The Sleepwalkers (89 page)

____________________

In
fact,
Copernicus
uses
altogether
forty-eight
epicycles
–
if
I
counted
them
correctly
(see
table,
note
9).

Moreover,
Copernicus
had
exaggerated
the
number
of
epicycles
in
the
Ptolemaic
system.
¹⁰
Brought
up
to
date
by
Peurbach
in
the
fifteenth
century,
the
number
of
circles
required
in
the
Ptolemaic
system
was
not
80,
as
Copernicus
said,
but
40.
¹¹

In
other
words,
contrary
to
popular,
and
even
academic
belief,
Copernicus
did
not
reduce
the
number
of
circles,
but
increased
them
(from
40
to
48).
¹²
How
could
this
mistaken
idea
survive
for
so
long,
and
be
repeated
by
so
many
eminent
authorities?
The
answer
is
that
very
few
people,
even
among
professional
historians
of
science,
have
read
Copernicus'
book,
because
the
Copernican
system
(as
opposed
to
the
heliocentric
idea)
is
hardly
worth
bothering
about.
Not
even
Galileo
seems
to
have
read
it,
as
we
shall
see.

The
manuscript
of
the
Revolutions
consists
of
212
sheets
in
small
folio.
It
contains
neither
the
author's
name
nor
any
of
the
prefatory
matter.
¹³

The
first
printed
edition
starts
with
Osiander's
preface,
followed
by
Cardinal
Schoenberg's
letter
and
by
Copernicus'
dedication
to
Paul
III.

The
work itself is divided into six books.

The
first
contains
a
broad
outline
of
the
theory,
followed
by
two
chapters
on
spherical
trigonometry;
the
second
is
entirely
devoted
to
the
mathematical
principles
of
astronomy.
The
third
concerns
the
motions
of
the
earth;
the
fourth,
the
motions
of
the
moon;
the
fifth
and
sixth,
the
motions
of
the
planets.

The
basic
principles
and
the
programme
of
the
work
are
all
set
out
in
the
first
eleven
chapters
of
the
first
book.
They
may
be
summed
up
as
follows.
The
universe
occupies
a
finite
space
bounded
by
the
sphere
of
the
fixed
stars.
In
the
centre
is
the
sun.
Both
the
sphere
of
the
stars
and
the
sun
are
at
rest.
Around
the
sun
revolve
the
planets
Mercury,
Venus,
Earth,
Mars,
Jupiter
and
Saturn,
in
that
order.
The
moon
revolves
round
the
earth.
The
apparent
daily
revolution
of
the
entire
firmament
is
due
to
the
rotation
of
the
earth
round
its
own
axis.
The
apparent
annual
motion
of
the
sun
in
the
ecliptic
is
due
to
the
annual
revolution
of
the
earth
in
its
orbit.
The
stations
and
retrogressions
of
the
planets
are
due
to
the
same
cause.
The
small
irregularities
of
the
seasons,
and
other
minor
irregularities,
are
due
to
the
"librations"
(oscillations,
wobbles)
of
the
earth's
axis.

This
synopsis
of
the
theory
occupies
less
than
twenty
pages
at
the
beginning
of
the
book,
or
about
five
per
cent
of
the
whole.
The
remaining
ninety-five
per
cent
consists
of
the
application
of
it.
And
when
that
is
completed,
there
is
hardly
anything
left
of
the
original
doctrine.
It
has,
so
to
speak,
destroyed
itself
in
the
process.
This
may
be
the
reason
why
no
summary,
conclusions,
or
winding-up
of
any
kind
is
found
at
the
end
of
the
book,
although
we
are
repeatedly
promised
it
in
the
text.

At
the
beginning
(Book
I,
chapter
10),
Copernicus
had
stated:
"in
the
midst
of
all
dwells
the
sun...
Sitting
on
the
royal
throne,
he
rules
the
family
of
planets
which
turn
around
him...
We
thus
find
in
this
arrangement
an
admirable
harmony
of
the
world."
But
in
Book
III,
when
it
comes
to
reconciling
the
doctrine
with
actual
observation,
the
earth
no
longer
turns
round
the
sun,
but
round
a
point
in
space
removed
from
the
sun
by
a
distance
of
about
three
times
the
sun's
diameter.
Nor
do
the
planets
revolve
round
the
sun
–
as
every
schoolboy
believes
that
Copernicus
taught.
The
planets
move
on
epicycles
of
epicycles,
centred
not
on
the
sun,
but
on
the
centre
of
the
earth's
orbit
.
There
are
thus
two
"royal
thrones":
the
sun,
and
that
imaginary
point
in
space
around
which
the
earth
moves.
The
year,
that
is,
the
duration
of
the
earth's
complete
revolution
round
the
sun,
has
a
decisive
influence
on
the
motions
of
all
other
planets.
In
short,
the
earth
appears
equal
in
importance
in
governing
the
solar
system
to
the
sun
itself,
and
in
fact
nearly
as
important
as
in
the
Aristotelian
or
Ptolemaic
system.