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C00002 00002	Dear Dr. Gilfillan:
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Dear Dr. Gilfillan:

	I liked your book %2Migration to the Stars%1, and I especially liked
the realistic attitude behind it, so rare in an age of wishful thinking.
Nevertheless, the main content of the letters concerns the areas in which
I don't agree with you.

	1. I am surprised that you don't see the difference between your
ideas and O'Neill's more sharply.  You regard migration to space as like
previous migrations in which man adapts himself to his new environment,
and you study the problem of how to migrate at minimum cost.  O'Neill is
an ecological Utopian.  He designs his ideal environment in space
regardless of cost, requires no adaptation on the part of the migrants,
and gets truly astronomical costs.

	2. Both you and O'Neill imagine migration as a project of the U.S.
Government or perhaps some world government and taking place under
non-competitive conditions.  While this is a possibility, the world
still has many rivalries, and moreover, one of the main values of migration
to space is that it will provide a frontier where any group can found a
society to their liking.  This provides even more reason to consider the
minimum ocst alternatives.

	3. I agree with your conclusion that it will take about a million
years to colonize our galaxy.

	4. In my opinion, the only presently visible chance that the planet
will become uninhabitable within the next 200 years is a nuclear war
between major powers.  Either fission or solar (at much higher but
still affordable cost) energy provides a source good for as long as the
sun will remain a main sequence star.  With this energy we can extract
all the minerals necessary (though perhaps not all presently used) for
our economy from average rock at a somewhat higher cost. (A factor of
ten in ccst seems unlikely but wouldn't break us).  Those countries
which do not control their population by change of custom or government
action will have it controlled for them by natural phenomena, but I don't
think the improvident will be able to bring down the world with them.
Certainly not if the provident don't succumb to extreme moralism.  If
the U.S. can refrain from bailing out New York City, then we will find
it much easier to resist requests to bail out Bangladesh next time.

	Although the case for migration into interplanetary space or to
other solar systems would be better if the human race on earth were
doomed, it isn't.  Therefore we must make do with lesser justifications
of which safety in case of disaster and providing a frontier are the
best.

	5. While the NASA Shuttle plan provides only very expensive
transportation to orbit, it may be cheap enough for some group to actually
start a colony.  In my opinion, a non-government group is more likely
to accept the risks involved in possibly irreversible migration, and
%2the cost of a small austere colony is within the financial resources
of some of the largest personal fortunes provided the Shuttle launches
can be purchased%1.  I would favor raising this possibility as soon as
the government has done as much as it will toward the Shuttle.

	6. You don't take into account the contention that interplanetary
space is more habitable than any planet whether in this solar system or
any other.  Therefore, your scenario of the colonists committing themselves
immediately to an inhospitable planet is unrealistic.  I think they would
first establish themselves in the asteroid belt of the new star
and settle the planet only when it was rather safe to do so.  If there
was known to be an asteroid belt, the technology required to use it
would be predictable in advance.  The most difficult part of this
technology would be the small scale use of low grade ores.  Therefore,
if the colonists arrive safely at the new star, their main risks will
be behind them.