallery I am
managing a non-partisan campaign information service for all of the
campaigns. This is an official project of the MIT Artificial
Intelligence Laboratory, so there are naturally a great many bugs to
be expected. The Clinton campaign happened to post at a time when we
had several bugs that were, as you now know, conspicuous.
I hope that those of you who are sending rude personal remarks to the
Clinton address on the subject of his breach of etiquette will learn
to think. Your actions are absurd.
Meanwhile, we have seen several examples of feedback from the network
into speeches, the Clinton health care policy, and even some of the
points made in the debates. Efforts to clog the mailboxes of the
campaigns are as clever and productive as shouting over a quiet but
thoughtful public speaker. The Bush mailbox is still clogged, and at
this point I can only ask the culprits to get some kind of life,
however minimal. Your infantile, vitreolic complaints about the
blindness of these posts will only ensure that no rational policy
maker will ever bother to look any closer.
Eric Loeb
MIT Artificial Intelligence Laboratory
1992 Presidential Campaign Information Service
------------------------------
Date: 26 Oct 92 04:06:06 GMT
From: Steve Masticola <masticol@cadenza.rutgers.edu>
Subject: Dyson sphere
Newsgroups: sci.astro,sci.space
jmc@SAIL.Stanford.EDU (John McCarthy) writes:
>Isn't it time someone did some high school physics as to how much air
>would be required?
>Let r be the earth's distance from the sun.
>r = 93e6 miles = 1.5e11 meters
Wouldn't it be a lot more convenient to make the sphere of a radius
such that its surface gravity is 1G, rather than placing it way out at
1 AU radius? If solar gravity at 1 AU radius is 6.1e-4 G, then you'd
need a radius of .025 AU (3.75e6 kilometers or 2.3e6 miles) to get 1G
acceleration at the surface. Gravity would be more conveniently close
to Earth's for habitation of the outside surface, and materials costs
would be much lower (about 6.1e-4 times as much material needed to
make the Dyson sphere.)
There would, of course, be a much greater problem of unwanted heating
of the surface of the Dyson sphere at that distance. We can assume
that any civilization capable of building the sphere so that it
doesn't collapse, controlling the position of the star inside,
elemental transmutation on a massive scale, etc. could direct the
waste heat where it wanted it. Here's one way they might do it.
To avoid atmospheric heating, the waste heat from the star could be
transmitted into space through cold targets in "chimneys" through the
atmosphere. Perhaps the entire inner surface of the sphere could be
made reflective, and power generation would occur in space outside the
Dyson sphere and its atmosphere.
There is, of course, the problem of compressive loads on the sphere:
they'd be much higher at .025 AU. If my math is right, the compressive
loads are inversely proportional to the radius of the sphere, so you'd
have to cope with 40 times as much compressive stress. But, again,
there may be a way out...
Another crackpot idea (as if _any_ of these ideas were anything _but_
crackpot :-): how about if the sphere was inflated? Balance the
gravity of the star by gas pressure inside the sphere. The sphere
could be much weaker then. But I can't see a way of keeping the gas
from collapsing into the star, unless you were to build the thing
inside the photosphere, which would make the surface uninhabitable due
to stronger gravity. You also couldn't have the open chimneys with an
inflated Dyson sphere; you'd have to channel the energy out through
something solid, or cap the chimenys. But since you won't be living on
the surface, who cares about waste heat, and why build the chimneys
anyway? :-)
- Steve "where are those repelatrons and gravpolarizers when I need them?"
masticol@cs.rutgers.edu.
------------------------------
Date: 24 Oct 92 18:33:37 GMT
From: train@ccwf.cc.utexas.edu
Subject: Recognizing a Dyson sphere if you saw one
Newsgroups: sci.astro,sci.space
In article <1992Oct19.055005.24078@infodev.cam.ac.uk> sl25@cus.cam.ac.uk (Steve Linton) writes:
>You`re looking for a body with a diameter of a few AU's radiating a black-body
>spectrum at a few hundred K, for a total power output roughly the same as that of
>a star. The spectrum might not be spot on, and deviations from black-body would
>like very unlike anything you might expect naturally - might have very sharp
>spikes, or sudden chops.
I may be wrong about this, I forget the aprroximate size of a dwarf star and don't have a book near me at the moment, but a sphere with a diameter of 2 AU's
wouldn't be anything near the size of a dwarf star would it? I thought dwarf
stars, at least white dwarfs, were about the size of the Earth.
Well, if I am mistaken, feel free to correct me. This stuff I will know for sure next semester when I take my astrophysics class.
