Image 1 Caption: Thomas Digges' (c.1546--1595)
diagram
(presented in his book
A Perfit Description of the
Caelestiall Orbes according to
the most aunciente doctrine of the
Pythagoreans, latelye revived by
Copernicus and by Geometricall Demonstrations approved, 1576)
of a heliocentric solar system
surrounding by an infinite (or quasi-infinite) space with
stars spread throughout: i.e., an
infinite (or quasi-infinite) universe.
Features:
- The colorization
is modern.
- Since the caption is in Elizabethan English,
we can even read his diagram sort of.
- Digges conception of the
universe can be called
the Copernican cosmos as opposed the
Copernican heliocentric solar system
of Nicolaus Copernicus (1473--1543) himself.
- Others, like Democritus
and Nicholas of Cusa (1401--1464),
had considered infinite universes
in the past, but NOT in the context of
Copernican heliocentrism.
Digges is the first to consider an infinite
universe in the context of a
heliocentric solar system.
- The idea that the stars
could be other suns with their own
planets
suggested itself pretty quickly to those who few
who accepted Copernicanism
even in the 16th century.
Their reasoning may be as follows:
- Heliocentrism requires the
celestial sphere of the stars
be very large since
stellar parallax
is NOT observed.
- This means the stars
are very far off, and so must be very bright.
- But then the stars could be
comparably bright as the
Sun.
- But then they could be other suns.
- But then they are NOT pasted on
a celestial sphere of the stars.
They are spread throughout space which may be infinite or quasi-infinite.
- There is NO physical
celestial sphere of the stars,
just an imaginary
celestial sphere
useful for sky maps (AKA star charts)
and celestial globes.
- The other suns could have
planetary systems
and their planets
could have
extraterrestrial beings.
- There could be a
plurality of worlds---which
which means the
Earth
and Solar System
are NOT special places---they are infinitesimal.
These ideas
caused Giordano Bruno (1548--1600)
to get into trouble with the
Roman Inquisition.
- The foregoing is piling speculation on speculation, but it all turned out to be
essentially right.
- Isaac Newton (1643--1727) thought of the
spread out stars as being the
fixed stars which defined the
fundamental inertial frame
called absolute space.
The idea of absolute space
did NOT survive the early
20th century and
the discovery of
the expansion of the universe,
general relativity,
and the
Friedmann equation (FE) models
of cosmology.
However, measuring rotation
local fixed stars well approximates
measuring rotation
relative to the
observable universe
(which is absolute
rotation
in our current thinking)
for most purposes for the
celestial frame (CEF)
of the Solar System.
So celestial dynamicists
before the early 20th century
using just Newtonian physics
with the absolute space
theory
explained the motions of the
Solar System adequately for the
observations of that time.
Those old celestial dynamicists
assumed any acceleration of the
COMFFI frame
of the Solar System
in absolute space
was exactly
canceled for calculational purposes by
the inertial force
of being in the
COMFFI frame
of the Solar System making that
reference frame an effective
inertial frame.
In the modern view, that
COMFFI frame
is a true inertial frame,
NOT an effective one.
- Probably, some/many/all astronomers
thought other planetary systems
existed from the late 17th century on.
But proof only came in the late 20th century
with the exoplanets.
Now we know that exoplanets
are at least as common as stars.
- Thomas Digges' caption for Image 1
(which is right on Image 1 in the orbital
paragraph) reads:
This orbe of the starres fixed vp extendeth hit self in altitvde sphericallye and
therefore immovable the pallace of the foelicitye garnished with the perpetvall
shininge gloriovs lightes innvmerable, farr excellinge ovr sonne both in
qvantitye and qvalitye the very covrt of ceoleestialll
angelles devoyd of
greefe and eplenished with perfite endlesse joye the habitacle for the
elect.
See, Early Modern English
isn't so tough.
Now on to Gorboduc (1561 play).
- Image 2 Caption: Portrait of
Sir Dudley Digges (1583--1639).
There seems to be NO portraits
of Thomas Digges (c.1546--1595), but maybe
the son was the
spit of the
father---except for looking
like a musketeer.
Images
- Credit/Permission:
Thomas Digges (c.1546--1595),
1576,
Colorized by Jean Gagnon (AKA User:Jeangagnon),
2007 /
Public domain.
Image link: Wikipedia:
File:ThomasDiggesmap.JPG.
- Credit/Permission: School of
Cornelius Johnson (1593--1661),
circa 1630
(uploaded to Wikimedia Commons
by User:MarmadukePercy,
2013) /
Public domain.
Image link: Wikipedia:
File:Sir Dudley Digges (c. 1583 - 1639).jpeg.
Local file: local link: copernican_cosmos_digges.html.
File: Copernicus file:
copernican_cosmos_digges.html.