From: Henry Spencer <henry@zoo.toronto.edu>
Newsgroups: sci.space.science
Subject: Re: Shadows the Theory
Date: Sat, 30 Dec 1995 18:42:51 GMT

In article <4bjvaf$1ia@newsbf02.news.aol.com> jocallagha@aol.com (JOcallagha) writes:
>...The shadow of the earth moving across the moon
>during a lunar eclipse went unnoticed by many.  Columbus, however,
>realized that this showed that the earth may be spherical...

If this reflects the quality of research that went into this theory, I
don't think I want to waste my time reading any further.

In Columbus's time, there was no serious doubt among the educated that the
Earth was spherical.  The debate was over its size.  Columbus thought it
was small enough that he could sail from Europe to the Indies directly;
most everyone else thought that Earth was large enough to make this voyage
prohibitively long for the seagoing technology of the time.  And they were
right, and Columbus was wrong!  Had he not found hitherto-unsuspected new
continents midway across the ocean, he and all his men would certainly
have died.  Crossing the Atlantic *or* the Pacific with the seagoing
technology of the time was a real hardship, and often killed a significant
fraction of the crew; crossing both in a single leap was quite impossible. 
-- 
Look, look, see Windows 95.  Buy, lemmings, buy!   |       Henry Spencer
Pay no attention to that cliff ahead...            |   henry@zoo.toronto.edu

From: Steinn Sigurdsson <steinn@harbor.sns.ias.edu>
Newsgroups: sci.space.policy
Subject: Re: Zubrin's character.
Date: 05 Jan 1997 15:17:38 -0500

fcrary@rintintin.Colorado.EDU (Frank Crary) writes:

> In article <32C8647E.54FB@erols.com>,  <melanied@erols.com> wrote:
> >> >He was considered a serious navigator at the time.  And he can hardly be
> >> >held accoutable for discovering continents that no one knew existed.
> >> >He's to be praised for pressing ahead, in spite of not knowing so much,
> >> >into the unknown.

> >> No. If he were competent, to the extent that he claimed, he should
> >> have known very well that China was too far to the east for any
> >> ship of his day to reach.

> >Sorry, but people sitting safely at a table 500 years later, calmly 
> >declaring what one of the great adventurers of all time should or should 
> >not have known----when no one else on the planet was doing anything but 
> >laughing--is not impressive.  I'll take a Columbus, anyday.

Funny, the thrust of this thread seems to be to
reject the modern-day Columbus' wannabes.
You seem far more inclined to the Chinese method
of exploration - get a big enough fleet together
to go all the way, but with start up costs high
enough that some bean counting mandarin will recall
and dismantle it just as the ships are getting somewhere.

> Then you'll get yourself killed. I'm not basing my opinions of
> Columbus on what _I_ know about the size of the world or the
> distance from Spain to Asia. Given the knowledge of _his_ time,
> he was wrong and should have known it. In his claims, he 
> used the smallest possible estimates of the size of the
> Earth, and the largest possible estimates of the size
> of Asia, to make his estimate of the length of the 
> journey as short as he possibly could. Given the information
> available to him, this was something between wildly optimistic
> and completely absurd. It turned out to be dead wrong. If
> you'd "take Columbus, anyday", then you mean you prefer
> people who do something they know is a bad idea, "succeed"
> by getting very lucky and survive only by finding something 
> they never expected.

This is most likely wrong. Columbus worked for several
years in the Bristol trade with Iceland. There he would
certainly have heard of the Greenland voyages and
probably of Vinland and Markland. Hence he would have had
additional data that the Spanish Court would conside
unreliable, but which was still correct.

Nor was Columbus the only one considering this.
Henry VII would probably have funded a voyage, and
shortly after Columbus Bristol ships did go to North America,
they would likely have done so whether Columbus had gone or not,
but the impetus for expansion would have been slower
without the South American gold.